From 69e96eaa4fef04ad543eda3eab787dbae99d8912 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Fri, 6 Jun 2014 07:13:59 +0000 Subject: perf probe: Improve an error message of perf probe --vars mode Fix an error message when failed to find given address in --vars mode. Without this fix, perf probe -V doesn't show the final "Error" message if it fails to find given source line. Moreover, it tells it fails to find "variables" instead of the source line. ----- # perf probe -V foo@bar Failed to find variables at foo@bar (0) ----- The result also shows mysterious error code. Actually the error returns 0 or -ENOENT means that it just fails to find the address of given source line. (0 means there is no matching address, and -ENOENT means there is an entry(DIE) but it has no instance, e.g. an empty inlined function) This fixes it to show what happened and the final error message as below. ----- # perf probe -V foo@bar Failed to find the address of foo@bar Error: Failed to show vars. ----- Signed-off-by: Masami Hiramatsu Cc: Ingo Molnar Cc: Jiri Olsa Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20140606071359.6788.84716.stgit@kbuild-fedora.novalocal Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/probe-event.c | 7 ++++++- tools/perf/util/probe-finder.c | 6 +++++- 2 files changed, 11 insertions(+), 2 deletions(-) (limited to 'tools/perf') diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index 0d1542f33d87..44c71417262f 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -721,9 +721,14 @@ static int show_available_vars_at(struct debuginfo *dinfo, ret = debuginfo__find_available_vars_at(dinfo, pev, &vls, max_vls, externs); if (ret <= 0) { - pr_err("Failed to find variables at %s (%d)\n", buf, ret); + if (ret == 0 || ret == -ENOENT) { + pr_err("Failed to find the address of %s\n", buf); + ret = -ENOENT; + } else + pr_warning("Debuginfo analysis failed.\n"); goto end; } + /* Some variables are found */ fprintf(stdout, "Available variables at %s\n", buf); for (i = 0; i < ret; i++) { diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index ce8faf47691a..98e304766416 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -1280,7 +1280,11 @@ out: return ret; } -/* Find available variables at given probe point */ +/* + * Find available variables at given probe point + * Return the number of found probe points. Return 0 if there is no + * matched probe point. Return <0 if an error occurs. + */ int debuginfo__find_available_vars_at(struct debuginfo *dbg, struct perf_probe_event *pev, struct variable_list **vls, -- cgit v1.2.2