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RE: [RFC][PATCH] retprobes - remove orig_ret_addr usage
- From: "Lynch, Rusty" <rusty dot lynch at intel dot com>
- To: "Ananth N Mavinakayanahalli" <amavin at redhat dot com>, "SystemTAP" <systemtap at sources dot redhat dot com>
- Date: Wed, 8 Jun 2005 08:37:26 -0700
- Subject: RE: [RFC][PATCH] retprobes - remove orig_ret_addr usage
>Hi,
>
>Here is a patch against 2.6.12-rc6-mm1 that removes usage of the static
>void *orig_ret_addr. We now populate the ret_addr from the previous
>kretprobe_instance in cases where the return address on stack has been
>changed to kretprobe_trampoline().
>
>Changes only done to i386. x86_64 may be similar. Rusty?
>
>Ananth
Yes, this should work for x86_64. I'm not so sure it is a good idea to
include the likely() wrapping comparison of *sara to
kretprobe_trampoline since we don't really know how this will be used.
(If for what ever reason a usage model tended to always have multiple
return probes registered for the same function, then the likely() call
would have a negative impact to performance.)
--rusty