* Mathieu Desnoyers <comp...@krystal.dyndns.org> wrote: > * Mathieu Desnoyers (mathieu.desnoy...@polymtl.ca) wrote: > > * Ingo Molnar (mi...@elte.hu) wrote: > > > > > > * Mathieu Desnoyers <mathieu.desnoy...@polymtl.ca> wrote: > > > > > > > Here is a new backtrace, taken with a huge amount of debugging active, > > > > which still > > > > points to an interrupt handler nested over kvm_mmu_pte_write as the > > > > culprit. It's > > > > weird that the kvm code gets called on my modest Pentium M laptop, > > > > which I think > > > > has no VT-x support at all. I am not running any KVM VMs on this > > > > machine. The > > > > problem still happens on 2.6.28.4, and Slub redzones did not identify > > > > any memory > > > > corruption. This could be due to kvm_mmu_pte_write which either should > > > > not be > > > > called at all, or due to improper interrupt disabling in this function. > > > > > > Does latest tip:master fix it? In particular this one: > > > > > > 9cf161a: x86/cpa: make sure cpa is safe to call in lazy mmu mode > > > > > > fixes a crasher related to KVM and mmu notifiers ... > > > > > > Ingo > > > > I'll try to apply commit > > 9cf161a: x86/cpa: make sure cpa is safe to call in lazy mmu mode > > > > To my 2.6.28.4 kernel to change the configuration minimally and see if > > it helps. I guess we'll have to wait a few days before the problem is > > reproduced, and even more if it's not. :) > > > > OK, it's been much faster to reproduce now that the patch above is > applied. New stack trace, different this time, but still pointing to > data corruption seen by get_next_timer_interrupt. It happens in the > first 5 minutes after bootup. > > > BUG: unable to handle kernel NULL pointer dereference at 00000000 > IP: [<c1049aaa>] get_next_timer_interrupt+0x4a/0x220 > *pde = 00000000 > Oops: 0000 [#1] PREEMPT DEBUG_PAGEALLOC > LTT NESTING LEVEL : 0 > last sysfs file: /sys/devices/pci0000:00/0000:00:1e.0/0000:0b:02.0/rf_kill > Modules linked in: soundcore snd snd_rawmidi serio_raw snd_seq_midi > cryptoloop snd_seq_oss snd_seq_device ipw2200 psmouse unix snd_timer snd_seq > usbhid loop nvram pcmcia joydev aes_i586 snd_seq_dummy evdev i2c_i801 > snd_seq_midi_event blowfish rsrc_nonstatic led_class ide_generic rfkill > ide_cd_mod edd acpi_cpufreq hid_logitech sir_dev pcmcia_core thinkpad_acpi > ltt_control ltt_statedump dm_mod snd_intel8x0m irtty_sir yenta_socket > snd_mixer_oss ac97_bus agpgart floppy snd_pcm button dm_log dm_region_hash > dm_mirror dm_snapshot snd_pcm_oss vfat thermal fat intel_agp snd_intel8x0 > nls_cp437 crc_ccitt irda nls_iso8859_1 snd_ac97_codec lp parport ppdev > bluetooth af_packet binfmt_misc parport_pc l2cap drm nsc_ircc ac rfcomm > output video radeon battery lockd libphy ntfs ipv6 tg3 snd_page_alloc sunrpc > nfs > > Pid: 0, comm: swapper Not tainted (2.6.28.4-trace-00235-g6523760-dirty #15) > 2687D5U > EIP: 0060:[<c1049aaa>] EFLAGS: 00010002 CPU: 0 > EIP is at get_next_timer_interrupt+0x4a/0x220 > EAX: 0000006c EBX: c14f2b84 ECX: 00000000 EDX: 00000000 > ESI: c14f2800 EDI: 0000006c EBP: c1489ec8 ESP: c1489e90 > DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068 > Process swapper (pid: 0, ti=c1488000 task=c14473a0 task.ti=c1488000) > Stack: > ffffbe6c ffffbe6b c14f2800 0000001e 00000000 00000030 00000000 c1489ec0 > c105a696 00000000 00000030 0000001e 00000001 ffffbe6b c1489f10 c1060bf8 > c1044f67 00000046 c1077601 00000001 c25f5d4f 0000001e c25e9f80 0000001e > Call Trace: > [<c105a696>] ? sched_clock_cpu+0xc6/0x120 > [<c1060bf8>] ? tick_nohz_stop_sched_tick+0x158/0x370 > [<c1044f67>] ? __do_softirq+0x177/0x1f0 > [<c1077601>] ? handle_edge_irq+0xd1/0x130 > [<c104523e>] ? irq_exit+0x7e/0x90 > [<c1021aad>] ? do_IRQ+0x7d/0x90 > [<c10207b4>] ? common_interrupt+0x28/0x30 > [<c1195d15>] ? acpi_idle_enter_simple+0x175/0x1e2 > [<c124b7ad>] ? cpuidle_idle_call+0x6d/0xb0 > [<c101ea15>] ? cpu_idle+0x55/0xb0 > [<c12f9781>] ? rest_init+0x61/0x70 > Code: 0f b6 f9 89 4d c8 89 f8 8b 75 d0 8b 54 c6 24 8b 0a 0f 18 01 90 8d 5c c6 > 24 39 da 75 1c e9 f9 00 00 00 8d b4 26 00 00 00 00 89 ca <8b> 09 0f 18 01 90 > 39 da 0f 84 e2 00 00 00 f6 42 14 01 75 ea 85 > EIP: [<c1049aaa>] get_next_timer_interrupt+0x4a/0x220 SS:ESP 0068:c1489e90 > ---[ end trace 32ebcf3d2f51bd62 ]--- > Kernel panic - not syncing: Attempted to kill the idle task! > BUG: spinlock lockup on CPU#0, swapper/0, c14f2800 > Pid: 0, comm: swapper Tainted: G D > 2.6.28.4-trace-00235-g6523760-dirty #15 > Call Trace: > [<c115ab5b>] _raw_spin_lock+0x10b/0x120 > [<c1302cb9>] _spin_lock_irq+0x49/0x50 > [<c1049309>] ? run_timer_softirq+0x29/0x1b0 > [<c1049309>] run_timer_softirq+0x29/0x1b0 > [<c101fcd0>] ? restore_nocheck_notrace+0x0/0xe > [<c1044ebe>] __do_softirq+0xce/0x1f0 > [<c1058cf5>] ? hrtimer_interrupt+0x185/0x1a0 > [<c104504d>] do_softirq+0x6d/0x80 > [<c1045245>] irq_exit+0x85/0x90 > [<c102ecb5>] smp_apic_timer_interrupt+0xd5/0x130 > [<c10207e9>] apic_timer_interrupt+0x2d/0x34 > [<c12ffd14>] ? panic+0x7b/0xf3 > [<c10430de>] do_exit+0x68e/0x810 > [<c103f98a>] ? print_oops_end_marker+0x2a/0x30 > [<c12ffdeb>] ? printk+0x5f/0x6c > [<c103f98a>] ? print_oops_end_marker+0x2a/0x30 > [<c1304191>] oops_end+0xa1/0xb0 > [<c1022164>] die+0x54/0x70 > [<c1305670>] ? do_page_fault+0x0/0xa60 > [<c1305ac7>] do_page_fault+0x457/0xa60 > [<c1302a19>] ? _spi....
hm, corrupted timer list? Have you tried my suggestions: debugojects, pagealloc, etc? Ingo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html