From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1039) id 025343858D3C; Fri, 22 Dec 2023 13:37:35 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 025343858D3C DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1703252255; bh=Lmm+1QN3eORsnKljJiWp+8d19ANI1TbejPiqxk5aL5o=; h=From:To:Subject:Date:From; b=PWfhtJg/45Eqh38Hmh51NsTtka+rhZAZem8RKyJTpUjPT4fxPMOcKt6kxYXJbJQdC koB5P5LILOBkjyFV5zo+tEWCGVgx7KWpL10SKqDjiKYT6jA0nZX2Ku7CMMwUKtTcdt +S3CFzEVev3FKMZNyF0fUiIlAxZ2IyY5QBYRNpIs= Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: H.J. Lu To: glibc-cvs@sourceware.org Subject: [glibc] x86-64: Fix the dtv field load for x32 [BZ #31184] X-Act-Checkin: glibc X-Git-Author: H.J. Lu X-Git-Refname: refs/heads/master X-Git-Oldrev: 61bac1a9d2ab80ebcbc51484722e6ea43414bec7 X-Git-Newrev: 3502440397bbb840e2f7223734aa5cc2cc0e29b6 Message-Id: <20231222133735.025343858D3C@sourceware.org> Date: Fri, 22 Dec 2023 13:37:35 +0000 (GMT) List-Id: https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=3502440397bbb840e2f7223734aa5cc2cc0e29b6 commit 3502440397bbb840e2f7223734aa5cc2cc0e29b6 Author: H.J. Lu Date: Wed Dec 20 16:31:43 2023 -0800 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. Diff: --- sysdeps/x86_64/dl-tlsdesc.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) 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