kprobes trampoline_p registration

[Ananth N Mavinakayanahalli]

On Mon, Jun 12, 2006 at 05:30:07AM -0400, Mike Grundy wrote:
> Hi - I noticed in 2.6.17-rc6 in the i386 kprobes.c the registration of the
> trampoline probe in arch_init_kprobes was removed. It looks like that pile of
> assembly in kretprobe_trampoline_holder does the clean up instead of using the
> regular mechanisms. Any particular reason for this? Should the other arches
> consider a similar mechanism?

Mike,

That is the result of Masami's kprobe booster patchset and is applicable
to i386 (there is a patch floating around for ia64 too).

Other archs that don't have a booster implementation (powerpc for
instance) still use the older trampoline probe mechanism for function
return probes. Until such time the other archs have the booster
implemented, they'll need the trampoline probe registered as part of
arch_init_kprobes().

Ananth