[PATCH] ld: Allow R_X86_64_GOTPCREL for call *__tls_get_addr@GOTPCREL(%rip)

[H.J. Lu]

On Thu, Jan 5, 2023 at 1:06 PM Fangrui Song via Binutils
<binutils@sourceware.org> wrote:
>
> _Thread_local int a;
> int main() { return a; }
>
> % gcc -fno-plt -fpic a.c -fuse-ld=bfd -Wa,-mrelax-relocations=no
> /usr/bin/ld.bfd: /tmp/ccSSBgrg.o: TLS transition from R_X86_64_TLSGD to R_X86_64_GOTTPOFF against `a' at 0xd in section `.text' failed
> /usr/bin/ld.bfd: failed to set dynamic section sizes: bad value
> collect2: error: ld returned 1 exit status
>
> This commit fixes the issue.
>
>     PR ld/24784
>     * bfd/elf64-x86-64.c (elf_x86_64_check_tls_transition): Allow
>       R_X86_64_GOTPCREL.
> ---
>  bfd/elf64-x86-64.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
> index 914f82d0151..095fe2e0fe6 100644
> --- a/bfd/elf64-x86-64.c
> +++ b/bfd/elf64-x86-64.c
> @@ -1241,7 +1241,7 @@ elf_x86_64_check_tls_transition (bfd *abfd,
>           if (largepic)
>             return r_type == R_X86_64_PLTOFF64;
>           else if (indirect_call)
> -           return r_type == R_X86_64_GOTPCRELX;
> +           return (r_type == R_X86_64_GOTPCRELX || r_type == R_X86_64_GOTPCREL);
>           else
>             return (r_type == R_X86_64_PC32 || r_type == R_X86_64_PLT32);
>         }
> --
> 2.39.0.314.g84b9a713c41-goog
>

Since the new TLS sequence was added after R_X86_64_GOTPCRELX was
required for call, R_X86_64_GOTPCREL should be invalid in this TLS sequence.

-- 
H.J.