From: Masami Hiramatsu <mhiramat@kernel.org>
To: Andi Kleen <andi@firstfloor.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>,
Arnaldo Carvalho de Melo <acme@redhat.com>,
Oleg Nesterov <oleg@redhat.com>,
Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
linux-kernel@vger.kernel.org, Andi Kleen <ak@linux.intel.com>
Subject: Re: [PATCH 4/4] perf-probe: Warn if the target function is GNU Indirect function
Date: Fri, 10 Jul 2020 12:30:08 +0900 [thread overview]
Message-ID: <20200710123008.3af0e5ea78a9ff95d36a29d8@kernel.org> (raw)
In-Reply-To: <20200709143654.pw2maoxivsjho6op@two.firstfloor.org>
On Thu, 9 Jul 2020 07:36:54 -0700
Andi Kleen <andi@firstfloor.org> wrote:
> > diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
> > index 1e95a336862c..671176d39569 100644
> > --- a/tools/perf/util/probe-event.c
> > +++ b/tools/perf/util/probe-event.c
> > @@ -379,6 +379,11 @@ static int find_alternative_probe_point(struct debuginfo *dinfo,
> > address = sym->start;
> > else
> > address = map->unmap_ip(map, sym->start) - map->reloc;
> > + if (sym->type == STT_GNU_IFUNC) {
> > + pr_warning("Warning: The probe address (0x%lx) is in a GNU indirect function.\n"
> > + "This may not work as you expected unless you intend to probe the indirect function.\n",
>
> I would say something like this.
>
> Consider identifying the final function used at run time and set the
> probe directly on that.
>
> I think that's more useful to the user.
Hmm, would you mean the default function which may be used for the symbol?
Let me check how we can find it.
Thank you,
--
Masami Hiramatsu <mhiramat@kernel.org>
next prev parent reply other threads:[~2020-07-10 3:30 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-09 8:06 [PATCH 0/4] perf-probe: Fix GNU IFUNC probe issue etc Masami Hiramatsu
2020-07-09 8:07 ` [PATCH 1/4] perf-probe: Avoid setting probes on same address on same event Masami Hiramatsu
2020-07-10 11:18 ` Srikar Dronamraju
2020-07-10 12:14 ` Masami Hiramatsu
2020-07-09 8:07 ` [PATCH 2/4] perf-probe: Fix wrong variable warning when the probe point is not found Masami Hiramatsu
2020-07-09 14:37 ` Andi Kleen
2020-07-10 11:16 ` Srikar Dronamraju
2020-07-09 8:07 ` [PATCH 3/4] perf-probe: Fix memory leakage " Masami Hiramatsu
2020-07-10 11:16 ` Srikar Dronamraju
2020-07-09 8:07 ` [PATCH 4/4] perf-probe: Warn if the target function is GNU Indirect function Masami Hiramatsu
2020-07-09 14:36 ` Andi Kleen
2020-07-10 3:30 ` Masami Hiramatsu [this message]
2020-07-10 11:55 ` Arnaldo Carvalho de Melo
2020-07-10 12:56 ` Masami Hiramatsu
2020-07-10 11:15 ` Srikar Dronamraju
2020-07-10 12:14 ` Masami Hiramatsu
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