From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Jones Subject: ax25_recvmsg lockup Date: Mon, 17 Jun 2013 10:28:03 -0400 Message-ID: <20130617142803.GB16732@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: netdev@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:57151 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754064Ab3FQReQ (ORCPT ); Mon, 17 Jun 2013 13:34:16 -0400 Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r5HHYFGm012637 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 17 Jun 2013 13:34:16 -0400 Received: from gelk.kernelslacker.org (ovpn-113-48.phx2.redhat.com [10.3.113.48]) by int-mx12.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id r5HHYAtn025189 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Mon, 17 Jun 2013 13:34:15 -0400 Received: from gelk.kernelslacker.org (localhost [127.0.0.1]) by gelk.kernelslacker.org (8.14.7/8.14.5) with ESMTP id r5HESEgE030511 for ; Mon, 17 Jun 2013 10:28:24 -0400 Received: (from davej@localhost) by gelk.kernelslacker.org (8.14.7/8.14.7/Submit) id r5HES4Xw030227 for netdev@vger.kernel.org; Mon, 17 Jun 2013 10:28:04 -0400 Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: With the right arguments from userspace, reading from an ax25 socket can spend long enough in the kernel that it triggers the softlockup detector. I hit a bunch of these traces in a trinity run that I left running over the weekend. Dave BUG: soft lockup - CPU#1 stuck for 22s! [trinity-child1:16261] Modules linked in: bridge 8021q garp stp tun fuse snd_seq_dummy rfcomm bnep nfnetlink hidp ipt_ULOG scsi_transport_iscsi can_bcm ipx p8023 p8022 x25 netrom nfc rose llc2 ax25 caif_socket irda caif pppoe pppox ppp_generic crc_ccitt slhc appletalk psnap can_raw llc can af_rxrpc atm af_key af_802154 rds phonet bluetooth rfkill coretemp hwmon kvm_intel kvm snd_hda_codec_realtek crc32c_intel ghash_clmulni_intel microcode snd_hda_codec_hdmi pcspkr snd_hda_intel snd_hda_codec snd_hwdep snd_seq snd_seq_device usb_debug snd_pcm e1000e snd_page_alloc snd_timer snd ptp pps_core soundcore xfs libcrc32c irq event stamp: 10012027 hardirqs last enabled at (10012026): [] restore_args+0x0/0x30 hardirqs last disabled at (10012027): [] apic_timer_interrupt+0x6a/0x80 softirqs last enabled at (9840102): [] __do_softirq+0x194/0x440 softirqs last disabled at (9840105): [] irq_exit+0xcd/0xe0 CPU: 1 PID: 16261 Comm: trinity-child1 Not tainted 3.10.0-rc6+ #15 [loadavg: 31.07 14.82 9.29 8/188 19161] task: ffff88023c62ca40 ti: ffff880228538000 task.ti: ffff880228538000 RIP: 0010:[] [] _raw_spin_unlock_irqrestore+0x67/0x80 RSP: 0018:ffff880244a03dd8 EFLAGS: 00000292 RAX: ffff88023c62ca40 RBX: ffffffff816ed220 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88023c62ca40 RBP: ffff880244a03de8 R08: 0000000010000101 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff880244a03d48 R13: ffffffff816f5d2f R14: ffff880244a03de8 R15: ffffffff81c4fa40 FS: 00007f187c62d740(0000) GS:ffff880244a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000004f171f8 CR3: 000000022b4fb000 CR4: 00000000001407e0 DR0: 0000000001fe7000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Stack: ffffffff81c4fa40 0000000000000292 ffff880244a03e08 ffffffff810fbf20 0000000000000000 0000000000000000 ffff880244a03eb8 ffffffff810fd0da 0000000000000000 ffff880244a03e40 0000000000000000 ffff880228539fd8 Call Trace: [] rcu_report_qs_rsp+0x30/0x70 [] rcu_report_qs_rnp+0x21a/0x2c0 [] rcu_process_callbacks+0x39f/0x520 [] __do_softirq+0xff/0x440 [] irq_exit+0xcd/0xe0 [] smp_apic_timer_interrupt+0x6b/0x9b [] apic_timer_interrupt+0x6f/0x80 [] ? retint_restore_args+0xe/0xe [] ? wait_for_completion_interruptible+0x180/0x180 [] ? preempt_schedule_irq+0x53/0x90 [] ? release_sock+0x193/0x1f0 [] retint_kernel+0x26/0x30 [] ? local_bh_enable_ip+0x82/0xf0 [] _raw_spin_unlock_bh+0x3a/0x40 [] release_sock+0x193/0x1f0 [] ax25_recvmsg+0xdf/0x210 [ax25] [] ? native_sched_clock+0x24/0x80 [] ? sched_clock_cpu+0xb5/0x100 [] sock_aio_read.part.8+0x116/0x130 [] sock_aio_read+0x21/0x30 [] do_sync_read+0x80/0xb0 [] vfs_read+0x14d/0x170 [] SyS_read+0x4c/0xa0 [] tracesys+0xdd/0xe2 Code: 00 e8 8e 47 00 00 65 48 8b 04 25 f0 b9 00 00 48 8b 80 38 e0 ff ff a8 08 75 13 5b 41 5c 5d c3 0f 1f 44 00 00 e8 ab ad 9c ff 53 9d cf 0f 1f 80 00 00 00 00 e8 bb ea ff ff eb df 66 0f 1f 84 00