[v6,1/2] gdb: Make tagged pointer support configurable.
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Commit Message
From: Christina Schimpe <christina.schimpe@intel.com>
The gdbarch function gdbarch_remove_non_address_bits adjusts addresses to
enable debugging of programs with tagged pointers on Linux, for instance for
ARM's feature top byte ignore (TBI).
Once the function is implemented for an architecture, it adjusts addresses for
memory access, breakpoints and watchpoints.
Linear address masking (LAM) is Intel's (R) implementation of tagged
pointer support. It requires certain adaptions to GDB's tagged pointer
support due to the following:
- LAM supports address tagging for data accesses only. Thus, specifying
breakpoints on tagged addresses is not a valid use case.
- In contrast to the implementation for ARM's TBI, the Linux kernel supports
tagged pointers for memory access.
This patch makes GDB's tagged pointer support configurable such that it is
possible to enable the address adjustment for a specific feature only (e.g
memory access, breakpoints or watchpoints). This way, one can make sure
that addresses are only adjusted when necessary. In case of LAM, this
avoids unnecessary parsing of the /proc/<pid>/status file to get the
untag mask.
Reviewed-By: Felix Willgerodt <felix.willgerodt@intel.com>
---
gdb/aarch64-linux-nat.c | 2 +-
gdb/aarch64-linux-tdep.c | 7 +++--
gdb/aarch64-tdep.c | 23 ++++++++------
gdb/aarch64-tdep.h | 6 ++++
gdb/breakpoint.c | 5 +--
gdb/gdbarch-gen.c | 66 ++++++++++++++++++++++++++++++++-------
gdb/gdbarch-gen.h | 49 ++++++++++++++++++++++-------
gdb/gdbarch_components.py | 53 ++++++++++++++++++++++++++-----
gdb/loongarch-linux-nat.c | 2 +-
gdb/target.c | 3 +-
10 files changed, 169 insertions(+), 47 deletions(-)
Comments
Hi Christina,
On 10/28/24 08:46, Schimpe, Christina wrote:
> From: Christina Schimpe <christina.schimpe@intel.com>
>
> The gdbarch function gdbarch_remove_non_address_bits adjusts addresses to
> enable debugging of programs with tagged pointers on Linux, for instance for
> ARM's feature top byte ignore (TBI).
> Once the function is implemented for an architecture, it adjusts addresses for
> memory access, breakpoints and watchpoints.
>
> Linear address masking (LAM) is Intel's (R) implementation of tagged
> pointer support. It requires certain adaptions to GDB's tagged pointer
> support due to the following:
> - LAM supports address tagging for data accesses only. Thus, specifying
> breakpoints on tagged addresses is not a valid use case.
> - In contrast to the implementation for ARM's TBI, the Linux kernel supports
> tagged pointers for memory access.
>
> This patch makes GDB's tagged pointer support configurable such that it is
> possible to enable the address adjustment for a specific feature only (e.g
> memory access, breakpoints or watchpoints). This way, one can make sure
> that addresses are only adjusted when necessary. In case of LAM, this
> avoids unnecessary parsing of the /proc/<pid>/status file to get the
> untag mask.
>
> Reviewed-By: Felix Willgerodt <felix.willgerodt@intel.com>
> ---
> gdb/aarch64-linux-nat.c | 2 +-
> gdb/aarch64-linux-tdep.c | 7 +++--
> gdb/aarch64-tdep.c | 23 ++++++++------
> gdb/aarch64-tdep.h | 6 ++++
> gdb/breakpoint.c | 5 +--
> gdb/gdbarch-gen.c | 66 ++++++++++++++++++++++++++++++++-------
> gdb/gdbarch-gen.h | 49 ++++++++++++++++++++++-------
> gdb/gdbarch_components.py | 53 ++++++++++++++++++++++++++-----
> gdb/loongarch-linux-nat.c | 2 +-
> gdb/target.c | 3 +-
> 10 files changed, 169 insertions(+), 47 deletions(-)
>
> diff --git a/gdb/aarch64-linux-nat.c b/gdb/aarch64-linux-nat.c
> index 0fa5bee500b..48ab765d880 100644
> --- a/gdb/aarch64-linux-nat.c
> +++ b/gdb/aarch64-linux-nat.c
> @@ -943,7 +943,7 @@ aarch64_linux_nat_target::stopped_data_address (CORE_ADDR *addr_p)
> kernel can potentially be tagged addresses. */
> struct gdbarch *gdbarch = thread_architecture (inferior_ptid);
> const CORE_ADDR addr_trap
> - = gdbarch_remove_non_address_bits (gdbarch, (CORE_ADDR) siginfo.si_addr);
> + = aarch64_remove_non_address_bits (gdbarch, (CORE_ADDR) siginfo.si_addr);
>
> /* Check if the address matches any watched address. */
> state = aarch64_get_debug_reg_state (inferior_ptid.pid ());
> diff --git a/gdb/aarch64-linux-tdep.c b/gdb/aarch64-linux-tdep.c
> index c608a84bc71..61c3be8b6f0 100644
> --- a/gdb/aarch64-linux-tdep.c
> +++ b/gdb/aarch64-linux-tdep.c
> @@ -2433,7 +2433,7 @@ static bool
> aarch64_linux_tagged_address_p (struct gdbarch *gdbarch, CORE_ADDR address)
> {
> /* Remove the top byte for the memory range check. */
> - address = gdbarch_remove_non_address_bits (gdbarch, address);
> + address = aarch64_remove_non_address_bits (gdbarch, address);
>
> /* Check if the page that contains ADDRESS is mapped with PROT_MTE. */
> if (!linux_address_in_memtag_page (address))
> @@ -2491,8 +2491,9 @@ aarch64_linux_report_signal_info (struct gdbarch *gdbarch,
> uiout->text ("\n");
>
> std::optional<CORE_ADDR> atag
> - = aarch64_mte_get_atag (gdbarch_remove_non_address_bits (gdbarch,
> - fault_addr));
> + = aarch64_mte_get_atag (
> + aarch64_remove_non_address_bits (gdbarch, fault_addr));
> +
> gdb_byte ltag = aarch64_mte_get_ltag (fault_addr);
>
> if (!atag.has_value ())
> diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c
> index 8a2a9b1e23c..91fec7879ed 100644
> --- a/gdb/aarch64-tdep.c
> +++ b/gdb/aarch64-tdep.c
> @@ -4121,7 +4121,7 @@ aarch64_memtag_matches_p (struct gdbarch *gdbarch,
>
> /* Fetch the allocation tag for ADDRESS. */
> std::optional<CORE_ADDR> atag
> - = aarch64_mte_get_atag (gdbarch_remove_non_address_bits (gdbarch, addr));
> + = aarch64_mte_get_atag (aarch64_remove_non_address_bits (gdbarch, addr));
>
> if (!atag.has_value ())
> return true;
> @@ -4160,7 +4160,7 @@ aarch64_set_memtags (struct gdbarch *gdbarch, struct value *address,
> else
> {
> /* Remove the top byte. */
> - addr = gdbarch_remove_non_address_bits (gdbarch, addr);
> + addr = aarch64_remove_non_address_bits (gdbarch, addr);
>
> /* With G being the number of tag granules and N the number of tags
> passed in, we can have the following cases:
> @@ -4209,7 +4209,7 @@ aarch64_get_memtag (struct gdbarch *gdbarch, struct value *address,
> else
> {
> /* Remove the top byte. */
> - addr = gdbarch_remove_non_address_bits (gdbarch, addr);
> + addr = aarch64_remove_non_address_bits (gdbarch, addr);
> std::optional<CORE_ADDR> atag = aarch64_mte_get_atag (addr);
>
> if (!atag.has_value ())
> @@ -4236,10 +4236,9 @@ aarch64_memtag_to_string (struct gdbarch *gdbarch, struct value *tag_value)
> return string_printf ("0x%s", phex_nz (tag, sizeof (tag)));
> }
>
> -/* AArch64 implementation of the remove_non_address_bits gdbarch hook. Remove
> - non address bits from a pointer value. */
> +/* See aarch64-tdep.h. */
>
> -static CORE_ADDR
> +CORE_ADDR
> aarch64_remove_non_address_bits (struct gdbarch *gdbarch, CORE_ADDR pointer)
> {
> /* By default, we assume TBI and discard the top 8 bits plus the VA range
> @@ -4750,9 +4749,15 @@ aarch64_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
> tdep->ra_sign_state_regnum = ra_sign_state_offset + num_regs;
>
> /* Architecture hook to remove bits of a pointer that are not part of the
> - address, like memory tags (MTE) and pointer authentication signatures. */
> - set_gdbarch_remove_non_address_bits (gdbarch,
> - aarch64_remove_non_address_bits);
> + address, like memory tags (MTE) and pointer authentication signatures.
> + Configure address adjustment for watch-, breakpoints and memory
s/watch-/watchpoints
> + transfer. */
> + set_gdbarch_remove_non_address_bits_watchpoint
> + (gdbarch, aarch64_remove_non_address_bits);
> + set_gdbarch_remove_non_address_bits_breakpoint
> + (gdbarch, aarch64_remove_non_address_bits);
> + set_gdbarch_remove_non_address_bits_memory
> + (gdbarch, aarch64_remove_non_address_bits);
>
> /* SME pseudo-registers. */
> if (tdep->has_sme ())
> diff --git a/gdb/aarch64-tdep.h b/gdb/aarch64-tdep.h
> index 50166fb4f24..13ea37de7a3 100644
> --- a/gdb/aarch64-tdep.h
> +++ b/gdb/aarch64-tdep.h
> @@ -205,4 +205,10 @@ bool aarch64_displaced_step_hw_singlestep (struct gdbarch *gdbarch);
>
> std::optional<CORE_ADDR> aarch64_mte_get_atag (CORE_ADDR address);
>
> +/* AArch64 implementation of the remove_non_address_bits gdbarch hooks.
> + Remove non address bits from a pointer value. */
> +
> +CORE_ADDR aarch64_remove_non_address_bits (struct gdbarch *gdbarch,
> + CORE_ADDR pointer);
> +
> #endif /* aarch64-tdep.h */
> diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
> index b7e4f5d0a45..9983e905e1b 100644
> --- a/gdb/breakpoint.c
> +++ b/gdb/breakpoint.c
> @@ -2313,7 +2313,8 @@ update_watchpoint (struct watchpoint *b, bool reparse)
> loc->gdbarch = v->type ()->arch ();
> loc->pspace = wp_pspace;
> loc->address
> - = gdbarch_remove_non_address_bits (loc->gdbarch, addr);
> + = gdbarch_remove_non_address_bits_watchpoint (loc->gdbarch,
> + addr);
> b->add_location (*loc);
>
> if (bitsize != 0)
> @@ -7538,7 +7539,7 @@ adjust_breakpoint_address (struct gdbarch *gdbarch,
> }
>
> adjusted_bpaddr
> - = gdbarch_remove_non_address_bits (gdbarch, adjusted_bpaddr);
> + = gdbarch_remove_non_address_bits_breakpoint (gdbarch, adjusted_bpaddr);
>
> /* An adjusted breakpoint address can significantly alter
> a user's expectations. Print a warning if an adjustment
> diff --git a/gdb/gdbarch-gen.c b/gdb/gdbarch-gen.c
> index 0d00cd7c993..d05c7a3cbdf 100644
> --- a/gdb/gdbarch-gen.c
> +++ b/gdb/gdbarch-gen.c
> @@ -143,7 +143,9 @@ struct gdbarch
> int frame_red_zone_size = 0;
> gdbarch_convert_from_func_ptr_addr_ftype *convert_from_func_ptr_addr = convert_from_func_ptr_addr_identity;
> gdbarch_addr_bits_remove_ftype *addr_bits_remove = core_addr_identity;
> - gdbarch_remove_non_address_bits_ftype *remove_non_address_bits = default_remove_non_address_bits;
> + gdbarch_remove_non_address_bits_watchpoint_ftype *remove_non_address_bits_watchpoint = default_remove_non_address_bits;
> + gdbarch_remove_non_address_bits_breakpoint_ftype *remove_non_address_bits_breakpoint = default_remove_non_address_bits;
> + gdbarch_remove_non_address_bits_memory_ftype *remove_non_address_bits_memory = default_remove_non_address_bits;
> gdbarch_memtag_to_string_ftype *memtag_to_string = default_memtag_to_string;
> gdbarch_tagged_address_p_ftype *tagged_address_p = default_tagged_address_p;
> gdbarch_memtag_matches_p_ftype *memtag_matches_p = default_memtag_matches_p;
> @@ -407,7 +409,9 @@ verify_gdbarch (struct gdbarch *gdbarch)
> /* Skip verify of frame_red_zone_size, invalid_p == 0. */
> /* Skip verify of convert_from_func_ptr_addr, invalid_p == 0. */
> /* Skip verify of addr_bits_remove, invalid_p == 0. */
> - /* Skip verify of remove_non_address_bits, invalid_p == 0. */
> + /* Skip verify of remove_non_address_bits_watchpoint, invalid_p == 0. */
> + /* Skip verify of remove_non_address_bits_breakpoint, invalid_p == 0. */
> + /* Skip verify of remove_non_address_bits_memory, invalid_p == 0. */
> /* Skip verify of memtag_to_string, invalid_p == 0. */
> /* Skip verify of tagged_address_p, invalid_p == 0. */
> /* Skip verify of memtag_matches_p, invalid_p == 0. */
> @@ -910,8 +914,14 @@ gdbarch_dump (struct gdbarch *gdbarch, struct ui_file *file)
> "gdbarch_dump: addr_bits_remove = <%s>\n",
> host_address_to_string (gdbarch->addr_bits_remove));
> gdb_printf (file,
> - "gdbarch_dump: remove_non_address_bits = <%s>\n",
> - host_address_to_string (gdbarch->remove_non_address_bits));
> + "gdbarch_dump: remove_non_address_bits_watchpoint = <%s>\n",
> + host_address_to_string (gdbarch->remove_non_address_bits_watchpoint));
> + gdb_printf (file,
> + "gdbarch_dump: remove_non_address_bits_breakpoint = <%s>\n",
> + host_address_to_string (gdbarch->remove_non_address_bits_breakpoint));
> + gdb_printf (file,
> + "gdbarch_dump: remove_non_address_bits_memory = <%s>\n",
> + host_address_to_string (gdbarch->remove_non_address_bits_memory));
> gdb_printf (file,
> "gdbarch_dump: memtag_to_string = <%s>\n",
> host_address_to_string (gdbarch->memtag_to_string));
> @@ -3198,20 +3208,54 @@ set_gdbarch_addr_bits_remove (struct gdbarch *gdbarch,
> }
>
> CORE_ADDR
> -gdbarch_remove_non_address_bits (struct gdbarch *gdbarch, CORE_ADDR pointer)
> +gdbarch_remove_non_address_bits_watchpoint (struct gdbarch *gdbarch, CORE_ADDR pointer)
> +{
> + gdb_assert (gdbarch != NULL);
> + gdb_assert (gdbarch->remove_non_address_bits_watchpoint != NULL);
> + if (gdbarch_debug >= 2)
> + gdb_printf (gdb_stdlog, "gdbarch_remove_non_address_bits_watchpoint called\n");
> + return gdbarch->remove_non_address_bits_watchpoint (gdbarch, pointer);
> +}
> +
> +void
> +set_gdbarch_remove_non_address_bits_watchpoint (struct gdbarch *gdbarch,
> + gdbarch_remove_non_address_bits_watchpoint_ftype remove_non_address_bits_watchpoint)
> +{
> + gdbarch->remove_non_address_bits_watchpoint = remove_non_address_bits_watchpoint;
> +}
> +
> +CORE_ADDR
> +gdbarch_remove_non_address_bits_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pointer)
> +{
> + gdb_assert (gdbarch != NULL);
> + gdb_assert (gdbarch->remove_non_address_bits_breakpoint != NULL);
> + if (gdbarch_debug >= 2)
> + gdb_printf (gdb_stdlog, "gdbarch_remove_non_address_bits_breakpoint called\n");
> + return gdbarch->remove_non_address_bits_breakpoint (gdbarch, pointer);
> +}
> +
> +void
> +set_gdbarch_remove_non_address_bits_breakpoint (struct gdbarch *gdbarch,
> + gdbarch_remove_non_address_bits_breakpoint_ftype remove_non_address_bits_breakpoint)
> +{
> + gdbarch->remove_non_address_bits_breakpoint = remove_non_address_bits_breakpoint;
> +}
> +
> +CORE_ADDR
> +gdbarch_remove_non_address_bits_memory (struct gdbarch *gdbarch, CORE_ADDR pointer)
> {
> gdb_assert (gdbarch != NULL);
> - gdb_assert (gdbarch->remove_non_address_bits != NULL);
> + gdb_assert (gdbarch->remove_non_address_bits_memory != NULL);
> if (gdbarch_debug >= 2)
> - gdb_printf (gdb_stdlog, "gdbarch_remove_non_address_bits called\n");
> - return gdbarch->remove_non_address_bits (gdbarch, pointer);
> + gdb_printf (gdb_stdlog, "gdbarch_remove_non_address_bits_memory called\n");
> + return gdbarch->remove_non_address_bits_memory (gdbarch, pointer);
> }
>
> void
> -set_gdbarch_remove_non_address_bits (struct gdbarch *gdbarch,
> - gdbarch_remove_non_address_bits_ftype remove_non_address_bits)
> +set_gdbarch_remove_non_address_bits_memory (struct gdbarch *gdbarch,
> + gdbarch_remove_non_address_bits_memory_ftype remove_non_address_bits_memory)
> {
> - gdbarch->remove_non_address_bits = remove_non_address_bits;
> + gdbarch->remove_non_address_bits_memory = remove_non_address_bits_memory;
> }
>
> std::string
> diff --git a/gdb/gdbarch-gen.h b/gdb/gdbarch-gen.h
> index b982fd7cd09..9fda85f860f 100644
> --- a/gdb/gdbarch-gen.h
> +++ b/gdb/gdbarch-gen.h
> @@ -684,19 +684,46 @@ extern CORE_ADDR gdbarch_addr_bits_remove (struct gdbarch *gdbarch, CORE_ADDR ad
> extern void set_gdbarch_addr_bits_remove (struct gdbarch *gdbarch, gdbarch_addr_bits_remove_ftype *addr_bits_remove);
>
> /* On some architectures, not all bits of a pointer are significant.
> - On AArch64, for example, the top bits of a pointer may carry a "tag", which
> - can be ignored by the kernel and the hardware. The "tag" can be regarded as
> - additional data associated with the pointer, but it is not part of the address.
> + On AArch64 and amd64, for example, the top bits of a pointer may carry a
> + "tag", which can be ignored by the kernel and the hardware. The "tag" can be
> + regarded as additional data associated with the pointer, but it is not part
> + of the address.
>
> Given a pointer for the architecture, this hook removes all the
> - non-significant bits and sign-extends things as needed. It gets used to remove
> - non-address bits from data pointers (for example, removing the AArch64 MTE tag
> - bits from a pointer) and from code pointers (removing the AArch64 PAC signature
> - from a pointer containing the return address). */
> -
> -typedef CORE_ADDR (gdbarch_remove_non_address_bits_ftype) (struct gdbarch *gdbarch, CORE_ADDR pointer);
> -extern CORE_ADDR gdbarch_remove_non_address_bits (struct gdbarch *gdbarch, CORE_ADDR pointer);
> -extern void set_gdbarch_remove_non_address_bits (struct gdbarch *gdbarch, gdbarch_remove_non_address_bits_ftype *remove_non_address_bits);
> + non-significant bits and sign-extends things as needed. It gets used to
> + remove non-address bits from pointers used for watchpoints. */
> +
> +typedef CORE_ADDR (gdbarch_remove_non_address_bits_watchpoint_ftype) (struct gdbarch *gdbarch, CORE_ADDR pointer);
> +extern CORE_ADDR gdbarch_remove_non_address_bits_watchpoint (struct gdbarch *gdbarch, CORE_ADDR pointer);
> +extern void set_gdbarch_remove_non_address_bits_watchpoint (struct gdbarch *gdbarch, gdbarch_remove_non_address_bits_watchpoint_ftype *remove_non_address_bits_watchpoint);
> +
> +/* On some architectures, not all bits of a pointer are significant.
> + On AArch64 and amd64, for example, the top bits of a pointer may carry a
> + "tag", which can be ignored by the kernel and the hardware. The "tag" can be
> + regarded as additional data associated with the pointer, but it is not part
> + of the address.
> +
> + Given a pointer for the architecture, this hook removes all the
> + non-significant bits and sign-extends things as needed. It gets used to
> + remove non-address bits from pointers used for breakpoints. */
> +
> +typedef CORE_ADDR (gdbarch_remove_non_address_bits_breakpoint_ftype) (struct gdbarch *gdbarch, CORE_ADDR pointer);
> +extern CORE_ADDR gdbarch_remove_non_address_bits_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pointer);
> +extern void set_gdbarch_remove_non_address_bits_breakpoint (struct gdbarch *gdbarch, gdbarch_remove_non_address_bits_breakpoint_ftype *remove_non_address_bits_breakpoint);
> +
> +/* On some architectures, not all bits of a pointer are significant.
> + On AArch64 and amd64, for example, the top bits of a pointer may carry a
> + "tag", which can be ignored by the kernel and the hardware. The "tag" can be
> + regarded as additional data associated with the pointer, but it is not part
> + of the address.
> +
> + Given a pointer for the architecture, this hook removes all the
> + non-significant bits and sign-extends things as needed. It gets used to
> + remove non-address bits from any pointer used to access memory. */
> +
> +typedef CORE_ADDR (gdbarch_remove_non_address_bits_memory_ftype) (struct gdbarch *gdbarch, CORE_ADDR pointer);
> +extern CORE_ADDR gdbarch_remove_non_address_bits_memory (struct gdbarch *gdbarch, CORE_ADDR pointer);
> +extern void set_gdbarch_remove_non_address_bits_memory (struct gdbarch *gdbarch, gdbarch_remove_non_address_bits_memory_ftype *remove_non_address_bits_memory);
>
> /* Return a string representation of the memory tag TAG. */
>
> diff --git a/gdb/gdbarch_components.py b/gdb/gdbarch_components.py
> index 4006380076d..cc7c6d8677b 100644
> --- a/gdb/gdbarch_components.py
> +++ b/gdb/gdbarch_components.py
> @@ -1232,18 +1232,55 @@ possible it should be in TARGET_READ_PC instead).
> Method(
> comment="""
> On some architectures, not all bits of a pointer are significant.
> -On AArch64, for example, the top bits of a pointer may carry a "tag", which
> -can be ignored by the kernel and the hardware. The "tag" can be regarded as
> -additional data associated with the pointer, but it is not part of the address.
> +On AArch64 and amd64, for example, the top bits of a pointer may carry a
> +"tag", which can be ignored by the kernel and the hardware. The "tag" can be
> +regarded as additional data associated with the pointer, but it is not part
> +of the address.
>
> Given a pointer for the architecture, this hook removes all the
> -non-significant bits and sign-extends things as needed. It gets used to remove
> -non-address bits from data pointers (for example, removing the AArch64 MTE tag
> -bits from a pointer) and from code pointers (removing the AArch64 PAC signature
> -from a pointer containing the return address).
> +non-significant bits and sign-extends things as needed. It gets used to
> +remove non-address bits from pointers used for watchpoints.
> """,
> type="CORE_ADDR",
> - name="remove_non_address_bits",
> + name="remove_non_address_bits_watchpoint",
> + params=[("CORE_ADDR", "pointer")],
> + predefault="default_remove_non_address_bits",
> + invalid=False,
> +)
> +
> +Method(
> + comment="""
> +On some architectures, not all bits of a pointer are significant.
> +On AArch64 and amd64, for example, the top bits of a pointer may carry a
> +"tag", which can be ignored by the kernel and the hardware. The "tag" can be
> +regarded as additional data associated with the pointer, but it is not part
> +of the address.
> +
> +Given a pointer for the architecture, this hook removes all the
> +non-significant bits and sign-extends things as needed. It gets used to
> +remove non-address bits from pointers used for breakpoints.
> +""",
> + type="CORE_ADDR",
> + name="remove_non_address_bits_breakpoint",
> + params=[("CORE_ADDR", "pointer")],
> + predefault="default_remove_non_address_bits",
> + invalid=False,
> +)
> +
> +Method(
> + comment="""
> +On some architectures, not all bits of a pointer are significant.
> +On AArch64 and amd64, for example, the top bits of a pointer may carry a
> +"tag", which can be ignored by the kernel and the hardware. The "tag" can be
> +regarded as additional data associated with the pointer, but it is not part
> +of the address.
> +
> +Given a pointer for the architecture, this hook removes all the
> +non-significant bits and sign-extends things as needed. It gets used to
> +remove non-address bits from any pointer used to access memory.
> +""",
> + type="CORE_ADDR",
> + name="remove_non_address_bits_memory",
> params=[("CORE_ADDR", "pointer")],
> predefault="default_remove_non_address_bits",
> invalid=False,
> diff --git a/gdb/loongarch-linux-nat.c b/gdb/loongarch-linux-nat.c
> index bc9927dd751..dc4a019614a 100644
> --- a/gdb/loongarch-linux-nat.c
> +++ b/gdb/loongarch-linux-nat.c
> @@ -613,7 +613,7 @@ loongarch_linux_nat_target::stopped_data_address (CORE_ADDR *addr_p)
> kernel can potentially be tagged addresses. */
> struct gdbarch *gdbarch = thread_architecture (inferior_ptid);
> const CORE_ADDR addr_trap
> - = gdbarch_remove_non_address_bits (gdbarch, (CORE_ADDR) siginfo.si_addr);
> + = aarch64_remove_non_address_bits (gdbarch, (CORE_ADDR) siginfo.si_addr);
>
> /* Check if the address matches any watched address. */
> state = loongarch_get_debug_reg_state (inferior_ptid.pid ());
I think the loongarch-linux-nat.c change is spurious. Could you please address that?
> diff --git a/gdb/target.c b/gdb/target.c
> index 4378c0572d2..b6d1abe82db 100644
> --- a/gdb/target.c
> +++ b/gdb/target.c
> @@ -1608,7 +1608,8 @@ memory_xfer_partial (struct target_ops *ops, enum target_object object,
> if (len == 0)
> return TARGET_XFER_EOF;
>
> - memaddr = gdbarch_remove_non_address_bits (current_inferior ()->arch (),
> + memaddr
> + = gdbarch_remove_non_address_bits_memory (current_inferior ()->arch (),
> memaddr);
>
> /* Fill in READBUF with breakpoint shadows, or WRITEBUF with
Hi Luis,
Thanks a lot for the review. I have one questions to your comment, please see below.
> -----Original Message-----
> From: Luis Machado <luis.machado@arm.com>
> Sent: Monday, November 4, 2024 12:18 PM
> To: Schimpe, Christina <christina.schimpe@intel.com>; gdb-
> patches@sourceware.org
> Subject: Re: [PATCH v6 1/2] gdb: Make tagged pointer support configurable.
>
> Hi Christina,
>
> On 10/28/24 08:46, Schimpe, Christina wrote:
> > From: Christina Schimpe <christina.schimpe@intel.com>
> >
> > The gdbarch function gdbarch_remove_non_address_bits adjusts addresses
> > to enable debugging of programs with tagged pointers on Linux, for
> > instance for ARM's feature top byte ignore (TBI).
> > Once the function is implemented for an architecture, it adjusts
> > addresses for memory access, breakpoints and watchpoints.
> >
> > Linear address masking (LAM) is Intel's (R) implementation of tagged
> > pointer support. It requires certain adaptions to GDB's tagged
> > pointer support due to the following:
> > - LAM supports address tagging for data accesses only. Thus, specifying
> > breakpoints on tagged addresses is not a valid use case.
> > - In contrast to the implementation for ARM's TBI, the Linux kernel supports
> > tagged pointers for memory access.
> >
> > This patch makes GDB's tagged pointer support configurable such that
> > it is possible to enable the address adjustment for a specific feature
> > only (e.g memory access, breakpoints or watchpoints). This way, one
> > can make sure that addresses are only adjusted when necessary. In
> > case of LAM, this avoids unnecessary parsing of the /proc/<pid>/status
> > file to get the untag mask.
> >
> > Reviewed-By: Felix Willgerodt <felix.willgerodt@intel.com>
> > ---
> > gdb/aarch64-linux-nat.c | 2 +-
> > gdb/aarch64-linux-tdep.c | 7 +++--
> > gdb/aarch64-tdep.c | 23 ++++++++------
> > gdb/aarch64-tdep.h | 6 ++++
> > gdb/breakpoint.c | 5 +--
> > gdb/gdbarch-gen.c | 66 ++++++++++++++++++++++++++++++++-------
> > gdb/gdbarch-gen.h | 49 ++++++++++++++++++++++-------
> > gdb/gdbarch_components.py | 53 ++++++++++++++++++++++++++-----
> > gdb/loongarch-linux-nat.c | 2 +-
> > gdb/target.c | 3 +-
> > 10 files changed, 169 insertions(+), 47 deletions(-)
> >
> > diff --git a/gdb/aarch64-linux-nat.c b/gdb/aarch64-linux-nat.c index
> > 0fa5bee500b..48ab765d880 100644
> > --- a/gdb/aarch64-linux-nat.c
> > +++ b/gdb/aarch64-linux-nat.c
> > @@ -943,7 +943,7 @@ aarch64_linux_nat_target::stopped_data_address
> (CORE_ADDR *addr_p)
> > kernel can potentially be tagged addresses. */
> > struct gdbarch *gdbarch = thread_architecture (inferior_ptid);
> > const CORE_ADDR addr_trap
> > - = gdbarch_remove_non_address_bits (gdbarch, (CORE_ADDR)
> siginfo.si_addr);
> > + = aarch64_remove_non_address_bits (gdbarch, (CORE_ADDR)
> > + siginfo.si_addr);
> >
> > /* Check if the address matches any watched address. */
> > state = aarch64_get_debug_reg_state (inferior_ptid.pid ()); diff
> > --git a/gdb/aarch64-linux-tdep.c b/gdb/aarch64-linux-tdep.c index
> > c608a84bc71..61c3be8b6f0 100644
> > --- a/gdb/aarch64-linux-tdep.c
> > +++ b/gdb/aarch64-linux-tdep.c
> > @@ -2433,7 +2433,7 @@ static bool
> > aarch64_linux_tagged_address_p (struct gdbarch *gdbarch, CORE_ADDR
> > address) {
> > /* Remove the top byte for the memory range check. */
> > - address = gdbarch_remove_non_address_bits (gdbarch, address);
> > + address = aarch64_remove_non_address_bits (gdbarch, address);
> >
> > /* Check if the page that contains ADDRESS is mapped with PROT_MTE. */
> > if (!linux_address_in_memtag_page (address)) @@ -2491,8 +2491,9 @@
> > aarch64_linux_report_signal_info (struct gdbarch *gdbarch,
> > uiout->text ("\n");
> >
> > std::optional<CORE_ADDR> atag
> > - = aarch64_mte_get_atag (gdbarch_remove_non_address_bits (gdbarch,
> > - fault_addr));
> > + = aarch64_mte_get_atag (
> > + aarch64_remove_non_address_bits (gdbarch, fault_addr));
> > +
> > gdb_byte ltag = aarch64_mte_get_ltag (fault_addr);
> >
> > if (!atag.has_value ())
> > diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c index
> > 8a2a9b1e23c..91fec7879ed 100644
> > --- a/gdb/aarch64-tdep.c
> > +++ b/gdb/aarch64-tdep.c
> > @@ -4121,7 +4121,7 @@ aarch64_memtag_matches_p (struct gdbarch
> > *gdbarch,
> >
> > /* Fetch the allocation tag for ADDRESS. */
> > std::optional<CORE_ADDR> atag
> > - = aarch64_mte_get_atag (gdbarch_remove_non_address_bits (gdbarch,
> addr));
> > + = aarch64_mte_get_atag (aarch64_remove_non_address_bits (gdbarch,
> > + addr));
> >
> > if (!atag.has_value ())
> > return true;
> > @@ -4160,7 +4160,7 @@ aarch64_set_memtags (struct gdbarch *gdbarch,
> struct value *address,
> > else
> > {
> > /* Remove the top byte. */
> > - addr = gdbarch_remove_non_address_bits (gdbarch, addr);
> > + addr = aarch64_remove_non_address_bits (gdbarch, addr);
> >
> > /* With G being the number of tag granules and N the number of tags
> > passed in, we can have the following cases:
> > @@ -4209,7 +4209,7 @@ aarch64_get_memtag (struct gdbarch *gdbarch,
> struct value *address,
> > else
> > {
> > /* Remove the top byte. */
> > - addr = gdbarch_remove_non_address_bits (gdbarch, addr);
> > + addr = aarch64_remove_non_address_bits (gdbarch, addr);
> > std::optional<CORE_ADDR> atag = aarch64_mte_get_atag (addr);
> >
> > if (!atag.has_value ())
> > @@ -4236,10 +4236,9 @@ aarch64_memtag_to_string (struct gdbarch
> *gdbarch, struct value *tag_value)
> > return string_printf ("0x%s", phex_nz (tag, sizeof (tag))); }
> >
> > -/* AArch64 implementation of the remove_non_address_bits gdbarch hook.
> Remove
> > - non address bits from a pointer value. */
> > +/* See aarch64-tdep.h. */
> >
> > -static CORE_ADDR
> > +CORE_ADDR
> > aarch64_remove_non_address_bits (struct gdbarch *gdbarch, CORE_ADDR
> > pointer) {
> > /* By default, we assume TBI and discard the top 8 bits plus the VA
> > range @@ -4750,9 +4749,15 @@ aarch64_gdbarch_init (struct gdbarch_info
> info, struct gdbarch_list *arches)
> > tdep->ra_sign_state_regnum = ra_sign_state_offset + num_regs;
> >
> > /* Architecture hook to remove bits of a pointer that are not part of the
> > - address, like memory tags (MTE) and pointer authentication signatures. */
> > - set_gdbarch_remove_non_address_bits (gdbarch,
> > - aarch64_remove_non_address_bits);
> > + address, like memory tags (MTE) and pointer authentication signatures.
> > + Configure address adjustment for watch-, breakpoints and memory
>
> s/watch-/watchpoints
Fill fix, thanks.
> > + transfer. */
> > + set_gdbarch_remove_non_address_bits_watchpoint
> > + (gdbarch, aarch64_remove_non_address_bits);
> > + set_gdbarch_remove_non_address_bits_breakpoint
> > + (gdbarch, aarch64_remove_non_address_bits);
> > + set_gdbarch_remove_non_address_bits_memory
> > + (gdbarch, aarch64_remove_non_address_bits);
> >
> > /* SME pseudo-registers. */
> > if (tdep->has_sme ())
> > diff --git a/gdb/aarch64-tdep.h b/gdb/aarch64-tdep.h index
> > 50166fb4f24..13ea37de7a3 100644
> > --- a/gdb/aarch64-tdep.h
> > +++ b/gdb/aarch64-tdep.h
> > @@ -205,4 +205,10 @@ bool aarch64_displaced_step_hw_singlestep (struct
> > gdbarch *gdbarch);
> >
> > std::optional<CORE_ADDR> aarch64_mte_get_atag (CORE_ADDR address);
> >
> > +/* AArch64 implementation of the remove_non_address_bits gdbarch hooks.
