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| author | H.J. Lu <hjl.tools@gmail.com> | 2023-12-20 16:31:43 -0800 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2023-12-23 07:49:23 -0800 |
| commit | 2d87262c1c4ed877a51a4689db0ac2e08fba2f43 (patch) | |
| tree | 61551f61f2a8592d705f60e676468b8f21645878 | |
| parent | 5f08ec08d03930050befec16fcc6264fa00c66fe (diff) | |
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x86-64: Fix the dtv field load for x32 [BZ #31184]
On x32, I got
FAIL: elf/tst-tlsgap
$ gdb elf/tst-tlsgap
...
open tst-tlsgap-mod1.so
Thread 2 "tst-tlsgap" received signal SIGSEGV, Segmentation fault.
[Switching to LWP 2268754]
_dl_tlsdesc_dynamic () at ../sysdeps/x86_64/dl-tlsdesc.S:108
108 movq (%rsi), %rax
(gdb) p/x $rsi
$4 = 0xf7dbf9005655fb18
(gdb)
This is caused by
_dl_tlsdesc_dynamic:
_CET_ENDBR
/* Preserve call-clobbered registers that we modify.
We need two scratch regs anyway. */
movq %rsi, -16(%rsp)
movq %fs:DTV_OFFSET, %rsi
Since the dtv field in TCB is a pointer, %fs:DTV_OFFSET is a 32-bit
location, not 64-bit. Load the dtv field to RSI_LP instead of rsi.
This fixes BZ #31184.
(cherry picked from commit 3502440397bbb840e2f7223734aa5cc2cc0e29b6)
| -rw-r--r-- | NEWS | 1 | ||||
| -rw-r--r-- | sysdeps/x86_64/dl-tlsdesc.S | 2 |
2 files changed, 2 insertions, 1 deletions
@@ -84,6 +84,7 @@ The following bugs are resolved with this release: [30515] _dl_find_object incorrectly returns 1 during early startup [30804] F_GETLK, F_SETLK, and F_SETLKW value change for powerpc64 with -D_FILE_OFFSET_BITS=64 + [31184] FAIL: elf/tst-tlsgap Security related changes: diff --git a/sysdeps/x86_64/dl-tlsdesc.S b/sysdeps/x86_64/dl-tlsdesc.S index 0db2cb4152..706856e095 100644 --- a/sysdeps/x86_64/dl-tlsdesc.S +++ b/sysdeps/x86_64/dl-tlsdesc.S @@ -102,7 +102,7 @@ _dl_tlsdesc_dynamic: /* Preserve call-clobbered registers that we modify. We need two scratch regs anyway. */ movq %rsi, -16(%rsp) - movq %fs:DTV_OFFSET, %rsi + mov %fs:DTV_OFFSET, %RSI_LP movq %rdi, -8(%rsp) movq TLSDESC_ARG(%rax), %rdi movq (%rsi), %rax |