Hi, On pon, kwi 13, 2009 at 09:20:38 -0500, Serge E. Hallyn wrote: > Quoting Môshe van der Sterre ([email protected]): > > Hello, > > > > I am working on the lxc userspace tools, and got this BUG a couple of > > times. > > Here are the reports: > > > > http://moshe.nl/tty-bugshot1.png > > http://moshe.nl/tty-bugshot2.png > > > > I am running 2.6.29.1 from kernel.org in a virtual machine under kvm. > > I have not been able to reliably reproduce it, but it happens only after > > the container is setup and ptrace is active on lxc-start. > > I think the first screen shot is while all ttys where allowed in > > cgroup.devices, the second one while only tty1 was allowed. > > Which distro is this - an uptodate F10, fresh F11, something else? > > Since it also happens when all ttys are allowed it probably isn't the > devices cgroup... Actually the devpts code seems the most likely > cause. Suka, can you take a look at the 2.6.29.1 source for anything > suspect? > > Môshe, can you send me tty_io.S after doing: > 'objdump -d drivers/char/tty_io.o > tty_io.S' > > as well as strace_output after doing: > 'strace -f -ostrace_output <your_lxc_start_command_here>' > ?
Sorry for digging up such an old thread but I have apparently been bitten by the same bug. I've been playing with libvirt 0.6.4 (which mounts devpts with option newinstance) and I got the oops below while strace'ing container init (upstart actually, got SIGINT and was about to exit; sorry, no strace available but I remember nothing extraordinary except for a "+++ Killed by SIGSEGV +++" at the end). The kernel was vanilla 2.6.30 (hand-rolled on Debian Lenny). The machine is quite uncomfortable to reboot but is not in production use, so I guess I can test some patches if needed. Best regards, Grzegorz Nosek Jul 3 23:23:31 sback kernel: [170809.413989] general protection fault: 0000 [#1] SMP Jul 3 23:23:31 sback kernel: [170809.414024] last sysfs file: /sys/class/net/lo/operstate Jul 3 23:23:31 sback kernel: [170809.414052] CPU 0 Jul 3 23:23:31 sback kernel: [170809.414074] Modules linked in: veth ipt_MASQUERADE iptable_nat nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack ipt_REJECT xt_tcpudp iptable_filter ip_tables x_tables bridge stp llc ipv6 w 83627hf lm85 hwmon_vid loop evdev tg3 libphy k8temp shpchp pci_hotplug i2c_nforce2 i2c_core container thermal processor thermal_sys button Jul 3 23:23:31 sback kernel: [170809.414272] Pid: 13974, comm: init Not tainted 2.6.30-sback #3 S2891 Jul 3 23:23:31 sback kernel: [170809.414301] RIP: 0010:[<ffffffff80437914>] [<ffffffff80437914>] tty_open+0x1fb/0x423 Jul 3 23:23:31 sback kernel: [170809.414354] RSP: 0018:ffff880068015cf8 EFLAGS: 00010246 Jul 3 23:23:31 sback kernel: [170809.414383] RAX: ffff88007e540800 RBX: ffff88007e540800 RCX: ffff88007e8cd708 Jul 3 23:23:31 sback kernel: [170809.414428] RDX: 6973646e65732f64 RSI: 0000000000000000 RDI: ffff880058c8dc10 Jul 3 23:23:31 sback kernel: [170809.414474] RBP: ffff880068015d48 R08: 0000000000000002 R09: 0000000000000000 Jul 3 23:23:31 sback kernel: [170809.414519] R10: 0000000000000167 R11: 0000000000000004 R12: ffff88013ede9000 Jul 3 23:23:31 sback kernel: [170809.414564] R13: ffff88013ede9008 R14: ffff88007e586c00 R15: 0000000000000100 Jul 3 23:23:31 sback kernel: [170809.414609] FS: 00007f4a887056e0(0000) GS:ffffc20000000000(0000) knlGS:0000000000000000 Jul 3 