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Date:   Wed, 02 Mar 2022 00:27:51 +0530
From:   "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
Subject: Re: [PATCH v2 12/39] x86/ibt,ftrace: Search for __fentry__ location
To:     Masami Hiramatsu <mhiramat@kernel.org>,
        Steven Rostedt <rostedt@goodmis.org>
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        Peter Zijlstra <peterz@infradead.org>, samitolvanen@google.com,
        x86@kernel.org
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Steven Rostedt wrote:
> On Fri, 25 Feb 2022 19:20:08 +0900
> Masami Hiramatsu <mhiramat@kernel.org> wrote:
>=20
>> > No. It only acts like ftrace_location_range(sym, sym_end) if the passe=
d
>> > in argument is the ip of the function (kallsyms returns offset =3D 0) =
=20
>>=20
>> Got it. So now ftrace_location() will return the ftrace address
>> when the ip =3D=3D func or ip =3D=3D mcount-call.

Won't this cause issues with ftrace_set_filter_ip() and others? If the=20
passed-in ip points to func+0 when the actual ftrace location is at some=20
offset, the ftrace location check in ftrace_match_addr() will now pass,=20
resulting in adding func+0 to the hash. Should we also update=20
ftrace_match_addr() to use the ip returned by ftrace_location()?


- Naveen