> > + Remove non address bits from a pointer value. */
> > +
> > +CORE_ADDR aarch64_remove_non_address_bits (struct gdbarch *gdbarch,
> > + CORE_ADDR pointer);
> > +
> > #endif /* aarch64-tdep.h */
> > diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c index
> > b7e4f5d0a45..9983e905e1b 100644
> > --- a/gdb/breakpoint.c
> > +++ b/gdb/breakpoint.c
> > @@ -2313,7 +2313,8 @@ update_watchpoint (struct watchpoint *b, bool
> reparse)
> > loc->gdbarch = v->type ()->arch ();
> > loc->pspace = wp_pspace;
> > loc->address
> > - = gdbarch_remove_non_address_bits (loc->gdbarch, addr);
> > + = gdbarch_remove_non_address_bits_watchpoint (loc-
> >gdbarch,
> > + addr);
> > b->add_location (*loc);
> >
> > if (bitsize != 0)
> > @@ -7538,7 +7539,7 @@ adjust_breakpoint_address (struct gdbarch
> *gdbarch,
> > }
> >
> > adjusted_bpaddr
> > - = gdbarch_remove_non_address_bits (gdbarch, adjusted_bpaddr);
> > + = gdbarch_remove_non_address_bits_breakpoint (gdbarch,
> > +adjusted_bpaddr);
> >
> > /* An adjusted breakpoint address can significantly alter
> > a user's expectations. Print a warning if an adjustment diff --git
> > a/gdb/gdbarch-gen.c b/gdb/gdbarch-gen.c index 0d00cd7c993..d05c7a3cbdf
> > 100644
> > --- a/gdb/gdbarch-gen.c
> > +++ b/gdb/gdbarch-gen.c
> > @@ -143,7 +143,9 @@ struct gdbarch
> > int frame_red_zone_size = 0;
> > gdbarch_convert_from_func_ptr_addr_ftype *convert_from_func_ptr_addr =
> convert_from_func_ptr_addr_identity;
> > gdbarch_addr_bits_remove_ftype *addr_bits_remove =
> > core_addr_identity;
> > - gdbarch_remove_non_address_bits_ftype *remove_non_address_bits =
> > default_remove_non_address_bits;
> > + gdbarch_remove_non_address_bits_watchpoint_ftype
> > + *remove_non_address_bits_watchpoint =
> > + default_remove_non_address_bits;
> > + gdbarch_remove_non_address_bits_breakpoint_ftype
> > + *remove_non_address_bits_breakpoint =
> > + default_remove_non_address_bits;
> > + gdbarch_remove_non_address_bits_memory_ftype
> > + *remove_non_address_bits_memory = default_remove_non_address_bits;
> > gdbarch_memtag_to_string_ftype *memtag_to_string =
> default_memtag_to_string;
> > gdbarch_tagged_address_p_ftype *tagged_address_p =
> default_tagged_address_p;
> > gdbarch_memtag_matches_p_ftype *memtag_matches_p =
> > default_memtag_matches_p; @@ -407,7 +409,9 @@ verify_gdbarch (struct
> gdbarch *gdbarch)
> > /* Skip verify of frame_red_zone_size, invalid_p == 0. */
> > /* Skip verify of convert_from_func_ptr_addr, invalid_p == 0. */
> > /* Skip verify of addr_bits_remove, invalid_p == 0. */
> > - /* Skip verify of remove_non_address_bits, invalid_p == 0. */
> > + /* Skip verify of remove_non_address_bits_watchpoint, invalid_p ==
> > + 0. */
> > + /* Skip verify of remove_non_address_bits_breakpoint, invalid_p ==
> > + 0. */
> > + /* Skip verify of remove_non_address_bits_memory, invalid_p == 0.
> > + */
> > /* Skip verify of memtag_to_string, invalid_p == 0. */
> > /* Skip verify of tagged_address_p, invalid_p == 0. */
> > /* Skip verify of memtag_matches_p, invalid_p == 0. */ @@ -910,8
> > +914,14 @@ gdbarch_dump (struct gdbarch *gdbarch, struct ui_file *file)
> > "gdbarch_dump: addr_bits_remove = <%s>\n",
> > host_address_to_string (gdbarch->addr_bits_remove));
> > gdb_printf (file,
> > - "gdbarch_dump: remove_non_address_bits = <%s>\n",
> > - host_address_to_string (gdbarch->remove_non_address_bits));
> > + "gdbarch_dump: remove_non_address_bits_watchpoint = <%s>\n",
> > + host_address_to_string
> > +(gdbarch->remove_non_address_bits_watchpoint));
> > + gdb_printf (file,
> > + "gdbarch_dump: remove_non_address_bits_breakpoint = <%s>\n",
> > + host_address_to_string
> > +(gdbarch->remove_non_address_bits_breakpoint));
> > + gdb_printf (file,
> > + "gdbarch_dump: remove_non_address_bits_memory = <%s>\n",
> > + host_address_to_string
> > +(gdbarch->remove_non_address_bits_memory));
> > gdb_printf (file,
> > "gdbarch_dump: memtag_to_string = <%s>\n",
> > host_address_to_string (gdbarch->memtag_to_string)); @@
> > -3198,20 +3208,54 @@ set_gdbarch_addr_bits_remove (struct gdbarch
> > *gdbarch, }
> >
> > CORE_ADDR
> > -gdbarch_remove_non_address_bits (struct gdbarch *gdbarch, CORE_ADDR
> > pointer)
> > +gdbarch_remove_non_address_bits_watchpoint (struct gdbarch *gdbarch,
> > +CORE_ADDR pointer) {
> > + gdb_assert (gdbarch != NULL);
> > + gdb_assert (gdbarch->remove_non_address_bits_watchpoint != NULL);
> > + if (gdbarch_debug >= 2)
> > + gdb_printf (gdb_stdlog,
> > +"gdbarch_remove_non_address_bits_watchpoint called\n");
> > + return gdbarch->remove_non_address_bits_watchpoint (gdbarch,
> > +pointer); }
> > +
> > +void
> > +set_gdbarch_remove_non_address_bits_watchpoint (struct gdbarch
> *gdbarch,
> > +
> gdbarch_remove_non_address_bits_watchpoint_ftype
> > +remove_non_address_bits_watchpoint)
> > +{
> > + gdbarch->remove_non_address_bits_watchpoint =
> > +remove_non_address_bits_watchpoint;
> > +}
> > +
> > +CORE_ADDR
> > +gdbarch_remove_non_address_bits_breakpoint (struct gdbarch *gdbarch,
> > +CORE_ADDR pointer) {
> > + gdb_assert (gdbarch != NULL);
> > + gdb_assert (gdbarch->remove_non_address_bits_breakpoint != NULL);
> > + if (gdbarch_debug >= 2)
> > + gdb_printf (gdb_stdlog,
> > +"gdbarch_remove_non_address_bits_breakpoint called\n");
> > + return gdbarch->remove_non_address_bits_breakpoint (gdbarch,
> > +pointer); }
> > +
> > +void
> > +set_gdbarch_remove_non_address_bits_breakpoint (struct gdbarch *gdbarch,
> > +
> gdbarch_remove_non_address_bits_breakpoint_ftype
> > +remove_non_address_bits_breakpoint)
> > +{
> > + gdbarch->remove_non_address_bits_breakpoint =
> > +remove_non_address_bits_breakpoint;
> > +}
> > +
> > +CORE_ADDR
> > +gdbarch_remove_non_address_bits_memory (struct gdbarch *gdbarch,
> > +CORE_ADDR pointer)
> > {
> > gdb_assert (gdbarch != NULL);
> > - gdb_assert (gdbarch->remove_non_address_bits != NULL);
> > + gdb_assert (gdbarch->remove_non_address_bits_memory != NULL);
> > if (gdbarch_debug >= 2)
> > - gdb_printf (gdb_stdlog, "gdbarch_remove_non_address_bits called\n");
> > - return gdbarch->remove_non_address_bits (gdbarch, pointer);
> > + gdb_printf (gdb_stdlog, "gdbarch_remove_non_address_bits_memory
> > + called\n"); return gdbarch->remove_non_address_bits_memory
> > + (gdbarch, pointer);
> > }
> >
> > void
> > -set_gdbarch_remove_non_address_bits (struct gdbarch *gdbarch,
> > - gdbarch_remove_non_address_bits_ftype
> remove_non_address_bits)
> > +set_gdbarch_remove_non_address_bits_memory (struct gdbarch *gdbarch,
> > +
> gdbarch_remove_non_address_bits_memory_ftype
> > +remove_non_address_bits_memory)
> > {
> > - gdbarch->remove_non_address_bits = remove_non_address_bits;
> > + gdbarch->remove_non_address_bits_memory =
> > + remove_non_address_bits_memory;
> > }
> >
> > std::string
> > diff --git a/gdb/gdbarch-gen.h b/gdb/gdbarch-gen.h index
> > b982fd7cd09..9fda85f860f 100644
> > --- a/gdb/gdbarch-gen.h
> > +++ b/gdb/gdbarch-gen.h
> > @@ -684,19 +684,46 @@ extern CORE_ADDR gdbarch_addr_bits_remove
> > (struct gdbarch *gdbarch, CORE_ADDR ad extern void
> > set_gdbarch_addr_bits_remove (struct gdbarch *gdbarch,
> > gdbarch_addr_bits_remove_ftype *addr_bits_remove);
> >
> > /* On some architectures, not all bits of a pointer are significant.
> > - On AArch64, for example, the top bits of a pointer may carry a "tag", which
> > - can be ignored by the kernel and the hardware. The "tag" can be regarded as
> > - additional data associated with the pointer, but it is not part of the address.
> > + On AArch64 and amd64, for example, the top bits of a pointer may carry a
> > + "tag", which can be ignored by the kernel and the hardware. The "tag" can
> be
> > + regarded as additional data associated with the pointer, but it is not part
> > + of the address.
> >
> > Given a pointer for the architecture, this hook removes all the
> > - non-significant bits and sign-extends things as needed. It gets used to
> remove
> > - non-address bits from data pointers (for example, removing the AArch64 MTE
> tag
> > - bits from a pointer) and from code pointers (removing the AArch64 PAC
> signature
> > - from a pointer containing the return address). */
> > -
> > -typedef CORE_ADDR (gdbarch_remove_non_address_bits_ftype) (struct
> > gdbarch *gdbarch, CORE_ADDR pointer); -extern CORE_ADDR
> > gdbarch_remove_non_address_bits (struct gdbarch *gdbarch, CORE_ADDR
> > pointer); -extern void set_gdbarch_remove_non_address_bits (struct
> > gdbarch *gdbarch, gdbarch_remove_non_address_bits_ftype
> > *remove_non_address_bits);
> > + non-significant bits and sign-extends things as needed. It gets used to
> > + remove non-address bits from pointers used for watchpoints. */
> > +
> > +typedef CORE_ADDR (gdbarch_remove_non_address_bits_watchpoint_ftype)
> > +(struct gdbarch *gdbarch, CORE_ADDR pointer); extern CORE_ADDR
> > +gdbarch_remove_non_address_bits_watchpoint (struct gdbarch *gdbarch,
> > +CORE_ADDR pointer); extern void
> > +set_gdbarch_remove_non_address_bits_watchpoint (struct gdbarch
> > +*gdbarch, gdbarch_remove_non_address_bits_watchpoint_ftype
> > +*remove_non_address_bits_watchpoint);
> > +
> > +/* On some architectures, not all bits of a pointer are significant.
> > + On AArch64 and amd64, for example, the top bits of a pointer may carry a
> > + "tag", which can be ignored by the kernel and the hardware. The "tag" can
> be
> > + regarded as additional data associated with the pointer, but it is not part
> > + of the address.
> > +
> > + Given a pointer for the architecture, this hook removes all the
> > + non-significant bits and sign-extends things as needed. It gets used to
> > + remove non-address bits from pointers used for breakpoints. */
> > +
> > +typedef CORE_ADDR (gdbarch_remove_non_address_bits_breakpoint_ftype)
> > +(struct gdbarch *gdbarch, CORE_ADDR pointer); extern CORE_ADDR
> > +gdbarch_remove_non_address_bits_breakpoint (struct gdbarch *gdbarch,
> > +CORE_ADDR pointer); extern void
> > +set_gdbarch_remove_non_address_bits_breakpoint (struct gdbarch
> > +*gdbarch, gdbarch_remove_non_address_bits_breakpoint_ftype
> > +*remove_non_address_bits_breakpoint);
> > +
> > +/* On some architectures, not all bits of a pointer are significant.
> > + On AArch64 and amd64, for example, the top bits of a pointer may carry a
> > + "tag", which can be ignored by the kernel and the hardware. The "tag" can
> be
> > + regarded as additional data associated with the pointer, but it is not part
> > + of the address.
> > +
> > + Given a pointer for the architecture, this hook removes all the
> > + non-significant bits and sign-extends things as needed. It gets used to
> > + remove non-address bits from any pointer used to access memory. */
> > +
> > +typedef CORE_ADDR (gdbarch_remove_non_address_bits_memory_ftype)
> > +(struct gdbarch *gdbarch, CORE_ADDR pointer); extern CORE_ADDR
> > +gdbarch_remove_non_address_bits_memory (struct gdbarch *gdbarch,
> > +CORE_ADDR pointer); extern void
> > +set_gdbarch_remove_non_address_bits_memory (struct gdbarch *gdbarch,
> > +gdbarch_remove_non_address_bits_memory_ftype
> > +*remove_non_address_bits_memory);
> >
> > /* Return a string representation of the memory tag TAG. */
> >
> > diff --git a/gdb/gdbarch_components.py b/gdb/gdbarch_components.py
> > index 4006380076d..cc7c6d8677b 100644
> > --- a/gdb/gdbarch_components.py
> > +++ b/gdb/gdbarch_components.py
> > @@ -1232,18 +1232,55 @@ possible it should be in TARGET_READ_PC
> instead).
> > Method(
> > comment="""
> > On some architectures, not all bits of a pointer are significant.
> > -On AArch64, for example, the top bits of a pointer may carry a "tag",
> > which -can be ignored by the kernel and the hardware. The "tag" can
> > be regarded as -additional data associated with the pointer, but it is not part of
> the address.
> > +On AArch64 and amd64, for example, the top bits of a pointer may
> > +carry a "tag", which can be ignored by the kernel and the hardware.
> > +The "tag" can be regarded as additional data associated with the
> > +pointer, but it is not part of the address.
> >
> > Given a pointer for the architecture, this hook removes all the
> > -non-significant bits and sign-extends things as needed. It gets used
> > to remove -non-address bits from data pointers (for example, removing
> > the AArch64 MTE tag -bits from a pointer) and from code pointers
> > (removing the AArch64 PAC signature -from a pointer containing the return
> address).
> > +non-significant bits and sign-extends things as needed. It gets used
> > +to remove non-address bits from pointers used for watchpoints.
> > """,
> > type="CORE_ADDR",
> > - name="remove_non_address_bits",
> > + name="remove_non_address_bits_watchpoint",
> > + params=[("CORE_ADDR", "pointer")],
> > + predefault="default_remove_non_address_bits",
> > + invalid=False,
> > +)
> > +
> > +Method(
> > + comment="""
> > +On some architectures, not all bits of a pointer are significant.
> > +On AArch64 and amd64, for example, the top bits of a pointer may
> > +carry a "tag", which can be ignored by the kernel and the hardware.
> > +The "tag" can be regarded as additional data associated with the
> > +pointer, but it is not part of the address.
> > +
> > +Given a pointer for the architecture, this hook removes all the
> > +non-significant bits and sign-extends things as needed. It gets used
> > +to remove non-address bits from pointers used for breakpoints.
> > +""",
> > + type="CORE_ADDR",
> > + name="remove_non_address_bits_breakpoint",
> > + params=[("CORE_ADDR", "pointer")],
> > + predefault="default_remove_non_address_bits",
> > + invalid=False,
> > +)
> > +
> > +Method(
> > + comment="""
> > +On some architectures, not all bits of a pointer are significant.
> > +On AArch64 and amd64, for example, the top bits of a pointer may
> > +carry a "tag", which can be ignored by the kernel and the hardware.
> > +The "tag" can be regarded as additional data associated with the
> > +pointer, but it is not part of the address.
> > +
> > +Given a pointer for the architecture, this hook removes all the
> > +non-significant bits and sign-extends things as needed. It gets used
> > +to remove non-address bits from any pointer used to access memory.
> > +""",
> > + type="CORE_ADDR",
> > + name="remove_non_address_bits_memory",
> > params=[("CORE_ADDR", "pointer")],
> > predefault="default_remove_non_address_bits",
> > invalid=False,
> > diff --git a/gdb/loongarch-linux-nat.c b/gdb/loongarch-linux-nat.c
> > index bc9927dd751..dc4a019614a 100644
> > --- a/gdb/loongarch-linux-nat.c
> > +++ b/gdb/loongarch-linux-nat.c
> > @@ -613,7 +613,7 @@ loongarch_linux_nat_target::stopped_data_address
> (CORE_ADDR *addr_p)
> > kernel can potentially be tagged addresses. */
> > struct gdbarch *gdbarch = thread_architecture (inferior_ptid);
> > const CORE_ADDR addr_trap
> > - = gdbarch_remove_non_address_bits (gdbarch, (CORE_ADDR)
> siginfo.si_addr);
> > + = aarch64_remove_non_address_bits (gdbarch, (CORE_ADDR)
> > + siginfo.si_addr);
> >
> > /* Check if the address matches any watched address. */
> > state = loongarch_get_debug_reg_state (inferior_ptid.pid ());
>
> I think the loongarch-linux-nat.c change is spurious. Could you please address
> that?
Why is it spurious? What do you mean exactly?
Thanks,
Christina
Intel Deutschland GmbH
Registered Address: Am Campeon 10, 85579 Neubiberg, Germany
Tel: +49 89 99 8853-0, www.intel.de
Managing Directors: Sean Fennelly, Jeffrey Schneiderman, Tiffany Doon Silva
Chairperson of the Supervisory Board: Nicole Lau
Registered Office: Munich
Commercial Register: Amtsgericht Muenchen HRB 186928
On 11/5/24 14:07, Schimpe, Christina wrote:
> Hi Luis,
>
> Thanks a lot for the review. I have one questions to your comment, please see below.
>
>> -----Original Message-----
>> From: Luis Machado <luis.machado@arm.com>
>> Sent: Monday, November 4, 2024 12:18 PM
>> To: Schimpe, Christina <christina.schimpe@intel.com>; gdb-
>> patches@sourceware.org
>> Subject: Re: [PATCH v6 1/2] gdb: Make tagged pointer support configurable.
>>
>> Hi Christina,
>>
>> On 10/28/24 08:46, Schimpe, Christina wrote:
>>> From: Christina Schimpe <christina.schimpe@intel.com>
>>>
>>> The gdbarch function gdbarch_remove_non_address_bits adjusts addresses
>>> to enable debugging of programs with tagged pointers on Linux, for
>>> instance for ARM's feature top byte ignore (TBI).
>>> Once the function is implemented for an architecture, it adjusts
>>> addresses for memory access, breakpoints and watchpoints.
>>>
>>> Linear address masking (LAM) is Intel's (R) implementation of tagged
>>> pointer support. It requires certain adaptions to GDB's tagged
>>> pointer support due to the following:
>>> - LAM supports address tagging for data accesses only. Thus, specifying
>>> breakpoints on tagged addresses is not a valid use case.
>>> - In contrast to the implementation for ARM's TBI, the Linux kernel supports
>>> tagged pointers for memory access.
>>>
>>> This patch makes GDB's tagged pointer support configurable such that
>>> it is possible to enable the address adjustment for a specific feature
>>> only (e.g memory access, breakpoints or watchpoints). This way, one
>>> can make sure that addresses are only adjusted when necessary. In
>>> case of LAM, this avoids unnecessary parsing of the /proc/<pid>/status
>>> file to get the untag mask.
>>>
>>> Reviewed-By: Felix Willgerodt <felix.willgerodt@intel.com>
>>> ---
>>> gdb/aarch64-linux-nat.c | 2 +-
>>> gdb/aarch64-linux-tdep.c | 7 +++--
>>> gdb/aarch64-tdep.c | 23 ++++++++------
>>> gdb/aarch64-tdep.h | 6 ++++
>>> gdb/breakpoint.c | 5 +--
>>> gdb/gdbarch-gen.c | 66 ++++++++++++++++++++++++++++++++-------
>>> gdb/gdbarch-gen.h | 49 ++++++++++++++++++++++-------
>>> gdb/gdbarch_components.py | 53 ++++++++++++++++++++++++++-----
>>> gdb/loongarch-linux-nat.c | 2 +-
>>> gdb/target.c | 3 +-
>>> 10 files changed, 169 insertions(+), 47 deletions(-)
>>>
>>> diff --git a/gdb/aarch64-linux-nat.c b/gdb/aarch64-linux-nat.c index
>>> 0fa5bee500b..48ab765d880 100644
>>> --- a/gdb/aarch64-linux-nat.c
>>> +++ b/gdb/aarch64-linux-nat.c
>>> @@ -943,7 +943,7 @@ aarch64_linux_nat_target::stopped_data_address
>> (CORE_ADDR *addr_p)
>>> kernel can potentially be tagged addresses. */
>>> struct gdbarch *gdbarch = thread_architecture (inferior_ptid);
>>> const CORE_ADDR addr_trap
>>> - = gdbarch_remove_non_address_bits (gdbarch, (CORE_ADDR)
>> siginfo.si_addr);
>>> + = aarch64_remove_non_address_bits (gdbarch, (CORE_ADDR)
>>> + siginfo.si_addr);
>>>
>>> /* Check if the address matches any watched address. */
>>> state = aarch64_get_debug_reg_state (inferior_ptid.pid ()); diff
>>> --git a/gdb/aarch64-linux-tdep.c b/gdb/aarch64-linux-tdep.c index
>>> c608a84bc71..61c3be8b6f0 100644
>>> --- a/gdb/aarch64-linux-tdep.c
>>> +++ b/gdb/aarch64-linux-tdep.c
>>> @@ -2433,7 +2433,7 @@ static bool
>>> aarch64_linux_tagged_address_p (struct gdbarch *gdbarch, CORE_ADDR
>>> address) {
>>> /* Remove the top byte for the memory range check. */
>>> - address = gdbarch_remove_non_address_bits (gdbarch, address);
>>> + address = aarch64_remove_non_address_bits (gdbarch, address);
>>>
>>> /* Check if the page that contains ADDRESS is mapped with PROT_MTE. */
>>> if (!linux_address_in_memtag_page (address)) @@ -2491,8 +2491,9 @@
>>> aarch64_linux_report_signal_info (struct gdbarch *gdbarch,
>>> uiout->text ("\n");
>>>
>>> std::optional<CORE_ADDR> atag
>>> - = aarch64_mte_get_atag (gdbarch_remove_non_address_bits (gdbarch,
>>> - fault_addr));
>>> + = aarch64_mte_get_atag (
>>> + aarch64_remove_non_address_bits (gdbarch, fault_addr));
>>> +
>>> gdb_byte ltag = aarch64_mte_get_ltag (fault_addr);
>>>
>>> if (!atag.has_value ())
>>> diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c index
>>> 8a2a9b1e23c..91fec7879ed 100644
>>> --- a/gdb/aarch64-tdep.c
>>> +++ b/gdb/aarch64-tdep.c
>>> @@ -4121,7 +4121,7 @@ aarch64_memtag_matches_p (struct gdbarch
>>> *gdbarch,
>>>
>>> /* Fetch the allocation tag for ADDRESS. */
>>> std::optional<CORE_ADDR> atag
>>> - = aarch64_mte_get_atag (gdbarch_remove_non_address_bits (gdbarch,
>> addr));
>>> + = aarch64_mte_get_atag (aarch64_remove_non_address_bits (gdbarch,
>>> + addr));
>>>
>>> if (!atag.has_value ())
>>> return true;
>>> @@ -4160,7 +4160,7 @@ aarch64_set_memtags (struct gdbarch *gdbarch,
>> struct value *address,
>>> else
>>> {
>>> /* Remove the top byte. */
>>> - addr = gdbarch_remove_non_address_bits (gdbarch, addr);
>>> + addr = aarch64_remove_non_address_bits (gdbarch, addr);
>>>
>>> /* With G being the number of tag granules and N the number of tags
>>> passed in, we can have the following cases:
>>> @@ -4209,7 +4209,7 @@ aarch64_get_memtag (struct gdbarch *gdbarch,
>> struct value *address,
>>> else
>>> {
>>> /* Remove the top byte. */
>>> - addr = gdbarch_remove_non_address_bits (gdbarch, addr);
>>> + addr = aarch64_remove_non_address_bits (gdbarch, addr);
>>> std::optional<CORE_ADDR> atag = aarch64_mte_get_atag (addr);
>>>
>>> if (!atag.has_value ())
>>> @@ -4236,10 +4236,9 @@ aarch64_memtag_to_string (struct gdbarch
>> *gdbarch, struct value *tag_value)
>>> return string_printf ("0x%s", phex_nz (tag, sizeof (tag))); }
>>>
>>> -/* AArch64 implementation of the remove_non_address_bits gdbarch hook.
>> Remove
>>> - non address bits from a pointer value. */
>>> +/* See aarch64-tdep.h. */
>>>
>>> -static CORE_ADDR
>>> +CORE_ADDR
>>> aarch64_remove_non_address_bits (struct gdbarch *gdbarch, CORE_ADDR
>>> pointer) {
>>> /* By default, we assume TBI and discard the top 8 bits plus the VA
>>> range @@ -4750,9 +4749,15 @@ aarch64_gdbarch_init (struct gdbarch_info
>> info, struct gdbarch_list *arches)
>>> tdep->ra_sign_state_regnum = ra_sign_state_offset + num_regs;
>>>
>>> /* Architecture hook to remove bits of a pointer that are not part of the
>>> - address, like memory tags (MTE) and pointer authentication signatures. */
>>> - set_gdbarch_remove_non_address_bits (gdbarch,
>>> - aarch64_remove_non_address_bits);
>>> + address, like memory tags (MTE) and pointer authentication signatures.
>>> + Configure address adjustment for watch-, breakpoints and memory
>>
>> s/watch-/watchpoints
>
> Fill fix, thanks.
>
>>> + transfer. */
>>> + set_gdbarch_remove_non_address_bits_watchpoint
>>> + (gdbarch, aarch64_remove_non_address_bits);
>>> + set_gdbarch_remove_non_address_bits_breakpoint
>>> + (gdbarch, aarch64_remove_non_address_bits);
>>> + set_gdbarch_remove_non_address_bits_memory
>>> + (gdbarch, aarch64_remove_non_address_bits);
>>>
>>> /* SME pseudo-registers. */
>>> if (tdep->has_sme ())
>>> diff --git a/gdb/aarch64-tdep.h b/gdb/aarch64-tdep.h index
>>> 50166fb4f24..13ea37de7a3 100644
>>> --- a/gdb/aarch64-tdep.h
>>> +++ b/gdb/aarch64-tdep.h
>>> @@ -205,4 +205,10 @@ bool aarch64_displaced_step_hw_singlestep (struct
>>> gdbarch *gdbarch);
>>>
>>> std::optional<CORE_ADDR> aarch64_mte_get_atag (CORE_ADDR address);
>>>
>>> +/* AArch64 implementation of the remove_non_address_bits gdbarch hooks.
>>> + Remove non address bits from a pointer value. */
>>> +
>>> +CORE_ADDR aarch64_remove_non_address_bits (struct gdbarch *gdbarch,
>>> + CORE_ADDR pointer);
>>> +
>>> #endif /* aarch64-tdep.h */
>>> diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c index
>>> b7e4f5d0a45..9983e905e1b 100644
>>> --- a/gdb/breakpoint.c
>>> +++ b/gdb/breakpoint.c
>>> @@ -2313,7 +2313,8 @@ update_watchpoint (struct watchpoint *b, bool
>> reparse)
>>> loc->gdbarch = v->type ()->arch ();
>>> loc->pspace = wp_pspace;
>>> loc->address
>>> - = gdbarch_remove_non_address_bits (loc->gdbarch, addr);
>>> + = gdbarch_remove_non_address_bits_watchpoint (loc-
>>> gdbarch,
>>> + addr);
>>> b->add_location (*loc);
>>>
>>> if (bitsize != 0)
>>> @@ -7538,7 +7539,7 @@ adjust_breakpoint_address (struct gdbarch
>> *gdbarch,
>>> }
>>>
>>> adjusted_bpaddr
>>> - = gdbarch_remove_non_address_bits (gdbarch, adjusted_bpaddr);
>>> + = gdbarch_remove_non_address_bits_breakpoint (gdbarch,
>>> +adjusted_bpaddr);
>>>
>>> /* An adjusted breakpoint address can significantly alter
>>> a user's expectations. Print a warning if an adjustment diff --git
>>> a/gdb/gdbarch-gen.c b/gdb/gdbarch-gen.c index 0d00cd7c993..d05c7a3cbdf
>>> 100644
>>> --- a/gdb/gdbarch-gen.c
>>> +++ b/gdb/gdbarch-gen.c
>>> @@ -143,7 +143,9 @@ struct gdbarch
>>> int frame_red_zone_size = 0;
>>> gdbarch_convert_from_func_ptr_addr_ftype *convert_from_func_ptr_addr =
>> convert_from_func_ptr_addr_identity;
>>> gdbarch_addr_bits_remove_ftype *addr_bits_remove =
>>> core_addr_identity;
>>> - gdbarch_remove_non_address_bits_ftype *remove_non_address_bits =
>>> default_remove_non_address_bits;
>>> + gdbarch_remove_non_address_bits_watchpoint_ftype
>>> + *remove_non_address_bits_watchpoint =
>>> + default_remove_non_address_bits;
>>> + gdbarch_remove_non_address_bits_breakpoint_ftype
>>> + *remove_non_address_bits_breakpoint =
>>> + default_remove_non_address_bits;
>>> + gdbarch_remove_non_address_bits_memory_ftype
>>> + *remove_non_address_bits_memory = default_remove_non_address_bits;
>>> gdbarch_memtag_to_string_ftype *memtag_to_string =
>> default_memtag_to_string;
>>> gdbarch_tagged_address_p_ftype *tagged_address_p =
>> default_tagged_address_p;
>>> gdbarch_memtag_matches_p_ftype *memtag_matches_p =
>>> default_memtag_matches_p; @@ -407,7 +409,9 @@ verify_gdbarch (struct
>> gdbarch *gdbarch)
>>> /* Skip verify of frame_red_zone_size, invalid_p == 0. */
>>> /* Skip verify of convert_from_func_ptr_addr, invalid_p == 0. */
>>> /* Skip verify of addr_bits_remove, invalid_p == 0. */
>>> - /* Skip verify of remove_non_address_bits, invalid_p == 0. */
>>> + /* Skip verify of remove_non_address_bits_watchpoint, invalid_p ==
>>> + 0. */
>>> + /* Skip verify of remove_non_address_bits_breakpoint, invalid_p ==
>>> + 0. */
>>> + /* Skip verify of remove_non_address_bits_memory, invalid_p == 0.
>>> + */
>>> /* Skip verify of memtag_to_string, invalid_p == 0. */
>>> /* Skip verify of tagged_address_p, invalid_p == 0. */
>>> /* Skip verify of memtag_matches_p, invalid_p == 0. */ @@ -910,8
>>> +914,14 @@ gdbarch_dump (struct gdbarch *gdbarch, struct ui_file *file)
>>> "gdbarch_dump: addr_bits_remove = <%s>\n",
>>> host_address_to_string (gdbarch->addr_bits_remove));
>>> gdb_printf (file,
>>> - "gdbarch_dump: remove_non_address_bits = <%s>\n",
>>> - host_address_to_string (gdbarch->remove_non_address_bits));
>>> + "gdbarch_dump: remove_non_address_bits_watchpoint = <%s>\n",
>>> + host_address_to_string
>>> +(gdbarch->remove_non_address_bits_watchpoint));
>>> + gdb_printf (file,
>>> + "gdbarch_dump: remove_non_address_bits_breakpoint = <%s>\n",
>>> + host_address_to_string
>>> +(gdbarch->remove_non_address_bits_breakpoint));
>>> + gdb_printf (file,
>>> + "gdbarch_dump: remove_non_address_bits_memory = <%s>\n",
>>> + host_address_to_string
>>> +(gdbarch->remove_non_address_bits_memory));
>>> gdb_printf (file,
>>> "gdbarch_dump: memtag_to_string = <%s>\n",
>>> host_address_to_string (gdbarch->memtag_to_string)); @@
>>> -3198,20 +3208,54 @@ set_gdbarch_addr_bits_remove (struct gdbarch
>>> *gdbarch, }
>>>
>>> CORE_ADDR
>>> -gdbarch_remove_non_address_bits (struct gdbarch *gdbarch, CORE_ADDR
>>> pointer)
>>> +gdbarch_remove_non_address_bits_watchpoint (struct gdbarch *gdbarch,
>>> +CORE_ADDR pointer) {
>>> + gdb_assert (gdbarch != NULL);
>>> + gdb_assert (gdbarch->remove_non_address_bits_watchpoint != NULL);
>>> + if (gdbarch_debug >= 2)
>>> + gdb_printf (gdb_stdlog,
>>> +"gdbarch_remove_non_address_bits_watchpoint called\n");
>>> + return gdbarch->remove_non_address_bits_watchpoint (gdbarch,
>>> +pointer); }
>>> +
>>> +void
>>> +set_gdbarch_remove_non_address_bits_watchpoint (struct gdbarch
>> *gdbarch,
>>> +
>> gdbarch_remove_non_address_bits_watchpoint_ftype
>>> +remove_non_address_bits_watchpoint)
>>> +{
>>> + gdbarch->remove_non_address_bits_watchpoint =
>>> +remove_non_address_bits_watchpoint;
>>> +}
>>> +
>>> +CORE_ADDR
>>> +gdbarch_remove_non_address_bits_breakpoint (struct gdbarch *gdbarch,
>>> +CORE_ADDR pointer) {
>>> + gdb_assert (gdbarch != NULL);
>>> + gdb_assert (gdbarch->remove_non_address_bits_breakpoint != NULL);
>>> + if (gdbarch_debug >= 2)
>>> + gdb_printf (gdb_stdlog,
>>> +"gdbarch_remove_non_address_bits_breakpoint called\n");
>>> + return gdbarch->remove_non_address_bits_breakpoint (gdbarch,
>>> +pointer); }
>>> +
>>> +void
>>> +set_gdbarch_remove_non_address_bits_breakpoint (struct gdbarch *gdbarch,
>>> +
>> gdbarch_remove_non_address_bits_breakpoint_ftype
>>> +remove_non_address_bits_breakpoint)
>>> +{
>>> + gdbarch->remove_non_address_bits_breakpoint =
>>> +remove_non_address_bits_breakpoint;
>>> +}
>>> +
>>> +CORE_ADDR
>>> +gdbarch_remove_non_address_bits_memory (struct gdbarch *gdbarch,
>>> +CORE_ADDR pointer)
>>> {
>>> gdb_assert (gdbarch != NULL);
>>> - gdb_assert (gdbarch->remove_non_address_bits != NULL);
>>> + gdb_assert (gdbarch->remove_non_address_bits_memory != NULL);
>>> if (gdbarch_debug >= 2)
>>> - gdb_printf (gdb_stdlog, "gdbarch_remove_non_address_bits called\n");
>>> - return gdbarch->remove_non_address_bits (gdbarch, pointer);
>>> + gdb_printf (gdb_stdlog, "gdbarch_remove_non_address_bits_memory
>>> + called\n"); return gdbarch->remove_non_address_bits_memory
>>> + (gdbarch, pointer);
>>> }
>>>
>>> void
>>> -set_gdbarch_remove_non_address_bits (struct gdbarch *gdbarch,
>>> - gdbarch_remove_non_address_bits_ftype
>> remove_non_address_bits)
>>> +set_gdbarch_remove_non_address_bits_memory (struct gdbarch *gdbarch,
>>> +
>> gdbarch_remove_non_address_bits_memory_ftype
>>> +remove_non_address_bits_memory)
>>> {
>>> - gdbarch->remove_non_address_bits = remove_non_address_bits;
>>> + gdbarch->remove_non_address_bits_memory =
>>> + remove_non_address_bits_memory;
>>> }
>>>
>>> std::string
>>> diff --git a/gdb/gdbarch-gen.h b/gdb/gdbarch-gen.h index
>>> b982fd7cd09..9fda85f860f 100644
>>> --- a/gdb/gdbarch-gen.h
>>> +++ b/gdb/gdbarch-gen.h
>>> @@ -684,19 +684,46 @@ extern CORE_ADDR gdbarch_addr_bits_remove
>>> (struct gdbarch *gdbarch, CORE_ADDR ad extern void
>>> set_gdbarch_addr_bits_remove (struct gdbarch *gdbarch,
>>> gdbarch_addr_bits_remove_ftype *addr_bits_remove);
>>>
>>> /* On some architectures, not all bits of a pointer are significant.