23:23:31 sback kernel: [170809.414656] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b Jul 3 23:23:31 sback kernel: [170809.414685] CR2: 00000000020cd000 CR3: 000000007dc1a000 CR4: 00000000000006e0 Jul 3 23:23:31 sback kernel: [170809.414730] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 Jul 3 23:23:31 sback kernel: [170809.414775] DR3: 0000000000000000 DR6: 00000000ffff4ff0 DR7: 0000000000000400 Jul 3 23:23:31 sback kernel: [170809.414821] Process init (pid: 13974, threadinfo ffff880068014000, task ffff880072560040) Jul 3 23:23:31 sback kernel: [170809.414868] Stack: Jul 3 23:23:31 sback kernel: [170809.414889] ffff88007e586c00 ffff880058c8dc10 0880000000008101 0000000000000001 Jul 3 23:23:31 sback kernel: [170809.414922] 0000000000000000 0000000000000000 0000000000000000 ffff88013ede9008 Jul 3 23:23:31 sback kernel: [170809.414971] 0000000000000000 ffff880058c8dc10 ffff880068015d98 ffffffff802d5b25 Jul 3 23:23:31 sback kernel: [170809.415036] Call Trace: Jul 3 23:23:31 sback kernel: [170809.415059] [<ffffffff802d5b25>] chrdev_open+0x15f/0x17e Jul 3 23:23:31 sback kernel: [170809.415090] [<ffffffff803baa3b>] ? selinux_dentry_open+0xf2/0xfb Jul 3 23:23:31 sback kernel: [170809.415125] [<ffffffff802d59c6>] ? chrdev_open+0x0/0x17e Jul 3 23:23:31 sback kernel: [170809.415154] [<ffffffff802d1082>] __dentry_open+0x155/0x274 Jul 3 23:23:31 sback kernel: [170809.415186] [<ffffffff802d1278>] nameidata_to_filp+0x46/0x57 Jul 3 23:23:31 sback kernel: [170809.415218] [<ffffffff802deb1b>] do_filp_open+0x4ca/0x924 Jul 3 23:23:31 sback kernel: [170809.415251] [<ffffffff802e7ce8>] ? alloc_fd+0x122/0x133 Jul 3 23:23:31 sback kernel: [170809.415281] [<ffffffff802d0e61>] do_sys_open+0x5b/0xdb Jul 3 23:23:31 sback kernel: [170809.415312] [<ffffffff802d0f14>] sys_open+0x20/0x22 Jul 3 23:23:31 sback kernel: [170809.415341] [<ffffffff8020bf36>] tracesys+0xd9/0xde Jul 3 23:23:31 sback kernel: [170809.415373] Code: 81 fb 00 f0 ff ff 76 11 48 c7 c7 60 61 7d 80 e8 c1 38 17 00 e9 a9 00 00 00 48 85 db 74 5c 80 bb 40 01 00 00 00 48 8b 53 08 78 64 <81> ba 9c 00 00 00 04 00 01 00 75 16 83 bb 48 01 00 0 0 00 75 4f Jul 3 23:23:31 sback kernel: [170809.415582] RIP [<ffffffff80437914>] tty_open+0x1fb/0x423 Jul 3 23:23:31 sback kernel: [170809.415612] RSP <ffff880068015cf8> Jul 3 23:23:31 sback kernel: [170809.415869] ---[ end trace e65e6319b2f34f5a ]--- Decoding the code yields: All code ======== 0: 81 fb 00 f0 ff ff cmp $0xfffff000,%ebx 6: 76 11 jbe 0x19 8: 48 c7 c7 60 61 7d 80 mov $0xffffffff807d6160,%rdi f: e8 c1 38 17 00 callq 0x1738d5 14: e9 a9 00 00 00 jmpq 0xc2 19: 48 85 db test %rbx,%rbx 1c: 74 5c je 0x7a 1e: 80 bb 40 01 00 00 00 cmpb $0x0,0x140(%rbx) 25: 48 8b 53 08 mov 0x8(%rbx),%rdx 29: 78 64 js 0x8f 2b:* 81 ba 9c 00 00 00 04 cmpl $0x10004,0x9c(%rdx) <-- trapping instruction 32: 00 01 00 35: 75 16 jne 0x4d 37: 83 .byte 0x83 38: bb 48 01 00 00 mov $0x148,%ebx Code starting with the faulting instruction =========================================== 0: 81 ba 9c 00 00 00 04 cmpl $0x10004,0x9c(%rdx) 7: 00 01 00 a: 75 16 jne 0x22 c: 83 .byte 0x83 d: bb 48 01 00 00 mov $0x148,%ebx _______________________________________________ Containers mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/containers _______________________________________________ Devel mailing list [email protected] https://openvz.org/mailman/listinfo/devel
