Re: recent -git: BUG in free_thread_xstate

["Vegard Nossum" <vegard.nossum@gmail.com>]

On Wed, Jul 23, 2008 at 10:23 PM, Vegard Nossum <vegard.nossum@gmail.com> wrote:
> My test is basically stressing the network and running CPU hotplug at
> the same time.

FWIW, a third run gives us this additional clue before going down with
the first error I posted in this thread:

=============================================================================
BUG task_struct: Poison overwritten
-----------------------------------------------------------------------------
INFO: 0xf3d00000-0xf3d0006b. First byte 0x1 instead of 0x6b
INFO: Allocated in copy_process+0x68/0x1130 age=4 cpu=0 pid=4338
INFO: Freed in free_task+0x2c/0x30 age=2 cpu=0 pid=4
INFO: Slab 0xc1c25c00 objects=8 used=3 fp=0xf3d00000 flags=0x400020c3
INFO: Object 0xf3d00000 @offset=0 fp=0xf3d03fc0
  Object 0xf3d00000:  01 40 66 00 00 16 ec ee ad b9 00 1c 26 8a 70 f8
.@f...<EC><U+EB79>..&.p<F8>
  Object 0xf3d00010:  08 00 45 00 00 54 00 00 40 00 40 01 b7 e8 c0 a8
..E..T..@.@.<B7><E8><C0><A8>
  Object 0xf3d00020:  00 c4 c0 a8 00 ac 08 00 6e c0 df 24 55 33 75 af
.<C4><C0><A8>.<AC>..n<C0><DF>$U3u<AF>
  Object 0xf3d00030:  87 48 69 ec 03 00 08 09 0a 0b 0c 0d 0e 0f 10 11
.Hi<EC>............
  Object 0xf3d00040:  12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f 20 21
...............!
  Object 0xf3d00050:  22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f 30 31
"#$%&'()*+,-./01
  Object 0xf3d00060:  32 33 34 35 36 37 89 e0 c8 4a fb e0 6b 6b 6b 6b
234567.<E0><C8>J<FB><E0>kkkk
  Object 0xf3d00070:  6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
kkkkkkkkkkkkkkkk
[...]
  Object 0xf3d00fb0:  6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b a5
kkkkkkkkkkkkkkk<A5>
 Redzone 0xf3d00fc0:  bb bb bb bb
<BB><BB><BB><BB>
 Padding 0xf3d00fe8:  5a 5a 5a 5a 5a 5a 5a 5a
ZZZZZZZZ
Pid: 3995, comm: bash Not tainted 2.6.26-06077-gc010b2f #100
 [<c01a0363>] print_trailer+0xd3/0x120
 [<c01a0485>] check_bytes_and_report+0xd5/0x100
 [<c01a06b1>] check_object+0x1b1/0x200
 [<c01a1f90>] __slab_alloc+0x510/0x5f0
 [<c01a2449>] kmem_cache_alloc+0xd9/0xe0
 [<c0135348>] ? copy_process+0x68/0x1130
 [<c0135348>] ? copy_process+0x68/0x1130
 [<c0135348>] copy_process+0x68/0x1130
 [<c02a59b7>] ? _raw_spin_trylock+0x17/0x50
 [<c013646d>] do_fork+0x5d/0x2b0
 [<c015bd5b>] ? trace_hardirqs_on+0xb/0x10
 [<c0297240>] ? copy_to_user+0x40/0x130
 [<c01024af>] sys_clone+0x2f/0x40
 [<c010404f>] sysenter_past_esp+0x78/0xc5
 =======================
FIX task_struct: Restoring 0xf3d00000-0xf3d0006b=0x6b
FIX task_struct: Marking all objects used


Vegard

-- 
"The animistic metaphor of the bug that maliciously sneaked in while
the programmer was not looking is intellectually dishonest as it
disguises that the error is the programmer's own creation."
	-- E. W. Dijkstra, EWD1036