From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id B980E384E78E; Tue, 13 Dec 2022 18:33:39 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org B980E384E78E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1670956419; bh=IKCNSCg8aJuC2vlDRbhWrFvUnMuV+u+ELY0kcmkdxTc=; h=From:To:Subject:Date:In-Reply-To:References:From; b=RU4ZxuQoY7xqsJ7YXE/IHDSdM8K6NDpDUrePcpzeXf/z3BpYd0fFir2PNreHYxv4f cOCLq/3Ajo9KSGJZ/VMIHQLXfPuQqJL5W8b8D46mO9GeAki1C2rS1G/EiS3bcUHf+K yfFbiVYP+O5VOVobNWT1W697rI386a+NhHHE38p0= From: "nars at yottadb dot com" To: glibc-bugs@sourceware.org Subject: [Bug libc/29863] Segmentation fault in memcmp-sse2.S if memory contents can concurrently change Date: Tue, 13 Dec 2022 18:33:39 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: glibc X-Bugzilla-Component: libc X-Bugzilla-Version: 2.36 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: nars at yottadb dot com X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Resolution: X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: unassigned at sourceware dot org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://sourceware.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 List-Id: https://sourceware.org/bugzilla/show_bug.cgi?id=3D29863 --- Comment #3 from Narayanan Iyer --- (In reply to Andrew Pinski from comment #1) > Is this defined code? Because you have a race condition here. Yes there is a race condition here. That is intentional and only to demonst= rate the underlying issue in memcmp-sse2.S. The `memcmp()` in one thread can return 1 or 0 depending on how the other thread changes the memory. I am fine with the non-deterministic return valu= e. But that should never result in a SIG-11 in my understanding. More importantly this code works fine prior to glibc 2.36. It fails only wi= th glibc 2.36. --=20 You are receiving this mail because: You are on the CC list for the bug.=