>>> - On AArch64, for example, the top bits of a pointer may carry a "tag", which
>>> - can be ignored by the kernel and the hardware. The "tag" can be regarded as
>>> - additional data associated with the pointer, but it is not part of the address.
>>> + On AArch64 and amd64, for example, the top bits of a pointer may carry a
>>> + "tag", which can be ignored by the kernel and the hardware. The "tag" can
>> be
>>> + regarded as additional data associated with the pointer, but it is not part
>>> + of the address.
>>>
>>> Given a pointer for the architecture, this hook removes all the
>>> - non-significant bits and sign-extends things as needed. It gets used to
>> remove
>>> - non-address bits from data pointers (for example, removing the AArch64 MTE
>> tag
>>> - bits from a pointer) and from code pointers (removing the AArch64 PAC
>> signature
>>> - from a pointer containing the return address). */
>>> -
>>> -typedef CORE_ADDR (gdbarch_remove_non_address_bits_ftype) (struct
>>> gdbarch *gdbarch, CORE_ADDR pointer); -extern CORE_ADDR
>>> gdbarch_remove_non_address_bits (struct gdbarch *gdbarch, CORE_ADDR
>>> pointer); -extern void set_gdbarch_remove_non_address_bits (struct
>>> gdbarch *gdbarch, gdbarch_remove_non_address_bits_ftype
>>> *remove_non_address_bits);
>>> + non-significant bits and sign-extends things as needed. It gets used to
>>> + remove non-address bits from pointers used for watchpoints. */
>>> +
>>> +typedef CORE_ADDR (gdbarch_remove_non_address_bits_watchpoint_ftype)
>>> +(struct gdbarch *gdbarch, CORE_ADDR pointer); extern CORE_ADDR
>>> +gdbarch_remove_non_address_bits_watchpoint (struct gdbarch *gdbarch,
>>> +CORE_ADDR pointer); extern void
>>> +set_gdbarch_remove_non_address_bits_watchpoint (struct gdbarch
>>> +*gdbarch, gdbarch_remove_non_address_bits_watchpoint_ftype
>>> +*remove_non_address_bits_watchpoint);
>>> +
>>> +/* On some architectures, not all bits of a pointer are significant.
>>> + On AArch64 and amd64, for example, the top bits of a pointer may carry a
>>> + "tag", which can be ignored by the kernel and the hardware. The "tag" can
>> be
>>> + regarded as additional data associated with the pointer, but it is not part
>>> + of the address.
>>> +
>>> + Given a pointer for the architecture, this hook removes all the
>>> + non-significant bits and sign-extends things as needed. It gets used to
>>> + remove non-address bits from pointers used for breakpoints. */
>>> +
>>> +typedef CORE_ADDR (gdbarch_remove_non_address_bits_breakpoint_ftype)
>>> +(struct gdbarch *gdbarch, CORE_ADDR pointer); extern CORE_ADDR
>>> +gdbarch_remove_non_address_bits_breakpoint (struct gdbarch *gdbarch,
>>> +CORE_ADDR pointer); extern void
>>> +set_gdbarch_remove_non_address_bits_breakpoint (struct gdbarch
>>> +*gdbarch, gdbarch_remove_non_address_bits_breakpoint_ftype
>>> +*remove_non_address_bits_breakpoint);
>>> +
>>> +/* On some architectures, not all bits of a pointer are significant.
>>> + On AArch64 and amd64, for example, the top bits of a pointer may carry a
>>> + "tag", which can be ignored by the kernel and the hardware. The "tag" can
>> be
>>> + regarded as additional data associated with the pointer, but it is not part
>>> + of the address.
>>> +
>>> + Given a pointer for the architecture, this hook removes all the
>>> + non-significant bits and sign-extends things as needed. It gets used to
>>> + remove non-address bits from any pointer used to access memory. */
>>> +
>>> +typedef CORE_ADDR (gdbarch_remove_non_address_bits_memory_ftype)
>>> +(struct gdbarch *gdbarch, CORE_ADDR pointer); extern CORE_ADDR
>>> +gdbarch_remove_non_address_bits_memory (struct gdbarch *gdbarch,
>>> +CORE_ADDR pointer); extern void
>>> +set_gdbarch_remove_non_address_bits_memory (struct gdbarch *gdbarch,
>>> +gdbarch_remove_non_address_bits_memory_ftype
>>> +*remove_non_address_bits_memory);
>>>
>>> /* Return a string representation of the memory tag TAG. */
>>>
>>> diff --git a/gdb/gdbarch_components.py b/gdb/gdbarch_components.py
>>> index 4006380076d..cc7c6d8677b 100644
>>> --- a/gdb/gdbarch_components.py
>>> +++ b/gdb/gdbarch_components.py
>>> @@ -1232,18 +1232,55 @@ possible it should be in TARGET_READ_PC
>> instead).
>>> Method(
>>> comment="""
>>> On some architectures, not all bits of a pointer are significant.
>>> -On AArch64, for example, the top bits of a pointer may carry a "tag",
>>> which -can be ignored by the kernel and the hardware. The "tag" can
>>> be regarded as -additional data associated with the pointer, but it is not part of
>> the address.
>>> +On AArch64 and amd64, for example, the top bits of a pointer may
>>> +carry a "tag", which can be ignored by the kernel and the hardware.
>>> +The "tag" can be regarded as additional data associated with the
>>> +pointer, but it is not part of the address.
>>>
>>> Given a pointer for the architecture, this hook removes all the
>>> -non-significant bits and sign-extends things as needed. It gets used
>>> to remove -non-address bits from data pointers (for example, removing
>>> the AArch64 MTE tag -bits from a pointer) and from code pointers
>>> (removing the AArch64 PAC signature -from a pointer containing the return
>> address).
>>> +non-significant bits and sign-extends things as needed. It gets used
>>> +to remove non-address bits from pointers used for watchpoints.
>>> """,
>>> type="CORE_ADDR",
>>> - name="remove_non_address_bits",
>>> + name="remove_non_address_bits_watchpoint",
>>> + params=[("CORE_ADDR", "pointer")],
>>> + predefault="default_remove_non_address_bits",
>>> + invalid=False,
>>> +)
>>> +
>>> +Method(
>>> + comment="""
>>> +On some architectures, not all bits of a pointer are significant.
>>> +On AArch64 and amd64, for example, the top bits of a pointer may
>>> +carry a "tag", which can be ignored by the kernel and the hardware.
>>> +The "tag" can be regarded as additional data associated with the
>>> +pointer, but it is not part of the address.
>>> +
>>> +Given a pointer for the architecture, this hook removes all the
>>> +non-significant bits and sign-extends things as needed. It gets used
>>> +to remove non-address bits from pointers used for breakpoints.
>>> +""",
>>> + type="CORE_ADDR",
>>> + name="remove_non_address_bits_breakpoint",
>>> + params=[("CORE_ADDR", "pointer")],
>>> + predefault="default_remove_non_address_bits",
>>> + invalid=False,
>>> +)
>>> +
>>> +Method(
>>> + comment="""
>>> +On some architectures, not all bits of a pointer are significant.
>>> +On AArch64 and amd64, for example, the top bits of a pointer may
>>> +carry a "tag", which can be ignored by the kernel and the hardware.
>>> +The "tag" can be regarded as additional data associated with the
>>> +pointer, but it is not part of the address.
>>> +
>>> +Given a pointer for the architecture, this hook removes all the
>>> +non-significant bits and sign-extends things as needed. It gets used
>>> +to remove non-address bits from any pointer used to access memory.
>>> +""",
>>> + type="CORE_ADDR",
>>> + name="remove_non_address_bits_memory",
>>> params=[("CORE_ADDR", "pointer")],
>>> predefault="default_remove_non_address_bits",
>>> invalid=False,
>>> diff --git a/gdb/loongarch-linux-nat.c b/gdb/loongarch-linux-nat.c
>>> index bc9927dd751..dc4a019614a 100644
>>> --- a/gdb/loongarch-linux-nat.c
>>> +++ b/gdb/loongarch-linux-nat.c
>>> @@ -613,7 +613,7 @@ loongarch_linux_nat_target::stopped_data_address
>> (CORE_ADDR *addr_p)
>>> kernel can potentially be tagged addresses. */
>>> struct gdbarch *gdbarch = thread_architecture (inferior_ptid);
>>> const CORE_ADDR addr_trap
>>> - = gdbarch_remove_non_address_bits (gdbarch, (CORE_ADDR)
>> siginfo.si_addr);
>>> + = aarch64_remove_non_address_bits (gdbarch, (CORE_ADDR)
>>> + siginfo.si_addr);
>>>
>>> /* Check if the address matches any watched address. */
>>> state = loongarch_get_debug_reg_state (inferior_ptid.pid ());
>>
>> I think the loongarch-linux-nat.c change is spurious. Could you please address
>> that?
>
> Why is it spurious? What do you mean exactly?
The intention behind this change isn't clear to me, but the Loongson native Linux layer
using a AArch64 architecture function does not make sense.
I haven't built a LoongArch native Linux target, but I'd guess that it will run into a build
error with this change, if built for LoongArch only.
The right approach, in my mind, is to drop this change, but you have to touch this code due to your
changes. It begs the question, why is the LoongArch native code calling
gdbarch_remove_non_address_bits here without even registering a function for the gdbarch hook to call?
Without this hook, we'll invoke the dummy implementation in
gdb/arch-utils.c:default_remove_non_address_bits, and that just returns the unmodified pointer.
This is a question for the LoongArch maintainer (cc-ed). If we don't hear back, we should probably
change the LoongArch code to not call gdbarch_remove_non_address_bits. I think that was the original
intention, but there might've been a copy/paste error somewhere.
> -----Original Message-----
> From: Luis Machado <luis.machado@arm.com>
> Sent: Tuesday, November 5, 2024 3:22 PM
> To: Schimpe, Christina <christina.schimpe@intel.com>; gdb-
> patches@sourceware.org
> Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
> Subject: Re: [PATCH v6 1/2] gdb: Make tagged pointer support configurable.
>
> On 11/5/24 14:07, Schimpe, Christina wrote:
> > Hi Luis,
> >
> > Thanks a lot for the review. I have one questions to your comment, please see
> below.
> >
> >> -----Original Message-----
> >> From: Luis Machado <luis.machado@arm.com>
> >> Sent: Monday, November 4, 2024 12:18 PM
> >> To: Schimpe, Christina <christina.schimpe@intel.com>; gdb-
> >> patches@sourceware.org
> >> Subject: Re: [PATCH v6 1/2] gdb: Make tagged pointer support configurable.
> >>
> >> Hi Christina,
> >>
> >> On 10/28/24 08:46, Schimpe, Christina wrote:
> >>> From: Christina Schimpe <christina.schimpe@intel.com>
> >>>
> >>> The gdbarch function gdbarch_remove_non_address_bits adjusts
> >>> addresses to enable debugging of programs with tagged pointers on
> >>> Linux, for instance for ARM's feature top byte ignore (TBI).
> >>> Once the function is implemented for an architecture, it adjusts
> >>> addresses for memory access, breakpoints and watchpoints.
> >>>
> >>> Linear address masking (LAM) is Intel's (R) implementation of tagged
> >>> pointer support. It requires certain adaptions to GDB's tagged
> >>> pointer support due to the following:
> >>> - LAM supports address tagging for data accesses only. Thus, specifying
> >>> breakpoints on tagged addresses is not a valid use case.
> >>> - In contrast to the implementation for ARM's TBI, the Linux kernel supports
> >>> tagged pointers for memory access.
> >>>
> >>> This patch makes GDB's tagged pointer support configurable such that
> >>> it is possible to enable the address adjustment for a specific
> >>> feature only (e.g memory access, breakpoints or watchpoints). This
> >>> way, one can make sure that addresses are only adjusted when
> >>> necessary. In case of LAM, this avoids unnecessary parsing of the
> >>> /proc/<pid>/status file to get the untag mask.
> >>>
> >>> Reviewed-By: Felix Willgerodt <felix.willgerodt@intel.com>
> >>> ---
> >>> gdb/aarch64-linux-nat.c | 2 +-
> >>> gdb/aarch64-linux-tdep.c | 7 +++--
> >>> gdb/aarch64-tdep.c | 23 ++++++++------
> >>> gdb/aarch64-tdep.h | 6 ++++
> >>> gdb/breakpoint.c | 5 +--
> >>> gdb/gdbarch-gen.c | 66 ++++++++++++++++++++++++++++++++-------
> >>> gdb/gdbarch-gen.h | 49 ++++++++++++++++++++++-------
> >>> gdb/gdbarch_components.py | 53 ++++++++++++++++++++++++++-----
> >>> gdb/loongarch-linux-nat.c | 2 +-
> >>> gdb/target.c | 3 +-
> >>> 10 files changed, 169 insertions(+), 47 deletions(-)
> >>>
> >>> diff --git a/gdb/aarch64-linux-nat.c b/gdb/aarch64-linux-nat.c index
> >>> 0fa5bee500b..48ab765d880 100644
> >>> --- a/gdb/aarch64-linux-nat.c
> >>> +++ b/gdb/aarch64-linux-nat.c
> >>> @@ -943,7 +943,7 @@ aarch64_linux_nat_target::stopped_data_address
> >> (CORE_ADDR *addr_p)
> >>> kernel can potentially be tagged addresses. */
> >>> struct gdbarch *gdbarch = thread_architecture (inferior_ptid);
> >>> const CORE_ADDR addr_trap
> >>> - = gdbarch_remove_non_address_bits (gdbarch, (CORE_ADDR)
> >> siginfo.si_addr);
> >>> + = aarch64_remove_non_address_bits (gdbarch, (CORE_ADDR)
> >>> + siginfo.si_addr);
> >>>
> >>> /* Check if the address matches any watched address. */
> >>> state = aarch64_get_debug_reg_state (inferior_ptid.pid ()); diff
> >>> --git a/gdb/aarch64-linux-tdep.c b/gdb/aarch64-linux-tdep.c index
> >>> c608a84bc71..61c3be8b6f0 100644
> >>> --- a/gdb/aarch64-linux-tdep.c
> >>> +++ b/gdb/aarch64-linux-tdep.c
> >>> @@ -2433,7 +2433,7 @@ static bool
> >>> aarch64_linux_tagged_address_p (struct gdbarch *gdbarch, CORE_ADDR
> >>> address) {
> >>> /* Remove the top byte for the memory range check. */
> >>> - address = gdbarch_remove_non_address_bits (gdbarch, address);
> >>> + address = aarch64_remove_non_address_bits (gdbarch, address);
> >>>
> >>> /* Check if the page that contains ADDRESS is mapped with PROT_MTE. */
> >>> if (!linux_address_in_memtag_page (address)) @@ -2491,8 +2491,9
> >>> @@ aarch64_linux_report_signal_info (struct gdbarch *gdbarch,
> >>> uiout->text ("\n");
> >>>
> >>> std::optional<CORE_ADDR> atag
> >>> - = aarch64_mte_get_atag (gdbarch_remove_non_address_bits (gdbarch,
> >>> - fault_addr));
> >>> + = aarch64_mte_get_atag (
> >>> + aarch64_remove_non_address_bits (gdbarch, fault_addr));
> >>> +
> >>> gdb_byte ltag = aarch64_mte_get_ltag (fault_addr);
> >>>
> >>> if (!atag.has_value ())
> >>> diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c index
> >>> 8a2a9b1e23c..91fec7879ed 100644
> >>> --- a/gdb/aarch64-tdep.c
> >>> +++ b/gdb/aarch64-tdep.c
> >>> @@ -4121,7 +4121,7 @@ aarch64_memtag_matches_p (struct gdbarch
> >>> *gdbarch,
> >>>
> >>> /* Fetch the allocation tag for ADDRESS. */
> >>> std::optional<CORE_ADDR> atag
> >>> - = aarch64_mte_get_atag (gdbarch_remove_non_address_bits (gdbarch,
> >> addr));
> >>> + = aarch64_mte_get_atag (aarch64_remove_non_address_bits
> >>> + (gdbarch, addr));
> >>>
> >>> if (!atag.has_value ())
> >>> return true;
> >>> @@ -4160,7 +4160,7 @@ aarch64_set_memtags (struct gdbarch *gdbarch,
> >> struct value *address,
> >>> else
> >>> {
> >>> /* Remove the top byte. */
> >>> - addr = gdbarch_remove_non_address_bits (gdbarch, addr);
> >>> + addr = aarch64_remove_non_address_bits (gdbarch, addr);
> >>>
> >>> /* With G being the number of tag granules and N the number of tags
> >>> passed in, we can have the following cases:
> >>> @@ -4209,7 +4209,7 @@ aarch64_get_memtag (struct gdbarch *gdbarch,
> >> struct value *address,
> >>> else
> >>> {
> >>> /* Remove the top byte. */
> >>> - addr = gdbarch_remove_non_address_bits (gdbarch, addr);
> >>> + addr = aarch64_remove_non_address_bits (gdbarch, addr);
> >>> std::optional<CORE_ADDR> atag = aarch64_mte_get_atag (addr);
> >>>
> >>> if (!atag.has_value ())
> >>> @@ -4236,10 +4236,9 @@ aarch64_memtag_to_string (struct gdbarch
> >> *gdbarch, struct value *tag_value)
> >>> return string_printf ("0x%s", phex_nz (tag, sizeof (tag))); }
> >>>
> >>> -/* AArch64 implementation of the remove_non_address_bits gdbarch hook.
> >> Remove
> >>> - non address bits from a pointer value. */
> >>> +/* See aarch64-tdep.h. */
> >>>
> >>> -static CORE_ADDR
> >>> +CORE_ADDR
> >>> aarch64_remove_non_address_bits (struct gdbarch *gdbarch, CORE_ADDR
> >>> pointer) {
> >>> /* By default, we assume TBI and discard the top 8 bits plus the
> >>> VA range @@ -4750,9 +4749,15 @@ aarch64_gdbarch_init (struct
> >>> gdbarch_info
> >> info, struct gdbarch_list *arches)
> >>> tdep->ra_sign_state_regnum = ra_sign_state_offset + num_regs;
> >>>
> >>> /* Architecture hook to remove bits of a pointer that are not part of the
> >>> - address, like memory tags (MTE) and pointer authentication signatures.
> */
> >>> - set_gdbarch_remove_non_address_bits (gdbarch,
> >>> - aarch64_remove_non_address_bits);
> >>> + address, like memory tags (MTE) and pointer authentication signatures.
> >>> + Configure address adjustment for watch-, breakpoints and
> >>> + memory
> >>
> >> s/watch-/watchpoints
> >
> > Fill fix, thanks.
> >
> >>> + transfer. */
> >>> + set_gdbarch_remove_non_address_bits_watchpoint
> >>> + (gdbarch, aarch64_remove_non_address_bits);
> >>> + set_gdbarch_remove_non_address_bits_breakpoint
> >>> + (gdbarch, aarch64_remove_non_address_bits);
> >>> + set_gdbarch_remove_non_address_bits_memory
> >>> + (gdbarch, aarch64_remove_non_address_bits);
> >>>
> >>> /* SME pseudo-registers. */
> >>> if (tdep->has_sme ())
> >>> diff --git a/gdb/aarch64-tdep.h b/gdb/aarch64-tdep.h index
> >>> 50166fb4f24..13ea37de7a3 100644
> >>> --- a/gdb/aarch64-tdep.h
> >>> +++ b/gdb/aarch64-tdep.h
> >>> @@ -205,4 +205,10 @@ bool aarch64_displaced_step_hw_singlestep
> >>> (struct gdbarch *gdbarch);
> >>>
> >>> std::optional<CORE_ADDR> aarch64_mte_get_atag (CORE_ADDR address);
> >>>
> >>> +/* AArch64 implementation of the remove_non_address_bits gdbarch
> hooks.
> >>> + Remove non address bits from a pointer value. */
> >>> +
> >>> +CORE_ADDR aarch64_remove_non_address_bits (struct gdbarch *gdbarch,
> >>> + CORE_ADDR pointer);
> >>> +
> >>> #endif /* aarch64-tdep.h */
> >>> diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c index
> >>> b7e4f5d0a45..9983e905e1b 100644
> >>> --- a/gdb/breakpoint.c
> >>> +++ b/gdb/breakpoint.c
> >>> @@ -2313,7 +2313,8 @@ update_watchpoint (struct watchpoint *b, bool
> >> reparse)
> >>> loc->gdbarch = v->type ()->arch ();
> >>> loc->pspace = wp_pspace;
> >>> loc->address
> >>> - = gdbarch_remove_non_address_bits (loc->gdbarch, addr);
> >>> + = gdbarch_remove_non_address_bits_watchpoint (loc-
> >>> gdbarch,
> >>> + addr);
> >>> b->add_location (*loc);
> >>>
> >>> if (bitsize != 0)
> >>> @@ -7538,7 +7539,7 @@ adjust_breakpoint_address (struct gdbarch
> >> *gdbarch,
> >>> }
> >>>
> >>> adjusted_bpaddr
> >>> - = gdbarch_remove_non_address_bits (gdbarch, adjusted_bpaddr);
> >>> + = gdbarch_remove_non_address_bits_breakpoint (gdbarch,
> >>> +adjusted_bpaddr);
> >>>
> >>> /* An adjusted breakpoint address can significantly alter
> >>> a user's expectations. Print a warning if an adjustment diff
> >>> --git a/gdb/gdbarch-gen.c b/gdb/gdbarch-gen.c index
> >>> 0d00cd7c993..d05c7a3cbdf
> >>> 100644
> >>> --- a/gdb/gdbarch-gen.c
> >>> +++ b/gdb/gdbarch-gen.c
> >>> @@ -143,7 +143,9 @@ struct gdbarch
> >>> int frame_red_zone_size = 0;
> >>> gdbarch_convert_from_func_ptr_addr_ftype
> >>> *convert_from_func_ptr_addr =
> >> convert_from_func_ptr_addr_identity;
> >>> gdbarch_addr_bits_remove_ftype *addr_bits_remove =
> >>> core_addr_identity;
> >>> - gdbarch_remove_non_address_bits_ftype *remove_non_address_bits =
> >>> default_remove_non_address_bits;
> >>> + gdbarch_remove_non_address_bits_watchpoint_ftype
> >>> + *remove_non_address_bits_watchpoint =
> >>> + default_remove_non_address_bits;
> >>> + gdbarch_remove_non_address_bits_breakpoint_ftype
> >>> + *remove_non_address_bits_breakpoint =
> >>> + default_remove_non_address_bits;
> >>> + gdbarch_remove_non_address_bits_memory_ftype
> >>> + *remove_non_address_bits_memory = default_remove_non_address_bits;
> >>> gdbarch_memtag_to_string_ftype *memtag_to_string =
> >> default_memtag_to_string;
> >>> gdbarch_tagged_address_p_ftype *tagged_address_p =
> >> default_tagged_address_p;
> >>> gdbarch_memtag_matches_p_ftype *memtag_matches_p =
> >>> default_memtag_matches_p; @@ -407,7 +409,9 @@ verify_gdbarch (struct
> >> gdbarch *gdbarch)
> >>> /* Skip verify of frame_red_zone_size, invalid_p == 0. */
> >>> /* Skip verify of convert_from_func_ptr_addr, invalid_p == 0. */
> >>> /* Skip verify of addr_bits_remove, invalid_p == 0. */
> >>> - /* Skip verify of remove_non_address_bits, invalid_p == 0. */
> >>> + /* Skip verify of remove_non_address_bits_watchpoint, invalid_p
> >>> + == 0. */
> >>> + /* Skip verify of remove_non_address_bits_breakpoint, invalid_p
> >>> + == 0. */
> >>> + /* Skip verify of remove_non_address_bits_memory, invalid_p == 0.
> >>> + */
> >>> /* Skip verify of memtag_to_string, invalid_p == 0. */
> >>> /* Skip verify of tagged_address_p, invalid_p == 0. */
> >>> /* Skip verify of memtag_matches_p, invalid_p == 0. */ @@ -910,8
> >>> +914,14 @@ gdbarch_dump (struct gdbarch *gdbarch, struct ui_file
> >>> +*file)
> >>> "gdbarch_dump: addr_bits_remove = <%s>\n",
> >>> host_address_to_string (gdbarch->addr_bits_remove));
> >>> gdb_printf (file,
> >>> - "gdbarch_dump: remove_non_address_bits = <%s>\n",
> >>> - host_address_to_string (gdbarch->remove_non_address_bits));
> >>> + "gdbarch_dump: remove_non_address_bits_watchpoint = <%s>\n",
> >>> + host_address_to_string
> >>> +(gdbarch->remove_non_address_bits_watchpoint));
> >>> + gdb_printf (file,
> >>> + "gdbarch_dump: remove_non_address_bits_breakpoint = <%s>\n",
> >>> + host_address_to_string
> >>> +(gdbarch->remove_non_address_bits_breakpoint));
> >>> + gdb_printf (file,
> >>> + "gdbarch_dump: remove_non_address_bits_memory = <%s>\n",
> >>> + host_address_to_string
> >>> +(gdbarch->remove_non_address_bits_memory));
> >>> gdb_printf (file,
> >>> "gdbarch_dump: memtag_to_string = <%s>\n",
> >>> host_address_to_string (gdbarch->memtag_to_string)); @@
> >>> -3198,20 +3208,54 @@ set_gdbarch_addr_bits_remove (struct gdbarch
> >>> *gdbarch, }
> >>>
> >>> CORE_ADDR
> >>> -gdbarch_remove_non_address_bits (struct gdbarch *gdbarch, CORE_ADDR
> >>> pointer)
> >>> +gdbarch_remove_non_address_bits_watchpoint (struct gdbarch
> >>> +*gdbarch, CORE_ADDR pointer) {
> >>> + gdb_assert (gdbarch != NULL);
> >>> + gdb_assert (gdbarch->remove_non_address_bits_watchpoint != NULL);
> >>> + if (gdbarch_debug >= 2)
> >>> + gdb_printf (gdb_stdlog,
> >>> +"gdbarch_remove_non_address_bits_watchpoint called\n");
> >>> + return gdbarch->remove_non_address_bits_watchpoint (gdbarch,
> >>> +pointer); }
> >>> +
> >>> +void
> >>> +set_gdbarch_remove_non_address_bits_watchpoint (struct gdbarch
> >> *gdbarch,
> >>> +
> >> gdbarch_remove_non_address_bits_watchpoint_ftype
> >>> +remove_non_address_bits_watchpoint)
> >>> +{
> >>> + gdbarch->remove_non_address_bits_watchpoint =
> >>> +remove_non_address_bits_watchpoint;
> >>> +}
> >>> +
> >>> +CORE_ADDR
> >>> +gdbarch_remove_non_address_bits_breakpoint (struct gdbarch
> >>> +*gdbarch, CORE_ADDR pointer) {
> >>> + gdb_assert (gdbarch != NULL);
> >>> + gdb_assert (gdbarch->remove_non_address_bits_breakpoint != NULL);
> >>> + if (gdbarch_debug >= 2)
> >>> + gdb_printf (gdb_stdlog,
> >>> +"gdbarch_remove_non_address_bits_breakpoint called\n");
> >>> + return gdbarch->remove_non_address_bits_breakpoint (gdbarch,
> >>> +pointer); }
> >>> +
> >>> +void
> >>> +set_gdbarch_remove_non_address_bits_breakpoint (struct gdbarch
> >>> +*gdbarch,
> >>> +
> >> gdbarch_remove_non_address_bits_breakpoint_ftype
> >>> +remove_non_address_bits_breakpoint)
> >>> +{
> >>> + gdbarch->remove_non_address_bits_breakpoint =
> >>> +remove_non_address_bits_breakpoint;
> >>> +}
> >>> +
> >>> +CORE_ADDR
> >>> +gdbarch_remove_non_address_bits_memory (struct gdbarch *gdbarch,
> >>> +CORE_ADDR pointer)
> >>> {
> >>> gdb_assert (gdbarch != NULL);
> >>> - gdb_assert (gdbarch->remove_non_address_bits != NULL);
> >>> + gdb_assert (gdbarch->remove_non_address_bits_memory != NULL);
> >>> if (gdbarch_debug >= 2)
> >>> - gdb_printf (gdb_stdlog, "gdbarch_remove_non_address_bits called\n");
> >>> - return gdbarch->remove_non_address_bits (gdbarch, pointer);
> >>> + gdb_printf (gdb_stdlog, "gdbarch_remove_non_address_bits_memory
> >>> + called\n"); return gdbarch->remove_non_address_bits_memory
> >>> + (gdbarch, pointer);
> >>> }
> >>>
> >>> void
> >>> -set_gdbarch_remove_non_address_bits (struct gdbarch *gdbarch,
> >>> - gdbarch_remove_non_address_bits_ftype
> >> remove_non_address_bits)
> >>> +set_gdbarch_remove_non_address_bits_memory (struct gdbarch
> >>> +*gdbarch,
> >>> +
> >> gdbarch_remove_non_address_bits_memory_ftype
> >>> +remove_non_address_bits_memory)
> >>> {
> >>> - gdbarch->remove_non_address_bits = remove_non_address_bits;
> >>> + gdbarch->remove_non_address_bits_memory =
> >>> + remove_non_address_bits_memory;
> >>> }
> >>>
> >>> std::string
> >>> diff --git a/gdb/gdbarch-gen.h b/gdb/gdbarch-gen.h index
> >>> b982fd7cd09..9fda85f860f 100644
> >>> --- a/gdb/gdbarch-gen.h
> >>> +++ b/gdb/gdbarch-gen.h
> >>> @@ -684,19 +684,46 @@ extern CORE_ADDR gdbarch_addr_bits_remove
> >>> (struct gdbarch *gdbarch, CORE_ADDR ad extern void
> >>> set_gdbarch_addr_bits_remove (struct gdbarch *gdbarch,
> >>> gdbarch_addr_bits_remove_ftype *addr_bits_remove);
> >>>
> >>> /* On some architectures, not all bits of a pointer are significant.
> >>> - On AArch64, for example, the top bits of a pointer may carry a "tag", which
> >>> - can be ignored by the kernel and the hardware. The "tag" can be regarded
> as
> >>> - additional data associated with the pointer, but it is not part of the
> address.
> >>> + On AArch64 and amd64, for example, the top bits of a pointer may carry a
> >>> + "tag", which can be ignored by the kernel and the hardware. The
> >>> + "tag" can
> >> be
> >>> + regarded as additional data associated with the pointer, but it is not part
> >>> + of the address.
> >>>
> >>> Given a pointer for the architecture, this hook removes all the
> >>> - non-significant bits and sign-extends things as needed. It gets used to
> >> remove
> >>> - non-address bits from data pointers (for example, removing the AArch64
> MTE
> >> tag
> >>> - bits from a pointer) and from code pointers (removing the AArch64 PAC
> >> signature
> >>> - from a pointer containing the return address). */
> >>> -
> >>> -typedef CORE_ADDR (gdbarch_remove_non_address_bits_ftype) (struct
> >>> gdbarch *gdbarch, CORE_ADDR pointer); -extern CORE_ADDR
> >>> gdbarch_remove_non_address_bits (struct gdbarch *gdbarch, CORE_ADDR
> >>> pointer); -extern void set_gdbarch_remove_non_address_bits (struct
> >>> gdbarch *gdbarch, gdbarch_remove_non_address_bits_ftype
> >>> *remove_non_address_bits);
> >>> + non-significant bits and sign-extends things as needed. It gets used to
> >>> + remove non-address bits from pointers used for watchpoints. */
> >>> +
> >>> +typedef CORE_ADDR
> >>> +(gdbarch_remove_non_address_bits_watchpoint_ftype)
> >>> +(struct gdbarch *gdbarch, CORE_ADDR pointer); extern CORE_ADDR
> >>> +gdbarch_remove_non_address_bits_watchpoint (struct gdbarch
> >>> +*gdbarch, CORE_ADDR pointer); extern void
> >>> +set_gdbarch_remove_non_address_bits_watchpoint (struct gdbarch
> >>> +*gdbarch, gdbarch_remove_non_address_bits_watchpoint_ftype
> >>> +*remove_non_address_bits_watchpoint);
> >>> +
> >>> +/* On some architectures, not all bits of a pointer are significant.
> >>> + On AArch64 and amd64, for example, the top bits of a pointer may carry a
> >>> + "tag", which can be ignored by the kernel and the hardware. The
> >>> +"tag" can
> >> be
> >>> + regarded as additional data associated with the pointer, but it is not part
> >>> + of the address.
