Re: [PATCH] Fix the multithread program core thread message error

[Amerigo Wang]

On Wed, Jul 01, 2009 at 11:27:41AM +0800, Hui Zhu wrote:
>Hi Amerigo,
>
>Thanks for your reply.
>
>On Wed, Jul 1, 2009 at 08:54, Amerigo Wang<xiyou.wangcong@xxxxxxxxx> wrote:
>>
>> Hi, Hui.
>>
>> On Tue, Jun 30, 2009 at 05:12:31PM +0800, Hui Zhu wrote:
>>>Fix the multithread program core thread message error.
>>>The thread message of core file is generated in
>>>elf_dump_thread_status. ÂThe register values is set by
>>>elf_core_copy_task_regs in this function.
>>>static inline int elf_core_copy_task_regs(struct task_struct *t,
>>> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Âelf_gregset_t* elfregs)
>>>{
>>>
>>> Â Â Â return ELF_CORE_COPY_TASK_REGS(t, elfregs);
>>> Â Â Â return 0;
>>>}
>>>If a arch doesn't define ELF_CORE_COPY_TASK_REGS, This function will do
>>>nothing. ÂThen the core file will not have the register message of
>>>thread.
>>>So add elf_core_copy_regs to set regiser values if
>>>ELF_CORE_COPY_TASK_REGS doesn't define.
>>
>>
>> You forgot your Signed-off-by line. :)
>
>Signed-off-by: Hui Zhu <hui.zhu@xxxxxxxxxxxxx>
>
>>
>> Hmmm, this patch looks sane for me. But could you please
>> send us your test program? i.e. how did you test this?
>>
>
>I test this issue in a arm board.  My test code is:

Thanks!

Hmm, this only affects the arch which neither has
CORE_DUMP_USE_REGSET nor ELF_CORE_COPY_TASK_REGS,
arm is one of them, but x86 not...

Could you please resend this patch with your
favourite Signed-off-by and also put the reproduce
steps below into your change log?

P.S. Add some Cc's for more reviews, don't drop
them when you resend your patch.


>#include <stdio.h>
>#include <pthread.h>
>#include <assert.h>
>
>void td1(void * i)
>{
>	while (1)
>	{
>		printf ("1\n");
>		sleep (1);
>	}
>
>	return;
>}
>
>void td2(void * i)
>{
>	while (1)
>	{
>		printf ("2\n");
>		sleep (1);
>	}
>
>	return;
>}
>
>int
>main(int argc,char *argv[],char *envp[])
>{
>	pthread_t	t1,t2;
>
>	pthread_create(&t1, NULL, (void*)td1, NULL);
>	pthread_create(&t2, NULL, (void*)td2, NULL);
>
>	sleep (10);
>
>	assert(0);
>
>	return (0);
>}
>
>The follow is how to reproduce this issue:
>arm-xxx-gcc -g -lpthread 1.c -o 1
>copy 1.c and 1 to a arm board.
>Goto this board.
>ulimit -c 1800000
>./1
># ./1
>1
>2
>1
>...
>...
>1
>1: 1.c:37: main: Assertion `0' failed.
>Aborted (core dumped)
>Then you can get a core file.
>gdb 1 core.xxx
>
>Without the patch:
>(gdb) info threads
>  3 process 909  0x00000000 in ?? ()
>  2 process 908  0x00000000 in ?? ()
>* 1 process 907  0x4a6e2238 in raise () from /lib/libc.so.6
>You can found that the pc of 909 and 908 is 0x00000000.
>
>With the patch:
>(gdb) info threads
>  3 process 885  0x4a749974 in nanosleep () from /lib/libc.so.6
>  2 process 884  0x4a749974 in nanosleep () from /lib/libc.so.6
>* 1 process 883  0x4a6e2238 in raise () from /lib/libc.so.6
>The pc of 885 and 884 is right.
>
>
>Thanks,
>Hui
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