Messages in this thread | | | Date | Sun, 21 May 2006 14:06:38 +0800 | From | "Liu haixiang" <> | Subject | Re: Oops in kthread |
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Hi Balbir,
The FDMA is my coded module. And in my code, I didn't call kthread in my code but only call kthread_run once to create one kernel thread CallbackManager.
So I don't understand why there is Oops from kthread and called by my CallbackManager.
Can anybody explain to me when kthread will be called by the kernel? Then I can understand well why Oops happen.
best regards
Liu haixiang
2006/5/20, Balbir Singh <bsingharora@gmail.com>: > On 5/20/06, Liu haixiang <liu.haixiang@gmail.com> wrote: > > Hi All, > > > > Today I debug one kernel thread created by kthread_run. And after > > several hours run, there is one Oops coming from kthread. Please see > > below mesage: > > ==================== > > Unable to handle kernel NULL pointer dereference at virtual address 00000000 > > pc = 00000000 > > *pde = 00000000 > > Oops: 0000 [#1] > > > > Pid : 261, Comm: CallbackManager > > PC is at 0x0 > > PC : 00000000 SP : 869bbf8c SR : 40008100 TEA : c016db88 Tainted: P > > R0 : 00000000 R1 : 00000000 R2 : 005770c5 R3 : 40008101 > > R4 : 8b000006 R5 : 00000003 R6 : 07b1ce60 R7 : 00000079 > > R8 : c01c0800 R9 : 07b1ce60 R10 : 00000003 R11 : 00000000 > > R12 : 0000004c R13 : 00000000 R14 : 00000079 > > MACH: 0000025c MACL: 000001c8 GBR : 00000000 PR : c01b514a > > > > Your kernel is Tainted. I do not see a list of loaded modules in the > oops log. A quick grep through the kernel sources did not reveal any > routine called "CallbackManager". From the trace CallbackManager > (which is also the name of the thread) belongs to a module called > fdma. > > Are you writing fdma or do you have the source code for it? If your > planning to submit fdma to the linux kernel, I would recommend that > you go through the coding standards for the kernel. I don't think > CallbackManager is an acceptable naming convention. > > > Call trace: > > [<8442d184>] kthread+0xe4/0x140 > > [<c01b4f80>] CallbackManager+0x0/0x2c0 [fdma] > > [<8440f4c0>] complete+0x0/0xc0 > > [<8442d080>] kthread_should_stop+0x0/0x20 > > [<84403004>] kernel_thread_helper+0x4/0x20 > > > > Then I do objdump the kernel/kthread.c. Please see attached dumped > > contents. And find the offset 0xe4. The assembly line code is: > > e4: 08 20 tst r0,r0 > > > > Does anybody can explain to me which C code in kthread create this > > Oops?Is there any easy way to translate assembly code to C? > > > > Try running objdump -d -l on the object file. It should dump the line > numbers and the corresponding disassembled assembly code. > > > best regards > > > > Liu haixiang > > > > > > > > Balbir > Linux Technology Center, > India Software Labs, > Bangalore > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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