diff options
| author | H.J. Lu <hjl.tools@gmail.com> | 2023-12-20 16:31:43 -0800 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2023-12-22 05:37:00 -0800 |
| commit | 3502440397bbb840e2f7223734aa5cc2cc0e29b6 (patch) | |
| tree | dc6ca80d1ce3455ae7fe5c24f44fc83c047a73de | |
| parent | 61bac1a9d2ab80ebcbc51484722e6ea43414bec7 (diff) | |
| download | glibc-3502440397bbb840e2f7223734aa5cc2cc0e29b6.tar.gz glibc-3502440397bbb840e2f7223734aa5cc2cc0e29b6.tar.xz glibc-3502440397bbb840e2f7223734aa5cc2cc0e29b6.zip | |
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.
| -rw-r--r-- | sysdeps/x86_64/dl-tlsdesc.S | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/sysdeps/x86_64/dl-tlsdesc.S b/sysdeps/x86_64/dl-tlsdesc.S index 5593897e29..c4823547d7 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 |