[PATCH] perf test: Skip wp modify test on old kernels

[Namhyung Kim <namhyung@kernel.org>]

It uses PERF_EVENT_IOC_MODIFY_ATTRIBUTES ioctl.	 The kernel would return
ENOTTY if it's not supported.  Update the skip reason in that case.

Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
I'd like to add Fixes: 2e85d5979e8d tag here but it'd conlict with the
later change in e47c6ecaae1d.

 tools/perf/tests/wp.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/tools/perf/tests/wp.c b/tools/perf/tests/wp.c
index 9d4c45184e71..99f048cd6faa 100644
--- a/tools/perf/tests/wp.c
+++ b/tools/perf/tests/wp.c
@@ -2,6 +2,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <errno.h>
 #include <sys/ioctl.h>
 #include <linux/hw_breakpoint.h>
 #include <linux/kernel.h>
@@ -137,8 +138,7 @@ static int test__wp_rw(struct test_suite *test __maybe_unused,
 #endif
 }
 
-static int test__wp_modify(struct test_suite *test __maybe_unused,
-			   int subtest __maybe_unused)
+static int test__wp_modify(struct test_suite *test, int subtest)
 {
 #if defined(__s390x__)
 	return TEST_SKIP;
@@ -160,6 +160,11 @@ static int test__wp_modify(struct test_suite *test __maybe_unused,
 	new_attr.disabled = 1;
 	ret = ioctl(fd, PERF_EVENT_IOC_MODIFY_ATTRIBUTES, &new_attr);
 	if (ret < 0) {
+		if (errno == ENOTTY) {
+			test->test_cases[subtest].skip_reason = "missing kernel support";
+			ret = TEST_SKIP;
+		}
+
 		pr_debug("ioctl(PERF_EVENT_IOC_MODIFY_ATTRIBUTES) failed\n");
 		close(fd);
 		return ret;
-- 
2.37.2.789.g6183377224-goog