From: H.J. Lu Date: Thu, 21 Dec 2023 00:31:43 +0000 (-0800) Subject: x86-64: Fix the dtv field load for x32 [BZ #31184] X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6a1168279d770ee9631d8d0409768ac67c96be3c;p=thirdparty%2Fglibc.git 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 ed72d2f2e6d..377660ece0f 100644 --- a/NEWS +++ b/NEWS @@ -87,6 +87,7 @@ 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 2.36 diff --git a/sysdeps/x86_64/dl-tlsdesc.S b/sysdeps/x86_64/dl-tlsdesc.S index 0db2cb41526..706856e095d 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