perf tools: Propagate perf_config() errors

Previously these were being ignored, sometimes silently.

Stop doing that, emitting debug messages and handling the errors.

Testing it:

  $ cat ~/.perfconfig
  cat: /home/acme/.perfconfig: No such file or directory
  $ perf stat -e cycles usleep 1

   Performance counter stats for 'usleep 1':

           938,996      cycles:u

       0.003813731 seconds time elapsed

  $ perf top --stdio
  Error:
  You may not have permission to collect system-wide stats.

  Consider tweaking /proc/sys/kernel/perf_event_paranoid,
  <SNIP>
  [ perf record: Captured and wrote 0.019 MB perf.data (7 samples) ]
  [acme@jouet linux]$ perf report --stdio
  # To display the perf.data header info, please use --header/--header-only options.
  # Overhead  Command  Shared Object      Symbol
  # ........  .......  .................  .........................
    71.77%  usleep   libc-2.24.so       [.] _dl_addr
    27.07%  usleep   ld-2.24.so         [.] _dl_next_ld_env_entry
     1.13%  usleep   [kernel.kallsyms]  [k] page_fault
  $
  $ touch ~/.perfconfig
  $ ls -la ~/.perfconfig
  -rw-rw-r--. 1 acme acme 0 Jan 27 12:14 /home/acme/.perfconfig
  $
  $ perf stat -e instructions usleep 1

   Performance counter stats for 'usleep 1':

           244,610      instructions:u

       0.000805383 seconds time elapsed

  $
  [root@jouet ~]# chown acme.acme ~/.perfconfig
  [root@jouet ~]# perf stat -e cycles usleep 1
    Warning: File /root/.perfconfig not owned by current user or root, ignoring it.

   Performance counter stats for 'usleep 1':

           937,615      cycles

       0.000836931 seconds time elapsed
  #

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-j2rq96so6xdqlr8p8rd6a3jx@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 10 insertions, 5 deletions

diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index 34bcf90f8871..6d5479e03e0d 100644
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -90,11 +90,12 @@ static int pager_command_config(const char *var, const char *value, void *data)
 /* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
 int check_pager_config(const char *cmd)
 {
+	int err;
 	struct pager_config c;
 	c.cmd = cmd;
 	c.val = -1;
-	perf_config(pager_command_config, &c);
-	return c.val;
+	err = perf_config(pager_command_config, &c);
+	return err ?: c.val;
 }
 
 static int browser_command_config(const char *var, const char *value, void *data)
@@ -113,11 +114,12 @@ static int browser_command_config(const char *var, const char *value, void *data
  */
 static int check_browser_config(const char *cmd)
 {
+	int err;
 	struct pager_config c;
 	c.cmd = cmd;
 	c.val = -1;
-	perf_config(browser_command_config, &c);
-	return c.val;
+	err = perf_config(browser_command_config, &c);
+	return err ?: c.val;
 }
 
 static void commit_pager_choice(void)
@@ -509,6 +511,7 @@ static void cache_line_size(int *cacheline_sizep)
 
 int main(int argc, const char **argv)
 {
+	int err;
 	const char *cmd;
 	char sbuf[STRERR_BUFSIZE];
 	int value;
@@ -534,7 +537,9 @@ int main(int argc, const char **argv)
 	srandom(time(NULL));
 
 	perf_config__init();
-	perf_config(perf_default_config, NULL);
+	err = perf_config(perf_default_config, NULL);
+	if (err)
+		return err;
 	set_buildid_dir(NULL);
 
 	/* get debugfs/tracefs mount point from /proc/mounts */