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authorH.J. Lu <hjl.tools@gmail.com>2023-12-20 16:31:43 -0800
committerH.J. Lu <hjl.tools@gmail.com>2023-12-23 06:06:26 -0800
commit35ea7549751d4f13a28c732e6ad68204f5e60a06 (patch)
treefab4949912a03fe266838461def7e49191984675
parent0de9082ed8d8f149ca87d569a73692046e236c18 (diff)
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--NEWS1
-rw-r--r--sysdeps/x86_64/dl-tlsdesc.S2
2 files changed, 2 insertions, 1 deletions
diff --git a/NEWS b/NEWS
index 5ac488bf9b..71057e4793 100644
--- a/NEWS
+++ b/NEWS
@@ -37,6 +37,7 @@ The following bugs are resolved with this release:
[30804] F_GETLK, F_SETLK, and F_SETLKW value change for powerpc64 with
-D_FILE_OFFSET_BITS=64
[30842] Stack read overflow in getaddrinfo in no-aaaa mode (CVE-2023-4527)
+ [31184] FAIL: elf/tst-tlsgap
Version 2.38
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