From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 9023 invoked by alias); 28 May 2010 11:49:20 -0000 Received: (qmail 8971 invoked by uid 48); 28 May 2010 11:49:06 -0000 Date: Fri, 28 May 2010 11:49:00 -0000 Message-ID: <20100528114906.8970.qmail@sourceware.org> X-Bugzilla-Reason: CC References: Subject: [Bug tree-optimization/44290] [4.5 Regression] arm linux kernel crahes when built with -fipa-sra In-Reply-To: Reply-To: gcc-bugzilla@gcc.gnu.org To: gcc-bugs@gcc.gnu.org From: "mikpe at it dot uu dot se" 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: 2010-05/txt/msg03120.txt.bz2 ------- Comment #6 from mikpe at it dot uu dot se 2010-05-28 11:49 ------- Confirmed. A linux-2.6.34 kernel configured for ARM and compiled with gcc-4.5-20100520 crashes during boot with a NULL pointer dereference in its copy_user_highpage() exactly at the point where it tries to start /sbin/init. HIGHMEM enabled or not makes no difference. The same kernel compiled with gcc-4.4.4 boots fine. Both gcc's were configured for armv5tel-unknown-linux-gnu --with-arch=armv5te --with-tune=xscale. The linux kernels were built for mach-iop32x/n2100 (XScale IOP80219). I note that copypage-xscale.c:xscale_mc_copy_user_highpage() calls a __naked function to do the bulk copy. Converting that to a plain inline function (changing 'pc' to 'lr' in the final instruction that restores the scrach regs), does not prevent the crash. So I suspect a plain C code miscompilation. I'll try to bisect it. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44290