Re: v2.6.26-rc7: BUG: unable to handle kernel NULL pointer dereference

Vegard Nossum
2008-06-22T14:47:39Z

On Sun, Jun 22, 2008 at 2:56 PM, Vegard Nossum <vegard.nossum@gmail.com> wrote:
> Initializing CPU#1
> APIC error on CPU0: 00(40)
> Stuck ??
> Inquiring remote APIC #1...
> ... APIC #1 ID: failed
> ... APIC #1 VERSION: failed
> ... APIC #1 SPIV: failed

Arch-specific __cpu_up() failed...

> BUG: unable to handle kernel NULL pointer dereference at 00000024
> IP: [<c01e0f06>] sysfs_remove_group+0x16/0xc0
> *pde = 00000000
> Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
>
> Pid: 3994, comm: bash Not tainted (2.6.26-rc7-00002-g8b2e474-dirty #29)
> EIP: 0060:[<c01e0f06>] EFLAGS: 00010282 CPU: 0
> EIP is at sysfs_remove_group+0x16/0xc0
> EAX: 00000008 EBX: 00000001 ECX: 00000004 EDX: c0694c14
> ESI: 00000004 EDI: c07015fc EBP: f3cbfe9c ESP: f3cbfe80
> DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
> Process bash (pid: 3994, ti=f3cbe000 task=f3cb4f60 task.ti=f3cbe000)
> Stack: c0302262 f4bcda40 f3cbfe98 00000008 00000001 00000004 00000000 f3cbfea8
> c05880b2 c07576c4 f3cbfec8 c014f567 00000001 00000004 c0753c90 0000001f
> 00000001 fffffffb f3cbfedc c014f5d9 0000001f 00000000 00000004 f3cbff00
> Call Trace:
> [<c0302262>] ? device_unregister+0x12/0x20

This is line 131 of fs/sysfs/group.c:

struct sysfs_dirent *dir_sd = kobj->sd;

> [<c05880b2>] ? topology_cpu_callback+0x32/0x70
> [<c014f567>] ? notifier_call_chain+0x37/0x70
> [<c014f5d9>] ? __raw_notifier_call_chain+0x19/0x20
> [<c0586f6e>] ? _cpu_up+0xee/0x100

This is line 314 of _cpu_up():

out_notify:
if (ret != 0)
__raw_notifier_call_chain(&cpu_chain,
CPU_UP_CANCELED | mod, hcpu, nr_calls, NULL);

> [<c0586fc9>] ? cpu_up+0x49/0x70
> [<c05678d8>] ? store_online+0x58/0x80
> [<c0567880>] ? store_online+0x0/0x80
> [<c0302a6b>] ? sysdev_store+0x2b/0x40
> [<c01df0f2>] ? sysfs_write_file+0xa2/0x100
> [<c01a0d06>] ? vfs_write+0x96/0x130
> [<c01df050>] ? sysfs_write_file+0x0/0x100
> [<c01a13cd>] ? sys_write+0x3d/0x70
> [<c010831b>] ? sysenter_past_esp+0x78/0xd1
> =======================
> Code: 8b 43 04 83 c3 04 85 c0 75 ed 5b 5e 5d c3 8d b4 26 00 00 00 00 55 89 e5 83 ec 1c 89 7d fc 89 d7 89 5d f4 89 75 f8 89 45 f0 8b 12 <8b> 70 1c 85 d2 74 53 89 f0 e8 bc f5 ff ff 85 c0 89 c3 74 59 8b
> EIP: [<c01e0f06>] sysfs_remove_group+0x16/0xc0 SS:ESP 0068:f3cbfe80
>
>

...adding a few related Ccs.

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