> >>> +
> >>> + Given a pointer for the architecture, this hook removes all the
> >>> + non-significant bits and sign-extends things as needed. It gets used to
> >>> + remove non-address bits from pointers used for breakpoints. */
> >>> +
> >>> +typedef CORE_ADDR
> >>> +(gdbarch_remove_non_address_bits_breakpoint_ftype)
> >>> +(struct gdbarch *gdbarch, CORE_ADDR pointer); extern CORE_ADDR
> >>> +gdbarch_remove_non_address_bits_breakpoint (struct gdbarch
> >>> +*gdbarch, CORE_ADDR pointer); extern void
> >>> +set_gdbarch_remove_non_address_bits_breakpoint (struct gdbarch
> >>> +*gdbarch, gdbarch_remove_non_address_bits_breakpoint_ftype
> >>> +*remove_non_address_bits_breakpoint);
> >>> +
> >>> +/* On some architectures, not all bits of a pointer are significant.
> >>> + On AArch64 and amd64, for example, the top bits of a pointer may carry a
> >>> + "tag", which can be ignored by the kernel and the hardware. The
> >>> +"tag" can
> >> be
> >>> + regarded as additional data associated with the pointer, but it is not part
> >>> + of the address.
> >>> +
> >>> + Given a pointer for the architecture, this hook removes all the
> >>> + non-significant bits and sign-extends things as needed. It gets used to
> >>> + remove non-address bits from any pointer used to access memory.
> >>> + */
> >>> +
> >>> +typedef CORE_ADDR (gdbarch_remove_non_address_bits_memory_ftype)
> >>> +(struct gdbarch *gdbarch, CORE_ADDR pointer); extern CORE_ADDR
> >>> +gdbarch_remove_non_address_bits_memory (struct gdbarch *gdbarch,
> >>> +CORE_ADDR pointer); extern void
> >>> +set_gdbarch_remove_non_address_bits_memory (struct gdbarch
> >>> +*gdbarch, gdbarch_remove_non_address_bits_memory_ftype
> >>> +*remove_non_address_bits_memory);
> >>>
> >>> /* Return a string representation of the memory tag TAG. */
> >>>
> >>> diff --git a/gdb/gdbarch_components.py b/gdb/gdbarch_components.py
> >>> index 4006380076d..cc7c6d8677b 100644
> >>> --- a/gdb/gdbarch_components.py
> >>> +++ b/gdb/gdbarch_components.py
> >>> @@ -1232,18 +1232,55 @@ possible it should be in TARGET_READ_PC
> >> instead).
> >>> Method(
> >>> comment="""
> >>> On some architectures, not all bits of a pointer are significant.
> >>> -On AArch64, for example, the top bits of a pointer may carry a
> >>> "tag", which -can be ignored by the kernel and the hardware. The
> >>> "tag" can be regarded as -additional data associated with the
> >>> pointer, but it is not part of
> >> the address.
> >>> +On AArch64 and amd64, for example, the top bits of a pointer may
> >>> +carry a "tag", which can be ignored by the kernel and the hardware.
> >>> +The "tag" can be regarded as additional data associated with the
> >>> +pointer, but it is not part of the address.
> >>>
> >>> Given a pointer for the architecture, this hook removes all the
> >>> -non-significant bits and sign-extends things as needed. It gets
> >>> used to remove -non-address bits from data pointers (for example,
> >>> removing the AArch64 MTE tag -bits from a pointer) and from code
> >>> pointers (removing the AArch64 PAC signature -from a pointer
> >>> containing the return
> >> address).
> >>> +non-significant bits and sign-extends things as needed. It gets
> >>> +used to remove non-address bits from pointers used for watchpoints.
> >>> """,
> >>> type="CORE_ADDR",
> >>> - name="remove_non_address_bits",
> >>> + name="remove_non_address_bits_watchpoint",
> >>> + params=[("CORE_ADDR", "pointer")],
> >>> + predefault="default_remove_non_address_bits",
> >>> + invalid=False,
> >>> +)
> >>> +
> >>> +Method(
> >>> + comment="""
> >>> +On some architectures, not all bits of a pointer are significant.
> >>> +On AArch64 and amd64, for example, the top bits of a pointer may
> >>> +carry a "tag", which can be ignored by the kernel and the hardware.
> >>> +The "tag" can be regarded as additional data associated with the
> >>> +pointer, but it is not part of the address.
> >>> +
> >>> +Given a pointer for the architecture, this hook removes all the
> >>> +non-significant bits and sign-extends things as needed. It gets
> >>> +used to remove non-address bits from pointers used for breakpoints.
> >>> +""",
> >>> + type="CORE_ADDR",
> >>> + name="remove_non_address_bits_breakpoint",
> >>> + params=[("CORE_ADDR", "pointer")],
> >>> + predefault="default_remove_non_address_bits",
> >>> + invalid=False,
> >>> +)
> >>> +
> >>> +Method(
> >>> + comment="""
> >>> +On some architectures, not all bits of a pointer are significant.
> >>> +On AArch64 and amd64, for example, the top bits of a pointer may
> >>> +carry a "tag", which can be ignored by the kernel and the hardware.
> >>> +The "tag" can be regarded as additional data associated with the
> >>> +pointer, but it is not part of the address.
> >>> +
> >>> +Given a pointer for the architecture, this hook removes all the
> >>> +non-significant bits and sign-extends things as needed. It gets
> >>> +used to remove non-address bits from any pointer used to access memory.
> >>> +""",
> >>> + type="CORE_ADDR",
> >>> + name="remove_non_address_bits_memory",
> >>> params=[("CORE_ADDR", "pointer")],
> >>> predefault="default_remove_non_address_bits",
> >>> invalid=False,
> >>> diff --git a/gdb/loongarch-linux-nat.c b/gdb/loongarch-linux-nat.c
> >>> index bc9927dd751..dc4a019614a 100644
> >>> --- a/gdb/loongarch-linux-nat.c
> >>> +++ b/gdb/loongarch-linux-nat.c
> >>> @@ -613,7 +613,7 @@ loongarch_linux_nat_target::stopped_data_address
> >> (CORE_ADDR *addr_p)
> >>> kernel can potentially be tagged addresses. */
> >>> struct gdbarch *gdbarch = thread_architecture (inferior_ptid);
> >>> const CORE_ADDR addr_trap
> >>> - = gdbarch_remove_non_address_bits (gdbarch, (CORE_ADDR)
> >> siginfo.si_addr);
> >>> + = aarch64_remove_non_address_bits (gdbarch, (CORE_ADDR)
> >>> + siginfo.si_addr);
> >>>
> >>> /* Check if the address matches any watched address. */
> >>> state = loongarch_get_debug_reg_state (inferior_ptid.pid ());
> >>
> >> I think the loongarch-linux-nat.c change is spurious. Could you
> >> please address that?
> >
> > Why is it spurious? What do you mean exactly?
>
> The intention behind this change isn't clear to me, but the Loongson native Linux
> layer using a AArch64 architecture function does not make sense.
>
> I haven't built a LoongArch native Linux target, but I'd guess that it will run into a
> build error with this change, if built for LoongArch only.
>
> The right approach, in my mind, is to drop this change, but you have to touch this
> code due to your changes. It begs the question, why is the LoongArch native code
> calling gdbarch_remove_non_address_bits here without even registering a
> function for the gdbarch hook to call?
Right, I agree.
> Without this hook, we'll invoke the dummy implementation in gdb/arch-
> utils.c:default_remove_non_address_bits, and that just returns the unmodified
> pointer.
True, that's probably why nobody noticed before.
> This is a question for the LoongArch maintainer (cc-ed). If we don't hear back, we
> should probably change the LoongArch code to not call
> gdbarch_remove_non_address_bits. I think that was the original intention, but
> there might've been a copy/paste error somewhere.
Ok. Let's wait a bit. Thanks for the detailed feedback.
Christina
Intel Deutschland GmbH
Registered Address: Am Campeon 10, 85579 Neubiberg, Germany
Tel: +49 89 99 8853-0, www.intel.de
Managing Directors: Sean Fennelly, Jeffrey Schneiderman, Tiffany Doon Silva
Chairperson of the Supervisory Board: Nicole Lau
Registered Office: Munich
Commercial Register: Amtsgericht Muenchen HRB 186928
On 11/5/24 14:40, Schimpe, Christina wrote:
>> -----Original Message-----
>> From: Luis Machado <luis.machado@arm.com>
>> Sent: Tuesday, November 5, 2024 3:22 PM
>> To: Schimpe, Christina <christina.schimpe@intel.com>; gdb-
>> patches@sourceware.org
>> Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
>> Subject: Re: [PATCH v6 1/2] gdb: Make tagged pointer support configurable.
>>
>> On 11/5/24 14:07, Schimpe, Christina wrote:
>>> Hi Luis,
>>>
>>> Thanks a lot for the review. I have one questions to your comment, please see
>> below.
>>>
>>>> -----Original Message-----
>>>> From: Luis Machado <luis.machado@arm.com>
>>>> Sent: Monday, November 4, 2024 12:18 PM
>>>> To: Schimpe, Christina <christina.schimpe@intel.com>; gdb-
>>>> patches@sourceware.org
>>>> Subject: Re: [PATCH v6 1/2] gdb: Make tagged pointer support configurable.
>>>>
>>>> Hi Christina,
>>>>
>>>> On 10/28/24 08:46, Schimpe, Christina wrote:
>>>>> From: Christina Schimpe <christina.schimpe@intel.com>
>>>>>
>>>>> The gdbarch function gdbarch_remove_non_address_bits adjusts
>>>>> addresses to enable debugging of programs with tagged pointers on
>>>>> Linux, for instance for ARM's feature top byte ignore (TBI).
>>>>> Once the function is implemented for an architecture, it adjusts
>>>>> addresses for memory access, breakpoints and watchpoints.
>>>>>
>>>>> Linear address masking (LAM) is Intel's (R) implementation of tagged
>>>>> pointer support. It requires certain adaptions to GDB's tagged
>>>>> pointer support due to the following:
>>>>> - LAM supports address tagging for data accesses only. Thus, specifying
>>>>> breakpoints on tagged addresses is not a valid use case.
>>>>> - In contrast to the implementation for ARM's TBI, the Linux kernel supports
>>>>> tagged pointers for memory access.
>>>>>
>>>>> This patch makes GDB's tagged pointer support configurable such that
>>>>> it is possible to enable the address adjustment for a specific
>>>>> feature only (e.g memory access, breakpoints or watchpoints). This
>>>>> way, one can make sure that addresses are only adjusted when
>>>>> necessary. In case of LAM, this avoids unnecessary parsing of the
>>>>> /proc/<pid>/status file to get the untag mask.
>>>>>
>>>>> Reviewed-By: Felix Willgerodt <felix.willgerodt@intel.com>
>>>>> ---
>>>>> gdb/aarch64-linux-nat.c | 2 +-
>>>>> gdb/aarch64-linux-tdep.c | 7 +++--
>>>>> gdb/aarch64-tdep.c | 23 ++++++++------
>>>>> gdb/aarch64-tdep.h | 6 ++++
>>>>> gdb/breakpoint.c | 5 +--
>>>>> gdb/gdbarch-gen.c | 66 ++++++++++++++++++++++++++++++++-------
>>>>> gdb/gdbarch-gen.h | 49 ++++++++++++++++++++++-------
>>>>> gdb/gdbarch_components.py | 53 ++++++++++++++++++++++++++-----
>>>>> gdb/loongarch-linux-nat.c | 2 +-
>>>>> gdb/target.c | 3 +-
>>>>> 10 files changed, 169 insertions(+), 47 deletions(-)
>>>>>
>>>>> diff --git a/gdb/aarch64-linux-nat.c b/gdb/aarch64-linux-nat.c index
>>>>> 0fa5bee500b..48ab765d880 100644
>>>>> --- a/gdb/aarch64-linux-nat.c
>>>>> +++ b/gdb/aarch64-linux-nat.c
>>>>> @@ -943,7 +943,7 @@ aarch64_linux_nat_target::stopped_data_address
>>>> (CORE_ADDR *addr_p)
>>>>> kernel can potentially be tagged addresses. */
>>>>> struct gdbarch *gdbarch = thread_architecture (inferior_ptid);
>>>>> const CORE_ADDR addr_trap
>>>>> - = gdbarch_remove_non_address_bits (gdbarch, (CORE_ADDR)
>>>> siginfo.si_addr);
>>>>> + = aarch64_remove_non_address_bits (gdbarch, (CORE_ADDR)
>>>>> + siginfo.si_addr);
>>>>>
>>>>> /* Check if the address matches any watched address. */
>>>>> state = aarch64_get_debug_reg_state (inferior_ptid.pid ()); diff
>>>>> --git a/gdb/aarch64-linux-tdep.c b/gdb/aarch64-linux-tdep.c index
>>>>> c608a84bc71..61c3be8b6f0 100644
>>>>> --- a/gdb/aarch64-linux-tdep.c
>>>>> +++ b/gdb/aarch64-linux-tdep.c
>>>>> @@ -2433,7 +2433,7 @@ static bool
>>>>> aarch64_linux_tagged_address_p (struct gdbarch *gdbarch, CORE_ADDR
>>>>> address) {
>>>>> /* Remove the top byte for the memory range check. */
>>>>> - address = gdbarch_remove_non_address_bits (gdbarch, address);
>>>>> + address = aarch64_remove_non_address_bits (gdbarch, address);
>>>>>
>>>>> /* Check if the page that contains ADDRESS is mapped with PROT_MTE. */
>>>>> if (!linux_address_in_memtag_page (address)) @@ -2491,8 +2491,9
>>>>> @@ aarch64_linux_report_signal_info (struct gdbarch *gdbarch,
>>>>> uiout->text ("\n");
>>>>>
>>>>> std::optional<CORE_ADDR> atag
>>>>> - = aarch64_mte_get_atag (gdbarch_remove_non_address_bits (gdbarch,
>>>>> - fault_addr));
>>>>> + = aarch64_mte_get_atag (
>>>>> + aarch64_remove_non_address_bits (gdbarch, fault_addr));
>>>>> +
>>>>> gdb_byte ltag = aarch64_mte_get_ltag (fault_addr);
>>>>>
>>>>> if (!atag.has_value ())
>>>>> diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c index
>>>>> 8a2a9b1e23c..91fec7879ed 100644
>>>>> --- a/gdb/aarch64-tdep.c
>>>>> +++ b/gdb/aarch64-tdep.c
>>>>> @@ -4121,7 +4121,7 @@ aarch64_memtag_matches_p (struct gdbarch
>>>>> *gdbarch,
>>>>>
>>>>> /* Fetch the allocation tag for ADDRESS. */
>>>>> std::optional<CORE_ADDR> atag
>>>>> - = aarch64_mte_get_atag (gdbarch_remove_non_address_bits (gdbarch,
>>>> addr));
>>>>> + = aarch64_mte_get_atag (aarch64_remove_non_address_bits
>>>>> + (gdbarch, addr));
>>>>>
>>>>> if (!atag.has_value ())
>>>>> return true;
>>>>> @@ -4160,7 +4160,7 @@ aarch64_set_memtags (struct gdbarch *gdbarch,
>>>> struct value *address,
>>>>> else
>>>>> {
>>>>> /* Remove the top byte. */
>>>>> - addr = gdbarch_remove_non_address_bits (gdbarch, addr);
>>>>> + addr = aarch64_remove_non_address_bits (gdbarch, addr);
>>>>>
>>>>> /* With G being the number of tag granules and N the number of tags
>>>>> passed in, we can have the following cases:
>>>>> @@ -4209,7 +4209,7 @@ aarch64_get_memtag (struct gdbarch *gdbarch,
>>>> struct value *address,
>>>>> else
>>>>> {
>>>>> /* Remove the top byte. */
>>>>> - addr = gdbarch_remove_non_address_bits (gdbarch, addr);
>>>>> + addr = aarch64_remove_non_address_bits (gdbarch, addr);
>>>>> std::optional<CORE_ADDR> atag = aarch64_mte_get_atag (addr);
>>>>>
>>>>> if (!atag.has_value ())
>>>>> @@ -4236,10 +4236,9 @@ aarch64_memtag_to_string (struct gdbarch
>>>> *gdbarch, struct value *tag_value)
>>>>> return string_printf ("0x%s", phex_nz (tag, sizeof (tag))); }
>>>>>
>>>>> -/* AArch64 implementation of the remove_non_address_bits gdbarch hook.
>>>> Remove
>>>>> - non address bits from a pointer value. */
>>>>> +/* See aarch64-tdep.h. */
>>>>>
>>>>> -static CORE_ADDR
>>>>> +CORE_ADDR
>>>>> aarch64_remove_non_address_bits (struct gdbarch *gdbarch, CORE_ADDR
>>>>> pointer) {
>>>>> /* By default, we assume TBI and discard the top 8 bits plus the
>>>>> VA range @@ -4750,9 +4749,15 @@ aarch64_gdbarch_init (struct
>>>>> gdbarch_info
>>>> info, struct gdbarch_list *arches)
>>>>> tdep->ra_sign_state_regnum = ra_sign_state_offset + num_regs;
>>>>>
>>>>> /* Architecture hook to remove bits of a pointer that are not part of the
>>>>> - address, like memory tags (MTE) and pointer authentication signatures.
>> */
>>>>> - set_gdbarch_remove_non_address_bits (gdbarch,
>>>>> - aarch64_remove_non_address_bits);
>>>>> + address, like memory tags (MTE) and pointer authentication signatures.
>>>>> + Configure address adjustment for watch-, breakpoints and
>>>>> + memory
>>>>
>>>> s/watch-/watchpoints
>>>
>>> Fill fix, thanks.
>>>
>>>>> + transfer. */
>>>>> + set_gdbarch_remove_non_address_bits_watchpoint
>>>>> + (gdbarch, aarch64_remove_non_address_bits);
>>>>> + set_gdbarch_remove_non_address_bits_breakpoint
>>>>> + (gdbarch, aarch64_remove_non_address_bits);
>>>>> + set_gdbarch_remove_non_address_bits_memory
>>>>> + (gdbarch, aarch64_remove_non_address_bits);
>>>>>
>>>>> /* SME pseudo-registers. */
>>>>> if (tdep->has_sme ())
>>>>> diff --git a/gdb/aarch64-tdep.h b/gdb/aarch64-tdep.h index
>>>>> 50166fb4f24..13ea37de7a3 100644
>>>>> --- a/gdb/aarch64-tdep.h
>>>>> +++ b/gdb/aarch64-tdep.h
>>>>> @@ -205,4 +205,10 @@ bool aarch64_displaced_step_hw_singlestep
>>>>> (struct gdbarch *gdbarch);
>>>>>
>>>>> std::optional<CORE_ADDR> aarch64_mte_get_atag (CORE_ADDR address);
>>>>>
>>>>> +/* AArch64 implementation of the remove_non_address_bits gdbarch
>> hooks.
>>>>> + Remove non address bits from a pointer value. */
>>>>> +
>>>>> +CORE_ADDR aarch64_remove_non_address_bits (struct gdbarch *gdbarch,
>>>>> + CORE_ADDR pointer);
>>>>> +
>>>>> #endif /* aarch64-tdep.h */
>>>>> diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c index
>>>>> b7e4f5d0a45..9983e905e1b 100644
>>>>> --- a/gdb/breakpoint.c
>>>>> +++ b/gdb/breakpoint.c
>>>>> @@ -2313,7 +2313,8 @@ update_watchpoint (struct watchpoint *b, bool
>>>> reparse)
>>>>> loc->gdbarch = v->type ()->arch ();
>>>>> loc->pspace = wp_pspace;
>>>>> loc->address
>>>>> - = gdbarch_remove_non_address_bits (loc->gdbarch, addr);
>>>>> + = gdbarch_remove_non_address_bits_watchpoint (loc-
>>>>> gdbarch,
>>>>> + addr);
>>>>> b->add_location (*loc);
>>>>>
>>>>> if (bitsize != 0)
>>>>> @@ -7538,7 +7539,7 @@ adjust_breakpoint_address (struct gdbarch
>>>> *gdbarch,
>>>>> }
>>>>>
>>>>> adjusted_bpaddr
>>>>> - = gdbarch_remove_non_address_bits (gdbarch, adjusted_bpaddr);
>>>>> + = gdbarch_remove_non_address_bits_breakpoint (gdbarch,
>>>>> +adjusted_bpaddr);
>>>>>
>>>>> /* An adjusted breakpoint address can significantly alter
>>>>> a user's expectations. Print a warning if an adjustment diff
>>>>> --git a/gdb/gdbarch-gen.c b/gdb/gdbarch-gen.c index
>>>>> 0d00cd7c993..d05c7a3cbdf
>>>>> 100644
>>>>> --- a/gdb/gdbarch-gen.c
>>>>> +++ b/gdb/gdbarch-gen.c
>>>>> @@ -143,7 +143,9 @@ struct gdbarch
>>>>> int frame_red_zone_size = 0;
>>>>> gdbarch_convert_from_func_ptr_addr_ftype
>>>>> *convert_from_func_ptr_addr =
>>>> convert_from_func_ptr_addr_identity;
>>>>> gdbarch_addr_bits_remove_ftype *addr_bits_remove =
>>>>> core_addr_identity;
>>>>> - gdbarch_remove_non_address_bits_ftype *remove_non_address_bits =
>>>>> default_remove_non_address_bits;
>>>>> + gdbarch_remove_non_address_bits_watchpoint_ftype
>>>>> + *remove_non_address_bits_watchpoint =
>>>>> + default_remove_non_address_bits;
>>>>> + gdbarch_remove_non_address_bits_breakpoint_ftype
>>>>> + *remove_non_address_bits_breakpoint =
>>>>> + default_remove_non_address_bits;
>>>>> + gdbarch_remove_non_address_bits_memory_ftype
>>>>> + *remove_non_address_bits_memory = default_remove_non_address_bits;
>>>>> gdbarch_memtag_to_string_ftype *memtag_to_string =
>>>> default_memtag_to_string;
>>>>> gdbarch_tagged_address_p_ftype *tagged_address_p =
>>>> default_tagged_address_p;
>>>>> gdbarch_memtag_matches_p_ftype *memtag_matches_p =
>>>>> default_memtag_matches_p; @@ -407,7 +409,9 @@ verify_gdbarch (struct
>>>> gdbarch *gdbarch)
>>>>> /* Skip verify of frame_red_zone_size, invalid_p == 0. */
>>>>> /* Skip verify of convert_from_func_ptr_addr, invalid_p == 0. */
>>>>> /* Skip verify of addr_bits_remove, invalid_p == 0. */
>>>>> - /* Skip verify of remove_non_address_bits, invalid_p == 0. */
>>>>> + /* Skip verify of remove_non_address_bits_watchpoint, invalid_p
>>>>> + == 0. */
>>>>> + /* Skip verify of remove_non_address_bits_breakpoint, invalid_p
>>>>> + == 0. */
>>>>> + /* Skip verify of remove_non_address_bits_memory, invalid_p == 0.
>>>>> + */
>>>>> /* Skip verify of memtag_to_string, invalid_p == 0. */
>>>>> /* Skip verify of tagged_address_p, invalid_p == 0. */
>>>>> /* Skip verify of memtag_matches_p, invalid_p == 0. */ @@ -910,8
>>>>> +914,14 @@ gdbarch_dump (struct gdbarch *gdbarch, struct ui_file
>>>>> +*file)
>>>>> "gdbarch_dump: addr_bits_remove = <%s>\n",
>>>>> host_address_to_string (gdbarch->addr_bits_remove));
>>>>> gdb_printf (file,
>>>>> - "gdbarch_dump: remove_non_address_bits = <%s>\n",
>>>>> - host_address_to_string (gdbarch->remove_non_address_bits));
>>>>> + "gdbarch_dump: remove_non_address_bits_watchpoint = <%s>\n",
>>>>> + host_address_to_string
>>>>> +(gdbarch->remove_non_address_bits_watchpoint));
>>>>> + gdb_printf (file,
>>>>> + "gdbarch_dump: remove_non_address_bits_breakpoint = <%s>\n",
>>>>> + host_address_to_string
>>>>> +(gdbarch->remove_non_address_bits_breakpoint));
>>>>> + gdb_printf (file,
>>>>> + "gdbarch_dump: remove_non_address_bits_memory = <%s>\n",
>>>>> + host_address_to_string
>>>>> +(gdbarch->remove_non_address_bits_memory));
>>>>> gdb_printf (file,
>>>>> "gdbarch_dump: memtag_to_string = <%s>\n",
>>>>> host_address_to_string (gdbarch->memtag_to_string)); @@
>>>>> -3198,20 +3208,54 @@ set_gdbarch_addr_bits_remove (struct gdbarch
>>>>> *gdbarch, }
>>>>>
>>>>> CORE_ADDR
>>>>> -gdbarch_remove_non_address_bits (struct gdbarch *gdbarch, CORE_ADDR
>>>>> pointer)
>>>>> +gdbarch_remove_non_address_bits_watchpoint (struct gdbarch
>>>>> +*gdbarch, CORE_ADDR pointer) {
>>>>> + gdb_assert (gdbarch != NULL);
>>>>> + gdb_assert (gdbarch->remove_non_address_bits_watchpoint != NULL);
>>>>> + if (gdbarch_debug >= 2)
>>>>> + gdb_printf (gdb_stdlog,
>>>>> +"gdbarch_remove_non_address_bits_watchpoint called\n");
>>>>> + return gdbarch->remove_non_address_bits_watchpoint (gdbarch,
>>>>> +pointer); }
>>>>> +
>>>>> +void
>>>>> +set_gdbarch_remove_non_address_bits_watchpoint (struct gdbarch
>>>> *gdbarch,
>>>>> +
>>>> gdbarch_remove_non_address_bits_watchpoint_ftype
>>>>> +remove_non_address_bits_watchpoint)
>>>>> +{
>>>>> + gdbarch->remove_non_address_bits_watchpoint =
>>>>> +remove_non_address_bits_watchpoint;
>>>>> +}
>>>>> +
>>>>> +CORE_ADDR
>>>>> +gdbarch_remove_non_address_bits_breakpoint (struct gdbarch
>>>>> +*gdbarch, CORE_ADDR pointer) {
>>>>> + gdb_assert (gdbarch != NULL);
>>>>> + gdb_assert (gdbarch->remove_non_address_bits_breakpoint != NULL);
>>>>> + if (gdbarch_debug >= 2)
>>>>> + gdb_printf (gdb_stdlog,
>>>>> +"gdbarch_remove_non_address_bits_breakpoint called\n");
>>>>> + return gdbarch->remove_non_address_bits_breakpoint (gdbarch,
>>>>> +pointer); }
>>>>> +
>>>>> +void
>>>>> +set_gdbarch_remove_non_address_bits_breakpoint (struct gdbarch
>>>>> +*gdbarch,
>>>>> +
>>>> gdbarch_remove_non_address_bits_breakpoint_ftype
>>>>> +remove_non_address_bits_breakpoint)
>>>>> +{
>>>>> + gdbarch->remove_non_address_bits_breakpoint =
>>>>> +remove_non_address_bits_breakpoint;
>>>>> +}
>>>>> +
>>>>> +CORE_ADDR
>>>>> +gdbarch_remove_non_address_bits_memory (struct gdbarch *gdbarch,
>>>>> +CORE_ADDR pointer)
>>>>> {
>>>>> gdb_assert (gdbarch != NULL);
>>>>> - gdb_assert (gdbarch->remove_non_address_bits != NULL);
>>>>> + gdb_assert (gdbarch->remove_non_address_bits_memory != NULL);
>>>>> if (gdbarch_debug >= 2)
>>>>> - gdb_printf (gdb_stdlog, "gdbarch_remove_non_address_bits called\n");
>>>>> - return gdbarch->remove_non_address_bits (gdbarch, pointer);
>>>>> + gdb_printf (gdb_stdlog, "gdbarch_remove_non_address_bits_memory
>>>>> + called\n"); return gdbarch->remove_non_address_bits_memory
>>>>> + (gdbarch, pointer);
>>>>> }
>>>>>
>>>>> void
>>>>> -set_gdbarch_remove_non_address_bits (struct gdbarch *gdbarch,
>>>>> - gdbarch_remove_non_address_bits_ftype
>>>> remove_non_address_bits)
>>>>> +set_gdbarch_remove_non_address_bits_memory (struct gdbarch
>>>>> +*gdbarch,
>>>>> +
>>>> gdbarch_remove_non_address_bits_memory_ftype
>>>>> +remove_non_address_bits_memory)
>>>>> {
>>>>> - gdbarch->remove_non_address_bits = remove_non_address_bits;
>>>>> + gdbarch->remove_non_address_bits_memory =
>>>>> + remove_non_address_bits_memory;
>>>>> }
>>>>>
>>>>> std::string
>>>>> diff --git a/gdb/gdbarch-gen.h b/gdb/gdbarch-gen.h index
>>>>> b982fd7cd09..9fda85f860f 100644
>>>>> --- a/gdb/gdbarch-gen.h
>>>>> +++ b/gdb/gdbarch-gen.h
>>>>> @@ -684,19 +684,46 @@ extern CORE_ADDR gdbarch_addr_bits_remove
>>>>> (struct gdbarch *gdbarch, CORE_ADDR ad extern void
>>>>> set_gdbarch_addr_bits_remove (struct gdbarch *gdbarch,
>>>>> gdbarch_addr_bits_remove_ftype *addr_bits_remove);
>>>>>
>>>>> /* On some architectures, not all bits of a pointer are significant.
>>>>> - On AArch64, for example, the top bits of a pointer may carry a "tag", which
>>>>> - can be ignored by the kernel and the hardware. The "tag" can be regarded
>> as
>>>>> - additional data associated with the pointer, but it is not part of the
>> address.
>>>>> + On AArch64 and amd64, for example, the top bits of a pointer may carry a
>>>>> + "tag", which can be ignored by the kernel and the hardware. The
>>>>> + "tag" can
>>>> be
>>>>> + regarded as additional data associated with the pointer, but it is not part
>>>>> + of the address.
>>>>>
>>>>> Given a pointer for the architecture, this hook removes all the
>>>>> - non-significant bits and sign-extends things as needed. It gets used to
>>>> remove
>>>>> - non-address bits from data pointers (for example, removing the AArch64
>> MTE
>>>> tag
>>>>> - bits from a pointer) and from code pointers (removing the AArch64 PAC
>>>> signature
>>>>> - from a pointer containing the return address). */
>>>>> -
>>>>> -typedef CORE_ADDR (gdbarch_remove_non_address_bits_ftype) (struct
>>>>> gdbarch *gdbarch, CORE_ADDR pointer); -extern CORE_ADDR
>>>>> gdbarch_remove_non_address_bits (struct gdbarch *gdbarch, CORE_ADDR
>>>>> pointer); -extern void set_gdbarch_remove_non_address_bits (struct
>>>>> gdbarch *gdbarch, gdbarch_remove_non_address_bits_ftype
>>>>> *remove_non_address_bits);
>>>>> + non-significant bits and sign-extends things as needed. It gets used to
>>>>> + remove non-address bits from pointers used for watchpoints. */
>>>>> +
>>>>> +typedef CORE_ADDR
>>>>> +(gdbarch_remove_non_address_bits_watchpoint_ftype)
>>>>> +(struct gdbarch *gdbarch, CORE_ADDR pointer); extern CORE_ADDR
>>>>> +gdbarch_remove_non_address_bits_watchpoint (struct gdbarch
>>>>> +*gdbarch, CORE_ADDR pointer); extern void
>>>>> +set_gdbarch_remove_non_address_bits_watchpoint (struct gdbarch
>>>>> +*gdbarch, gdbarch_remove_non_address_bits_watchpoint_ftype
>>>>> +*remove_non_address_bits_watchpoint);
>>>>> +
>>>>> +/* On some architectures, not all bits of a pointer are significant.
>>>>> + On AArch64 and amd64, for example, the top bits of a pointer may carry a
>>>>> + "tag", which can be ignored by the kernel and the hardware. The
>>>>> +"tag" can
>>>> be
>>>>> + regarded as additional data associated with the pointer, but it is not part
>>>>> + of the address.
>>>>> +
>>>>> + Given a pointer for the architecture, this hook removes all the
>>>>> + non-significant bits and sign-extends things as needed. It gets used to
>>>>> + remove non-address bits from pointers used for breakpoints. */
>>>>> +
>>>>> +typedef CORE_ADDR
>>>>> +(gdbarch_remove_non_address_bits_breakpoint_ftype)
>>>>> +(struct gdbarch *gdbarch, CORE_ADDR pointer); extern CORE_ADDR
>>>>> +gdbarch_remove_non_address_bits_breakpoint (struct gdbarch
>>>>> +*gdbarch, CORE_ADDR pointer); extern void
>>>>> +set_gdbarch_remove_non_address_bits_breakpoint (struct gdbarch
>>>>> +*gdbarch, gdbarch_remove_non_address_bits_breakpoint_ftype
>>>>> +*remove_non_address_bits_breakpoint);
>>>>> +
>>>>> +/* On some architectures, not all bits of a pointer are significant.
>>>>> + On AArch64 and amd64, for example, the top bits of a pointer may carry a
>>>>> + "tag", which can be ignored by the kernel and the hardware. The
>>>>> +"tag" can
>>>> be
>>>>> + regarded as additional data associated with the pointer, but it is not part
>>>>> + of the address.
>>>>> +
>>>>> + Given a pointer for the architecture, this hook removes all the
>>>>> + non-significant bits and sign-extends things as needed. It gets used to
>>>>> + remove non-address bits from any pointer used to access memory.
>>>>> + */
>>>>> +
>>>>> +typedef CORE_ADDR (gdbarch_remove_non_address_bits_memory_ftype)
>>>>> +(struct gdbarch *gdbarch, CORE_ADDR pointer); extern CORE_ADDR
>>>>> +gdbarch_remove_non_address_bits_memory (struct gdbarch *gdbarch,
>>>>> +CORE_ADDR pointer); extern void
>>>>> +set_gdbarch_remove_non_address_bits_memory (struct gdbarch
>>>>> +*gdbarch, gdbarch_remove_non_address_bits_memory_ftype
>>>>> +*remove_non_address_bits_memory);
>>>>>
>>>>> /* Return a string representation of the memory tag TAG. */
>>>>>
>>>>> diff --git a/gdb/gdbarch_components.py b/gdb/gdbarch_components.py
>>>>> index 4006380076d..cc7c6d8677b 100644
>>>>> --- a/gdb/gdbarch_components.py
>>>>> +++ b/gdb/gdbarch_components.py
>>>>> @@ -1232,18 +1232,55 @@ possible it should be in TARGET_READ_PC
>>>> instead).
>>>>> Method(
>>>>> comment="""
>>>>> On some architectures, not all bits of a pointer are significant.
>>>>> -On AArch64, for example, the top bits of a pointer may carry a
>>>>> "tag", which -can be ignored by the kernel and the hardware. The
>>>>> "tag" can be regarded as -additional data associated with the
>>>>> pointer, but it is not part of
>>>> the address.
>>>>> +On AArch64 and amd64, for example, the top bits of a pointer may
>>>>> +carry a "tag", which can be ignored by the kernel and the hardware.
