Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755086AbYH0Vav (ORCPT ); Wed, 27 Aug 2008 17:30:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750784AbYH0Vaj (ORCPT ); Wed, 27 Aug 2008 17:30:39 -0400 Received: from mu-out-0910.google.com ([209.85.134.188]:31391 "EHLO mu-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752772AbYH0Vai (ORCPT ); Wed, 27 Aug 2008 17:30:38 -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:in-reply-to:user-agent; b=oMt5q3C3ibk7veeytBWZrivQ5raswEwETvDW+Vd9oCrqTmvBDfwwo5/aX2UD4CUQ41 vgy+I1Sf6E01Jp5hfxYpTcV0eTXFuOJp2s41gYGx6DzaoknqTXTEwM+kLyUc3OvhXMB7 Wvsr+k51Cpah92VwdjNA5cJnEPHnT8l3QzkM8= Date: Thu, 28 Aug 2008 01:32:11 +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: <20080827213211.GA31861@x200.localdomain> References: <20080826220102.89635154233@magilla.localdomain> <20080826220157.397C7154233@magilla.localdomain> <20080826225519.GC27724@x200.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080826225519.GC27724@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: 3141 Lines: 57 > 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: kernel/utrace.c:532 if (likely(!utrace->stopped)) BUG: unable to handle kernel paging request at ffff88017c51c958 IP: [] utrace_stop+0x9b/0x120 PGD 202063 PUD b067 PMD 17d8e5163 PTE 800000017c51c160 Oops: 0000 [1] PREEMPT SMP DEBUG_PAGEALLOC last sysfs file: /sys/kernel/uevent_seqnum CPU 0 Modules linked in: ipt_MASQUERADE iptable_nat nf_nat nf_conntrack_ipv4 xt_state nf_conntrack iptable_filter ip_tables xt_tcpudp ip6table_filter ip6_tables x_tables ipv6 sr_mod cdrom Pid: 32731, comm: exe Tainted: G W 2.6.27-rc4-next-20080827-utrace #4 RIP: 0010:[] [] utrace_stop+0x9b/0x120 RSP: 0000:ffff88017c521c38 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff88017c02b880 RCX: 0000000000000000 RDX: 000000000000ebea RSI: 00000000ffffffff RDI: 0000000000000001 RBP: ffff88017c521c58 R08: 0000000000000002 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000001 R12: ffff88017c51c8e8 R13: ffff88017c51c918 R14: ffff88017c51c8e8 R15: ffff88017c02b880 FS: 00007fe23dcf66f0(0000) GS:ffffffff8054b600(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: ffff88017c51c958 CR3: 000000017c077000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process exe (pid: 32731, threadinfo ffff88017c520000, task ffff88017c02b880) Stack: ffff88017c51c8e8 ffff88017c521ce8 ffff88017c51c8e8 ffff88017c02b880 ffff88017c521c88 ffffffff8025e4b0 ffff88017f92e360 ffff88017c51c8f8 ffff88017f92e360 ffff88017c51c8f0 ffff88017c521d38 ffffffff8025fb05 Call Trace: [] finish_resume_report+0xa0/0xd0 [] utrace_get_signal+0x305/0x710 [] get_signal_to_deliver+0x24c/0x310 [] do_notify_resume+0xd4/0x860 [] ? trace_hardirqs_off+0xd/0x10 [] ? _spin_unlock_irqrestore+0x42/0x80 [] ? hrtimer_start+0x11a/0x1f0 [] ? trace_hardirqs_on+0xd/0x10 [] ? _spin_unlock_irq+0x36/0x60 [] ? finish_task_switch+0x68/0xe0 [] ? finish_task_switch+0x0/0xe0 [] ? thread_return+0xa4/0x548 [] ? sysret_signal+0x19/0x29 [] ptregscall_common+0x67/0xb0 Code: 42 78 48 8b bb 60 04 00 00 48 81 c7 08 08 00 00 e8 db f4 1c 00 4c 89 ef e8 33 f3 1c 00 66 83 7b 1a 05 74 1a e8 97 c0 1c 00 31 c0 <41> f6 44 24 70 01 75 32 48 83 c4 08 5b 41 5c 41 5d c9 c3 48 c7 RIP [] utrace_stop+0x9b/0x120 RSP CR2: ffff88017c51c958 ---[ end trace 4eaa2a86a8e2da22 ]--- -- 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/