Control: retitle -1 WARNING from rcu_preempt_check_blocked_tasks() in Xen VM Control: tag -1 moreinfo On Sun, 2013-07-21 at 21:26 +0200, Oliver Lorenz wrote: > Package: src:linux > Version: 3.2.46-1 > Severity: normal > > Dear Maintainer, > > I saw the segmentation fault in my logs today. Don't know what caused it or how > to reproduce it. Please don't assume that a call trace indicates a segmentation fault. You have to look at the message before it. In this case it is a WARNING which indicates a error detected in software and is usually non-fatal. [...] > [66283.532082] ------------[ cut here ]------------ > [66283.532092] WARNING: at /build/linux-s5x2oE/linux-3.2.46/kernel/rcutree_plugin.h:1011 rcu_start_gp+0x12f/0x20f() > [66283.532096] Modules linked in: xt_connlimit xt_tcpudp xt_state ipt_REJECT nf_nat_irc nf_nat_ftp iptable_nat nf_nat nf_conntrack_irc nf_conntrack_ftp nf_conntrack_ipv4 nf_defrag_ipv4 nf_conntrack ip6table_filter ip6_tables tun xt_multiport iptable_filter ip_tables x_tables evdev snd_pcm snd_page_alloc coretemp crc32c_intel snd_timer snd ghash_clmulni_intel soundcore aesni_intel pcspkr aes_x86_64 aes_generic cryptd ext4 crc16 jbd2 mbcache xen_blkfront xen_netfront > [66283.532131] Pid: 14, comm: ksoftirqd/2 Not tainted 3.2.0-4-amd64 #1 Debian 3.2.46-1 > [66283.532134] Call Trace: > [66283.532140] [<ffffffff81046b75>] ? warn_slowpath_common+0x78/0x8c > [66283.532145] [<ffffffff8109509a>] ? rcu_start_gp+0x12f/0x20f > [66283.532150] [<ffffffff81095947>] ? __rcu_process_callbacks+0x11d/0x2ce > [66283.532153] [<ffffffff81095b22>] ? rcu_process_callbacks+0x2a/0x54 > [66283.532158] [<ffffffff8104c1ac>] ? __do_softirq+0xb9/0x177 > [66283.532161] [<ffffffff8104c2e4>] ? run_ksoftirqd+0x7a/0x118 > [66283.532165] [<ffffffff8104c26a>] ? __do_softirq+0x177/0x177 > [66283.532170] [<ffffffff8105f48d>] ? kthread+0x76/0x7e > [66283.532176] [<ffffffff81355cb4>] ? kernel_thread_helper+0x4/0x10 > [66283.532180] [<ffffffff81353d73>] ? int_ret_from_sys_call+0x7/0x1b > [66283.532184] [<ffffffff8134ee7c>] ? retint_restore_args+0x5/0x6 > [66283.532189] [<ffffffff81355cb0>] ? gs_change+0x13/0x13 > [66283.532191] ---[ end trace 325beebbbd3ea67c ]--- [...] According to <http://thread.gmane.org/gmane.linux.kernel/1243708/focus=1243798>, this WARNING could sometimes appear 'legitimately' i.e. it wouldn't indicate a real error. (Which would mean the WARNING is itself buggy!) Unfortunately, there is nothing here that could tell us where the bug is. If this error reoccurs then perhaps you can identify some triggering behaviour. And if it recocurs frequently, I can provide a patch based on the thread linked above which you can then use to gather information for debugging. Ben. -- Ben Hutchings The most exhausting thing in life is being insincere. - Anne Morrow Lindberg
Attachment:
signature.asc
Description: This is a digitally signed message part