[1/4] aarch64: Create definitions for AARCH64_RA_SIGN_STATE register
Commit Message
This register will be used to indicate whether a return address is
mangled with a PAC or not, in accordance with the DWARF AARCH64 ABI [1].
[1] https://github.com/ARM-software/abi-aa/blob/main/aadwarf64/aadwarf64.rst#41dwarf-register-names
Signed-off-by: German Gomez <german.gomez@arm.com>
---
backends/aarch64_init.c | 6 +++---
backends/aarch64_initreg.c | 2 ++
backends/aarch64_regs.c | 5 ++++-
libdw/dwarf.h | 5 +++++
tests/run-addrcfi.sh | 1 +
tests/run-allregs.sh | 1 +
6 files changed, 16 insertions(+), 4 deletions(-)
Comments
Hi German,
On Mon, 2022-04-25 at 14:03 +0000, German Gomez via Elfutils-devel
wrote:
> This register will be used to indicate whether a return address is
> mangled with a PAC or not, in accordance with the DWARF AARCH64 ABI [1].
>
> [1] https://github.com/ARM-software/abi-aa/blob/main/aadwarf64/aadwarf64.rst#41dwarf-register-names
This looks good. With one nit:
> diff --git a/libdw/dwarf.h b/libdw/dwarf.h
> index 3ce7f236..f234c411 100644
> --- a/libdw/dwarf.h
> +++ b/libdw/dwarf.h
> @@ -1011,6 +1011,11 @@ enum
> DW_EH_PE_indirect = 0x80
> };
>
> +/* AARCH64 DWARF registers. */
> +enum
> + {
> + DW_AARCH64_RA_SIGN_STATE = 34
> + };
>
> /* DWARF XXX. */
> #define DW_ADDR_none 0
dwarf.h is a public header. I rather not define this DW constant here.
Especially since it doesn't seem to have common name (binutils-gdb
calls this AARCH64_DWARF_RA_SIGN_STATE, but only defines it in a
private header). Lets move this into cfi.c as private implementation
detail in the next patch.
Thanks,
Mark
@@ -55,10 +55,10 @@ aarch64_init (Elf *elf __attribute__ ((unused)),
HOOK (eh, data_marker_symbol);
HOOK (eh, abi_cfi);
- /* X0-X30 (31 regs) + SP + 1 Reserved + ELR, 30 Reserved regs (34-43)
+ /* X0-X30 (31 regs) + SP + 1 Reserved + ELR + RA_SIGN_STATE, 30 Reserved regs (34-43)
+ V0-V31 (32 regs, least significant 64 bits only)
- + ALT_FRAME_RETURN_COLUMN (used when LR isn't used) = 97 DWARF regs. */
- eh->frame_nregs = 97;
+ + ALT_FRAME_RETURN_COLUMN (used when LR isn't used) = 98 DWARF regs. */
+ eh->frame_nregs = 98;
HOOK (eh, set_initial_registers_tid);
HOOK (eh, unwind);
@@ -73,6 +73,8 @@ aarch64_set_initial_registers_tid (pid_t tid __attribute__ ((unused)),
/* ELR cannot be found. */
+ /* RA_SIGN_STATE cannot be found */
+
/* FP registers (only 64bits are used). */
struct user_fpsimd_struct fregs;
iovec.iov_base = &fregs;
@@ -87,7 +87,10 @@ aarch64_register_info (Ebl *ebl __attribute__ ((unused)),
case 33:
return regtype ("integer", DW_ATE_address, "elr");
- case 34 ... 63:
+ case 34:
+ return regtype ("integer", DW_ATE_unsigned, "ra_sign_state");
+
+ case 35 ... 63:
return 0;
case 64 ... 95:
@@ -1011,6 +1011,11 @@ enum
DW_EH_PE_indirect = 0x80
};
+/* AARCH64 DWARF registers. */
+enum
+ {
+ DW_AARCH64_RA_SIGN_STATE = 34
+ };
/* DWARF XXX. */
#define DW_ADDR_none 0
@@ -3639,6 +3639,7 @@ dwarf_cfi_addrframe (.eh_frame): no matching address range
integer reg30 (x30): same_value
integer reg31 (sp): location expression: call_frame_cfa stack_value
integer reg33 (elr): undefined
+ integer reg34 (ra_sign_state): undefined
FP/SIMD reg64 (v0): undefined
FP/SIMD reg65 (v1): undefined
FP/SIMD reg66 (v2): undefined
@@ -2693,6 +2693,7 @@ integer registers:
30: x30 (x30), signed 64 bits
31: sp (sp), address 64 bits
33: elr (elr), address 64 bits
+ 34: ra_sign_state (ra_sign_state), unsigned 64 bits
FP/SIMD registers:
64: v0 (v0), unsigned 128 bits
65: v1 (v1), unsigned 128 bits