Messages in this thread | | | Subject | Re: Query: Crash is coming during /prod/PID/stat and do_exit of same task | From | "Kohli, Gaurav" <> | Date | Tue, 16 Jan 2018 15:14:59 +0530 |
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On 1/16/2018 12:50 PM, Alexey Dobriyan wrote:
> On Tue, Jan 16, 2018 at 11:06:47AM +0530, Kohli, Gaurav wrote: >> On 1/10/2018 10:50 AM, Alexey Dobriyan wrote: >> >>>> We are seeing crash in do_task_stat while accessing stack pointer, It >>>> seems same task has already completed do_exit call. >>>> So it seems a race between them: >>> Please, post exact kernel version and struct task_struct::usage if you >>> still have that kernel core (or even full task_struct) >> Hi Alexey, >> >> We are working on 4.9.65 and Please find below usage value and other task_struct value, >> please let me know if some other data required as well. > Kernel stacks live their own lives nowadays, the code needs try_get_task_stack(). > Hi Alexey,
Yes , agree we have to put some check like below
if (permitted && (task->flags & PF_DUMPCORE) && try_get_task_stack(task)) {
eip = KSTK_EIP(task);
esp = KSTK_ESP(task);
}
Or instead of this also , can't we check whether task is in exiting path or not by checking some flags like PF_EXITING.
Regards
Gaurav
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