>>>>> +The "tag" can be regarded as additional data associated with the
>>>>> +pointer, but it is not part of the address.
>>>>>
>>>>> Given a pointer for the architecture, this hook removes all the
>>>>> -non-significant bits and sign-extends things as needed. It gets
>>>>> used to remove -non-address bits from data pointers (for example,
>>>>> removing the AArch64 MTE tag -bits from a pointer) and from code
>>>>> pointers (removing the AArch64 PAC signature -from a pointer
>>>>> containing the return
>>>> address).
>>>>> +non-significant bits and sign-extends things as needed. It gets
>>>>> +used to remove non-address bits from pointers used for watchpoints.
>>>>> """,
>>>>> type="CORE_ADDR",
>>>>> - name="remove_non_address_bits",
>>>>> + name="remove_non_address_bits_watchpoint",
>>>>> + params=[("CORE_ADDR", "pointer")],
>>>>> + predefault="default_remove_non_address_bits",
>>>>> + invalid=False,
>>>>> +)
>>>>> +
>>>>> +Method(
>>>>> + comment="""
>>>>> +On some architectures, not all bits of a pointer are significant.
>>>>> +On AArch64 and amd64, for example, the top bits of a pointer may
>>>>> +carry a "tag", which can be ignored by the kernel and the hardware.
>>>>> +The "tag" can be regarded as additional data associated with the
>>>>> +pointer, but it is not part of the address.
>>>>> +
>>>>> +Given a pointer for the architecture, this hook removes all the
>>>>> +non-significant bits and sign-extends things as needed. It gets
>>>>> +used to remove non-address bits from pointers used for breakpoints.
>>>>> +""",
>>>>> + type="CORE_ADDR",
>>>>> + name="remove_non_address_bits_breakpoint",
>>>>> + params=[("CORE_ADDR", "pointer")],
>>>>> + predefault="default_remove_non_address_bits",
>>>>> + invalid=False,
>>>>> +)
>>>>> +
>>>>> +Method(
>>>>> + comment="""
>>>>> +On some architectures, not all bits of a pointer are significant.
>>>>> +On AArch64 and amd64, for example, the top bits of a pointer may
>>>>> +carry a "tag", which can be ignored by the kernel and the hardware.
>>>>> +The "tag" can be regarded as additional data associated with the
>>>>> +pointer, but it is not part of the address.
>>>>> +
>>>>> +Given a pointer for the architecture, this hook removes all the
>>>>> +non-significant bits and sign-extends things as needed. It gets
>>>>> +used to remove non-address bits from any pointer used to access memory.
>>>>> +""",
>>>>> + type="CORE_ADDR",
>>>>> + name="remove_non_address_bits_memory",
>>>>> params=[("CORE_ADDR", "pointer")],
>>>>> predefault="default_remove_non_address_bits",
>>>>> invalid=False,
>>>>> diff --git a/gdb/loongarch-linux-nat.c b/gdb/loongarch-linux-nat.c
>>>>> index bc9927dd751..dc4a019614a 100644
>>>>> --- a/gdb/loongarch-linux-nat.c
>>>>> +++ b/gdb/loongarch-linux-nat.c
>>>>> @@ -613,7 +613,7 @@ loongarch_linux_nat_target::stopped_data_address
>>>> (CORE_ADDR *addr_p)
>>>>> kernel can potentially be tagged addresses. */
>>>>> struct gdbarch *gdbarch = thread_architecture (inferior_ptid);
>>>>> const CORE_ADDR addr_trap
>>>>> - = gdbarch_remove_non_address_bits (gdbarch, (CORE_ADDR)
>>>> siginfo.si_addr);
>>>>> + = aarch64_remove_non_address_bits (gdbarch, (CORE_ADDR)
>>>>> + siginfo.si_addr);
>>>>>
>>>>> /* Check if the address matches any watched address. */
>>>>> state = loongarch_get_debug_reg_state (inferior_ptid.pid ());
>>>>
>>>> I think the loongarch-linux-nat.c change is spurious. Could you
>>>> please address that?
>>>
>>> Why is it spurious? What do you mean exactly?
>>
>> The intention behind this change isn't clear to me, but the Loongson native Linux
>> layer using a AArch64 architecture function does not make sense.
>>
>> I haven't built a LoongArch native Linux target, but I'd guess that it will run into a
>> build error with this change, if built for LoongArch only.
>>
>> The right approach, in my mind, is to drop this change, but you have to touch this
>> code due to your changes. It begs the question, why is the LoongArch native code
>> calling gdbarch_remove_non_address_bits here without even registering a
>> function for the gdbarch hook to call?
>
> Right, I agree.
>
>> Without this hook, we'll invoke the dummy implementation in gdb/arch-
>> utils.c:default_remove_non_address_bits, and that just returns the unmodified
>> pointer.
>
> True, that's probably why nobody noticed before.
>
>> This is a question for the LoongArch maintainer (cc-ed). If we don't hear back, we
>> should probably change the LoongArch code to not call
>> gdbarch_remove_non_address_bits. I think that was the original intention, but
>> there might've been a copy/paste error somewhere.
>
> Ok. Let's wait a bit. Thanks for the detailed feedback.
Alternatively, if you could replace, in the LoongArch code, gdbarch_remove_non_address_bits
with one of the three new hooks, that should work as well. I think even cleaner would be to
just drop the hook for Loongarch and assign siginfo.si_addr directly to addr_trap in the code.
Then we wouldn't need to delay this change further. How does thar sound for a v7 (and hopefully last)?
> -----Original Message-----
> From: Luis Machado <luis.machado@arm.com>
> Sent: Tuesday, November 5, 2024 3:51 PM
> To: Schimpe, Christina <christina.schimpe@intel.com>; gdb-
> patches@sourceware.org
> Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
> Subject: Re: [PATCH v6 1/2] gdb: Make tagged pointer support configurable.
>
> On 11/5/24 14:40, Schimpe, Christina wrote:
> >> -----Original Message-----
> >> From: Luis Machado <luis.machado@arm.com>
> >> Sent: Tuesday, November 5, 2024 3:22 PM
> >> To: Schimpe, Christina <christina.schimpe@intel.com>; gdb-
> >> patches@sourceware.org
> >> Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
> >> Subject: Re: [PATCH v6 1/2] gdb: Make tagged pointer support configurable.
> >>
> >> On 11/5/24 14:07, Schimpe, Christina wrote:
> >>> Hi Luis,
> >>>
> >>> Thanks a lot for the review. I have one questions to your comment,
> >>> please see
> >> below.
> >>>
> >>>> -----Original Message-----
> >>>> From: Luis Machado <luis.machado@arm.com>
> >>>> Sent: Monday, November 4, 2024 12:18 PM
> >>>> To: Schimpe, Christina <christina.schimpe@intel.com>; gdb-
> >>>> patches@sourceware.org
> >>>> Subject: Re: [PATCH v6 1/2] gdb: Make tagged pointer support configurable.
> >>>>
> >>>> Hi Christina,
> >>>>
> >>>> On 10/28/24 08:46, Schimpe, Christina wrote:
> >>>>> From: Christina Schimpe <christina.schimpe@intel.com>
> >>>>>
> >>>>> The gdbarch function gdbarch_remove_non_address_bits adjusts
> >>>>> addresses to enable debugging of programs with tagged pointers on
> >>>>> Linux, for instance for ARM's feature top byte ignore (TBI).
> >>>>> Once the function is implemented for an architecture, it adjusts
> >>>>> addresses for memory access, breakpoints and watchpoints.
> >>>>>
> >>>>> Linear address masking (LAM) is Intel's (R) implementation of
> >>>>> tagged pointer support. It requires certain adaptions to GDB's
> >>>>> tagged pointer support due to the following:
> >>>>> - LAM supports address tagging for data accesses only. Thus, specifying
> >>>>> breakpoints on tagged addresses is not a valid use case.
> >>>>> - In contrast to the implementation for ARM's TBI, the Linux kernel
> supports
> >>>>> tagged pointers for memory access.
> >>>>>
> >>>>> This patch makes GDB's tagged pointer support configurable such
> >>>>> that it is possible to enable the address adjustment for a
> >>>>> specific feature only (e.g memory access, breakpoints or
> >>>>> watchpoints). This way, one can make sure that addresses are only
> >>>>> adjusted when necessary. In case of LAM, this avoids unnecessary
> >>>>> parsing of the /proc/<pid>/status file to get the untag mask.
> >>>>>
> >>>>> Reviewed-By: Felix Willgerodt <felix.willgerodt@intel.com>
> >>>>> ---
> >>>>> gdb/aarch64-linux-nat.c | 2 +-
> >>>>> gdb/aarch64-linux-tdep.c | 7 +++--
> >>>>> gdb/aarch64-tdep.c | 23 ++++++++------
> >>>>> gdb/aarch64-tdep.h | 6 ++++
> >>>>> gdb/breakpoint.c | 5 +--
> >>>>> gdb/gdbarch-gen.c | 66 ++++++++++++++++++++++++++++++++------
> -
> >>>>> gdb/gdbarch-gen.h | 49 ++++++++++++++++++++++-------
> >>>>> gdb/gdbarch_components.py | 53 ++++++++++++++++++++++++++-----
> >>>>> gdb/loongarch-linux-nat.c | 2 +-
> >>>>> gdb/target.c | 3 +-
> >>>>> 10 files changed, 169 insertions(+), 47 deletions(-)
> >>>>>
> >>>>> diff --git a/gdb/aarch64-linux-nat.c b/gdb/aarch64-linux-nat.c
> >>>>> index
> >>>>> 0fa5bee500b..48ab765d880 100644
> >>>>> --- a/gdb/aarch64-linux-nat.c
> >>>>> +++ b/gdb/aarch64-linux-nat.c
> >>>>> @@ -943,7 +943,7 @@ aarch64_linux_nat_target::stopped_data_address
> >>>> (CORE_ADDR *addr_p)
> >>>>> kernel can potentially be tagged addresses. */
> >>>>> struct gdbarch *gdbarch = thread_architecture (inferior_ptid);
> >>>>> const CORE_ADDR addr_trap
> >>>>> - = gdbarch_remove_non_address_bits (gdbarch, (CORE_ADDR)
> >>>> siginfo.si_addr);
> >>>>> + = aarch64_remove_non_address_bits (gdbarch, (CORE_ADDR)
> >>>>> + siginfo.si_addr);
> >>>>>
> >>>>> /* Check if the address matches any watched address. */
> >>>>> state = aarch64_get_debug_reg_state (inferior_ptid.pid ());
> >>>>> diff --git a/gdb/aarch64-linux-tdep.c b/gdb/aarch64-linux-tdep.c
> >>>>> index
> >>>>> c608a84bc71..61c3be8b6f0 100644
> >>>>> --- a/gdb/aarch64-linux-tdep.c
> >>>>> +++ b/gdb/aarch64-linux-tdep.c
> >>>>> @@ -2433,7 +2433,7 @@ static bool
> >>>>> aarch64_linux_tagged_address_p (struct gdbarch *gdbarch,
> >>>>> CORE_ADDR
> >>>>> address) {
> >>>>> /* Remove the top byte for the memory range check. */
> >>>>> - address = gdbarch_remove_non_address_bits (gdbarch, address);
> >>>>> + address = aarch64_remove_non_address_bits (gdbarch, address);
> >>>>>
> >>>>> /* Check if the page that contains ADDRESS is mapped with PROT_MTE.
> */
> >>>>> if (!linux_address_in_memtag_page (address)) @@ -2491,8 +2491,9
> >>>>> @@ aarch64_linux_report_signal_info (struct gdbarch *gdbarch,
> >>>>> uiout->text ("\n");
> >>>>>
> >>>>> std::optional<CORE_ADDR> atag
> >>>>> - = aarch64_mte_get_atag (gdbarch_remove_non_address_bits (gdbarch,
> >>>>> - fault_addr));
> >>>>> + = aarch64_mte_get_atag (
> >>>>> + aarch64_remove_non_address_bits (gdbarch, fault_addr));
> >>>>> +
> >>>>> gdb_byte ltag = aarch64_mte_get_ltag (fault_addr);
> >>>>>
> >>>>> if (!atag.has_value ())
> >>>>> diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c index
> >>>>> 8a2a9b1e23c..91fec7879ed 100644
> >>>>> --- a/gdb/aarch64-tdep.c
> >>>>> +++ b/gdb/aarch64-tdep.c
> >>>>> @@ -4121,7 +4121,7 @@ aarch64_memtag_matches_p (struct gdbarch
> >>>>> *gdbarch,
> >>>>>
> >>>>> /* Fetch the allocation tag for ADDRESS. */
> >>>>> std::optional<CORE_ADDR> atag
> >>>>> - = aarch64_mte_get_atag (gdbarch_remove_non_address_bits
> (gdbarch,
> >>>> addr));
> >>>>> + = aarch64_mte_get_atag (aarch64_remove_non_address_bits
> >>>>> + (gdbarch, addr));
> >>>>>
> >>>>> if (!atag.has_value ())
> >>>>> return true;
> >>>>> @@ -4160,7 +4160,7 @@ aarch64_set_memtags (struct gdbarch
> >>>>> *gdbarch,
> >>>> struct value *address,
> >>>>> else
> >>>>> {
> >>>>> /* Remove the top byte. */
> >>>>> - addr = gdbarch_remove_non_address_bits (gdbarch, addr);
> >>>>> + addr = aarch64_remove_non_address_bits (gdbarch, addr);
> >>>>>
> >>>>> /* With G being the number of tag granules and N the number of tags
> >>>>> passed in, we can have the following cases:
> >>>>> @@ -4209,7 +4209,7 @@ aarch64_get_memtag (struct gdbarch
> *gdbarch,
> >>>> struct value *address,
> >>>>> else
> >>>>> {
> >>>>> /* Remove the top byte. */
> >>>>> - addr = gdbarch_remove_non_address_bits (gdbarch, addr);
> >>>>> + addr = aarch64_remove_non_address_bits (gdbarch, addr);
> >>>>> std::optional<CORE_ADDR> atag = aarch64_mte_get_atag
> >>>>> (addr);
> >>>>>
> >>>>> if (!atag.has_value ())
> >>>>> @@ -4236,10 +4236,9 @@ aarch64_memtag_to_string (struct gdbarch
> >>>> *gdbarch, struct value *tag_value)
> >>>>> return string_printf ("0x%s", phex_nz (tag, sizeof (tag))); }
> >>>>>
> >>>>> -/* AArch64 implementation of the remove_non_address_bits gdbarch
> hook.
> >>>> Remove
> >>>>> - non address bits from a pointer value. */
> >>>>> +/* See aarch64-tdep.h. */
> >>>>>
> >>>>> -static CORE_ADDR
> >>>>> +CORE_ADDR
> >>>>> aarch64_remove_non_address_bits (struct gdbarch *gdbarch,
> >>>>> CORE_ADDR
> >>>>> pointer) {
> >>>>> /* By default, we assume TBI and discard the top 8 bits plus
> >>>>> the VA range @@ -4750,9 +4749,15 @@ aarch64_gdbarch_init (struct
> >>>>> gdbarch_info
> >>>> info, struct gdbarch_list *arches)
> >>>>> tdep->ra_sign_state_regnum = ra_sign_state_offset + num_regs;
> >>>>>
> >>>>> /* Architecture hook to remove bits of a pointer that are not part of the
> >>>>> - address, like memory tags (MTE) and pointer authentication signatures.
> >> */
> >>>>> - set_gdbarch_remove_non_address_bits (gdbarch,
> >>>>> - aarch64_remove_non_address_bits);
> >>>>> + address, like memory tags (MTE) and pointer authentication
> signatures.
> >>>>> + Configure address adjustment for watch-, breakpoints and
> >>>>> + memory
> >>>>
> >>>> s/watch-/watchpoints
> >>>
> >>> Fill fix, thanks.
> >>>
> >>>>> + transfer. */
> >>>>> + set_gdbarch_remove_non_address_bits_watchpoint
> >>>>> + (gdbarch, aarch64_remove_non_address_bits);
> >>>>> + set_gdbarch_remove_non_address_bits_breakpoint
> >>>>> + (gdbarch, aarch64_remove_non_address_bits);
> >>>>> + set_gdbarch_remove_non_address_bits_memory
> >>>>> + (gdbarch, aarch64_remove_non_address_bits);
> >>>>>
> >>>>> /* SME pseudo-registers. */
> >>>>> if (tdep->has_sme ())
> >>>>> diff --git a/gdb/aarch64-tdep.h b/gdb/aarch64-tdep.h index
> >>>>> 50166fb4f24..13ea37de7a3 100644
> >>>>> --- a/gdb/aarch64-tdep.h
> >>>>> +++ b/gdb/aarch64-tdep.h
> >>>>> @@ -205,4 +205,10 @@ bool aarch64_displaced_step_hw_singlestep
> >>>>> (struct gdbarch *gdbarch);
> >>>>>
> >>>>> std::optional<CORE_ADDR> aarch64_mte_get_atag (CORE_ADDR
> >>>>> address);
> >>>>>
> >>>>> +/* AArch64 implementation of the remove_non_address_bits gdbarch
> >> hooks.
> >>>>> + Remove non address bits from a pointer value. */
> >>>>> +
> >>>>> +CORE_ADDR aarch64_remove_non_address_bits (struct gdbarch
> *gdbarch,
> >>>>> + CORE_ADDR pointer);
> >>>>> +
> >>>>> #endif /* aarch64-tdep.h */
> >>>>> diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c index
> >>>>> b7e4f5d0a45..9983e905e1b 100644
> >>>>> --- a/gdb/breakpoint.c
> >>>>> +++ b/gdb/breakpoint.c
> >>>>> @@ -2313,7 +2313,8 @@ update_watchpoint (struct watchpoint *b,
> >>>>> bool
> >>>> reparse)
> >>>>> loc->gdbarch = v->type ()->arch ();
> >>>>> loc->pspace = wp_pspace;
> >>>>> loc->address
> >>>>> - = gdbarch_remove_non_address_bits (loc->gdbarch, addr);
> >>>>> + = gdbarch_remove_non_address_bits_watchpoint (loc-
> >>>>> gdbarch,
> >>>>> + addr);
> >>>>> b->add_location (*loc);
> >>>>>
> >>>>> if (bitsize != 0)
> >>>>> @@ -7538,7 +7539,7 @@ adjust_breakpoint_address (struct gdbarch
> >>>> *gdbarch,
> >>>>> }
> >>>>>
> >>>>> adjusted_bpaddr
> >>>>> - = gdbarch_remove_non_address_bits (gdbarch, adjusted_bpaddr);
> >>>>> + = gdbarch_remove_non_address_bits_breakpoint (gdbarch,
> >>>>> +adjusted_bpaddr);
> >>>>>
> >>>>> /* An adjusted breakpoint address can significantly alter
> >>>>> a user's expectations. Print a warning if an adjustment diff
> >>>>> --git a/gdb/gdbarch-gen.c b/gdb/gdbarch-gen.c index
> >>>>> 0d00cd7c993..d05c7a3cbdf
> >>>>> 100644
> >>>>> --- a/gdb/gdbarch-gen.c
> >>>>> +++ b/gdb/gdbarch-gen.c
> >>>>> @@ -143,7 +143,9 @@ struct gdbarch
> >>>>> int frame_red_zone_size = 0;
> >>>>> gdbarch_convert_from_func_ptr_addr_ftype
> >>>>> *convert_from_func_ptr_addr =
> >>>> convert_from_func_ptr_addr_identity;
> >>>>> gdbarch_addr_bits_remove_ftype *addr_bits_remove =
> >>>>> core_addr_identity;
> >>>>> - gdbarch_remove_non_address_bits_ftype *remove_non_address_bits
> >>>>> = default_remove_non_address_bits;
> >>>>> + gdbarch_remove_non_address_bits_watchpoint_ftype
> >>>>> + *remove_non_address_bits_watchpoint =
> >>>>> + default_remove_non_address_bits;
> >>>>> + gdbarch_remove_non_address_bits_breakpoint_ftype
> >>>>> + *remove_non_address_bits_breakpoint =
> >>>>> + default_remove_non_address_bits;
> >>>>> + gdbarch_remove_non_address_bits_memory_ftype
> >>>>> + *remove_non_address_bits_memory =
> >>>>> + default_remove_non_address_bits;
> >>>>> gdbarch_memtag_to_string_ftype *memtag_to_string =
> >>>> default_memtag_to_string;
> >>>>> gdbarch_tagged_address_p_ftype *tagged_address_p =
> >>>> default_tagged_address_p;
> >>>>> gdbarch_memtag_matches_p_ftype *memtag_matches_p =
> >>>>> default_memtag_matches_p; @@ -407,7 +409,9 @@ verify_gdbarch
> >>>>> (struct
> >>>> gdbarch *gdbarch)
> >>>>> /* Skip verify of frame_red_zone_size, invalid_p == 0. */
> >>>>> /* Skip verify of convert_from_func_ptr_addr, invalid_p == 0. */
> >>>>> /* Skip verify of addr_bits_remove, invalid_p == 0. */
> >>>>> - /* Skip verify of remove_non_address_bits, invalid_p == 0. */
> >>>>> + /* Skip verify of remove_non_address_bits_watchpoint, invalid_p
> >>>>> + == 0. */
> >>>>> + /* Skip verify of remove_non_address_bits_breakpoint, invalid_p
> >>>>> + == 0. */
> >>>>> + /* Skip verify of remove_non_address_bits_memory, invalid_p == 0.
> >>>>> + */
> >>>>> /* Skip verify of memtag_to_string, invalid_p == 0. */
> >>>>> /* Skip verify of tagged_address_p, invalid_p == 0. */
> >>>>> /* Skip verify of memtag_matches_p, invalid_p == 0. */ @@
> >>>>> -910,8
> >>>>> +914,14 @@ gdbarch_dump (struct gdbarch *gdbarch, struct ui_file
> >>>>> +*file)
> >>>>> "gdbarch_dump: addr_bits_remove = <%s>\n",
> >>>>> host_address_to_string (gdbarch->addr_bits_remove));
> >>>>> gdb_printf (file,
> >>>>> - "gdbarch_dump: remove_non_address_bits = <%s>\n",
> >>>>> - host_address_to_string (gdbarch->remove_non_address_bits));
> >>>>> + "gdbarch_dump: remove_non_address_bits_watchpoint = <%s>\n",
> >>>>> + host_address_to_string
> >>>>> +(gdbarch->remove_non_address_bits_watchpoint));
> >>>>> + gdb_printf (file,
> >>>>> + "gdbarch_dump: remove_non_address_bits_breakpoint = <%s>\n",
> >>>>> + host_address_to_string
> >>>>> +(gdbarch->remove_non_address_bits_breakpoint));
> >>>>> + gdb_printf (file,
> >>>>> + "gdbarch_dump: remove_non_address_bits_memory = <%s>\n",
> >>>>> + host_address_to_string
> >>>>> +(gdbarch->remove_non_address_bits_memory));
> >>>>> gdb_printf (file,
> >>>>> "gdbarch_dump: memtag_to_string = <%s>\n",
> >>>>> host_address_to_string (gdbarch->memtag_to_string)); @@
> >>>>> -3198,20 +3208,54 @@ set_gdbarch_addr_bits_remove (struct gdbarch
> >>>>> *gdbarch, }
> >>>>>
> >>>>> CORE_ADDR
> >>>>> -gdbarch_remove_non_address_bits (struct gdbarch *gdbarch,
> >>>>> CORE_ADDR
> >>>>> pointer)
> >>>>> +gdbarch_remove_non_address_bits_watchpoint (struct gdbarch
> >>>>> +*gdbarch, CORE_ADDR pointer) {
> >>>>> + gdb_assert (gdbarch != NULL);
> >>>>> + gdb_assert (gdbarch->remove_non_address_bits_watchpoint !=
> >>>>> +NULL);
> >>>>> + if (gdbarch_debug >= 2)
> >>>>> + gdb_printf (gdb_stdlog,
> >>>>> +"gdbarch_remove_non_address_bits_watchpoint called\n");
> >>>>> + return gdbarch->remove_non_address_bits_watchpoint (gdbarch,
> >>>>> +pointer); }
> >>>>> +
> >>>>> +void
> >>>>> +set_gdbarch_remove_non_address_bits_watchpoint (struct gdbarch
> >>>> *gdbarch,
> >>>>> +
> >>>> gdbarch_remove_non_address_bits_watchpoint_ftype
> >>>>> +remove_non_address_bits_watchpoint)
> >>>>> +{
> >>>>> + gdbarch->remove_non_address_bits_watchpoint =
> >>>>> +remove_non_address_bits_watchpoint;
> >>>>> +}
> >>>>> +
> >>>>> +CORE_ADDR
> >>>>> +gdbarch_remove_non_address_bits_breakpoint (struct gdbarch
> >>>>> +*gdbarch, CORE_ADDR pointer) {
> >>>>> + gdb_assert (gdbarch != NULL);
> >>>>> + gdb_assert (gdbarch->remove_non_address_bits_breakpoint !=
> >>>>> +NULL);
> >>>>> + if (gdbarch_debug >= 2)
> >>>>> + gdb_printf (gdb_stdlog,
> >>>>> +"gdbarch_remove_non_address_bits_breakpoint called\n");
> >>>>> + return gdbarch->remove_non_address_bits_breakpoint (gdbarch,
> >>>>> +pointer); }
> >>>>> +
> >>>>> +void
> >>>>> +set_gdbarch_remove_non_address_bits_breakpoint (struct gdbarch
> >>>>> +*gdbarch,
> >>>>> +
> >>>> gdbarch_remove_non_address_bits_breakpoint_ftype
> >>>>> +remove_non_address_bits_breakpoint)
> >>>>> +{
> >>>>> + gdbarch->remove_non_address_bits_breakpoint =
> >>>>> +remove_non_address_bits_breakpoint;
> >>>>> +}
> >>>>> +
> >>>>> +CORE_ADDR
> >>>>> +gdbarch_remove_non_address_bits_memory (struct gdbarch *gdbarch,
> >>>>> +CORE_ADDR pointer)
> >>>>> {
> >>>>> gdb_assert (gdbarch != NULL);
> >>>>> - gdb_assert (gdbarch->remove_non_address_bits != NULL);
> >>>>> + gdb_assert (gdbarch->remove_non_address_bits_memory != NULL);
> >>>>> if (gdbarch_debug >= 2)
> >>>>> - gdb_printf (gdb_stdlog, "gdbarch_remove_non_address_bits called\n");
> >>>>> - return gdbarch->remove_non_address_bits (gdbarch, pointer);
> >>>>> + gdb_printf (gdb_stdlog,
> >>>>> + "gdbarch_remove_non_address_bits_memory
> >>>>> + called\n"); return gdbarch->remove_non_address_bits_memory
> >>>>> + (gdbarch, pointer);
> >>>>> }
> >>>>>
> >>>>> void
> >>>>> -set_gdbarch_remove_non_address_bits (struct gdbarch *gdbarch,
> >>>>> - gdbarch_remove_non_address_bits_ftype
> >>>> remove_non_address_bits)
> >>>>> +set_gdbarch_remove_non_address_bits_memory (struct gdbarch
> >>>>> +*gdbarch,
> >>>>> +
> >>>> gdbarch_remove_non_address_bits_memory_ftype
> >>>>> +remove_non_address_bits_memory)
> >>>>> {
> >>>>> - gdbarch->remove_non_address_bits = remove_non_address_bits;
> >>>>> + gdbarch->remove_non_address_bits_memory =
> >>>>> + remove_non_address_bits_memory;
> >>>>> }
> >>>>>
> >>>>> std::string
> >>>>> diff --git a/gdb/gdbarch-gen.h b/gdb/gdbarch-gen.h index
> >>>>> b982fd7cd09..9fda85f860f 100644
> >>>>> --- a/gdb/gdbarch-gen.h
> >>>>> +++ b/gdb/gdbarch-gen.h
> >>>>> @@ -684,19 +684,46 @@ extern CORE_ADDR gdbarch_addr_bits_remove
> >>>>> (struct gdbarch *gdbarch, CORE_ADDR ad extern void
> >>>>> set_gdbarch_addr_bits_remove (struct gdbarch *gdbarch,
> >>>>> gdbarch_addr_bits_remove_ftype *addr_bits_remove);
> >>>>>
> >>>>> /* On some architectures, not all bits of a pointer are significant.
> >>>>> - On AArch64, for example, the top bits of a pointer may carry a "tag",
> which
> >>>>> - can be ignored by the kernel and the hardware. The "tag" can be
> regarded
> >> as
> >>>>> - additional data associated with the pointer, but it is not part of the
> >> address.
> >>>>> + On AArch64 and amd64, for example, the top bits of a pointer may carry
> a
> >>>>> + "tag", which can be ignored by the kernel and the hardware.
> >>>>> + The "tag" can
> >>>> be
> >>>>> + regarded as additional data associated with the pointer, but it is not
> part
> >>>>> + of the address.
> >>>>>
> >>>>> Given a pointer for the architecture, this hook removes all the
> >>>>> - non-significant bits and sign-extends things as needed. It gets used to
> >>>> remove
> >>>>> - non-address bits from data pointers (for example, removing the AArch64
> >> MTE
> >>>> tag
> >>>>> - bits from a pointer) and from code pointers (removing the AArch64 PAC
> >>>> signature
> >>>>> - from a pointer containing the return address). */
> >>>>> -
> >>>>> -typedef CORE_ADDR (gdbarch_remove_non_address_bits_ftype) (struct
> >>>>> gdbarch *gdbarch, CORE_ADDR pointer); -extern CORE_ADDR
> >>>>> gdbarch_remove_non_address_bits (struct gdbarch *gdbarch,
> >>>>> CORE_ADDR pointer); -extern void
> >>>>> set_gdbarch_remove_non_address_bits (struct gdbarch *gdbarch,
> >>>>> gdbarch_remove_non_address_bits_ftype
> >>>>> *remove_non_address_bits);
> >>>>> + non-significant bits and sign-extends things as needed. It gets used to
> >>>>> + remove non-address bits from pointers used for watchpoints. */
> >>>>> +
> >>>>> +typedef CORE_ADDR
> >>>>> +(gdbarch_remove_non_address_bits_watchpoint_ftype)
> >>>>> +(struct gdbarch *gdbarch, CORE_ADDR pointer); extern CORE_ADDR
> >>>>> +gdbarch_remove_non_address_bits_watchpoint (struct gdbarch
> >>>>> +*gdbarch, CORE_ADDR pointer); extern void
> >>>>> +set_gdbarch_remove_non_address_bits_watchpoint (struct gdbarch
> >>>>> +*gdbarch, gdbarch_remove_non_address_bits_watchpoint_ftype
> >>>>> +*remove_non_address_bits_watchpoint);
> >>>>> +
> >>>>> +/* On some architectures, not all bits of a pointer are significant.
> >>>>> + On AArch64 and amd64, for example, the top bits of a pointer may carry
> a
> >>>>> + "tag", which can be ignored by the kernel and the hardware.
> >>>>> +The "tag" can
> >>>> be
> >>>>> + regarded as additional data associated with the pointer, but it is not
> part
> >>>>> + of the address.
> >>>>> +
> >>>>> + Given a pointer for the architecture, this hook removes all the
> >>>>> + non-significant bits and sign-extends things as needed. It gets used to
> >>>>> + remove non-address bits from pointers used for breakpoints. */
> >>>>> +
> >>>>> +typedef CORE_ADDR
> >>>>> +(gdbarch_remove_non_address_bits_breakpoint_ftype)
> >>>>> +(struct gdbarch *gdbarch, CORE_ADDR pointer); extern CORE_ADDR
> >>>>> +gdbarch_remove_non_address_bits_breakpoint (struct gdbarch
> >>>>> +*gdbarch, CORE_ADDR pointer); extern void
> >>>>> +set_gdbarch_remove_non_address_bits_breakpoint (struct gdbarch
> >>>>> +*gdbarch, gdbarch_remove_non_address_bits_breakpoint_ftype
> >>>>> +*remove_non_address_bits_breakpoint);
> >>>>> +
> >>>>> +/* On some architectures, not all bits of a pointer are significant.
> >>>>> + On AArch64 and amd64, for example, the top bits of a pointer may carry
> a
> >>>>> + "tag", which can be ignored by the kernel and the hardware.
> >>>>> +The "tag" can
> >>>> be
> >>>>> + regarded as additional data associated with the pointer, but it is not
> part
> >>>>> + of the address.
> >>>>> +
> >>>>> + Given a pointer for the architecture, this hook removes all the
> >>>>> + non-significant bits and sign-extends things as needed. It gets used to
> >>>>> + remove non-address bits from any pointer used to access memory.
> >>>>> + */
> >>>>> +
> >>>>> +typedef CORE_ADDR
> (gdbarch_remove_non_address_bits_memory_ftype)
> >>>>> +(struct gdbarch *gdbarch, CORE_ADDR pointer); extern CORE_ADDR
> >>>>> +gdbarch_remove_non_address_bits_memory (struct gdbarch *gdbarch,
> >>>>> +CORE_ADDR pointer); extern void
> >>>>> +set_gdbarch_remove_non_address_bits_memory (struct gdbarch
> >>>>> +*gdbarch, gdbarch_remove_non_address_bits_memory_ftype
> >>>>> +*remove_non_address_bits_memory);
> >>>>>
> >>>>> /* Return a string representation of the memory tag TAG. */
> >>>>>
> >>>>> diff --git a/gdb/gdbarch_components.py b/gdb/gdbarch_components.py
> >>>>> index 4006380076d..cc7c6d8677b 100644
> >>>>> --- a/gdb/gdbarch_components.py
> >>>>> +++ b/gdb/gdbarch_components.py
> >>>>> @@ -1232,18 +1232,55 @@ possible it should be in TARGET_READ_PC
> >>>> instead).
> >>>>> Method(
> >>>>> comment="""
> >>>>> On some architectures, not all bits of a pointer are significant.
> >>>>> -On AArch64, for example, the top bits of a pointer may carry a
> >>>>> "tag", which -can be ignored by the kernel and the hardware. The
> >>>>> "tag" can be regarded as -additional data associated with the
> >>>>> pointer, but it is not part of
> >>>> the address.
> >>>>> +On AArch64 and amd64, for example, the top bits of a pointer may
> >>>>> +carry a "tag", which can be ignored by the kernel and the hardware.
> >>>>> +The "tag" can be regarded as additional data associated with the
> >>>>> +pointer, but it is not part of the address.
> >>>>>
> >>>>> Given a pointer for the architecture, this hook removes all the
> >>>>> -non-significant bits and sign-extends things as needed. It gets
> >>>>> used to remove -non-address bits from data pointers (for example,
> >>>>> removing the AArch64 MTE tag -bits from a pointer) and from code
> >>>>> pointers (removing the AArch64 PAC signature -from a pointer
> >>>>> containing the return
> >>>> address).
> >>>>> +non-significant bits and sign-extends things as needed. It gets
> >>>>> +used to remove non-address bits from pointers used for watchpoints.
