[PATCH 1/2] perf tests: Fix to get negative exit codes

[He Kuang <hekuang@huawei.com>]

WEXITSTATUS consists of the least significant 8 bits of the status
argument, so we should convert the value to signed char if we have valid
negative exit codes. And the return value of test->func() contains
negative values:

  enum {
          TEST_OK   =  0,
          TEST_FAIL = -1,
          TEST_SKIP = -2,
  };

Before this patch:

  $ perf test -v 1
  ...
  test child finished with 254
  ---- end ----
  vmlinux symtab matches kallsyms: FAILED!

After this patch:

  $ perf test -v 1
  ...
  test child finished with -2
  ---- end ----
  vmlinux symtab matches kallsyms: Skip

Signed-off-by: He Kuang <hekuang@huawei.com>
---
 tools/perf/tests/builtin-test.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index 4f40981..f42af98 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -219,7 +219,7 @@ static int run_test(struct test *test)
 	wait(&status);
 
 	if (WIFEXITED(status)) {
-		err = WEXITSTATUS(status);
+		err = (signed char)WEXITSTATUS(status);
 		pr_debug("test child finished with %d\n", err);
 	} else if (WIFSIGNALED(status)) {
 		err = -1;
-- 
1.8.5.2