Re: Fwd: [PATCH] kretprobe instance recycled by parent process

[bibo mao <bibo_mao@linux.intel.com>]

Zhou Yingchao wrote:
>>>> When kretprobe probe schedule() function, if probed process exit then
>>>> schedule() function will never return, so some kretprobe instance will
>>>> never be recycled. By this patch the parent process will recycle
>>>> retprobe instance of probed function, there will be no memory leak of
>>>> kretprobe instance. This patch is based on 2.6.16-rc3.
>>> Is there any process which can exit without go through the do_exit() path?
>>> --
>> When process exits through do_exit() function, it will call schedule()
>> function. But if schedule() function is probed by kretprobe, this time
>> schedule() function will not return never because process has exited.
>>
>> bibo,mao
>>
> 
> In the original path, doesn't the call path of
> do_exit()->exit_thread()->kprobe_flush_task(current) recycle the
> kretprobe instance? Is there anything misundstood?
> --
yes, it is right. The old recycle method is
    do_exit()->exit_thread()->kprobe_flush_task(current)
             ->schedule()
At last line of do_exit() it will call schedule() function, and this 
time it will never return. But if schedule function is probed, who is 
responsible for recycling it?

bibo,mao