Patch 1 of 2 for aarch64 ILP32 support in gdb
Commit Message
This is a follow up to a post from some time ago to enable aarch64
ILP32 support in gdb.
https://sourceware.org/ml/binutils/2016-09/msg00004.html
Andrew Pinksi submitted these patches and I have updated them,
addressed the comments that were made at the time, and retested
them. Andrew broke them down into 3 patches I am submitting it as two
patches, this first one is the changes to bfd. This patch removes the
ilp32/lp64 checking that is done in compatible and moves it to
elfNN_aarch64_merge_private_bfd_data. Doing it in compatible is too
early for gdb. The patch also adds an endianness check to
elfNN_aarch64_merge_private_bfd_data. The second patch will contain
the gdb changes.
Steve Ellcey
sellcey@cavium.com
2017-01-24 Andrew Pinski <apinski@cavium.com>
Steve Ellcey <sellcey@cavium.com>
* cpu-aarch64.c (compatible):
Don't reject different ILP32/LP64 ABI's here.
* elfnn-aarch64.c (elfNN_aarch64_merge_private_bfd_data):
Add an error message on why endianess is rejected.
Reject different ILP32/LP64 ABI settings.
Comments
Hi Steve,
> 2017-01-24 Andrew Pinski <apinski@cavium.com>
> Steve Ellcey <sellcey@cavium.com>
>
> * cpu-aarch64.c (compatible):
> Don't reject different ILP32/LP64 ABI's here.
> * elfnn-aarch64.c (elfNN_aarch64_merge_private_bfd_data):
> Add an error message on why endianess is rejected.
> Reject different ILP32/LP64 ABI settings.
Approved - please apply.
Cheers
Nick
On 17-01-24 16:18:49, Steve Ellcey wrote:
> --- a/bfd/cpu-aarch64.c
> +++ b/bfd/cpu-aarch64.c
> @@ -25,7 +25,8 @@
>
> /* This routine is provided two arch_infos and works out which Aarch64
> machine which would be compatible with both and returns a pointer
> - to its info structure. */
> + to its info structure. ABI (ilp32 vs. lp64) and endianness compatibility
> + are checked in elfNN_aarch64_merge_private_bfd_data. */
>
> static const bfd_arch_info_type *
> compatible (const bfd_arch_info_type * a, const bfd_arch_info_type * b)
> @@ -38,10 +39,6 @@ compatible (const bfd_arch_info_type * a, const bfd_arch_info_type * b)
> if (a->mach == b->mach)
> return a;
>
> - /* Don't allow mixing ilp32 with lp64. */
> - if ((a->mach & bfd_mach_aarch64_ilp32) != (b->mach & bfd_mach_aarch64_ilp32))
> - return NULL;
> -
Hi Steve,
GDB uses this function to check if selected arch is compatible with
the target arch. If I load an ilp32 binary in aarch64 gdb, and connect
to gdbserver, I'll get a warning as below,
Reading symbols from ../1.o...(no debugging symbols found)...done.
(gdb) target remote linaro-junor1-1:1234
Remote debugging using linaro-junor1-1:1234
warning: Selected architecture aarch64:ilp32 is not compatible with reported target architecture aarch64
with your patch applied, the warning goes way.
(gdb) target remote linaro-junor1-1:1234
Remote debugging using linaro-junor1-1:1234
Reading /scratch/yao/toolchain/gcc-7/aarch64-linux-gnu/sysroot/lib/ld-linux-aarch64.so.1 from remote target...
Reading /scratch/yao/toolchain/gcc-7/aarch64-linux-gnu/sysroot/lib/ld-linux-aarch64.so.1 from remote target...
Reading symbols from target:/scratch/yao/toolchain/gcc-7/aarch64-linux-gnu/sysroot/lib/ld-linux-aarch64.so.1...done.
Python Exception <type 'exceptions.NameError'> Installation error: gdb.execute_unwinders function is missing:
0x0000ffffb7fd2d00 in _start () from target:/scratch/yao/toolchain/gcc-7/aarch64-linux-gnu/sysroot/lib/ld-linux-aarch64.so.1
IMO, the warning above is useful, since aarch64:ilp32 is not supported
in gdb, can we commit this patch after ilp32 is supported in GDB (if
this patch only affects GDB).
On Wed, 2017-01-25 at 15:36 +0000, Yao Qi wrote:
>
> Hi Steve,
> GDB uses this function to check if selected arch is compatible with
> the target arch. If I load an ilp32 binary in aarch64 gdb, and
> connect
> to gdbserver, I'll get a warning as below,
>
> IMO, the warning above is useful, since aarch64:ilp32 is not
> supported
> in gdb, can we commit this patch after ilp32 is supported in GDB (if
> this patch only affects GDB).
I submitted the GDB support for ilp32 as patch 2 of 2 to binutils
and gdb-patches so I can wait a little while and see if someone
approves that patch before checking this part in.
https://sourceware.org/ml/binutils/2017-01/msg00416.html
https://sourceware.org/ml/gdb-patches/2017-01/msg00509.html
Steve Ellcey
sellcey@cavium.com
@@ -25,7 +25,8 @@
/* This routine is provided two arch_infos and works out which Aarch64
machine which would be compatible with both and returns a pointer
- to its info structure. */
+ to its info structure. ABI (ilp32 vs. lp64) and endianness compatibility
+ are checked in elfNN_aarch64_merge_private_bfd_data. */
static const bfd_arch_info_type *
compatible (const bfd_arch_info_type * a, const bfd_arch_info_type * b)
@@ -38,10 +39,6 @@ compatible (const bfd_arch_info_type * a, const bfd_arch_info_type * b)
if (a->mach == b->mach)
return a;
- /* Don't allow mixing ilp32 with lp64. */
- if ((a->mach & bfd_mach_aarch64_ilp32) != (b->mach & bfd_mach_aarch64_ilp32))
- return NULL;
-
/* Otherwise if either a or b is the 'default' machine
then it can be polymorphed into the other. */
if (a->the_default)
@@ -6597,11 +6597,26 @@ elfNN_aarch64_merge_private_bfd_data (bfd *ibfd, struct bfd_link_info *info)
/* Check if we have the same endianess. */
if (!_bfd_generic_verify_endian_match (ibfd, info))
- return FALSE;
+ {
+ (*_bfd_error_handler)
+ (_("%B: endianness incompatible with that of the selected emulation"),
+ ibfd);
+ return FALSE;
+ }
if (!is_aarch64_elf (ibfd) || !is_aarch64_elf (obfd))
return TRUE;
+ /* Don't allow mixing ilp32 with lp64. */
+ if ((bfd_get_arch_info (ibfd)->mach & bfd_mach_aarch64_ilp32)
+ != (bfd_get_arch_info (obfd)->mach & bfd_mach_aarch64_ilp32))
+ {
+ (*_bfd_error_handler)
+ (_("%B: ABI is incompatible with that of the selected emulation: \"%s\" != \"%s\""),
+ ibfd, bfd_get_target (ibfd), bfd_get_target (obfd));
+ return FALSE;
+ }
+
/* The input BFD must have had its flags initialised. */
/* The following seems bogus to me -- The flags are initialized in
the assembler but I don't think an elf_flags_init field is