Messages in this thread |  | | | Date | Wed, 25 Nov 2009 11:12:57 -0500 | | From | Masami Hiramatsu <> | | Subject | Re: [PATCH -tip v5 07/10] kprobes/x86: Support kprobes jump optimization on x86 |
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Masami Hiramatsu wrote: > Jason Baron wrote: >> Also, with multiple users we don't want to trample over each others code >> patching. Thus, if each sub-system could register some type of >> 'is_reserved()' callback, and then we can call all these call backs from >> the '__multibyte_poke()' routine before we do any patching to make sure >> that we aren't trampling on each others code. After a successful >> patching, each sub-system can update its reserved set of code as >> appropriate. I can code a prototype here, if this makes sense. > > Hmm, we have to implement it carefully, because here kprobes already > inserted int3 and optprobe rewrites the int3 again. If is_reserved() > returns 1 and multibyte_poke returns error, we can't optimize it anymore.
IMHO, all text-modifiers except kprobes provide is_reserved() callback and kprobes cancels probing if its target address is reserved, since only kprobes changes texts anywhere while others changes texts at fixed addresses.
Anyway, I think this will be another bugfix for current kprobes/alternative.
Thank you, -- Masami Hiramatsu
Software Engineer Hitachi Computer Products (America), Inc. Software Solutions Division
e-mail: mhiramat@redhat.com
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