Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755725AbYH0V7Z (ORCPT ); Wed, 27 Aug 2008 17:59:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753294AbYH0V7R (ORCPT ); Wed, 27 Aug 2008 17:59:17 -0400 Received: from nf-out-0910.google.com ([64.233.182.186]:14186 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752495AbYH0V7Q (ORCPT ); Wed, 27 Aug 2008 17:59:16 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:content-transfer-encoding :in-reply-to:user-agent; b=F2kC725cvspDum4hM+j5Dl8nmAhUcjFOEEuNVxx8xYqiNv/Ur7XxLVgkUS6SajNyjg h0jggHgqbYtMh+ZJkIPz7tGIA67cEuFwXBXjDd+orNohzMPjrqkAlFx24j1toWMNHSGx zuel+maqPH4Cza3+PiOgY71gGomlOSm3HKAzo= Date: Thu, 28 Aug 2008 02:00:50 +0400 From: Alexey Dobriyan To: Roland McGrath Cc: Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] utrace core Message-ID: <20080827220050.GA32334@x200.localdomain> References: <20080826220102.89635154233@magilla.localdomain> <20080826220157.397C7154233@magilla.localdomain> <20080826225519.GC27724@x200.localdomain> <20080827213211.GA31861@x200.localdomain> <20080827214652.GA32163@x200.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20080827214652.GA32163@x200.localdomain> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3118 Lines: 60 On Thu, Aug 28, 2008 at 01:46:52AM +0400, Alexey Dobriyan wrote: > On Thu, Aug 28, 2008 at 01:32:11AM +0400, Alexey Dobriyan wrote: > > > And run to confirm that attach/detach/exec program still crashes it. > > > There is PREEMPT_RCU now so it will be even more not funny. > > > > As promised, quickly reproducible via expt_ptratt.c: > > Another one: And overwritten poison if run in parallel with while true; do killall -9 expl_ptratt killall -9 exe done ============================================================================= BUG utrace: Poison overwritten ----------------------------------------------------------------------------- INFO: 0xffff88017c31e7b0-0xffff88017c31e7f0. First byte 0x6c instead of 0x6b INFO: Allocated in utrace_attach_task+0x1f4/0x3d0 age=13 cpu=1 pid=5377 INFO: Freed in utrace_free+0x16/0x20 age=5 cpu=1 pid=5377 INFO: Slab 0xffffe2000532ae90 objects=21 used=2 fp=0xffff88017c31e780 flags=0x80000000000000c3 INFO: Object 0xffff88017c31e780 @offset=1920 fp=0xffff88017c31e540 Bytes b4 0xffff88017c31e770: fc 1f ff ff 00 00 00 00 5a 5a 5a 5a 5a 5a 5a 5a ?.??....ZZZZZZZZ Object 0xffff88017c31e780: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk Object 0xffff88017c31e790: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk Object 0xffff88017c31e7a0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk Object 0xffff88017c31e7b0: 6c 6c 6b 6b 6b 6b 6b 6b ff ff ff ff 6b 6b 6b 6b llkkkkkk????kkkk Object 0xffff88017c31e7c0: ff ff ff ff ff ff ff ff 6b 6b 6b 6b 6b 6b 6b 6b ????????kkkkkkkk Object 0xffff88017c31e7d0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk Object 0xffff88017c31e7e0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk Object 0xffff88017c31e7f0: 6a 6b 6b 6b 6b 6b 6b a5 jkkkkkk? Redzone 0xffff88017c31e7f8: bb bb bb bb bb bb bb bb ???????? Padding 0xffff88017c31e838: 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZ Pid: 5382, comm: expl_ptratt Tainted: G W 2.6.27-rc4-next-20080827-utrace #5 Call Trace: [] print_trailer+0xf9/0x160 [] check_bytes_and_report+0xa5/0xd0 [] check_object+0xa8/0x250 [] __slab_alloc+0x4f3/0x670 [] ? utrace_attach_task+0x1f4/0x3d0 [] ? utrace_attach_task+0x1f4/0x3d0 [] kmem_cache_alloc+0xb1/0xd0 [] utrace_attach_task+0x1f4/0x3d0 [] ptrace_attach_utrace+0x27/0x80 [] ptrace_attach+0x48/0x1b0 [] sys_ptrace+0xc0/0xd0 [] system_call_fastpath+0x16/0x1b FIX utrace: Restoring 0xffff88017c31e7b0-0xffff88017c31e7f0=0x6b FIX utrace: Marking all objects used -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/