From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 16705 invoked by alias); 12 Feb 2013 07:08:36 -0000 Received: (qmail 16542 invoked by uid 48); 12 Feb 2013 07:08:19 -0000 From: "bugdal at aerifal dot cx" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/55431] Invalid auxv search in ppc linux-unwind code. Date: Tue, 12 Feb 2013 07:08:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: target X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: bugdal at aerifal dot cx X-Bugzilla-Status: ASSIGNED X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: amodra at gmail dot com X-Bugzilla-Target-Milestone: --- X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org X-SW-Source: 2013-02/txt/msg01130.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55431 --- Comment #6 from Rich Felker 2013-02-12 07:08:14 UTC --- That sounds highly doubtful. The sigcontext is (necessarily) on the stack, so the only way accessing past the end of sigcontext could fault is if the access were so far beyond the end to go completely off the stack. The only way this might be plausible is under sigaltstack. In any case, why would this code be reading beyond the end? Does the kernel use different incompatible sigcontext structures based on which vector registers exist on the cpu?