> >>>>> """,
> >>>>> type="CORE_ADDR",
> >>>>> - name="remove_non_address_bits",
> >>>>> + name="remove_non_address_bits_watchpoint",
> >>>>> + params=[("CORE_ADDR", "pointer")],
> >>>>> + predefault="default_remove_non_address_bits",
> >>>>> + invalid=False,
> >>>>> +)
> >>>>> +
> >>>>> +Method(
> >>>>> + comment="""
> >>>>> +On some architectures, not all bits of a pointer are significant.
> >>>>> +On AArch64 and amd64, for example, the top bits of a pointer may
> >>>>> +carry a "tag", which can be ignored by the kernel and the hardware.
> >>>>> +The "tag" can be regarded as additional data associated with the
> >>>>> +pointer, but it is not part of the address.
> >>>>> +
> >>>>> +Given a pointer for the architecture, this hook removes all the
> >>>>> +non-significant bits and sign-extends things as needed. It gets
> >>>>> +used to remove non-address bits from pointers used for breakpoints.
> >>>>> +""",
> >>>>> + type="CORE_ADDR",
> >>>>> + name="remove_non_address_bits_breakpoint",
> >>>>> + params=[("CORE_ADDR", "pointer")],
> >>>>> + predefault="default_remove_non_address_bits",
> >>>>> + invalid=False,
> >>>>> +)
> >>>>> +
> >>>>> +Method(
> >>>>> + comment="""
> >>>>> +On some architectures, not all bits of a pointer are significant.
> >>>>> +On AArch64 and amd64, for example, the top bits of a pointer may
> >>>>> +carry a "tag", which can be ignored by the kernel and the hardware.
> >>>>> +The "tag" can be regarded as additional data associated with the
> >>>>> +pointer, but it is not part of the address.
> >>>>> +
> >>>>> +Given a pointer for the architecture, this hook removes all the
> >>>>> +non-significant bits and sign-extends things as needed. It gets
> >>>>> +used to remove non-address bits from any pointer used to access
> memory.
> >>>>> +""",
> >>>>> + type="CORE_ADDR",
> >>>>> + name="remove_non_address_bits_memory",
> >>>>> params=[("CORE_ADDR", "pointer")],
> >>>>> predefault="default_remove_non_address_bits",
> >>>>> invalid=False,
> >>>>> diff --git a/gdb/loongarch-linux-nat.c b/gdb/loongarch-linux-nat.c
> >>>>> index bc9927dd751..dc4a019614a 100644
> >>>>> --- a/gdb/loongarch-linux-nat.c
> >>>>> +++ b/gdb/loongarch-linux-nat.c
> >>>>> @@ -613,7 +613,7 @@
> >>>>> loongarch_linux_nat_target::stopped_data_address
> >>>> (CORE_ADDR *addr_p)
> >>>>> kernel can potentially be tagged addresses. */
> >>>>> struct gdbarch *gdbarch = thread_architecture (inferior_ptid);
> >>>>> const CORE_ADDR addr_trap
> >>>>> - = gdbarch_remove_non_address_bits (gdbarch, (CORE_ADDR)
> >>>> siginfo.si_addr);
> >>>>> + = aarch64_remove_non_address_bits (gdbarch, (CORE_ADDR)
> >>>>> + siginfo.si_addr);
> >>>>>
> >>>>> /* Check if the address matches any watched address. */
> >>>>> state = loongarch_get_debug_reg_state (inferior_ptid.pid ());
> >>>>
> >>>> I think the loongarch-linux-nat.c change is spurious. Could you
> >>>> please address that?
> >>>
> >>> Why is it spurious? What do you mean exactly?
> >>
> >> The intention behind this change isn't clear to me, but the Loongson
> >> native Linux layer using a AArch64 architecture function does not make sense.
> >>
> >> I haven't built a LoongArch native Linux target, but I'd guess that
> >> it will run into a build error with this change, if built for LoongArch only.
> >>
> >> The right approach, in my mind, is to drop this change, but you have
> >> to touch this code due to your changes. It begs the question, why is
> >> the LoongArch native code calling gdbarch_remove_non_address_bits
> >> here without even registering a function for the gdbarch hook to call?
> >
> > Right, I agree.
> >
> >> Without this hook, we'll invoke the dummy implementation in gdb/arch-
> >> utils.c:default_remove_non_address_bits, and that just returns the
> >> unmodified pointer.
> >
> > True, that's probably why nobody noticed before.
> >
> >> This is a question for the LoongArch maintainer (cc-ed). If we don't
> >> hear back, we should probably change the LoongArch code to not call
> >> gdbarch_remove_non_address_bits. I think that was the original
> >> intention, but there might've been a copy/paste error somewhere.
> >
> > Ok. Let's wait a bit. Thanks for the detailed feedback.
>
> Alternatively, if you could replace, in the LoongArch code,
> gdbarch_remove_non_address_bits with one of the three new hooks, that should
> work as well. I think even cleaner would be to just drop the hook for Loongarch
> and assign siginfo.si_addr directly to addr_trap in the code.
I am also in favour of your second suggestion to drop the hook here.
In that case, it should be separate patch I think.
I could post it independently of this series and quickly merge before posting a v7 of my series.
LoongArch doesn't supported tagged addresses, does it? If it's not supported,
I would suggest to fix it as follows:
diff --git a/gdb/loongarch-linux-nat.c b/gdb/loongarch-linux-nat.c
index dc4a019614a..fd3581bbd30 100644
--- a/gdb/loongarch-linux-nat.c
+++ b/gdb/loongarch-linux-nat.c
@@ -608,17 +608,11 @@ loongarch_linux_nat_target::stopped_data_address (CORE_ADDR *addr_p)
if (siginfo.si_signo != SIGTRAP || (siginfo.si_code & 0xffff) != TRAP_HWBKPT)
return false;
- /* Make sure to ignore the top byte, otherwise we may not recognize a
- hardware watchpoint hit. The stopped data addresses coming from the
- kernel can potentially be tagged addresses. */
- struct gdbarch *gdbarch = thread_architecture (inferior_ptid);
- const CORE_ADDR addr_trap
- = aarch64_remove_non_address_bits (gdbarch, (CORE_ADDR) siginfo.si_addr);
-
/* Check if the address matches any watched address. */
state = loongarch_get_debug_reg_state (inferior_ptid.pid ());
- return loongarch_stopped_data_address (state, addr_trap, addr_p);
+ return
+ loongarch_stopped_data_address (state, (CORE_ADDR) siginfo.si_addr, addr_p);
Does that make sense to you?
> Then we wouldn't need to delay this change further. How does thar sound for a v7
> (and hopefully last)?
That sounds good to me.
Christina
Intel Deutschland GmbH
Registered Address: Am Campeon 10, 85579 Neubiberg, Germany
Tel: +49 89 99 8853-0, www.intel.de
Managing Directors: Sean Fennelly, Jeffrey Schneiderman, Tiffany Doon Silva
Chairperson of the Supervisory Board: Nicole Lau
Registered Office: Munich
Commercial Register: Amtsgericht Muenchen HRB 186928
On 11/5/24 15:09, Schimpe, Christina wrote:
>> -----Original Message-----
>> From: Luis Machado <luis.machado@arm.com>
>> Sent: Tuesday, November 5, 2024 3:51 PM
>> To: Schimpe, Christina <christina.schimpe@intel.com>; gdb-
>> patches@sourceware.org
>> Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
>> Subject: Re: [PATCH v6 1/2] gdb: Make tagged pointer support configurable.
>>
>> On 11/5/24 14:40, Schimpe, Christina wrote:
>>>> -----Original Message-----
>>>> From: Luis Machado <luis.machado@arm.com>
>>>> Sent: Tuesday, November 5, 2024 3:22 PM
>>>> To: Schimpe, Christina <christina.schimpe@intel.com>; gdb-
>>>> patches@sourceware.org
>>>> Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
>>>> Subject: Re: [PATCH v6 1/2] gdb: Make tagged pointer support configurable.
>>>>
>>>> On 11/5/24 14:07, Schimpe, Christina wrote:
>>>>> Hi Luis,
>>>>>
>>>>> Thanks a lot for the review. I have one questions to your comment,
>>>>> please see
>>>> below.
>>>>>
>>>>>> -----Original Message-----
>>>>>> From: Luis Machado <luis.machado@arm.com>
>>>>>> Sent: Monday, November 4, 2024 12:18 PM
>>>>>> To: Schimpe, Christina <christina.schimpe@intel.com>; gdb-
>>>>>> patches@sourceware.org
>>>>>> Subject: Re: [PATCH v6 1/2] gdb: Make tagged pointer support configurable.
>>>>>>
>>>>>> Hi Christina,
>>>>>>
>>>>>> On 10/28/24 08:46, Schimpe, Christina wrote:
>>>>>>> From: Christina Schimpe <christina.schimpe@intel.com>
>>>>>>>
>>>>>>> The gdbarch function gdbarch_remove_non_address_bits adjusts
>>>>>>> addresses to enable debugging of programs with tagged pointers on
>>>>>>> Linux, for instance for ARM's feature top byte ignore (TBI).
>>>>>>> Once the function is implemented for an architecture, it adjusts
>>>>>>> addresses for memory access, breakpoints and watchpoints.
>>>>>>>
>>>>>>> Linear address masking (LAM) is Intel's (R) implementation of
>>>>>>> tagged pointer support. It requires certain adaptions to GDB's
>>>>>>> tagged pointer support due to the following:
>>>>>>> - LAM supports address tagging for data accesses only. Thus, specifying
>>>>>>> breakpoints on tagged addresses is not a valid use case.
>>>>>>> - In contrast to the implementation for ARM's TBI, the Linux kernel
>> supports
>>>>>>> tagged pointers for memory access.
>>>>>>>
>>>>>>> This patch makes GDB's tagged pointer support configurable such
>>>>>>> that it is possible to enable the address adjustment for a
>>>>>>> specific feature only (e.g memory access, breakpoints or
>>>>>>> watchpoints). This way, one can make sure that addresses are only
>>>>>>> adjusted when necessary. In case of LAM, this avoids unnecessary
>>>>>>> parsing of the /proc/<pid>/status file to get the untag mask.
>>>>>>>
>>>>>>> Reviewed-By: Felix Willgerodt <felix.willgerodt@intel.com>
>>>>>>> ---
>>>>>>> gdb/aarch64-linux-nat.c | 2 +-
>>>>>>> gdb/aarch64-linux-tdep.c | 7 +++--
>>>>>>> gdb/aarch64-tdep.c | 23 ++++++++------
>>>>>>> gdb/aarch64-tdep.h | 6 ++++
>>>>>>> gdb/breakpoint.c | 5 +--
>>>>>>> gdb/gdbarch-gen.c | 66 ++++++++++++++++++++++++++++++++------
>> -
>>>>>>> gdb/gdbarch-gen.h | 49 ++++++++++++++++++++++-------
>>>>>>> gdb/gdbarch_components.py | 53 ++++++++++++++++++++++++++-----
>>>>>>> gdb/loongarch-linux-nat.c | 2 +-
>>>>>>> gdb/target.c | 3 +-
>>>>>>> 10 files changed, 169 insertions(+), 47 deletions(-)
>>>>>>>
>>>>>>> diff --git a/gdb/aarch64-linux-nat.c b/gdb/aarch64-linux-nat.c
>>>>>>> index
>>>>>>> 0fa5bee500b..48ab765d880 100644
>>>>>>> --- a/gdb/aarch64-linux-nat.c
>>>>>>> +++ b/gdb/aarch64-linux-nat.c
>>>>>>> @@ -943,7 +943,7 @@ aarch64_linux_nat_target::stopped_data_address
>>>>>> (CORE_ADDR *addr_p)
>>>>>>> kernel can potentially be tagged addresses. */
>>>>>>> struct gdbarch *gdbarch = thread_architecture (inferior_ptid);
>>>>>>> const CORE_ADDR addr_trap
>>>>>>> - = gdbarch_remove_non_address_bits (gdbarch, (CORE_ADDR)
>>>>>> siginfo.si_addr);
>>>>>>> + = aarch64_remove_non_address_bits (gdbarch, (CORE_ADDR)
>>>>>>> + siginfo.si_addr);
>>>>>>>
>>>>>>> /* Check if the address matches any watched address. */
>>>>>>> state = aarch64_get_debug_reg_state (inferior_ptid.pid ());
>>>>>>> diff --git a/gdb/aarch64-linux-tdep.c b/gdb/aarch64-linux-tdep.c
>>>>>>> index
>>>>>>> c608a84bc71..61c3be8b6f0 100644
>>>>>>> --- a/gdb/aarch64-linux-tdep.c
>>>>>>> +++ b/gdb/aarch64-linux-tdep.c
>>>>>>> @@ -2433,7 +2433,7 @@ static bool
>>>>>>> aarch64_linux_tagged_address_p (struct gdbarch *gdbarch,
>>>>>>> CORE_ADDR
>>>>>>> address) {
>>>>>>> /* Remove the top byte for the memory range check. */
>>>>>>> - address = gdbarch_remove_non_address_bits (gdbarch, address);
>>>>>>> + address = aarch64_remove_non_address_bits (gdbarch, address);
>>>>>>>
>>>>>>> /* Check if the page that contains ADDRESS is mapped with PROT_MTE.
>> */
>>>>>>> if (!linux_address_in_memtag_page (address)) @@ -2491,8 +2491,9
>>>>>>> @@ aarch64_linux_report_signal_info (struct gdbarch *gdbarch,
>>>>>>> uiout->text ("\n");
>>>>>>>
>>>>>>> std::optional<CORE_ADDR> atag
>>>>>>> - = aarch64_mte_get_atag (gdbarch_remove_non_address_bits (gdbarch,
>>>>>>> - fault_addr));
>>>>>>> + = aarch64_mte_get_atag (
>>>>>>> + aarch64_remove_non_address_bits (gdbarch, fault_addr));
>>>>>>> +
>>>>>>> gdb_byte ltag = aarch64_mte_get_ltag (fault_addr);
>>>>>>>
>>>>>>> if (!atag.has_value ())
>>>>>>> diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c index
>>>>>>> 8a2a9b1e23c..91fec7879ed 100644
>>>>>>> --- a/gdb/aarch64-tdep.c
>>>>>>> +++ b/gdb/aarch64-tdep.c
>>>>>>> @@ -4121,7 +4121,7 @@ aarch64_memtag_matches_p (struct gdbarch
>>>>>>> *gdbarch,
>>>>>>>
>>>>>>> /* Fetch the allocation tag for ADDRESS. */
>>>>>>> std::optional<CORE_ADDR> atag
>>>>>>> - = aarch64_mte_get_atag (gdbarch_remove_non_address_bits
>> (gdbarch,
>>>>>> addr));
>>>>>>> + = aarch64_mte_get_atag (aarch64_remove_non_address_bits
>>>>>>> + (gdbarch, addr));
>>>>>>>
>>>>>>> if (!atag.has_value ())
>>>>>>> return true;
>>>>>>> @@ -4160,7 +4160,7 @@ aarch64_set_memtags (struct gdbarch
>>>>>>> *gdbarch,
>>>>>> struct value *address,
>>>>>>> else
>>>>>>> {
>>>>>>> /* Remove the top byte. */
>>>>>>> - addr = gdbarch_remove_non_address_bits (gdbarch, addr);
>>>>>>> + addr = aarch64_remove_non_address_bits (gdbarch, addr);
>>>>>>>
>>>>>>> /* With G being the number of tag granules and N the number of tags
>>>>>>> passed in, we can have the following cases:
>>>>>>> @@ -4209,7 +4209,7 @@ aarch64_get_memtag (struct gdbarch
>> *gdbarch,
>>>>>> struct value *address,
>>>>>>> else
>>>>>>> {
>>>>>>> /* Remove the top byte. */
>>>>>>> - addr = gdbarch_remove_non_address_bits (gdbarch, addr);
>>>>>>> + addr = aarch64_remove_non_address_bits (gdbarch, addr);
>>>>>>> std::optional<CORE_ADDR> atag = aarch64_mte_get_atag
>>>>>>> (addr);
>>>>>>>
>>>>>>> if (!atag.has_value ())
>>>>>>> @@ -4236,10 +4236,9 @@ aarch64_memtag_to_string (struct gdbarch
>>>>>> *gdbarch, struct value *tag_value)
>>>>>>> return string_printf ("0x%s", phex_nz (tag, sizeof (tag))); }
>>>>>>>
>>>>>>> -/* AArch64 implementation of the remove_non_address_bits gdbarch
>> hook.
>>>>>> Remove
>>>>>>> - non address bits from a pointer value. */
>>>>>>> +/* See aarch64-tdep.h. */
>>>>>>>
>>>>>>> -static CORE_ADDR
>>>>>>> +CORE_ADDR
>>>>>>> aarch64_remove_non_address_bits (struct gdbarch *gdbarch,
>>>>>>> CORE_ADDR
>>>>>>> pointer) {
>>>>>>> /* By default, we assume TBI and discard the top 8 bits plus
>>>>>>> the VA range @@ -4750,9 +4749,15 @@ aarch64_gdbarch_init (struct
>>>>>>> gdbarch_info
>>>>>> info, struct gdbarch_list *arches)
>>>>>>> tdep->ra_sign_state_regnum = ra_sign_state_offset + num_regs;
>>>>>>>
>>>>>>> /* Architecture hook to remove bits of a pointer that are not part of the
>>>>>>> - address, like memory tags (MTE) and pointer authentication signatures.
>>>> */
>>>>>>> - set_gdbarch_remove_non_address_bits (gdbarch,
>>>>>>> - aarch64_remove_non_address_bits);
>>>>>>> + address, like memory tags (MTE) and pointer authentication
>> signatures.
>>>>>>> + Configure address adjustment for watch-, breakpoints and
>>>>>>> + memory
>>>>>>
>>>>>> s/watch-/watchpoints
>>>>>
>>>>> Fill fix, thanks.
>>>>>
>>>>>>> + transfer. */
>>>>>>> + set_gdbarch_remove_non_address_bits_watchpoint
>>>>>>> + (gdbarch, aarch64_remove_non_address_bits);
>>>>>>> + set_gdbarch_remove_non_address_bits_breakpoint
>>>>>>> + (gdbarch, aarch64_remove_non_address_bits);
>>>>>>> + set_gdbarch_remove_non_address_bits_memory
>>>>>>> + (gdbarch, aarch64_remove_non_address_bits);
>>>>>>>
>>>>>>> /* SME pseudo-registers. */
>>>>>>> if (tdep->has_sme ())
>>>>>>> diff --git a/gdb/aarch64-tdep.h b/gdb/aarch64-tdep.h index
>>>>>>> 50166fb4f24..13ea37de7a3 100644
>>>>>>> --- a/gdb/aarch64-tdep.h
>>>>>>> +++ b/gdb/aarch64-tdep.h
>>>>>>> @@ -205,4 +205,10 @@ bool aarch64_displaced_step_hw_singlestep
>>>>>>> (struct gdbarch *gdbarch);
>>>>>>>
>>>>>>> std::optional<CORE_ADDR> aarch64_mte_get_atag (CORE_ADDR
>>>>>>> address);
>>>>>>>
>>>>>>> +/* AArch64 implementation of the remove_non_address_bits gdbarch
>>>> hooks.
>>>>>>> + Remove non address bits from a pointer value. */
>>>>>>> +
>>>>>>> +CORE_ADDR aarch64_remove_non_address_bits (struct gdbarch
>> *gdbarch,
>>>>>>> + CORE_ADDR pointer);
>>>>>>> +
>>>>>>> #endif /* aarch64-tdep.h */
>>>>>>> diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c index
>>>>>>> b7e4f5d0a45..9983e905e1b 100644
>>>>>>> --- a/gdb/breakpoint.c
>>>>>>> +++ b/gdb/breakpoint.c
>>>>>>> @@ -2313,7 +2313,8 @@ update_watchpoint (struct watchpoint *b,
>>>>>>> bool
>>>>>> reparse)
>>>>>>> loc->gdbarch = v->type ()->arch ();
>>>>>>> loc->pspace = wp_pspace;
>>>>>>> loc->address
>>>>>>> - = gdbarch_remove_non_address_bits (loc->gdbarch, addr);
>>>>>>> + = gdbarch_remove_non_address_bits_watchpoint (loc-
>>>>>>> gdbarch,
>>>>>>> + addr);
>>>>>>> b->add_location (*loc);
>>>>>>>
>>>>>>> if (bitsize != 0)
>>>>>>> @@ -7538,7 +7539,7 @@ adjust_breakpoint_address (struct gdbarch
>>>>>> *gdbarch,
>>>>>>> }
>>>>>>>
>>>>>>> adjusted_bpaddr
>>>>>>> - = gdbarch_remove_non_address_bits (gdbarch, adjusted_bpaddr);
>>>>>>> + = gdbarch_remove_non_address_bits_breakpoint (gdbarch,
>>>>>>> +adjusted_bpaddr);
>>>>>>>
>>>>>>> /* An adjusted breakpoint address can significantly alter
>>>>>>> a user's expectations. Print a warning if an adjustment diff
>>>>>>> --git a/gdb/gdbarch-gen.c b/gdb/gdbarch-gen.c index
>>>>>>> 0d00cd7c993..d05c7a3cbdf
>>>>>>> 100644
>>>>>>> --- a/gdb/gdbarch-gen.c
>>>>>>> +++ b/gdb/gdbarch-gen.c
>>>>>>> @@ -143,7 +143,9 @@ struct gdbarch
>>>>>>> int frame_red_zone_size = 0;
>>>>>>> gdbarch_convert_from_func_ptr_addr_ftype
>>>>>>> *convert_from_func_ptr_addr =
>>>>>> convert_from_func_ptr_addr_identity;
>>>>>>> gdbarch_addr_bits_remove_ftype *addr_bits_remove =
>>>>>>> core_addr_identity;
>>>>>>> - gdbarch_remove_non_address_bits_ftype *remove_non_address_bits
>>>>>>> = default_remove_non_address_bits;
>>>>>>> + gdbarch_remove_non_address_bits_watchpoint_ftype
>>>>>>> + *remove_non_address_bits_watchpoint =
>>>>>>> + default_remove_non_address_bits;
>>>>>>> + gdbarch_remove_non_address_bits_breakpoint_ftype
>>>>>>> + *remove_non_address_bits_breakpoint =
>>>>>>> + default_remove_non_address_bits;
>>>>>>> + gdbarch_remove_non_address_bits_memory_ftype
>>>>>>> + *remove_non_address_bits_memory =
>>>>>>> + default_remove_non_address_bits;
>>>>>>> gdbarch_memtag_to_string_ftype *memtag_to_string =
>>>>>> default_memtag_to_string;
>>>>>>> gdbarch_tagged_address_p_ftype *tagged_address_p =
>>>>>> default_tagged_address_p;
>>>>>>> gdbarch_memtag_matches_p_ftype *memtag_matches_p =
>>>>>>> default_memtag_matches_p; @@ -407,7 +409,9 @@ verify_gdbarch
>>>>>>> (struct
>>>>>> gdbarch *gdbarch)
>>>>>>> /* Skip verify of frame_red_zone_size, invalid_p == 0. */
>>>>>>> /* Skip verify of convert_from_func_ptr_addr, invalid_p == 0. */
>>>>>>> /* Skip verify of addr_bits_remove, invalid_p == 0. */
>>>>>>> - /* Skip verify of remove_non_address_bits, invalid_p == 0. */
>>>>>>> + /* Skip verify of remove_non_address_bits_watchpoint, invalid_p
>>>>>>> + == 0. */
>>>>>>> + /* Skip verify of remove_non_address_bits_breakpoint, invalid_p
>>>>>>> + == 0. */
>>>>>>> + /* Skip verify of remove_non_address_bits_memory, invalid_p == 0.
>>>>>>> + */
>>>>>>> /* Skip verify of memtag_to_string, invalid_p == 0. */
>>>>>>> /* Skip verify of tagged_address_p, invalid_p == 0. */
>>>>>>> /* Skip verify of memtag_matches_p, invalid_p == 0. */ @@
>>>>>>> -910,8
>>>>>>> +914,14 @@ gdbarch_dump (struct gdbarch *gdbarch, struct ui_file
>>>>>>> +*file)
>>>>>>> "gdbarch_dump: addr_bits_remove = <%s>\n",
>>>>>>> host_address_to_string (gdbarch->addr_bits_remove));
>>>>>>> gdb_printf (file,
>>>>>>> - "gdbarch_dump: remove_non_address_bits = <%s>\n",
>>>>>>> - host_address_to_string (gdbarch->remove_non_address_bits));
>>>>>>> + "gdbarch_dump: remove_non_address_bits_watchpoint = <%s>\n",
>>>>>>> + host_address_to_string
>>>>>>> +(gdbarch->remove_non_address_bits_watchpoint));
>>>>>>> + gdb_printf (file,
>>>>>>> + "gdbarch_dump: remove_non_address_bits_breakpoint = <%s>\n",
>>>>>>> + host_address_to_string
>>>>>>> +(gdbarch->remove_non_address_bits_breakpoint));
>>>>>>> + gdb_printf (file,
>>>>>>> + "gdbarch_dump: remove_non_address_bits_memory = <%s>\n",
>>>>>>> + host_address_to_string
>>>>>>> +(gdbarch->remove_non_address_bits_memory));
>>>>>>> gdb_printf (file,
>>>>>>> "gdbarch_dump: memtag_to_string = <%s>\n",
>>>>>>> host_address_to_string (gdbarch->memtag_to_string)); @@
>>>>>>> -3198,20 +3208,54 @@ set_gdbarch_addr_bits_remove (struct gdbarch
>>>>>>> *gdbarch, }
>>>>>>>
>>>>>>> CORE_ADDR
>>>>>>> -gdbarch_remove_non_address_bits (struct gdbarch *gdbarch,
>>>>>>> CORE_ADDR
>>>>>>> pointer)
>>>>>>> +gdbarch_remove_non_address_bits_watchpoint (struct gdbarch
>>>>>>> +*gdbarch, CORE_ADDR pointer) {
>>>>>>> + gdb_assert (gdbarch != NULL);
>>>>>>> + gdb_assert (gdbarch->remove_non_address_bits_watchpoint !=
>>>>>>> +NULL);
>>>>>>> + if (gdbarch_debug >= 2)
>>>>>>> + gdb_printf (gdb_stdlog,
>>>>>>> +"gdbarch_remove_non_address_bits_watchpoint called\n");
>>>>>>> + return gdbarch->remove_non_address_bits_watchpoint (gdbarch,
>>>>>>> +pointer); }
>>>>>>> +
>>>>>>> +void
>>>>>>> +set_gdbarch_remove_non_address_bits_watchpoint (struct gdbarch
>>>>>> *gdbarch,
>>>>>>> +
>>>>>> gdbarch_remove_non_address_bits_watchpoint_ftype
>>>>>>> +remove_non_address_bits_watchpoint)
>>>>>>> +{
>>>>>>> + gdbarch->remove_non_address_bits_watchpoint =
>>>>>>> +remove_non_address_bits_watchpoint;
>>>>>>> +}
>>>>>>> +
>>>>>>> +CORE_ADDR
>>>>>>> +gdbarch_remove_non_address_bits_breakpoint (struct gdbarch
>>>>>>> +*gdbarch, CORE_ADDR pointer) {
>>>>>>> + gdb_assert (gdbarch != NULL);
>>>>>>> + gdb_assert (gdbarch->remove_non_address_bits_breakpoint !=
>>>>>>> +NULL);
>>>>>>> + if (gdbarch_debug >= 2)
>>>>>>> + gdb_printf (gdb_stdlog,
>>>>>>> +"gdbarch_remove_non_address_bits_breakpoint called\n");
>>>>>>> + return gdbarch->remove_non_address_bits_breakpoint (gdbarch,
>>>>>>> +pointer); }
>>>>>>> +
>>>>>>> +void
>>>>>>> +set_gdbarch_remove_non_address_bits_breakpoint (struct gdbarch
>>>>>>> +*gdbarch,
>>>>>>> +
>>>>>> gdbarch_remove_non_address_bits_breakpoint_ftype
>>>>>>> +remove_non_address_bits_breakpoint)
>>>>>>> +{
>>>>>>> + gdbarch->remove_non_address_bits_breakpoint =
>>>>>>> +remove_non_address_bits_breakpoint;
>>>>>>> +}
>>>>>>> +
>>>>>>> +CORE_ADDR
>>>>>>> +gdbarch_remove_non_address_bits_memory (struct gdbarch *gdbarch,
>>>>>>> +CORE_ADDR pointer)
>>>>>>> {
>>>>>>> gdb_assert (gdbarch != NULL);
>>>>>>> - gdb_assert (gdbarch->remove_non_address_bits != NULL);
>>>>>>> + gdb_assert (gdbarch->remove_non_address_bits_memory != NULL);
>>>>>>> if (gdbarch_debug >= 2)
>>>>>>> - gdb_printf (gdb_stdlog, "gdbarch_remove_non_address_bits called\n");
>>>>>>> - return gdbarch->remove_non_address_bits (gdbarch, pointer);
>>>>>>> + gdb_printf (gdb_stdlog,
>>>>>>> + "gdbarch_remove_non_address_bits_memory
>>>>>>> + called\n"); return gdbarch->remove_non_address_bits_memory
>>>>>>> + (gdbarch, pointer);
>>>>>>> }
>>>>>>>
>>>>>>> void
>>>>>>> -set_gdbarch_remove_non_address_bits (struct gdbarch *gdbarch,
>>>>>>> - gdbarch_remove_non_address_bits_ftype
>>>>>> remove_non_address_bits)
>>>>>>> +set_gdbarch_remove_non_address_bits_memory (struct gdbarch
>>>>>>> +*gdbarch,
>>>>>>> +
>>>>>> gdbarch_remove_non_address_bits_memory_ftype
>>>>>>> +remove_non_address_bits_memory)
>>>>>>> {
>>>>>>> - gdbarch->remove_non_address_bits = remove_non_address_bits;
>>>>>>> + gdbarch->remove_non_address_bits_memory =
>>>>>>> + remove_non_address_bits_memory;
>>>>>>> }
>>>>>>>
>>>>>>> std::string
>>>>>>> diff --git a/gdb/gdbarch-gen.h b/gdb/gdbarch-gen.h index
>>>>>>> b982fd7cd09..9fda85f860f 100644
>>>>>>> --- a/gdb/gdbarch-gen.h
>>>>>>> +++ b/gdb/gdbarch-gen.h
>>>>>>> @@ -684,19 +684,46 @@ extern CORE_ADDR gdbarch_addr_bits_remove
>>>>>>> (struct gdbarch *gdbarch, CORE_ADDR ad extern void
>>>>>>> set_gdbarch_addr_bits_remove (struct gdbarch *gdbarch,
>>>>>>> gdbarch_addr_bits_remove_ftype *addr_bits_remove);
>>>>>>>
>>>>>>> /* On some architectures, not all bits of a pointer are significant.
>>>>>>> - On AArch64, for example, the top bits of a pointer may carry a "tag",
>> which
>>>>>>> - can be ignored by the kernel and the hardware. The "tag" can be
>> regarded
>>>> as
>>>>>>> - additional data associated with the pointer, but it is not part of the
>>>> address.
>>>>>>> + On AArch64 and amd64, for example, the top bits of a pointer may carry
>> a
>>>>>>> + "tag", which can be ignored by the kernel and the hardware.
>>>>>>> + The "tag" can
>>>>>> be
>>>>>>> + regarded as additional data associated with the pointer, but it is not
>> part
>>>>>>> + of the address.
>>>>>>>
>>>>>>> Given a pointer for the architecture, this hook removes all the
>>>>>>> - non-significant bits and sign-extends things as needed. It gets used to
>>>>>> remove
>>>>>>> - non-address bits from data pointers (for example, removing the AArch64
>>>> MTE
>>>>>> tag
>>>>>>> - bits from a pointer) and from code pointers (removing the AArch64 PAC
>>>>>> signature
>>>>>>> - from a pointer containing the return address). */
>>>>>>> -
>>>>>>> -typedef CORE_ADDR (gdbarch_remove_non_address_bits_ftype) (struct
>>>>>>> gdbarch *gdbarch, CORE_ADDR pointer); -extern CORE_ADDR
>>>>>>> gdbarch_remove_non_address_bits (struct gdbarch *gdbarch,
>>>>>>> CORE_ADDR pointer); -extern void
>>>>>>> set_gdbarch_remove_non_address_bits (struct gdbarch *gdbarch,
>>>>>>> gdbarch_remove_non_address_bits_ftype
>>>>>>> *remove_non_address_bits);
>>>>>>> + non-significant bits and sign-extends things as needed. It gets used to
>>>>>>> + remove non-address bits from pointers used for watchpoints. */
>>>>>>> +
>>>>>>> +typedef CORE_ADDR
>>>>>>> +(gdbarch_remove_non_address_bits_watchpoint_ftype)
>>>>>>> +(struct gdbarch *gdbarch, CORE_ADDR pointer); extern CORE_ADDR
>>>>>>> +gdbarch_remove_non_address_bits_watchpoint (struct gdbarch
>>>>>>> +*gdbarch, CORE_ADDR pointer); extern void
>>>>>>> +set_gdbarch_remove_non_address_bits_watchpoint (struct gdbarch
>>>>>>> +*gdbarch, gdbarch_remove_non_address_bits_watchpoint_ftype
>>>>>>> +*remove_non_address_bits_watchpoint);
>>>>>>> +
>>>>>>> +/* On some architectures, not all bits of a pointer are significant.
>>>>>>> + On AArch64 and amd64, for example, the top bits of a pointer may carry
>> a
>>>>>>> + "tag", which can be ignored by the kernel and the hardware.
>>>>>>> +The "tag" can
>>>>>> be
>>>>>>> + regarded as additional data associated with the pointer, but it is not
>> part
>>>>>>> + of the address.
>>>>>>> +
>>>>>>> + Given a pointer for the architecture, this hook removes all the
>>>>>>> + non-significant bits and sign-extends things as needed. It gets used to
>>>>>>> + remove non-address bits from pointers used for breakpoints. */
>>>>>>> +
>>>>>>> +typedef CORE_ADDR
>>>>>>> +(gdbarch_remove_non_address_bits_breakpoint_ftype)
>>>>>>> +(struct gdbarch *gdbarch, CORE_ADDR pointer); extern CORE_ADDR
>>>>>>> +gdbarch_remove_non_address_bits_breakpoint (struct gdbarch
>>>>>>> +*gdbarch, CORE_ADDR pointer); extern void
>>>>>>> +set_gdbarch_remove_non_address_bits_breakpoint (struct gdbarch
>>>>>>> +*gdbarch, gdbarch_remove_non_address_bits_breakpoint_ftype
>>>>>>> +*remove_non_address_bits_breakpoint);
>>>>>>> +
>>>>>>> +/* On some architectures, not all bits of a pointer are significant.
>>>>>>> + On AArch64 and amd64, for example, the top bits of a pointer may carry
>> a
>>>>>>> + "tag", which can be ignored by the kernel and the hardware.
