From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1791) id 04D563857C46; Tue, 4 Oct 2022 13:05:06 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 04D563857C46 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1664888706; bh=j3ao1TXycNRsrSEa4lIX2vFjg3dj71P30RL37FXTwsg=; h=From:To:Subject:Date:From; b=B4EEgGyvkt5QdMeqzYhLiFwsr9cdCPaV/ns4ZjqqxBg/hsnkYtR/LRBZ05sFXyh/7 Q/zhDv9+HkbWEZvznBniGcGPxocl0wd7+zK0hEfetzVwfF9l+0JjwEgk/Jy9C1JPyU rbzqHS9ZoFM+h0MY05SuVwRVuZnpAWHMIADSLdAg= Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Adhemerval Zanella To: glibc-cvs@sourceware.org Subject: [glibc/azanella/clang] elf: Use volatile to set __rseq_size and __rseq_offset X-Act-Checkin: glibc X-Git-Author: Adhemerval Zanella X-Git-Refname: refs/heads/azanella/clang X-Git-Oldrev: fc18a5d7594b56f7d9bb3d6f4f22d316d86d4076 X-Git-Newrev: bea75ec35c3b0108fd8dcc27b1dc52df1350b96a Message-Id: <20221004130506.04D563857C46@sourceware.org> Date: Tue, 4 Oct 2022 13:05:06 +0000 (GMT) List-Id: https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=bea75ec35c3b0108fd8dcc27b1dc52df1350b96a commit bea75ec35c3b0108fd8dcc27b1dc52df1350b96a Author: Adhemerval Zanella Date: Sun Apr 3 11:23:20 2022 -0300 elf: Use volatile to set __rseq_size and __rseq_offset To avoid compiler to optimize them away. Diff: --- sysdeps/nptl/dl-tls_init_tp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/sysdeps/nptl/dl-tls_init_tp.c b/sysdeps/nptl/dl-tls_init_tp.c index 53fba774a5..01ff90117c 100644 --- a/sysdeps/nptl/dl-tls_init_tp.c +++ b/sysdeps/nptl/dl-tls_init_tp.c @@ -109,7 +109,7 @@ __tls_init_tp (void) { /* We need a writable view of the variables. They are in .data.relro and are not yet write-protected. */ - extern unsigned int size __asm__ ("__rseq_size"); + extern volatile unsigned int size __asm__ ("__rseq_size"); size = sizeof (pd->rseq_area); } @@ -119,7 +119,7 @@ __tls_init_tp (void) all targets support __thread_pointer, so set __rseq_offset only if thre rseq registration may have happened because RSEQ_SIG is defined. */ - extern ptrdiff_t offset __asm__ ("__rseq_offset"); + extern volatile ptrdiff_t offset __asm__ ("__rseq_offset"); offset = (char *) &pd->rseq_area - (char *) __thread_pointer (); #endif }