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)

diff --git a/NEWS b/NEWS
index 625780a01aa3d5ca40d446bc998fd9b47803463c..ef3a0a4ca7dbce1dcaf35a4f5c6015b1d64a36c6 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -160,6 +160,7 @@ The following bugs are resolved with this release:
   [30151] gshadow: Matching sgetsgent, sgetsgent_r ERANGE handling
   [30163] posix: Fix system blocks SIGCHLD erroneously
   [30305] x86_64: Fix asm constraints in feraiseexcept
+  [31184] FAIL: elf/tst-tlsgap
 
 \f
 Version 2.34

diff --git a/sysdeps/x86_64/dl-tlsdesc.S b/sysdeps/x86_64/dl-tlsdesc.S
index ca9236bed86596456b40890a1b157b1409a87d8b..18f862f0032b269b1bd92fb42086358481168b74 100644 (file)
--- 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