random bug generator (was: 2.6.21-git4 Scheduler, NOHZ, VFS bugs)

[Michal Piotrowski <michal.k.k.piotrowski@gmail.com>]

Hi,

Michal Piotrowski napisał(a):
> On 04/05/07, Andrew Morton <akpm@linux-foundation.org> wrote:
>> On Fri, 04 May 2007 18:20:51 +0200 Michal Piotrowski
>> <michal.k.k.piotrowski@gmail.com> wrote:
>>
>> > I ran this script tree times,
>> >
>> > #! /bin/sh
>> >
>> > for i in `find /sys/ -type f`
>> > do
>> >     echo "wyświetlam $i"
>> >     sudo cat $i > /dev/null
>> > done
>> >
>> > First run - scheduler bug
>> > Second run - NOHZ bug
>> > Third - VFS bug
>> >
>> > Hmmmm...
>> >
>> > [93298.252601] BUG: at /mnt/md0/devel/linux-git/kernel/sched.c:3241
>> add_preempt_count()
>> > [93298.260334]  [<c0105039>] show_trace_log_lvl+0x1a/0x2f
>> > [93298.265507]  [<c0105720>] show_trace+0x12/0x14
>> > [93298.269974]  [<c01057d2>] dump_stack+0x16/0x18
>> > [93298.274434]  [<c011d18a>] add_preempt_count+0x89/0x8b
>> > [93298.279501]  [<c0126492>] irq_enter+0xd/0x2e
>> > [93298.283788]  [<c0114c1e>] smp_apic_timer_interrupt+0x2a/0x84
>> > [93298.289458]  [<c0104b2b>] apic_timer_interrupt+0x33/0x38
>> > [93298.294783]  [<c0257b79>] show_uevent+0x58/0xcd
>> > [93298.299329]  =======================
>> > [93390.468056] NOHZ: local_softirq_pending 22
>> > [93447.105850] NOHZ: local_softirq_pending 22
>> > [93450.332884] BUG: unable to handle kernel paging request at
>> virtual address 3e343c0c
>> > [93450.340626]  printing eip:
>> > [93450.343333] c018e2bc
>> > [93450.345520] *pde = 00000000
>> > [93450.348314] Oops: 0000 [#1]
>>
>> Nice.  What was the last file which it read before crashing?
>>
>> Are you able to consistently crash it by reading just that file?
> 
> Random files, random bugs (usually it starts with a slab corruption).
> 
> git-bisect will give an answer.

So this is a random bug generator...

git-bisect bad
16574dccd8f62dc1b585325f8a6a0aab10047ed8 is first bad commit
commit 16574dccd8f62dc1b585325f8a6a0aab10047ed8
Author: Kay Sievers <kay.sievers@vrfy.org>
Date:   Fri Apr 6 01:40:38 2007 +0200

    Driver core: make uevent-environment available in uevent-file

    This allows sysfs to show the environment variables that are available
    if the uevent happens.  This lets userspace not have to cache all of
    this information as the kernel already knows it.

    Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

:040000 040000 34152258985968083c04ab003ced54d73e92a790 c3301e8cd7705c293817c6747b3cc59d6cbf14bb M      drivers

http://www.stardust.webpages.pl/files/tbf/bitis-gabonica/2.6.21-git4/git-config

Regards,
Michal

-- 
Michal K. K. Piotrowski
Kernel Monkeys
(http://kernel.wikidot.com/start)