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| author | Fangrui Song <maskray@google.com> | 2023-03-10 11:55:09 -0800 |
|---|---|---|
| committer | Fangrui Song <i@maskray.me> | 2023-03-10 11:55:09 -0800 |
| commit | 2cef48423031d23d319692ceced5ad0110625f69 (patch) | |
| tree | 08175c10a6d1e59b3685e495e866b998bca9ad8e /bfd | |
| parent | d58854b6dd88e05dbf2a5d1c32c5acb7bd6ea274 (diff) | |
| download | binutils-2cef48423031d23d319692ceced5ad0110625f69.zip binutils-2cef48423031d23d319692ceced5ad0110625f69.tar.gz binutils-2cef48423031d23d319692ceced5ad0110625f69.tar.bz2 | |
ld: Allow R_386_GOT32 for call *__tls_get_addr@GOT(%reg)
Similar to d58854b6dd88e05dbf2a5d1c32c5acb7bd6ea274 for x86_64.
_Thread_local int a;
int main() { return a; }
% gcc -m32 -fno-plt -fpic a.c -fuse-ld=bfd -Wa,-mrelax-relocations=no
/usr/bin/ld.bfd: /tmp/ccR8Yexy.o: TLS transition from R_386_TLS_GD to R_386_TLS_IE_32 against `a' at 0x15 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.
There is an argument that the -fno-plt TLS sequence was added after
R_386_GOT32X was required for call *func@GOT(%ebx), so R_386_GOT32 was
intended to be unsupported.
Unfortunately this standpoint has caused interop difficulty: some
projects specify -mrelax-relocations=no to build relocatable object
files compatible with older linkers (e.g.
https://github.com/IHaskell/IHaskell/issues/636) or do so by accident
(e.g. https://github.com/rust-lang/rust/pull/106511 not addressed as of
today). Many uses have not been cleaned up in practice, and compiling
with -fno-plt will lead to the `TLS transition from R_386_TLS_GD ...`
error which is hard to reason about.
It seems easier to apply this simple change to prevent the footgun.
PR ld/24784
* bfd/elf32-i386.c (elf_i386_check_tls_transition): Allow R_386_GOT32.
Diffstat (limited to 'bfd')
| -rw-r--r-- | bfd/elf32-i386.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c index a542029..7e6823b 100644 --- a/bfd/elf32-i386.c +++ b/bfd/elf32-i386.c @@ -963,7 +963,8 @@ elf_i386_check_tls_transition (asection *sec, || !((struct elf_x86_link_hash_entry *) h)->tls_get_addr) return false; else if (indirect_call) - return (ELF32_R_TYPE (rel[1].r_info) == R_386_GOT32X); + return (ELF32_R_TYPE (rel[1].r_info) == R_386_GOT32X + || ELF32_R_TYPE (rel[1].r_info) == R_386_GOT32); else return (ELF32_R_TYPE (rel[1].r_info) == R_386_PC32 || ELF32_R_TYPE (rel[1].r_info) == R_386_PLT32); |