Messages in this thread | | | Date | Fri, 29 Jan 2010 02:01:58 -0500 | From | Masami Hiramatsu <> | Subject | Re: [PATCH 4/9] perf session: Create kernel maps in the constructor |
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Arnaldo Carvalho de Melo wrote: > Em Thu, Jan 28, 2010 at 03:59:38PM -0500, Masami Hiramatsu escreveu: >>> you'll get ipv6.ko located and loaded, mod->dso->long_name thus will >>> have the file to use with libdwarf and sym->start will have the >>> unrelocated address, and mod->start will have where ipv6 is loaded in >>> kernel space > >> Oh, nice :-) Is that available for the modules which aren't loaded? > > No it isn't, what usecase do you see where you would like to look at non > loaded modules? Traversing the /lib/modules passed can be made to just > create DSOs, not maps if we need it. Maps when created using one of these > DSOs would find them on the list.
One usecase I thought is probing module init code for checking/debugging driver initialization routine. For this purpose, build-id checking also should be solved. If the module is not loaded, we can't check build-id in that time. I think we can compare it when loading the module, in kernel, if we can pass target build-id to kprobe-tracer.
>> And yeah, I'd like to support modules and it will requires some >> enhancement in kprobe-tracer too. > > Ok > > <SNIP> >>> With the recent modifications done to untie the session and symbol >>> layers, 'perf probe' now can use just the symbols layer. > >> Could you remove session.kmap too? >> other parts look good to me. > > I'll haven't done that just to keep the patch as small as possible :-) > But will do before submitting.
Thanks! :-)
-- Masami Hiramatsu
Software Engineer Hitachi Computer Products (America), Inc. Software Solutions Division
e-mail: mhiramat@redhat.com
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