perf session: Return error code for perf_session__new() function on failure

This patch is to return error code of perf_new_session function on
failure instead of NULL.

Test Results:

Before Fix:

  $ perf c2c report -input
  failed to open nput: No such file or directory

  $ echo $?
  0
  $

After Fix:

  $ perf c2c report -input
  failed to open nput: No such file or directory

  $ echo $?
  254
  $

Committer notes:

Fix 'perf tests topology' case, where we use that TEST_ASSERT_VAL(...,
session), i.e. we need to pass zero in case of failure, which was the
case before when NULL was returned by perf_session__new() for failure,
but now we need to negate the result of IS_ERR(session) to respect that
TEST_ASSERT_VAL) expectation of zero meaning failure.

Reported-by: Nageswara R Sastry <[email protected]>
Signed-off-by: Mamatha Inamdar <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Tested-by: Nageswara R Sastry <[email protected]>
Acked-by: Ravi Bangoria <[email protected]>
Reviewed-by: Jiri Olsa <[email protected]>
Reviewed-by: Mukesh Ojha <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Alexey Budankov <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Jeremie Galarneau <[email protected]>
Cc: Kate Stewart <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Shawn Landden <[email protected]>
Cc: Song Liu <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Tzvetomir Stoyanov <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

1 files changed, 3 insertions, 2 deletions

diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c
index 553c651fa0a2..8db8fc9bddef 100644
--- a/tools/perf/builtin-annotate.c
+++ b/tools/perf/builtin-annotate.c
@@ -40,6 +40,7 @@
 #include <dlfcn.h>
 #include <errno.h>
 #include <linux/bitmap.h>
+#include <linux/err.h>
 
 struct perf_annotate {
 	struct perf_tool tool;
@@ -584,8 +585,8 @@ int cmd_annotate(int argc, const char **argv)
 	data.path = input_name;
 
 	annotate.session = perf_session__new(&data, false, &annotate.tool);
-	if (annotate.session == NULL)
-		return -1;
+	if (IS_ERR(annotate.session))
+		return PTR_ERR(annotate.session);
 
 	annotate.has_br_stack = perf_header__has_feat(&annotate.session->header,
 						      HEADER_BRANCH_STACK);