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

From: bibo mao
Date: Wed Feb 15 2006 - 01:20:52 EST


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
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