>>>>>>> +The "tag" can
>>>>>> be
>>>>>>> + regarded as additional data associated with the pointer, but it is not
>> part
>>>>>>> + of the address.
>>>>>>> +
>>>>>>> + Given a pointer for the architecture, this hook removes all the
>>>>>>> + non-significant bits and sign-extends things as needed. It gets used to
>>>>>>> + remove non-address bits from any pointer used to access memory.
>>>>>>> + */
>>>>>>> +
>>>>>>> +typedef CORE_ADDR
>> (gdbarch_remove_non_address_bits_memory_ftype)
>>>>>>> +(struct gdbarch *gdbarch, CORE_ADDR pointer); extern CORE_ADDR
>>>>>>> +gdbarch_remove_non_address_bits_memory (struct gdbarch *gdbarch,
>>>>>>> +CORE_ADDR pointer); extern void
>>>>>>> +set_gdbarch_remove_non_address_bits_memory (struct gdbarch
>>>>>>> +*gdbarch, gdbarch_remove_non_address_bits_memory_ftype
>>>>>>> +*remove_non_address_bits_memory);
>>>>>>>
>>>>>>> /* Return a string representation of the memory tag TAG. */
>>>>>>>
>>>>>>> diff --git a/gdb/gdbarch_components.py b/gdb/gdbarch_components.py
>>>>>>> index 4006380076d..cc7c6d8677b 100644
>>>>>>> --- a/gdb/gdbarch_components.py
>>>>>>> +++ b/gdb/gdbarch_components.py
>>>>>>> @@ -1232,18 +1232,55 @@ possible it should be in TARGET_READ_PC
>>>>>> instead).
>>>>>>> Method(
>>>>>>> comment="""
>>>>>>> On some architectures, not all bits of a pointer are significant.
>>>>>>> -On AArch64, for example, the top bits of a pointer may carry a
>>>>>>> "tag", which -can be ignored by the kernel and the hardware. The
>>>>>>> "tag" can be regarded as -additional data associated with the
>>>>>>> pointer, but it is not part of
>>>>>> the address.
>>>>>>> +On AArch64 and amd64, for example, the top bits of a pointer may
>>>>>>> +carry a "tag", which can be ignored by the kernel and the hardware.
>>>>>>> +The "tag" can be regarded as additional data associated with the
>>>>>>> +pointer, but it is not part of the address.
>>>>>>>
>>>>>>> Given a pointer for the architecture, this hook removes all the
>>>>>>> -non-significant bits and sign-extends things as needed. It gets
>>>>>>> used to remove -non-address bits from data pointers (for example,
>>>>>>> removing the AArch64 MTE tag -bits from a pointer) and from code
>>>>>>> pointers (removing the AArch64 PAC signature -from a pointer
>>>>>>> containing the return
>>>>>> address).
>>>>>>> +non-significant bits and sign-extends things as needed. It gets
>>>>>>> +used to remove non-address bits from pointers used for watchpoints.
>>>>>>> """,
>>>>>>> type="CORE_ADDR",
>>>>>>> - name="remove_non_address_bits",
>>>>>>> + name="remove_non_address_bits_watchpoint",
>>>>>>> + params=[("CORE_ADDR", "pointer")],
>>>>>>> + predefault="default_remove_non_address_bits",
>>>>>>> + invalid=False,
>>>>>>> +)
>>>>>>> +
>>>>>>> +Method(
>>>>>>> + comment="""
>>>>>>> +On some architectures, not all bits of a pointer are significant.
>>>>>>> +On AArch64 and amd64, for example, the top bits of a pointer may
>>>>>>> +carry a "tag", which can be ignored by the kernel and the hardware.
>>>>>>> +The "tag" can be regarded as additional data associated with the
>>>>>>> +pointer, but it is not part of the address.
>>>>>>> +
>>>>>>> +Given a pointer for the architecture, this hook removes all the
>>>>>>> +non-significant bits and sign-extends things as needed. It gets
>>>>>>> +used to remove non-address bits from pointers used for breakpoints.
>>>>>>> +""",
>>>>>>> + type="CORE_ADDR",
>>>>>>> + name="remove_non_address_bits_breakpoint",
>>>>>>> + params=[("CORE_ADDR", "pointer")],
>>>>>>> + predefault="default_remove_non_address_bits",
>>>>>>> + invalid=False,
>>>>>>> +)
>>>>>>> +
>>>>>>> +Method(
>>>>>>> + comment="""
>>>>>>> +On some architectures, not all bits of a pointer are significant.
>>>>>>> +On AArch64 and amd64, for example, the top bits of a pointer may
>>>>>>> +carry a "tag", which can be ignored by the kernel and the hardware.
>>>>>>> +The "tag" can be regarded as additional data associated with the
>>>>>>> +pointer, but it is not part of the address.
>>>>>>> +
>>>>>>> +Given a pointer for the architecture, this hook removes all the
>>>>>>> +non-significant bits and sign-extends things as needed. It gets
>>>>>>> +used to remove non-address bits from any pointer used to access
>> memory.
>>>>>>> +""",
>>>>>>> + type="CORE_ADDR",
>>>>>>> + name="remove_non_address_bits_memory",
>>>>>>> params=[("CORE_ADDR", "pointer")],
>>>>>>> predefault="default_remove_non_address_bits",
>>>>>>> invalid=False,
>>>>>>> diff --git a/gdb/loongarch-linux-nat.c b/gdb/loongarch-linux-nat.c
>>>>>>> index bc9927dd751..dc4a019614a 100644
>>>>>>> --- a/gdb/loongarch-linux-nat.c
>>>>>>> +++ b/gdb/loongarch-linux-nat.c
>>>>>>> @@ -613,7 +613,7 @@
>>>>>>> loongarch_linux_nat_target::stopped_data_address
>>>>>> (CORE_ADDR *addr_p)
>>>>>>> kernel can potentially be tagged addresses. */
>>>>>>> struct gdbarch *gdbarch = thread_architecture (inferior_ptid);
>>>>>>> const CORE_ADDR addr_trap
>>>>>>> - = gdbarch_remove_non_address_bits (gdbarch, (CORE_ADDR)
>>>>>> siginfo.si_addr);
>>>>>>> + = aarch64_remove_non_address_bits (gdbarch, (CORE_ADDR)
>>>>>>> + siginfo.si_addr);
>>>>>>>
>>>>>>> /* Check if the address matches any watched address. */
>>>>>>> state = loongarch_get_debug_reg_state (inferior_ptid.pid ());
>>>>>>
>>>>>> I think the loongarch-linux-nat.c change is spurious. Could you
>>>>>> please address that?
>>>>>
>>>>> Why is it spurious? What do you mean exactly?
>>>>
>>>> The intention behind this change isn't clear to me, but the Loongson
>>>> native Linux layer using a AArch64 architecture function does not make sense.
>>>>
>>>> I haven't built a LoongArch native Linux target, but I'd guess that
>>>> it will run into a build error with this change, if built for LoongArch only.
>>>>
>>>> The right approach, in my mind, is to drop this change, but you have
>>>> to touch this code due to your changes. It begs the question, why is
>>>> the LoongArch native code calling gdbarch_remove_non_address_bits
>>>> here without even registering a function for the gdbarch hook to call?
>>>
>>> Right, I agree.
>>>
>>>> Without this hook, we'll invoke the dummy implementation in gdb/arch-
>>>> utils.c:default_remove_non_address_bits, and that just returns the
>>>> unmodified pointer.
>>>
>>> True, that's probably why nobody noticed before.
>>>
>>>> This is a question for the LoongArch maintainer (cc-ed). If we don't
>>>> hear back, we should probably change the LoongArch code to not call
>>>> gdbarch_remove_non_address_bits. I think that was the original
>>>> intention, but there might've been a copy/paste error somewhere.
>>>
>>> Ok. Let's wait a bit. Thanks for the detailed feedback.
>>
>> Alternatively, if you could replace, in the LoongArch code,
>> gdbarch_remove_non_address_bits with one of the three new hooks, that should
>> work as well. I think even cleaner would be to just drop the hook for Loongarch
>> and assign siginfo.si_addr directly to addr_trap in the code.
>
> I am also in favour of your second suggestion to drop the hook here.
> In that case, it should be separate patch I think.
> I could post it independently of this series and quickly merge before posting a v7 of my series.
Yes, a separate one would be nice, please.
>
> LoongArch doesn't supported tagged addresses, does it? If it's not supported,
> I would suggest to fix it as follows:
>
> diff --git a/gdb/loongarch-linux-nat.c b/gdb/loongarch-linux-nat.c
> index dc4a019614a..fd3581bbd30 100644
> --- a/gdb/loongarch-linux-nat.c
> +++ b/gdb/loongarch-linux-nat.c
> @@ -608,17 +608,11 @@ loongarch_linux_nat_target::stopped_data_address (CORE_ADDR *addr_p)
> if (siginfo.si_signo != SIGTRAP || (siginfo.si_code & 0xffff) != TRAP_HWBKPT)
> return false;
>
> - /* Make sure to ignore the top byte, otherwise we may not recognize a
> - hardware watchpoint hit. The stopped data addresses coming from the
> - kernel can potentially be tagged addresses. */
> - struct gdbarch *gdbarch = thread_architecture (inferior_ptid);
> - const CORE_ADDR addr_trap
> - = aarch64_remove_non_address_bits (gdbarch, (CORE_ADDR) siginfo.si_addr);
> -
> /* Check if the address matches any watched address. */
> state = loongarch_get_debug_reg_state (inferior_ptid.pid ());
>
> - return loongarch_stopped_data_address (state, addr_trap, addr_p);
> + return
> + loongarch_stopped_data_address (state, (CORE_ADDR) siginfo.si_addr, addr_p);
>
> Does that make sense to you?
>
It does. Thanks!
> -----Original Message-----
> From: Luis Machado <luis.machado@arm.com>
> Sent: Tuesday, November 5, 2024 4:14 PM
> To: Schimpe, Christina <christina.schimpe@intel.com>; gdb-
> patches@sourceware.org
> Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
> Subject: Re: [PATCH v6 1/2] gdb: Make tagged pointer support configurable.
>
> On 11/5/24 15:09, Schimpe, Christina wrote:
> >> -----Original Message-----
> >> From: Luis Machado <luis.machado@arm.com>
> >> Sent: Tuesday, November 5, 2024 3:51 PM
> >> To: Schimpe, Christina <christina.schimpe@intel.com>; gdb-
> >> patches@sourceware.org
> >> Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
> >> Subject: Re: [PATCH v6 1/2] gdb: Make tagged pointer support configurable.
> >>
> >> On 11/5/24 14:40, Schimpe, Christina wrote:
> >>>> -----Original Message-----
> >>>> From: Luis Machado <luis.machado@arm.com>
> >>>> Sent: Tuesday, November 5, 2024 3:22 PM
> >>>> To: Schimpe, Christina <christina.schimpe@intel.com>; gdb-
> >>>> patches@sourceware.org
> >>>> Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
> >>>> Subject: Re: [PATCH v6 1/2] gdb: Make tagged pointer support configurable.
> >>>>
> >>>> On 11/5/24 14:07, Schimpe, Christina wrote:
> >>>>> Hi Luis,
> >>>>>
> >>>>> Thanks a lot for the review. I have one questions to your comment,
> >>>>> please see
> >>>> below.
> >>>>>
> >>>>>> -----Original Message-----
> >>>>>> From: Luis Machado <luis.machado@arm.com>
> >>>>>> Sent: Monday, November 4, 2024 12:18 PM
> >>>>>> To: Schimpe, Christina <christina.schimpe@intel.com>; gdb-
> >>>>>> patches@sourceware.org
> >>>>>> Subject: Re: [PATCH v6 1/2] gdb: Make tagged pointer support
> configurable.
> >>>>>>
> >>>>>> Hi Christina,
> >>>>>>
> >>>>>> On 10/28/24 08:46, Schimpe, Christina wrote:
> >>>>>>> From: Christina Schimpe <christina.schimpe@intel.com>
> >>>>>>>
> >>>>>>> The gdbarch function gdbarch_remove_non_address_bits adjusts
> >>>>>>> addresses to enable debugging of programs with tagged pointers
> >>>>>>> on Linux, for instance for ARM's feature top byte ignore (TBI).
> >>>>>>> Once the function is implemented for an architecture, it adjusts
> >>>>>>> addresses for memory access, breakpoints and watchpoints.
> >>>>>>>
> >>>>>>> Linear address masking (LAM) is Intel's (R) implementation of
> >>>>>>> tagged pointer support. It requires certain adaptions to GDB's
> >>>>>>> tagged pointer support due to the following:
> >>>>>>> - LAM supports address tagging for data accesses only. Thus, specifying
> >>>>>>> breakpoints on tagged addresses is not a valid use case.
> >>>>>>> - In contrast to the implementation for ARM's TBI, the Linux
> >>>>>>> kernel
> >> supports
> >>>>>>> tagged pointers for memory access.
> >>>>>>>
> >>>>>>> This patch makes GDB's tagged pointer support configurable such
> >>>>>>> that it is possible to enable the address adjustment for a
> >>>>>>> specific feature only (e.g memory access, breakpoints or
> >>>>>>> watchpoints). This way, one can make sure that addresses are
> >>>>>>> only adjusted when necessary. In case of LAM, this avoids
> >>>>>>> unnecessary parsing of the /proc/<pid>/status file to get the untag
> mask.
> >>>>>>>
> >>>>>>> Reviewed-By: Felix Willgerodt <felix.willgerodt@intel.com>
> >>>>>>> ---
> >>>>>>> gdb/aarch64-linux-nat.c | 2 +-
> >>>>>>> gdb/aarch64-linux-tdep.c | 7 +++--
> >>>>>>> gdb/aarch64-tdep.c | 23 ++++++++------
> >>>>>>> gdb/aarch64-tdep.h | 6 ++++
> >>>>>>> gdb/breakpoint.c | 5 +--
> >>>>>>> gdb/gdbarch-gen.c | 66 ++++++++++++++++++++++++++++++++---
> ---
> >> -
> >>>>>>> gdb/gdbarch-gen.h | 49 ++++++++++++++++++++++-------
> >>>>>>> gdb/gdbarch_components.py | 53 ++++++++++++++++++++++++++-----
> >>>>>>> gdb/loongarch-linux-nat.c | 2 +-
> >>>>>>> gdb/target.c | 3 +-
> >>>>>>> 10 files changed, 169 insertions(+), 47 deletions(-)
> >>>>>>>
> >>>>>>> diff --git a/gdb/aarch64-linux-nat.c b/gdb/aarch64-linux-nat.c
> >>>>>>> index
> >>>>>>> 0fa5bee500b..48ab765d880 100644
> >>>>>>> --- a/gdb/aarch64-linux-nat.c
> >>>>>>> +++ b/gdb/aarch64-linux-nat.c
> >>>>>>> @@ -943,7 +943,7 @@
> >>>>>>> aarch64_linux_nat_target::stopped_data_address
> >>>>>> (CORE_ADDR *addr_p)
> >>>>>>> kernel can potentially be tagged addresses. */
> >>>>>>> struct gdbarch *gdbarch = thread_architecture (inferior_ptid);
> >>>>>>> const CORE_ADDR addr_trap
> >>>>>>> - = gdbarch_remove_non_address_bits (gdbarch, (CORE_ADDR)
> >>>>>> siginfo.si_addr);
> >>>>>>> + = aarch64_remove_non_address_bits (gdbarch, (CORE_ADDR)
> >>>>>>> + siginfo.si_addr);
> >>>>>>>
> >>>>>>> /* Check if the address matches any watched address. */
> >>>>>>> state = aarch64_get_debug_reg_state (inferior_ptid.pid ());
> >>>>>>> diff --git a/gdb/aarch64-linux-tdep.c b/gdb/aarch64-linux-tdep.c
> >>>>>>> index
> >>>>>>> c608a84bc71..61c3be8b6f0 100644
> >>>>>>> --- a/gdb/aarch64-linux-tdep.c
> >>>>>>> +++ b/gdb/aarch64-linux-tdep.c
> >>>>>>> @@ -2433,7 +2433,7 @@ static bool
> >>>>>>> aarch64_linux_tagged_address_p (struct gdbarch *gdbarch,
> >>>>>>> CORE_ADDR
> >>>>>>> address) {
> >>>>>>> /* Remove the top byte for the memory range check. */
> >>>>>>> - address = gdbarch_remove_non_address_bits (gdbarch, address);
> >>>>>>> + address = aarch64_remove_non_address_bits (gdbarch, address);
> >>>>>>>
> >>>>>>> /* Check if the page that contains ADDRESS is mapped with
> PROT_MTE.
> >> */
> >>>>>>> if (!linux_address_in_memtag_page (address)) @@ -2491,8
> >>>>>>> +2491,9 @@ aarch64_linux_report_signal_info (struct gdbarch
> *gdbarch,
> >>>>>>> uiout->text ("\n");
> >>>>>>>
> >>>>>>> std::optional<CORE_ADDR> atag
> >>>>>>> - = aarch64_mte_get_atag (gdbarch_remove_non_address_bits
> (gdbarch,
> >>>>>>> -
> fault_addr));
> >>>>>>> + = aarch64_mte_get_atag (
> >>>>>>> + aarch64_remove_non_address_bits (gdbarch, fault_addr));
> >>>>>>> +
> >>>>>>> gdb_byte ltag = aarch64_mte_get_ltag (fault_addr);
> >>>>>>>
> >>>>>>> if (!atag.has_value ())
> >>>>>>> diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c index
> >>>>>>> 8a2a9b1e23c..91fec7879ed 100644
> >>>>>>> --- a/gdb/aarch64-tdep.c
> >>>>>>> +++ b/gdb/aarch64-tdep.c
> >>>>>>> @@ -4121,7 +4121,7 @@ aarch64_memtag_matches_p (struct
> gdbarch
> >>>>>>> *gdbarch,
> >>>>>>>
> >>>>>>> /* Fetch the allocation tag for ADDRESS. */
> >>>>>>> std::optional<CORE_ADDR> atag
> >>>>>>> - = aarch64_mte_get_atag (gdbarch_remove_non_address_bits
> >> (gdbarch,
> >>>>>> addr));
> >>>>>>> + = aarch64_mte_get_atag (aarch64_remove_non_address_bits
> >>>>>>> + (gdbarch, addr));
> >>>>>>>
> >>>>>>> if (!atag.has_value ())
> >>>>>>> return true;
> >>>>>>> @@ -4160,7 +4160,7 @@ aarch64_set_memtags (struct gdbarch
> >>>>>>> *gdbarch,
> >>>>>> struct value *address,
> >>>>>>> else
> >>>>>>> {
> >>>>>>> /* Remove the top byte. */
> >>>>>>> - addr = gdbarch_remove_non_address_bits (gdbarch, addr);
> >>>>>>> + addr = aarch64_remove_non_address_bits (gdbarch, addr);
> >>>>>>>
> >>>>>>> /* With G being the number of tag granules and N the number of
> tags
> >>>>>>> passed in, we can have the following cases:
> >>>>>>> @@ -4209,7 +4209,7 @@ aarch64_get_memtag (struct gdbarch
> >> *gdbarch,
> >>>>>> struct value *address,
> >>>>>>> else
> >>>>>>> {
> >>>>>>> /* Remove the top byte. */
> >>>>>>> - addr = gdbarch_remove_non_address_bits (gdbarch, addr);
> >>>>>>> + addr = aarch64_remove_non_address_bits (gdbarch, addr);
> >>>>>>> std::optional<CORE_ADDR> atag = aarch64_mte_get_atag
> >>>>>>> (addr);
> >>>>>>>
> >>>>>>> if (!atag.has_value ())
> >>>>>>> @@ -4236,10 +4236,9 @@ aarch64_memtag_to_string (struct gdbarch
> >>>>>> *gdbarch, struct value *tag_value)
> >>>>>>> return string_printf ("0x%s", phex_nz (tag, sizeof (tag)));
> >>>>>>> }
> >>>>>>>
> >>>>>>> -/* AArch64 implementation of the remove_non_address_bits
> >>>>>>> gdbarch
> >> hook.
> >>>>>> Remove
> >>>>>>> - non address bits from a pointer value. */
> >>>>>>> +/* See aarch64-tdep.h. */
> >>>>>>>
> >>>>>>> -static CORE_ADDR
> >>>>>>> +CORE_ADDR
> >>>>>>> aarch64_remove_non_address_bits (struct gdbarch *gdbarch,
> >>>>>>> CORE_ADDR
> >>>>>>> pointer) {
> >>>>>>> /* By default, we assume TBI and discard the top 8 bits plus
> >>>>>>> the VA range @@ -4750,9 +4749,15 @@ aarch64_gdbarch_init (struct
> >>>>>>> gdbarch_info
> >>>>>> info, struct gdbarch_list *arches)
> >>>>>>> tdep->ra_sign_state_regnum = ra_sign_state_offset +
> >>>>>>> num_regs;
> >>>>>>>
> >>>>>>> /* Architecture hook to remove bits of a pointer that are not part of
> the
> >>>>>>> - address, like memory tags (MTE) and pointer authentication
> signatures.
> >>>> */
> >>>>>>> - set_gdbarch_remove_non_address_bits (gdbarch,
> >>>>>>> -
> aarch64_remove_non_address_bits);
> >>>>>>> + address, like memory tags (MTE) and pointer authentication
> >> signatures.
> >>>>>>> + Configure address adjustment for watch-, breakpoints and
> >>>>>>> + memory
> >>>>>>
> >>>>>> s/watch-/watchpoints
> >>>>>
> >>>>> Fill fix, thanks.
> >>>>>
> >>>>>>> + transfer. */
> >>>>>>> + set_gdbarch_remove_non_address_bits_watchpoint
> >>>>>>> + (gdbarch, aarch64_remove_non_address_bits);
> >>>>>>> + set_gdbarch_remove_non_address_bits_breakpoint
> >>>>>>> + (gdbarch, aarch64_remove_non_address_bits);
> >>>>>>> + set_gdbarch_remove_non_address_bits_memory
> >>>>>>> + (gdbarch, aarch64_remove_non_address_bits);
> >>>>>>>
> >>>>>>> /* SME pseudo-registers. */
> >>>>>>> if (tdep->has_sme ())
> >>>>>>> diff --git a/gdb/aarch64-tdep.h b/gdb/aarch64-tdep.h index
> >>>>>>> 50166fb4f24..13ea37de7a3 100644
> >>>>>>> --- a/gdb/aarch64-tdep.h
> >>>>>>> +++ b/gdb/aarch64-tdep.h
> >>>>>>> @@ -205,4 +205,10 @@ bool aarch64_displaced_step_hw_singlestep
> >>>>>>> (struct gdbarch *gdbarch);
> >>>>>>>
> >>>>>>> std::optional<CORE_ADDR> aarch64_mte_get_atag (CORE_ADDR
> >>>>>>> address);
> >>>>>>>
> >>>>>>> +/* AArch64 implementation of the remove_non_address_bits
> >>>>>>> +gdbarch
> >>>> hooks.
> >>>>>>> + Remove non address bits from a pointer value. */
> >>>>>>> +
> >>>>>>> +CORE_ADDR aarch64_remove_non_address_bits (struct gdbarch
> >> *gdbarch,
> >>>>>>> + CORE_ADDR pointer);
> >>>>>>> +
> >>>>>>> #endif /* aarch64-tdep.h */
> >>>>>>> diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c index
> >>>>>>> b7e4f5d0a45..9983e905e1b 100644
> >>>>>>> --- a/gdb/breakpoint.c
> >>>>>>> +++ b/gdb/breakpoint.c
> >>>>>>> @@ -2313,7 +2313,8 @@ update_watchpoint (struct watchpoint *b,
> >>>>>>> bool
> >>>>>> reparse)
> >>>>>>> loc->gdbarch = v->type ()->arch ();
> >>>>>>> loc->pspace = wp_pspace;
> >>>>>>> loc->address
> >>>>>>> - = gdbarch_remove_non_address_bits (loc->gdbarch,
> addr);
> >>>>>>> + = gdbarch_remove_non_address_bits_watchpoint
> (loc-
> >>>>>>> gdbarch,
> >>>>>>> +
> addr);
> >>>>>>> b->add_location (*loc);
> >>>>>>>
> >>>>>>> if (bitsize != 0)
> >>>>>>> @@ -7538,7 +7539,7 @@ adjust_breakpoint_address (struct gdbarch
> >>>>>> *gdbarch,
> >>>>>>> }
> >>>>>>>
> >>>>>>> adjusted_bpaddr
> >>>>>>> - = gdbarch_remove_non_address_bits (gdbarch,
> adjusted_bpaddr);
> >>>>>>> + = gdbarch_remove_non_address_bits_breakpoint (gdbarch,
> >>>>>>> +adjusted_bpaddr);
> >>>>>>>
> >>>>>>> /* An adjusted breakpoint address can significantly alter
> >>>>>>> a user's expectations. Print a warning if an adjustment diff
> >>>>>>> --git a/gdb/gdbarch-gen.c b/gdb/gdbarch-gen.c index
> >>>>>>> 0d00cd7c993..d05c7a3cbdf
> >>>>>>> 100644
> >>>>>>> --- a/gdb/gdbarch-gen.c
> >>>>>>> +++ b/gdb/gdbarch-gen.c
> >>>>>>> @@ -143,7 +143,9 @@ struct gdbarch
> >>>>>>> int frame_red_zone_size = 0;
> >>>>>>> gdbarch_convert_from_func_ptr_addr_ftype
> >>>>>>> *convert_from_func_ptr_addr =
> >>>>>> convert_from_func_ptr_addr_identity;
> >>>>>>> gdbarch_addr_bits_remove_ftype *addr_bits_remove =
> >>>>>>> core_addr_identity;
> >>>>>>> - gdbarch_remove_non_address_bits_ftype
> >>>>>>> *remove_non_address_bits = default_remove_non_address_bits;
> >>>>>>> + gdbarch_remove_non_address_bits_watchpoint_ftype
> >>>>>>> + *remove_non_address_bits_watchpoint =
> >>>>>>> + default_remove_non_address_bits;
> >>>>>>> + gdbarch_remove_non_address_bits_breakpoint_ftype
> >>>>>>> + *remove_non_address_bits_breakpoint =
> >>>>>>> + default_remove_non_address_bits;
> >>>>>>> + gdbarch_remove_non_address_bits_memory_ftype
> >>>>>>> + *remove_non_address_bits_memory =
> >>>>>>> + default_remove_non_address_bits;
> >>>>>>> gdbarch_memtag_to_string_ftype *memtag_to_string =
> >>>>>> default_memtag_to_string;
> >>>>>>> gdbarch_tagged_address_p_ftype *tagged_address_p =
> >>>>>> default_tagged_address_p;
> >>>>>>> gdbarch_memtag_matches_p_ftype *memtag_matches_p =
> >>>>>>> default_memtag_matches_p; @@ -407,7 +409,9 @@ verify_gdbarch
> >>>>>>> (struct
> >>>>>> gdbarch *gdbarch)
> >>>>>>> /* Skip verify of frame_red_zone_size, invalid_p == 0. */
> >>>>>>> /* Skip verify of convert_from_func_ptr_addr, invalid_p == 0. */
> >>>>>>> /* Skip verify of addr_bits_remove, invalid_p == 0. */
> >>>>>>> - /* Skip verify of remove_non_address_bits, invalid_p == 0.
> >>>>>>> */
> >>>>>>> + /* Skip verify of remove_non_address_bits_watchpoint,
> >>>>>>> + invalid_p == 0. */
> >>>>>>> + /* Skip verify of remove_non_address_bits_breakpoint,
> >>>>>>> + invalid_p == 0. */
> >>>>>>> + /* Skip verify of remove_non_address_bits_memory, invalid_p == 0.
> >>>>>>> + */
> >>>>>>> /* Skip verify of memtag_to_string, invalid_p == 0. */
> >>>>>>> /* Skip verify of tagged_address_p, invalid_p == 0. */
> >>>>>>> /* Skip verify of memtag_matches_p, invalid_p == 0. */ @@
> >>>>>>> -910,8
> >>>>>>> +914,14 @@ gdbarch_dump (struct gdbarch *gdbarch, struct ui_file
> >>>>>>> +*file)
> >>>>>>> "gdbarch_dump: addr_bits_remove = <%s>\n",
> >>>>>>> host_address_to_string (gdbarch->addr_bits_remove));
> >>>>>>> gdb_printf (file,
> >>>>>>> - "gdbarch_dump: remove_non_address_bits = <%s>\n",
> >>>>>>> - host_address_to_string (gdbarch-
> >remove_non_address_bits));
> >>>>>>> + "gdbarch_dump: remove_non_address_bits_watchpoint =
> <%s>\n",
> >>>>>>> + host_address_to_string
> >>>>>>> +(gdbarch->remove_non_address_bits_watchpoint));
> >>>>>>> + gdb_printf (file,
> >>>>>>> + "gdbarch_dump: remove_non_address_bits_breakpoint =
> <%s>\n",
> >>>>>>> + host_address_to_string
> >>>>>>> +(gdbarch->remove_non_address_bits_breakpoint));
> >>>>>>> + gdb_printf (file,
> >>>>>>> + "gdbarch_dump: remove_non_address_bits_memory =
> <%s>\n",
> >>>>>>> + host_address_to_string
> >>>>>>> +(gdbarch->remove_non_address_bits_memory));
> >>>>>>> gdb_printf (file,
> >>>>>>> "gdbarch_dump: memtag_to_string = <%s>\n",
> >>>>>>> host_address_to_string (gdbarch->memtag_to_string)); @@
> >>>>>>> -3198,20 +3208,54 @@ set_gdbarch_addr_bits_remove (struct
> >>>>>>> gdbarch *gdbarch, }
> >>>>>>>
> >>>>>>> CORE_ADDR
> >>>>>>> -gdbarch_remove_non_address_bits (struct gdbarch *gdbarch,
> >>>>>>> CORE_ADDR
> >>>>>>> pointer)
> >>>>>>> +gdbarch_remove_non_address_bits_watchpoint (struct gdbarch
> >>>>>>> +*gdbarch, CORE_ADDR pointer) {
> >>>>>>> + gdb_assert (gdbarch != NULL);
> >>>>>>> + gdb_assert (gdbarch->remove_non_address_bits_watchpoint !=
> >>>>>>> +NULL);
> >>>>>>> + if (gdbarch_debug >= 2)
> >>>>>>> + gdb_printf (gdb_stdlog,
> >>>>>>> +"gdbarch_remove_non_address_bits_watchpoint called\n");
> >>>>>>> + return gdbarch->remove_non_address_bits_watchpoint (gdbarch,
> >>>>>>> +pointer); }
> >>>>>>> +
> >>>>>>> +void
> >>>>>>> +set_gdbarch_remove_non_address_bits_watchpoint (struct gdbarch
> >>>>>> *gdbarch,
> >>>>>>> +
> >>>>>> gdbarch_remove_non_address_bits_watchpoint_ftype
> >>>>>>> +remove_non_address_bits_watchpoint)
> >>>>>>> +{
> >>>>>>> + gdbarch->remove_non_address_bits_watchpoint =
> >>>>>>> +remove_non_address_bits_watchpoint;
> >>>>>>> +}
> >>>>>>> +
> >>>>>>> +CORE_ADDR
> >>>>>>> +gdbarch_remove_non_address_bits_breakpoint (struct gdbarch
> >>>>>>> +*gdbarch, CORE_ADDR pointer) {
> >>>>>>> + gdb_assert (gdbarch != NULL);
> >>>>>>> + gdb_assert (gdbarch->remove_non_address_bits_breakpoint !=
> >>>>>>> +NULL);
> >>>>>>> + if (gdbarch_debug >= 2)
> >>>>>>> + gdb_printf (gdb_stdlog,
> >>>>>>> +"gdbarch_remove_non_address_bits_breakpoint called\n");
> >>>>>>> + return gdbarch->remove_non_address_bits_breakpoint (gdbarch,
> >>>>>>> +pointer); }
> >>>>>>> +
> >>>>>>> +void
> >>>>>>> +set_gdbarch_remove_non_address_bits_breakpoint (struct gdbarch
> >>>>>>> +*gdbarch,
> >>>>>>> +
> >>>>>> gdbarch_remove_non_address_bits_breakpoint_ftype
> >>>>>>> +remove_non_address_bits_breakpoint)
> >>>>>>> +{
> >>>>>>> + gdbarch->remove_non_address_bits_breakpoint =
> >>>>>>> +remove_non_address_bits_breakpoint;
> >>>>>>> +}
> >>>>>>> +
> >>>>>>> +CORE_ADDR
> >>>>>>> +gdbarch_remove_non_address_bits_memory (struct gdbarch
> >>>>>>> +*gdbarch, CORE_ADDR pointer)
> >>>>>>> {
> >>>>>>> gdb_assert (gdbarch != NULL);
> >>>>>>> - gdb_assert (gdbarch->remove_non_address_bits != NULL);
> >>>>>>> + gdb_assert (gdbarch->remove_non_address_bits_memory != NULL);
> >>>>>>> if (gdbarch_debug >= 2)
> >>>>>>> - gdb_printf (gdb_stdlog, "gdbarch_remove_non_address_bits
> called\n");
> >>>>>>> - return gdbarch->remove_non_address_bits (gdbarch, pointer);
> >>>>>>> + gdb_printf (gdb_stdlog,
> >>>>>>> + "gdbarch_remove_non_address_bits_memory
> >>>>>>> + called\n"); return gdbarch->remove_non_address_bits_memory
> >>>>>>> + (gdbarch, pointer);
> >>>>>>> }
> >>>>>>>
> >>>>>>> void
> >>>>>>> -set_gdbarch_remove_non_address_bits (struct gdbarch *gdbarch,
> >>>>>>> -
> gdbarch_remove_non_address_bits_ftype
> >>>>>> remove_non_address_bits)
> >>>>>>> +set_gdbarch_remove_non_address_bits_memory (struct gdbarch
> >>>>>>> +*gdbarch,
> >>>>>>> +
> >>>>>> gdbarch_remove_non_address_bits_memory_ftype
> >>>>>>> +remove_non_address_bits_memory)
> >>>>>>> {
> >>>>>>> - gdbarch->remove_non_address_bits = remove_non_address_bits;
> >>>>>>> + gdbarch->remove_non_address_bits_memory =
> >>>>>>> + remove_non_address_bits_memory;
> >>>>>>> }
> >>>>>>>
> >>>>>>> std::string
> >>>>>>> diff --git a/gdb/gdbarch-gen.h b/gdb/gdbarch-gen.h index
> >>>>>>> b982fd7cd09..9fda85f860f 100644
> >>>>>>> --- a/gdb/gdbarch-gen.h
> >>>>>>> +++ b/gdb/gdbarch-gen.h
> >>>>>>> @@ -684,19 +684,46 @@ extern CORE_ADDR
> gdbarch_addr_bits_remove
> >>>>>>> (struct gdbarch *gdbarch, CORE_ADDR ad extern void
> >>>>>>> set_gdbarch_addr_bits_remove (struct gdbarch *gdbarch,
> >>>>>>> gdbarch_addr_bits_remove_ftype *addr_bits_remove);
> >>>>>>>
> >>>>>>> /* On some architectures, not all bits of a pointer are significant.
