Re: [Xenomai-core] rt_sem_create bug when registring in proc

["stephane ancelot" <sancelot@domain.hid>]

Le Sun, 28 Sep 2008 16:25:56 +0200, Philippe Gerum <rpm@xenomai.org> a  
écrit:

> stephane ancelot wrote:
>> Hi,
>> I have the following kernel bug, when using a string name in
>> rt_sem_create. using NULL as name do not report this problem.
>>
>> BUG: unable to handle kernel paging request at virtual address de82a268
>> printing eip: c025d51a *pde = 1dd3e067 *pte = 00000000
>> Oops: 0000 [#1] PREEMPT
>> Modules linked in: xxxxxx(P) elok_s(P) e100 mii
>>
>
> You did not specify the Xenomai version in use. Looking at this output,  
> you may
> want to search the bug in your proprietary module code first; it seems  
> that you
> passed a string laid into the data segment of a module that has been  
> unloaded,
> without removing the semaphore it had initially created.
>

Hi,

You are right, the semaphore was created in a thread meanwhile a bad coded  
init module was unloading it. (return missing in init routine ) thanks.
Best Regards
Steph




>> Pid: 4, comm: events/0 Tainted: P        (2.6.24.2-ipipe #3)
>> EIP: 0060:[<c025d51a>] EFLAGS: 00010246 CPU: 0
>> EIP is at strlen+0xa/0x20
>> EAX: 00000000 EBX: 00008124 ECX: ffffffff EDX: de82a268
>> ESI: de82a268 EDI: de82a268 EBP: 00000001 ESP: ddc27e8c
>>   DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068
>> Process events/0 (pid: 4, ti=ddc26000 task=ddc19ab0 task.ti=ddc26000)<0>
>> I-pipe domain Linux
>> Stack: ddc27ebc c01e445b dde783c0 c0257d2a dde78140 de82a268 de82a268
>> c016e7a0
>>         c048aebc 00000000 c01e46d4 00000001 dde78140 c04fbac4 c016338c
>> 00000200
>>         00000000 ffffffff ffffffff 0000007b 00000002 00000000 dde783c0
>> dde78140
>> Call Trace:
>>   [<c01e445b>] proc_create+0x4b/0x110
>>   [<c0257d2a>] idr_get_new+0xa/0x30
>>   [<c016e7a0>] __sem_read_proc+0x0/0x130
>>   [<c01e46d4>] create_proc_entry+0x44/0x90
>>   [<c016338c>] registry_proc_callback+0xa1c/0xb00
>>   [<c01130c1>] update_curr+0x71/0x100
>>   [<c0113148>] update_curr+0xf8/0x100
>>   [<c01132ef>] set_next_entity+0x1f/0x50
>>   [<c0162970>] registry_proc_callback+0x0/0xb00
>>   [<c0129516>] run_workqueue+0xb6/0x1a0
>>   [<c039ff8f>] schedule+0x1df/0x3d0
>>   [<c0129e9d>] worker_thread+0x6d/0xa0
>>   [<c012d670>] autoremove_wake_function+0x0/0x50
>>   [<c0129e30>] worker_thread+0x0/0xa0
>>   [<c012d302>] kthread+0x42/0x70
>>   [<c012d2c0>] kthread+0x0/0x70
>>   [<c010398b>] kernel_thread_helper+0x7/0x1c
>>   =======================
>> Code: 00 56 89 c6 89 d0 88 c4 ac 38 e0 74 09 84 c0 75 f7 be 01 00 00 00  
>> 89
>> f0 48 5e c3 8d b6 00 00 00 00 57 b9 ff ff ff ff 89 c7 31 c0 <f2> ae f7  
>> d1
>> 49 5f 89 c8 c3 8d b6 00 00 00 00 8d bc 27 00 00 00
>> EIP: [<c025d51a>] strlen+0xa/0x20 SS:ESP 0068:ddc27e8c
>> ---[ end trace 614a6309c2874abe ]---
>>
>> Best regards
>> S.Ancelot
>>
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