On Mon, Nov 23, 2015 at 04:21:34PM +0300, Maxim Ostapenko wrote:
> Yeah, right. I've asked about kernel headers just to make sure I correctly
> understand the issue.
>
> Actually, I see such code in
> lib/sanitizer_common/sanitizer_platform_limits_posix.cc:
>
> #if defined(PTRACE_GETVFPREGS) && defined(PTRACE_SETVFPREGS)
> int ptrace_getvfpregs = PTRACE_GETVFPREGS;
> int ptrace_setvfpregs = PTRACE_SETVFPREGS;
> #else
> int ptrace_getvfpregs = -1;
> int ptrace_setvfpregs = -1;
> #endif
>
> and in ptrace interceptor:
>
> else if (request == ptrace_setvfpregs)
> COMMON_INTERCEPTOR_READ_RANGE(ctx, data, struct_user_vfpregs_struct_sz);
> else if (request == ptrace_getvfpregs)
> COMMON_INTERCEPTOR_WRITE_RANGE(ctx, data, struct_user_vfpregs_struct_sz)
>
> So, perhaps we can do the same thing with ARM_VFPREGS_SIZE, something like
> this?
>
> diff --git
> a/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc
> b/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc
> index 9866cc9..20ff224 100644
> --- a/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc
> +++ b/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc
> @@ -323,10 +323,14 @@ unsigned struct_ElfW_Phdr_sz = sizeof(Elf_Phdr);
> unsigned struct_user_fpxregs_struct_sz = sizeof(struct
> user_fpxregs_struct);
> #endif // __x86_64 || __mips64 || __powerpc64__ || __aarch64__ || __arm__
> #ifdef __arm__
> +#if defined(ARM_VFPREGS_SIZE)
> unsigned struct_user_vfpregs_struct_sz = ARM_VFPREGS_SIZE;
> #else
> unsigned struct_user_vfpregs_struct_sz = 0;
> #endif
> +#else
> + unsigned struct_user_vfpregs_struct_sz = 0;
> +#endif
Maybe, but then it would need to be approved upstream.
If you just define ARM_VFPREGS_SIZE to 0 or whatever else in
the GCC owned wrapper headers, you can avoid that.
I guess talk to upstream.
Jakub
