Re: [PATCH][RFC] kprobes: Add user entry-handler in kretprobes

Abhishek Sagar wrote:

the entry handler is called with the appropriate return instance. I
haven't put any explicit "match" test here for ri. The reason is that
the correct ri would be passed to both the entry and return handlers
as trampoline_handler() explicitly matches them to the correct task.
Note that all pending return instances of a function are chained in
LIFO order. S the entry-handler which gets called last, should have
its return handler called first (in case of multiple pending return
instances).


No, eventhough return instances are chained in an order, order of execution of return handler entirely depends on which process returns first(some process may return from 2 line of the function and some process may return from last line
of the function). So entry_handler() which gets executed last doesn't guarantee that its return handler will be executed first(because it took a lot time
to return).

So only thing to match the entry_handler() with its return_handler() is return probe instance(ri)'s address, which user has to take care explicitly (Hence I feel sol a) would be nice).

Thanks
Srinivasa DS

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