Messages in this thread | | | Date | Fri, 25 Feb 2022 19:20:08 +0900 | From | Masami Hiramatsu <> | Subject | Re: [PATCH v2 12/39] x86/ibt,ftrace: Search for __fentry__ location |
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On Thu, 24 Feb 2022 21:19:19 -0500 Steven Rostedt <rostedt@goodmis.org> wrote:
> On Fri, 25 Feb 2022 10:34:49 +0900 > Masami Hiramatsu <mhiramat@kernel.org> wrote: > > > > > > + if (!rec) { > > > > > + if (!kallsyms_lookup_size_offset(ip, &size, &offset)) > > > > > + goto out; > > > > > + > > > > > + if (!offset) > > > > > > > > Isn't this 'if (offset)' ? > > > > > > No, the point to only look for the fentry location if the ip passed in > > > points to the start of the function. IOW, +0 offset. > > > > OK, so this means ftrace_location() will be same as > > ftrace_location_range(sym, sym_end) ? > > No. It only acts like ftrace_location_range(sym, sym_end) if the passed > in argument is the ip of the function (kallsyms returns offset = 0)
Got it. So now ftrace_location() will return the ftrace address when the ip == func or ip == mcount-call.
Thank you,
-- Masami Hiramatsu <mhiramat@kernel.org>
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