Re: [PUSHED OBV] Fix loongarch_iterate_over_regset_sections for non-native targets.

[Tiezhu Yang <yangtiezhu@loongson.cn>]

On 05/24/2022 02:15 AM, John Baldwin wrote:
> Define a constant for the number of registers stored in a register set
> and use this with register_size to compute the size of the
> general-purpose register set in core dumps.
>
> This also fixes the build on hosts such as FreeBSD that do not define
> an elf_gregset_t type.

Hi John,

Sorry for the related issues on FreeBSD,
the original patch is only tested on LoongArch Linux,
thank you very much for your test and fix.

> ---
>  gdb/loongarch-linux-tdep.c | 14 ++++++++++++--
>  1 file changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/gdb/loongarch-linux-tdep.c b/gdb/loongarch-linux-tdep.c
> index f13756dd003..bbb43abe13f 100644
> --- a/gdb/loongarch-linux-tdep.c
> +++ b/gdb/loongarch-linux-tdep.c
> @@ -29,6 +29,11 @@
>  #include "trad-frame.h"
>  #include "tramp-frame.h"
>
> +/* The general-purpose regset consists of 32 R registers, plus PC,
> +   and BADV registers.  */
> +
> +#define LOONGARCH_LINUX_NUM_GREGSET	(34)

LOONGARCH_LINUX_NUM_GREGSET should be defined as 45 (32 + 1 + 1 + 11)
due to reserved 11 for extension in glibc, otherwise when execute:

   make check-gdb TESTS="gdb.base/corefile.exp"

there exists the following failed testcase:

   (gdb) core-file 
/home/loongson/build.git/gdb/testsuite/outputs/gdb.base/corefile/corefile.core
   [New LWP 7742]
   warning: Unexpected size of section `.reg/7742' in core file.
   Core was generated by 
`/home/loongson/build.git/gdb/testsuite/outputs/gdb.base/corefile/corefile'.
   Program terminated with signal SIGABRT, Aborted.
   warning: Unexpected size of section `.reg/7742' in core file.
   #0  0x000000fff76f4e24 in raise () from 
/lib/loongarch64-linux-gnu/libc.so.6
   (gdb) FAIL: gdb.base/corefile.exp: core-file warning-free

I will send a patch to fix the above issue.

Thanks,
Tiezhu

> +
>  /* Unpack an elf_gregset_t into GDB's register cache.  */
>
>  static void
> @@ -172,8 +177,13 @@ loongarch_iterate_over_regset_sections (struct gdbarch *gdbarch,
>  					void *cb_data,
>  					const struct regcache *regcache)
>  {
> -  cb (".reg", sizeof (elf_gregset_t), sizeof (elf_gregset_t),
> -      &loongarch_gregset, NULL, cb_data);
> +  loongarch_gdbarch_tdep *tdep
> +    = (loongarch_gdbarch_tdep *) gdbarch_tdep (gdbarch);
> +  auto regs = tdep->regs;
> +  int regsize = register_size (gdbarch, regs.r);
> +
> +  cb (".reg", LOONGARCH_LINUX_NUM_GREGSET * regsize,
> +      LOONGARCH_LINUX_NUM_GREGSET * regsize, &loongarch_gregset, NULL, cb_data);
>  }
>
>  /* Initialize LoongArch Linux ABI info.  */
>