Print two possible reasons /sys/kernel/debug/gup_test cannot be opened to help users of this test diagnose failures.
Signed-off-by: Sidhartha Kumar sidhartha.kumar@oracle.com Cc: stable@vger.kernel.org # 5.15+ --- tools/testing/selftests/vm/gup_test.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/vm/gup_test.c b/tools/testing/selftests/vm/gup_test.c index fe043f67798b0..c496bcefa7a0e 100644 --- a/tools/testing/selftests/vm/gup_test.c +++ b/tools/testing/selftests/vm/gup_test.c @@ -205,7 +205,9 @@ int main(int argc, char **argv)
gup_fd = open("/sys/kernel/debug/gup_test", O_RDWR); if (gup_fd == -1) { - perror("open"); + perror("failed to open /sys/kernel/debug/gup_test"); + printf("check if CONFIG_GUP_TEST is enabled in kernel config\n"); + printf("check if debugfs is mounted at /sys/kernel/debug\n"); exit(1); }