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| author | H.J. Lu <hjl.tools@gmail.com> | 2023-12-20 19:42:12 -0800 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2023-12-23 09:05:42 -0800 |
| commit | 2143fcd54025df8ee1e95a31b2cbadcb2e3547ac (patch) | |
| tree | f90a872256f39ace8d8d8fa92423087026abdd5d | |
| parent | ba52b325c43e863fe29e7f83990175c37e379099 (diff) | |
| download | glibc-2143fcd54025df8ee1e95a31b2cbadcb2e3547ac.tar.gz glibc-2143fcd54025df8ee1e95a31b2cbadcb2e3547ac.tar.xz glibc-2143fcd54025df8ee1e95a31b2cbadcb2e3547ac.zip | |
x86-64: Fix the tcb field load for x32 [BZ #31185]
_dl_tlsdesc_undefweak and _dl_tlsdesc_dynamic access the thread pointer
via the tcb field in TCB:
_dl_tlsdesc_undefweak:
_CET_ENDBR
movq 8(%rax), %rax
subq %fs:0, %rax
ret
_dl_tlsdesc_dynamic:
...
subq %fs:0, %rax
movq -8(%rsp), %rdi
ret
Since the tcb field in TCB is a pointer, %fs:0 is a 32-bit location,
not 64-bit. It should use "sub %fs:0, %RAX_LP" instead. Since
_dl_tlsdesc_undefweak returns ptrdiff_t and _dl_make_tlsdesc_dynamic
returns void *, RAX_LP is appropriate here for x32 and x86-64. This
fixes BZ #31185.
(cherry picked from commit 81be2a61dafc168327c1639e97b6dae128c7ccf3)
| -rw-r--r-- | NEWS | 1 | ||||
| -rw-r--r-- | sysdeps/x86_64/dl-tlsdesc.S | 4 |
2 files changed, 3 insertions, 2 deletions
diff --git a/NEWS b/NEWS index ef3a0a4ca7..af73ed99f5 100644 --- a/NEWS +++ b/NEWS @@ -161,6 +161,7 @@ The following bugs are resolved with this release: [30163] posix: Fix system blocks SIGCHLD erroneously [30305] x86_64: Fix asm constraints in feraiseexcept [31184] FAIL: elf/tst-tlsgap + [31185] Incorrect thread point access in _dl_tlsdesc_undefweak and _dl_tlsdesc_dynamic Version 2.34 diff --git a/sysdeps/x86_64/dl-tlsdesc.S b/sysdeps/x86_64/dl-tlsdesc.S index 18f862f003..37b183a0d8 100644 --- a/sysdeps/x86_64/dl-tlsdesc.S +++ b/sysdeps/x86_64/dl-tlsdesc.S @@ -61,7 +61,7 @@ _dl_tlsdesc_return: _dl_tlsdesc_undefweak: _CET_ENDBR movq 8(%rax), %rax - subq %fs:0, %rax + sub %fs:0, %RAX_LP ret cfi_endproc .size _dl_tlsdesc_undefweak, .-_dl_tlsdesc_undefweak @@ -116,7 +116,7 @@ _dl_tlsdesc_dynamic: addq TLSDESC_MODOFF(%rdi), %rax .Lret: movq -16(%rsp), %rsi - subq %fs:0, %rax + sub %fs:0, %RAX_LP movq -8(%rsp), %rdi ret .Lslow: |