From: Masami Hiramatsu <mhiramat@kernel.org>
To: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
linux-kernel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
Jiri Olsa <jolsa@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Namhyung Kim <namhyung@kernel.org>,
David Ahern <dsahern@gmail.com>
Subject: [PATCH perf/core 2/4] perf-probe: Skip if the function address is 0
Date: Sat, 24 Sep 2016 00:35:07 +0900 [thread overview]
Message-ID: <147464490707.29804.14277897643725143867.stgit@devbox> (raw)
In-Reply-To: <147464488719.29804.13099016520754675018.stgit@devbox>
Skip probes if the entry address of the target function is 0.
This can happen if we handles c++ debuginfo.
E.g. without this fix, below case still fail.
----
$ ./perf probe -x /usr/lib64/libstdc++.so.6 -vD is_open
probe-definition(0): is_open
symbol:is_open file:(null) line:0 offset:0 return:0 lazy:(null)
0 arguments
symbol:catch file:(null) line:0 offset:0 return:0 lazy:(null)
symbol:throw file:(null) line:0 offset:0 return:0 lazy:(null)
symbol:rethrow file:(null) line:0 offset:0 return:0 lazy:(null)
Open Debuginfo file: /usr/lib/debug/usr/lib64/libstdc++.so.6.0.22.debug
Try to find probe point from debuginfo.
Matched function: is_open [295df]
found inline addr: 0x8ca80
Probe point found: is_open+0
found inline addr: 0x8ca70
Probe point found: is_open+0
found inline addr: 0x8ca60
Probe point found: is_open+0
Matched function: is_open [6527f]
Matched function: is_open [9fe8a]
Probe point found: is_open+0
Matched function: is_open [19710b]
found inline addr: 0xecca9
Probe point found: stdio_filebuf+57
found inline addr: 0x0
Probe point found: swap+0
Matched function: is_open [19fc9d]
Probe point found: is_open+0
Found 7 probe_trace_events.
p:probe_libstdc++/is_open /usr/lib64/libstdc++.so.6.0.22:0x8ca80
p:probe_libstdc++/is_open_1 /usr/lib64/libstdc++.so.6.0.22:0x8ca70
p:probe_libstdc++/is_open_2 /usr/lib64/libstdc++.so.6.0.22:0x8ca60
p:probe_libstdc++/is_open_3 /usr/lib64/libstdc++.so.6.0.22:0xb0ad0
p:probe_libstdc++/is_open_4 /usr/lib64/libstdc++.so.6.0.22:0xecca9
Failed to synthesize probe trace event.
Error: Failed to add events. Reason: Invalid argument (Code: -22)
----
This is because some instances have entry_pc == 0 (see 19710b and
19fc9d). With this fix, those are skipped.
----
$ ./perf probe -x /usr/lib64/libstdc++.so.6 -D is_open
p:probe_libstdc++/is_open /usr/lib64/libstdc++.so.6.0.22:0x8ca80
p:probe_libstdc++/is_open_1 /usr/lib64/libstdc++.so.6.0.22:0x8ca70
p:probe_libstdc++/is_open_2 /usr/lib64/libstdc++.so.6.0.22:0x8ca60
p:probe_libstdc++/is_open_3 /usr/lib64/libstdc++.so.6.0.22:0xb0ad0
p:probe_libstdc++/is_open_4 /usr/lib64/libstdc++.so.6.0.22:0xecca9
----
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
tools/perf/util/probe-finder.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index 5fe8325..df4debe 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -955,6 +955,11 @@ static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
dwarf_diename(in_die));
return -ENOENT;
}
+ if (addr == 0) {
+ pr_debug("%s has no valid entry address. skipped.\n",
+ dwarf_diename(in_die));
+ return -ENOENT;
+ }
pf->addr = addr;
pf->addr += pp->offset;
pr_debug("found inline addr: 0x%jx\n",
@@ -998,8 +1003,13 @@ static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
} else if (die_is_func_instance(sp_die)) {
/* Instances always have the entry address */
dwarf_entrypc(sp_die, &pf->addr);
+ /* But in some case the entry address is 0 */
+ if (pf->addr == 0) {
+ pr_debug("%s has no entry PC. Skipped\n",
+ dwarf_diename(sp_die));
+ param->retval = 0;
/* Real function */
- if (pp->lazy_line)
+ } else if (pp->lazy_line)
param->retval = find_probe_point_lazy(sp_die, pf);
else {
skip_prologue(sp_die, pf);
next prev parent reply other threads:[~2016-09-23 15:35 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-23 15:34 [PATCH perf/core 0/4] perf-probe fixes for C++ Masami Hiramatsu
2016-09-23 15:34 ` [PATCH perf/core 1/4] perf-probe: Ignore the error of finding inline instance Masami Hiramatsu
2016-09-29 18:19 ` [tip:perf/core] perf probe: " tip-bot for Masami Hiramatsu
2016-09-23 15:35 ` Masami Hiramatsu [this message]
2016-09-29 18:19 ` [tip:perf/core] perf probe: Skip if the function address is 0 tip-bot for Masami Hiramatsu
2016-09-23 15:35 ` [PATCH perf/core 3/4] perf-probe: Fix to cut off incompatible chars from group name Masami Hiramatsu
2016-09-29 18:20 ` [tip:perf/core] perf probe: " tip-bot for Masami Hiramatsu
2016-09-23 15:35 ` [PATCH perf/core 4/4] perf-probe: Match linkage name with mangled name Masami Hiramatsu
2016-09-29 18:20 ` [tip:perf/core] perf probe: " tip-bot for Masami Hiramatsu
2016-09-25 11:14 ` [PATCH perf/core 0/4] perf-probe fixes for C++ Jiri Olsa
2016-09-27 18:11 ` Masami Hiramatsu
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