> >>>>>>> - On AArch64, for example, the top bits of a pointer may carry a "tag",
> >> which
> >>>>>>> - can be ignored by the kernel and the hardware. The "tag" can be
> >> regarded
> >>>> as
> >>>>>>> - additional data associated with the pointer, but it is not part of the
> >>>> address.
> >>>>>>> + On AArch64 and amd64, for example, the top bits of a pointer
> >>>>>>> + may carry
> >> a
> >>>>>>> + "tag", which can be ignored by the kernel and the hardware.
> >>>>>>> + The "tag" can
> >>>>>> be
> >>>>>>> + regarded as additional data associated with the pointer, but
> >>>>>>> + it is not
> >> part
> >>>>>>> + of the address.
> >>>>>>>
> >>>>>>> Given a pointer for the architecture, this hook removes all the
> >>>>>>> - non-significant bits and sign-extends things as needed. It gets used to
> >>>>>> remove
> >>>>>>> - non-address bits from data pointers (for example, removing the
> AArch64
> >>>> MTE
> >>>>>> tag
> >>>>>>> - bits from a pointer) and from code pointers (removing the AArch64
> PAC
> >>>>>> signature
> >>>>>>> - from a pointer containing the return address). */
> >>>>>>> -
> >>>>>>> -typedef CORE_ADDR (gdbarch_remove_non_address_bits_ftype)
> >>>>>>> (struct gdbarch *gdbarch, CORE_ADDR pointer); -extern CORE_ADDR
> >>>>>>> gdbarch_remove_non_address_bits (struct gdbarch *gdbarch,
> >>>>>>> CORE_ADDR pointer); -extern void
> >>>>>>> set_gdbarch_remove_non_address_bits (struct gdbarch *gdbarch,
> >>>>>>> gdbarch_remove_non_address_bits_ftype
> >>>>>>> *remove_non_address_bits);
> >>>>>>> + non-significant bits and sign-extends things as needed. It gets used
> to
> >>>>>>> + remove non-address bits from pointers used for watchpoints.
> >>>>>>> + */
> >>>>>>> +
> >>>>>>> +typedef CORE_ADDR
> >>>>>>> +(gdbarch_remove_non_address_bits_watchpoint_ftype)
> >>>>>>> +(struct gdbarch *gdbarch, CORE_ADDR pointer); extern CORE_ADDR
> >>>>>>> +gdbarch_remove_non_address_bits_watchpoint (struct gdbarch
> >>>>>>> +*gdbarch, CORE_ADDR pointer); extern void
> >>>>>>> +set_gdbarch_remove_non_address_bits_watchpoint (struct gdbarch
> >>>>>>> +*gdbarch, gdbarch_remove_non_address_bits_watchpoint_ftype
> >>>>>>> +*remove_non_address_bits_watchpoint);
> >>>>>>> +
> >>>>>>> +/* On some architectures, not all bits of a pointer are significant.
> >>>>>>> + On AArch64 and amd64, for example, the top bits of a pointer
> >>>>>>> +may carry
> >> a
> >>>>>>> + "tag", which can be ignored by the kernel and the hardware.
> >>>>>>> +The "tag" can
> >>>>>> be
> >>>>>>> + regarded as additional data associated with the pointer, but
> >>>>>>> + it is not
> >> part
> >>>>>>> + of the address.
> >>>>>>> +
> >>>>>>> + Given a pointer for the architecture, this hook removes all the
> >>>>>>> + non-significant bits and sign-extends things as needed. It gets used
> to
> >>>>>>> + remove non-address bits from pointers used for breakpoints.
> >>>>>>> + */
> >>>>>>> +
> >>>>>>> +typedef CORE_ADDR
> >>>>>>> +(gdbarch_remove_non_address_bits_breakpoint_ftype)
> >>>>>>> +(struct gdbarch *gdbarch, CORE_ADDR pointer); extern CORE_ADDR
> >>>>>>> +gdbarch_remove_non_address_bits_breakpoint (struct gdbarch
> >>>>>>> +*gdbarch, CORE_ADDR pointer); extern void
> >>>>>>> +set_gdbarch_remove_non_address_bits_breakpoint (struct gdbarch
> >>>>>>> +*gdbarch, gdbarch_remove_non_address_bits_breakpoint_ftype
> >>>>>>> +*remove_non_address_bits_breakpoint);
> >>>>>>> +
> >>>>>>> +/* On some architectures, not all bits of a pointer are significant.
> >>>>>>> + On AArch64 and amd64, for example, the top bits of a pointer
> >>>>>>> +may carry
> >> a
> >>>>>>> + "tag", which can be ignored by the kernel and the hardware.
> >>>>>>> +The "tag" can
> >>>>>> be
> >>>>>>> + regarded as additional data associated with the pointer, but
> >>>>>>> + it is not
> >> part
> >>>>>>> + of the address.
> >>>>>>> +
> >>>>>>> + Given a pointer for the architecture, this hook removes all the
> >>>>>>> + non-significant bits and sign-extends things as needed. It gets used
> to
> >>>>>>> + remove non-address bits from any pointer used to access memory.
> >>>>>>> + */
> >>>>>>> +
> >>>>>>> +typedef CORE_ADDR
> >> (gdbarch_remove_non_address_bits_memory_ftype)
> >>>>>>> +(struct gdbarch *gdbarch, CORE_ADDR pointer); extern CORE_ADDR
> >>>>>>> +gdbarch_remove_non_address_bits_memory (struct gdbarch
> >>>>>>> +*gdbarch, CORE_ADDR pointer); extern void
> >>>>>>> +set_gdbarch_remove_non_address_bits_memory (struct gdbarch
> >>>>>>> +*gdbarch, gdbarch_remove_non_address_bits_memory_ftype
> >>>>>>> +*remove_non_address_bits_memory);
> >>>>>>>
> >>>>>>> /* Return a string representation of the memory tag TAG. */
> >>>>>>>
> >>>>>>> diff --git a/gdb/gdbarch_components.py
> >>>>>>> b/gdb/gdbarch_components.py index 4006380076d..cc7c6d8677b
> >>>>>>> 100644
> >>>>>>> --- a/gdb/gdbarch_components.py
> >>>>>>> +++ b/gdb/gdbarch_components.py
> >>>>>>> @@ -1232,18 +1232,55 @@ possible it should be in TARGET_READ_PC
> >>>>>> instead).
> >>>>>>> Method(
> >>>>>>> comment="""
> >>>>>>> On some architectures, not all bits of a pointer are significant.
> >>>>>>> -On AArch64, for example, the top bits of a pointer may carry a
> >>>>>>> "tag", which -can be ignored by the kernel and the hardware.
> >>>>>>> The "tag" can be regarded as -additional data associated with
> >>>>>>> the pointer, but it is not part of
> >>>>>> the address.
> >>>>>>> +On AArch64 and amd64, for example, the top bits of a pointer
> >>>>>>> +may carry a "tag", which can be ignored by the kernel and the
> hardware.
> >>>>>>> +The "tag" can be regarded as additional data associated with
> >>>>>>> +the pointer, but it is not part of the address.
> >>>>>>>
> >>>>>>> Given a pointer for the architecture, this hook removes all the
> >>>>>>> -non-significant bits and sign-extends things as needed. It
> >>>>>>> gets used to remove -non-address bits from data pointers (for
> >>>>>>> example, removing the AArch64 MTE tag -bits from a pointer) and
> >>>>>>> from code pointers (removing the AArch64 PAC signature -from a
> >>>>>>> pointer containing the return
> >>>>>> address).
> >>>>>>> +non-significant bits and sign-extends things as needed. It
> >>>>>>> +gets used to remove non-address bits from pointers used for
> watchpoints.
> >>>>>>> """,
> >>>>>>> type="CORE_ADDR",
> >>>>>>> - name="remove_non_address_bits",
> >>>>>>> + name="remove_non_address_bits_watchpoint",
> >>>>>>> + params=[("CORE_ADDR", "pointer")],
> >>>>>>> + predefault="default_remove_non_address_bits",
> >>>>>>> + invalid=False,
> >>>>>>> +)
> >>>>>>> +
> >>>>>>> +Method(
> >>>>>>> + comment="""
> >>>>>>> +On some architectures, not all bits of a pointer are significant.
> >>>>>>> +On AArch64 and amd64, for example, the top bits of a pointer
> >>>>>>> +may carry a "tag", which can be ignored by the kernel and the
> hardware.
> >>>>>>> +The "tag" can be regarded as additional data associated with
> >>>>>>> +the pointer, but it is not part of the address.
> >>>>>>> +
> >>>>>>> +Given a pointer for the architecture, this hook removes all the
> >>>>>>> +non-significant bits and sign-extends things as needed. It
> >>>>>>> +gets used to remove non-address bits from pointers used for
> breakpoints.
> >>>>>>> +""",
> >>>>>>> + type="CORE_ADDR",
> >>>>>>> + name="remove_non_address_bits_breakpoint",
> >>>>>>> + params=[("CORE_ADDR", "pointer")],
> >>>>>>> + predefault="default_remove_non_address_bits",
> >>>>>>> + invalid=False,
> >>>>>>> +)
> >>>>>>> +
> >>>>>>> +Method(
> >>>>>>> + comment="""
> >>>>>>> +On some architectures, not all bits of a pointer are significant.
> >>>>>>> +On AArch64 and amd64, for example, the top bits of a pointer
> >>>>>>> +may carry a "tag", which can be ignored by the kernel and the
> hardware.
> >>>>>>> +The "tag" can be regarded as additional data associated with
> >>>>>>> +the pointer, but it is not part of the address.
> >>>>>>> +
> >>>>>>> +Given a pointer for the architecture, this hook removes all the
> >>>>>>> +non-significant bits and sign-extends things as needed. It
> >>>>>>> +gets used to remove non-address bits from any pointer used to
> >>>>>>> +access
> >> memory.
> >>>>>>> +""",
> >>>>>>> + type="CORE_ADDR",
> >>>>>>> + name="remove_non_address_bits_memory",
> >>>>>>> params=[("CORE_ADDR", "pointer")],
> >>>>>>> predefault="default_remove_non_address_bits",
> >>>>>>> invalid=False,
> >>>>>>> diff --git a/gdb/loongarch-linux-nat.c
> >>>>>>> b/gdb/loongarch-linux-nat.c index bc9927dd751..dc4a019614a
> >>>>>>> 100644
> >>>>>>> --- a/gdb/loongarch-linux-nat.c
> >>>>>>> +++ b/gdb/loongarch-linux-nat.c
> >>>>>>> @@ -613,7 +613,7 @@
> >>>>>>> loongarch_linux_nat_target::stopped_data_address
> >>>>>> (CORE_ADDR *addr_p)
> >>>>>>> kernel can potentially be tagged addresses. */
> >>>>>>> struct gdbarch *gdbarch = thread_architecture (inferior_ptid);
> >>>>>>> const CORE_ADDR addr_trap
> >>>>>>> - = gdbarch_remove_non_address_bits (gdbarch, (CORE_ADDR)
> >>>>>> siginfo.si_addr);
> >>>>>>> + = aarch64_remove_non_address_bits (gdbarch, (CORE_ADDR)
> >>>>>>> + siginfo.si_addr);
> >>>>>>>
> >>>>>>> /* Check if the address matches any watched address. */
> >>>>>>> state = loongarch_get_debug_reg_state (inferior_ptid.pid ());
> >>>>>>
> >>>>>> I think the loongarch-linux-nat.c change is spurious. Could you
> >>>>>> please address that?
> >>>>>
> >>>>> Why is it spurious? What do you mean exactly?
> >>>>
> >>>> The intention behind this change isn't clear to me, but the
> >>>> Loongson native Linux layer using a AArch64 architecture function does not
> make sense.
> >>>>
> >>>> I haven't built a LoongArch native Linux target, but I'd guess that
> >>>> it will run into a build error with this change, if built for LoongArch only.
> >>>>
> >>>> The right approach, in my mind, is to drop this change, but you
> >>>> have to touch this code due to your changes. It begs the question,
> >>>> why is the LoongArch native code calling
> >>>> gdbarch_remove_non_address_bits here without even registering a
> function for the gdbarch hook to call?
> >>>
> >>> Right, I agree.
> >>>
> >>>> Without this hook, we'll invoke the dummy implementation in
> >>>> gdb/arch- utils.c:default_remove_non_address_bits, and that just
> >>>> returns the unmodified pointer.
> >>>
> >>> True, that's probably why nobody noticed before.
> >>>
> >>>> This is a question for the LoongArch maintainer (cc-ed). If we
> >>>> don't hear back, we should probably change the LoongArch code to
> >>>> not call gdbarch_remove_non_address_bits. I think that was the
> >>>> original intention, but there might've been a copy/paste error somewhere.
> >>>
> >>> Ok. Let's wait a bit. Thanks for the detailed feedback.
> >>
> >> Alternatively, if you could replace, in the LoongArch code,
> >> gdbarch_remove_non_address_bits with one of the three new hooks, that
> >> should work as well. I think even cleaner would be to just drop the
> >> hook for Loongarch and assign siginfo.si_addr directly to addr_trap in the code.
> >
> > I am also in favour of your second suggestion to drop the hook here.
> > In that case, it should be separate patch I think.
> > I could post it independently of this series and quickly merge before posting a v7
> of my series.
>
> Yes, a separate one would be nice, please.
>
> >
> > LoongArch doesn't supported tagged addresses, does it? If it's not
> > supported, I would suggest to fix it as follows:
> >
> > diff --git a/gdb/loongarch-linux-nat.c b/gdb/loongarch-linux-nat.c
> > index dc4a019614a..fd3581bbd30 100644
> > --- a/gdb/loongarch-linux-nat.c
> > +++ b/gdb/loongarch-linux-nat.c
> > @@ -608,17 +608,11 @@ loongarch_linux_nat_target::stopped_data_address
> (CORE_ADDR *addr_p)
> > if (siginfo.si_signo != SIGTRAP || (siginfo.si_code & 0xffff) != TRAP_HWBKPT)
> > return false;
> >
> > - /* Make sure to ignore the top byte, otherwise we may not recognize a
> > - hardware watchpoint hit. The stopped data addresses coming from the
> > - kernel can potentially be tagged addresses. */
> > - struct gdbarch *gdbarch = thread_architecture (inferior_ptid);
> > - const CORE_ADDR addr_trap
> > - = aarch64_remove_non_address_bits (gdbarch, (CORE_ADDR)
> siginfo.si_addr);
> > -
> > /* Check if the address matches any watched address. */
> > state = loongarch_get_debug_reg_state (inferior_ptid.pid ());
> >
> > - return loongarch_stopped_data_address (state, addr_trap, addr_p);
> > + return
> > + loongarch_stopped_data_address (state, (CORE_ADDR)
> > + siginfo.si_addr, addr_p);
> >
> > Does that make sense to you?
> >
>
> It does. Thanks!
This is the patch for LoongArch: https://sourceware.org/pipermail/gdb-patches/2024-November/212974.html
Christina
Intel Deutschland GmbH
Registered Address: Am Campeon 10, 85579 Neubiberg, Germany
Tel: +49 89 99 8853-0, www.intel.de
Managing Directors: Sean Fennelly, Jeffrey Schneiderman, Tiffany Doon Silva
Chairperson of the Supervisory Board: Nicole Lau
Registered Office: Munich
Commercial Register: Amtsgericht Muenchen HRB 186928
@@ -943,7 +943,7 @@ aarch64_linux_nat_target::stopped_data_address (CORE_ADDR *addr_p)
kernel can potentially be tagged addresses. */
struct gdbarch *gdbarch = thread_architecture (inferior_ptid);
const CORE_ADDR addr_trap
- = gdbarch_remove_non_address_bits (gdbarch, (CORE_ADDR) siginfo.si_addr);
+ = aarch64_remove_non_address_bits (gdbarch, (CORE_ADDR) siginfo.si_addr);
/* Check if the address matches any watched address. */
state = aarch64_get_debug_reg_state (inferior_ptid.pid ());
@@ -2433,7 +2433,7 @@ static bool
aarch64_linux_tagged_address_p (struct gdbarch *gdbarch, CORE_ADDR address)
{
/* Remove the top byte for the memory range check. */
- address = gdbarch_remove_non_address_bits (gdbarch, address);
+ address = aarch64_remove_non_address_bits (gdbarch, address);
/* Check if the page that contains ADDRESS is mapped with PROT_MTE. */
if (!linux_address_in_memtag_page (address))
@@ -2491,8 +2491,9 @@ aarch64_linux_report_signal_info (struct gdbarch *gdbarch,
uiout->text ("\n");
std::optional<CORE_ADDR> atag
- = aarch64_mte_get_atag (gdbarch_remove_non_address_bits (gdbarch,
- fault_addr));
+ = aarch64_mte_get_atag (
+ aarch64_remove_non_address_bits (gdbarch, fault_addr));
+
gdb_byte ltag = aarch64_mte_get_ltag (fault_addr);
if (!atag.has_value ())
@@ -4121,7 +4121,7 @@ aarch64_memtag_matches_p (struct gdbarch *gdbarch,
/* Fetch the allocation tag for ADDRESS. */
std::optional<CORE_ADDR> atag
- = aarch64_mte_get_atag (gdbarch_remove_non_address_bits (gdbarch, addr));
+ = aarch64_mte_get_atag (aarch64_remove_non_address_bits (gdbarch, addr));
if (!atag.has_value ())
return true;
@@ -4160,7 +4160,7 @@ aarch64_set_memtags (struct gdbarch *gdbarch, struct value *address,
else
{
/* Remove the top byte. */
- addr = gdbarch_remove_non_address_bits (gdbarch, addr);
+ addr = aarch64_remove_non_address_bits (gdbarch, addr);
/* With G being the number of tag granules and N the number of tags
passed in, we can have the following cases:
@@ -4209,7 +4209,7 @@ aarch64_get_memtag (struct gdbarch *gdbarch, struct value *address,
else
{
/* Remove the top byte. */
- addr = gdbarch_remove_non_address_bits (gdbarch, addr);
+ addr = aarch64_remove_non_address_bits (gdbarch, addr);
std::optional<CORE_ADDR> atag = aarch64_mte_get_atag (addr);
if (!atag.has_value ())
@@ -4236,10 +4236,9 @@ aarch64_memtag_to_string (struct gdbarch *gdbarch, struct value *tag_value)
return string_printf ("0x%s", phex_nz (tag, sizeof (tag)));
}
-/* AArch64 implementation of the remove_non_address_bits gdbarch hook. Remove
- non address bits from a pointer value. */
+/* See aarch64-tdep.h. */
-static CORE_ADDR
+CORE_ADDR
aarch64_remove_non_address_bits (struct gdbarch *gdbarch, CORE_ADDR pointer)
{
/* By default, we assume TBI and discard the top 8 bits plus the VA range
@@ -4750,9 +4749,15 @@ aarch64_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
tdep->ra_sign_state_regnum = ra_sign_state_offset + num_regs;
/* Architecture hook to remove bits of a pointer that are not part of the
- address, like memory tags (MTE) and pointer authentication signatures. */
- set_gdbarch_remove_non_address_bits (gdbarch,
- aarch64_remove_non_address_bits);
+ address, like memory tags (MTE) and pointer authentication signatures.
+ Configure address adjustment for watch-, breakpoints and memory
+ transfer. */
+ set_gdbarch_remove_non_address_bits_watchpoint
+ (gdbarch, aarch64_remove_non_address_bits);
+ set_gdbarch_remove_non_address_bits_breakpoint
+ (gdbarch, aarch64_remove_non_address_bits);
+ set_gdbarch_remove_non_address_bits_memory
+ (gdbarch, aarch64_remove_non_address_bits);
/* SME pseudo-registers. */
if (tdep->has_sme ())
@@ -205,4 +205,10 @@ bool aarch64_displaced_step_hw_singlestep (struct gdbarch *gdbarch);
std::optional<CORE_ADDR> aarch64_mte_get_atag (CORE_ADDR address);
+/* AArch64 implementation of the remove_non_address_bits gdbarch hooks.
+ Remove non address bits from a pointer value. */
+
+CORE_ADDR aarch64_remove_non_address_bits (struct gdbarch *gdbarch,
+ CORE_ADDR pointer);
+
#endif /* aarch64-tdep.h */
@@ -2313,7 +2313,8 @@ update_watchpoint (struct watchpoint *b, bool reparse)
loc->gdbarch = v->type ()->arch ();
loc->pspace = wp_pspace;
loc->address
- = gdbarch_remove_non_address_bits (loc->gdbarch, addr);
+ = gdbarch_remove_non_address_bits_watchpoint (loc->gdbarch,
+ addr);
b->add_location (*loc);
if (bitsize != 0)
@@ -7538,7 +7539,7 @@ adjust_breakpoint_address (struct gdbarch *gdbarch,
}
adjusted_bpaddr
- = gdbarch_remove_non_address_bits (gdbarch, adjusted_bpaddr);
+ = gdbarch_remove_non_address_bits_breakpoint (gdbarch, adjusted_bpaddr);
/* An adjusted breakpoint address can significantly alter
a user's expectations. Print a warning if an adjustment
@@ -143,7 +143,9 @@ struct gdbarch
int frame_red_zone_size = 0;
gdbarch_convert_from_func_ptr_addr_ftype *convert_from_func_ptr_addr = convert_from_func_ptr_addr_identity;
gdbarch_addr_bits_remove_ftype *addr_bits_remove = core_addr_identity;
- gdbarch_remove_non_address_bits_ftype *remove_non_address_bits = default_remove_non_address_bits;
+ gdbarch_remove_non_address_bits_watchpoint_ftype *remove_non_address_bits_watchpoint = default_remove_non_address_bits;
+ gdbarch_remove_non_address_bits_breakpoint_ftype *remove_non_address_bits_breakpoint = default_remove_non_address_bits;
+ gdbarch_remove_non_address_bits_memory_ftype *remove_non_address_bits_memory = default_remove_non_address_bits;
gdbarch_memtag_to_string_ftype *memtag_to_string = default_memtag_to_string;
gdbarch_tagged_address_p_ftype *tagged_address_p = default_tagged_address_p;
gdbarch_memtag_matches_p_ftype *memtag_matches_p = default_memtag_matches_p;
@@ -407,7 +409,9 @@ verify_gdbarch (struct gdbarch *gdbarch)
/* Skip verify of frame_red_zone_size, invalid_p == 0. */
/* Skip verify of convert_from_func_ptr_addr, invalid_p == 0. */
/* Skip verify of addr_bits_remove, invalid_p == 0. */
- /* Skip verify of remove_non_address_bits, invalid_p == 0. */
+ /* Skip verify of remove_non_address_bits_watchpoint, invalid_p == 0. */
+ /* Skip verify of remove_non_address_bits_breakpoint, invalid_p == 0. */
+ /* Skip verify of remove_non_address_bits_memory, invalid_p == 0. */
/* Skip verify of memtag_to_string, invalid_p == 0. */
/* Skip verify of tagged_address_p, invalid_p == 0. */
/* Skip verify of memtag_matches_p, invalid_p == 0. */
@@ -910,8 +914,14 @@ gdbarch_dump (struct gdbarch *gdbarch, struct ui_file *file)
"gdbarch_dump: addr_bits_remove = <%s>\n",
host_address_to_string (gdbarch->addr_bits_remove));
gdb_printf (file,
- "gdbarch_dump: remove_non_address_bits = <%s>\n",
- host_address_to_string (gdbarch->remove_non_address_bits));
+ "gdbarch_dump: remove_non_address_bits_watchpoint = <%s>\n",
+ host_address_to_string (gdbarch->remove_non_address_bits_watchpoint));
+ gdb_printf (file,
+ "gdbarch_dump: remove_non_address_bits_breakpoint = <%s>\n",
+ host_address_to_string (gdbarch->remove_non_address_bits_breakpoint));
+ gdb_printf (file,
+ "gdbarch_dump: remove_non_address_bits_memory = <%s>\n",
+ host_address_to_string (gdbarch->remove_non_address_bits_memory));
gdb_printf (file,
"gdbarch_dump: memtag_to_string = <%s>\n",
host_address_to_string (gdbarch->memtag_to_string));
@@ -3198,20 +3208,54 @@ set_gdbarch_addr_bits_remove (struct gdbarch *gdbarch,
}
CORE_ADDR
-gdbarch_remove_non_address_bits (struct gdbarch *gdbarch, CORE_ADDR pointer)
+gdbarch_remove_non_address_bits_watchpoint (struct gdbarch *gdbarch, CORE_ADDR pointer)
+{
+ gdb_assert (gdbarch != NULL);
+ gdb_assert (gdbarch->remove_non_address_bits_watchpoint != NULL);
+ if (gdbarch_debug >= 2)
+ gdb_printf (gdb_stdlog, "gdbarch_remove_non_address_bits_watchpoint called\n");
+ return gdbarch->remove_non_address_bits_watchpoint (gdbarch, pointer);
+}
+
+void
+set_gdbarch_remove_non_address_bits_watchpoint (struct gdbarch *gdbarch,
+ gdbarch_remove_non_address_bits_watchpoint_ftype remove_non_address_bits_watchpoint)
+{
+ gdbarch->remove_non_address_bits_watchpoint = remove_non_address_bits_watchpoint;
+}
+
+CORE_ADDR
+gdbarch_remove_non_address_bits_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pointer)
+{
+ gdb_assert (gdbarch != NULL);
+ gdb_assert (gdbarch->remove_non_address_bits_breakpoint != NULL);
+ if (gdbarch_debug >= 2)
+ gdb_printf (gdb_stdlog, "gdbarch_remove_non_address_bits_breakpoint called\n");
+ return gdbarch->remove_non_address_bits_breakpoint (gdbarch, pointer);
+}
+
+void
+set_gdbarch_remove_non_address_bits_breakpoint (struct gdbarch *gdbarch,
+ gdbarch_remove_non_address_bits_breakpoint_ftype remove_non_address_bits_breakpoint)
+{
+ gdbarch->remove_non_address_bits_breakpoint = remove_non_address_bits_breakpoint;
+}
+
+CORE_ADDR
+gdbarch_remove_non_address_bits_memory (struct gdbarch *gdbarch, CORE_ADDR pointer)
{
gdb_assert (gdbarch != NULL);
- gdb_assert (gdbarch->remove_non_address_bits != NULL);
+ gdb_assert (gdbarch->remove_non_address_bits_memory != NULL);
if (gdbarch_debug >= 2)
- gdb_printf (gdb_stdlog, "gdbarch_remove_non_address_bits called\n");
- return gdbarch->remove_non_address_bits (gdbarch, pointer);
+ gdb_printf (gdb_stdlog, "gdbarch_remove_non_address_bits_memory called\n");
+ return gdbarch->remove_non_address_bits_memory (gdbarch, pointer);
}
void
-set_gdbarch_remove_non_address_bits (struct gdbarch *gdbarch,
- gdbarch_remove_non_address_bits_ftype remove_non_address_bits)
+set_gdbarch_remove_non_address_bits_memory (struct gdbarch *gdbarch,
+ gdbarch_remove_non_address_bits_memory_ftype remove_non_address_bits_memory)
{
- gdbarch->remove_non_address_bits = remove_non_address_bits;
+ gdbarch->remove_non_address_bits_memory = remove_non_address_bits_memory;
}
std::string
@@ -684,19 +684,46 @@ extern CORE_ADDR gdbarch_addr_bits_remove (struct gdbarch *gdbarch, CORE_ADDR ad
extern void set_gdbarch_addr_bits_remove (struct gdbarch *gdbarch, gdbarch_addr_bits_remove_ftype *addr_bits_remove);
/* On some architectures, not all bits of a pointer are significant.
- On AArch64, for example, the top bits of a pointer may carry a "tag", which
- can be ignored by the kernel and the hardware. The "tag" can be regarded as
- additional data associated with the pointer, but it is not part of the address.
+ On AArch64 and amd64, for example, the top bits of a pointer may carry a
+ "tag", which can be ignored by the kernel and the hardware. The "tag" can be
+ regarded as additional data associated with the pointer, but it is not part
+ of the address.
Given a pointer for the architecture, this hook removes all the
- non-significant bits and sign-extends things as needed. It gets used to remove
- non-address bits from data pointers (for example, removing the AArch64 MTE tag
- bits from a pointer) and from code pointers (removing the AArch64 PAC signature
- from a pointer containing the return address). */
-
-typedef CORE_ADDR (gdbarch_remove_non_address_bits_ftype) (struct gdbarch *gdbarch, CORE_ADDR pointer);
-extern CORE_ADDR gdbarch_remove_non_address_bits (struct gdbarch *gdbarch, CORE_ADDR pointer);
-extern void set_gdbarch_remove_non_address_bits (struct gdbarch *gdbarch, gdbarch_remove_non_address_bits_ftype *remove_non_address_bits);
+ non-significant bits and sign-extends things as needed. It gets used to
+ remove non-address bits from pointers used for watchpoints. */
+
+typedef CORE_ADDR (gdbarch_remove_non_address_bits_watchpoint_ftype) (struct gdbarch *gdbarch, CORE_ADDR pointer);
+extern CORE_ADDR gdbarch_remove_non_address_bits_watchpoint (struct gdbarch *gdbarch, CORE_ADDR pointer);
+extern void set_gdbarch_remove_non_address_bits_watchpoint (struct gdbarch *gdbarch, gdbarch_remove_non_address_bits_watchpoint_ftype *remove_non_address_bits_watchpoint);
+
+/* On some architectures, not all bits of a pointer are significant.
+ On AArch64 and amd64, for example, the top bits of a pointer may carry a
+ "tag", which can be ignored by the kernel and the hardware. The "tag" can be
+ regarded as additional data associated with the pointer, but it is not part
+ of the address.
+
+ Given a pointer for the architecture, this hook removes all the
+ non-significant bits and sign-extends things as needed. It gets used to
+ remove non-address bits from pointers used for breakpoints. */
+
+typedef CORE_ADDR (gdbarch_remove_non_address_bits_breakpoint_ftype) (struct gdbarch *gdbarch, CORE_ADDR pointer);
+extern CORE_ADDR gdbarch_remove_non_address_bits_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pointer);
+extern void set_gdbarch_remove_non_address_bits_breakpoint (struct gdbarch *gdbarch, gdbarch_remove_non_address_bits_breakpoint_ftype *remove_non_address_bits_breakpoint);
+
+/* On some architectures, not all bits of a pointer are significant.
+ On AArch64 and amd64, for example, the top bits of a pointer may carry a
+ "tag", which can be ignored by the kernel and the hardware. The "tag" can be
+ regarded as additional data associated with the pointer, but it is not part
+ of the address.
+
+ Given a pointer for the architecture, this hook removes all the
+ non-significant bits and sign-extends things as needed. It gets used to
+ remove non-address bits from any pointer used to access memory. */
+
+typedef CORE_ADDR (gdbarch_remove_non_address_bits_memory_ftype) (struct gdbarch *gdbarch, CORE_ADDR pointer);
+extern CORE_ADDR gdbarch_remove_non_address_bits_memory (struct gdbarch *gdbarch, CORE_ADDR pointer);
+extern void set_gdbarch_remove_non_address_bits_memory (struct gdbarch *gdbarch, gdbarch_remove_non_address_bits_memory_ftype *remove_non_address_bits_memory);
/* Return a string representation of the memory tag TAG. */
@@ -1232,18 +1232,55 @@ possible it should be in TARGET_READ_PC instead).
Method(
comment="""
On some architectures, not all bits of a pointer are significant.
-On AArch64, for example, the top bits of a pointer may carry a "tag", which
-can be ignored by the kernel and the hardware. The "tag" can be regarded as
-additional data associated with the pointer, but it is not part of the address.
+On AArch64 and amd64, for example, the top bits of a pointer may carry a
+"tag", which can be ignored by the kernel and the hardware. The "tag" can be
+regarded as additional data associated with the pointer, but it is not part
+of the address.
Given a pointer for the architecture, this hook removes all the
-non-significant bits and sign-extends things as needed. It gets used to remove
-non-address bits from data pointers (for example, removing the AArch64 MTE tag
-bits from a pointer) and from code pointers (removing the AArch64 PAC signature
-from a pointer containing the return address).
+non-significant bits and sign-extends things as needed. It gets used to
+remove non-address bits from pointers used for watchpoints.
""",
type="CORE_ADDR",
- name="remove_non_address_bits",
+ name="remove_non_address_bits_watchpoint",
+ params=[("CORE_ADDR", "pointer")],
+ predefault="default_remove_non_address_bits",
+ invalid=False,
+)
+
+Method(
+ comment="""
+On some architectures, not all bits of a pointer are significant.
+On AArch64 and amd64, for example, the top bits of a pointer may carry a
+"tag", which can be ignored by the kernel and the hardware. The "tag" can be
+regarded as additional data associated with the pointer, but it is not part
+of the address.
+
+Given a pointer for the architecture, this hook removes all the
+non-significant bits and sign-extends things as needed. It gets used to
+remove non-address bits from pointers used for breakpoints.
+""",
+ type="CORE_ADDR",
+ name="remove_non_address_bits_breakpoint",
+ params=[("CORE_ADDR", "pointer")],
+ predefault="default_remove_non_address_bits",
+ invalid=False,
+)
+
+Method(
+ comment="""
+On some architectures, not all bits of a pointer are significant.
+On AArch64 and amd64, for example, the top bits of a pointer may carry a
+"tag", which can be ignored by the kernel and the hardware. The "tag" can be
+regarded as additional data associated with the pointer, but it is not part
+of the address.
+
+Given a pointer for the architecture, this hook removes all the
+non-significant bits and sign-extends things as needed. It gets used to
+remove non-address bits from any pointer used to access memory.
+""",
+ type="CORE_ADDR",
+ name="remove_non_address_bits_memory",
params=[("CORE_ADDR", "pointer")],
predefault="default_remove_non_address_bits",
invalid=False,
@@ -613,7 +613,7 @@ loongarch_linux_nat_target::stopped_data_address (CORE_ADDR *addr_p)
kernel can potentially be tagged addresses. */
struct gdbarch *gdbarch = thread_architecture (inferior_ptid);
const CORE_ADDR addr_trap
- = gdbarch_remove_non_address_bits (gdbarch, (CORE_ADDR) siginfo.si_addr);
+ = aarch64_remove_non_address_bits (gdbarch, (CORE_ADDR) siginfo.si_addr);
/* Check if the address matches any watched address. */
state = loongarch_get_debug_reg_state (inferior_ptid.pid ());
@@ -1608,7 +1608,8 @@ memory_xfer_partial (struct target_ops *ops, enum target_object object,
if (len == 0)
return TARGET_XFER_EOF;
- memaddr = gdbarch_remove_non_address_bits (current_inferior ()->arch (),
+ memaddr
+ = gdbarch_remove_non_address_bits_memory (current_inferior ()->arch (),
memaddr);
/* Fill in READBUF with breakpoint shadows, or WRITEBUF with