[merged mm-hotfixes-stable] selftests-cachestat-test-for-cachestat-availability.patch removed from -mm tree

[merged mm-hotfixes-stable] selftests-cachestat-test-for-cachestat-availability.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: selftests: cachestat: test for cachestat availability
has been removed from the -mm tree.  Its filename was
     selftests-cachestat-test-for-cachestat-availability.patch

This patch was dropped because it was merged into the mm-hotfixes-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Andre Przywara <andre.przywara@arm.com>
Subject: selftests: cachestat: test for cachestat availability
Date: Mon, 21 Aug 2023 17:05:33 +0100

Patch series "selftests: cachestat: fix run on older kernels", v2.

I ran all kernel selftests on some test machine, and stumbled upon
cachestat failing (among others).  These patches fix the run on older
kernels and when the current directory is on a tmpfs instance.


This patch (of 2):

As cachestat is a new syscall, it won't be available on older kernels, for
instance those running on a development machine.  At the moment the test
reports all tests as "not ok" in this case.

Test for the cachestat syscall availability first, before doing further
tests, and bail out early with a TAP SKIP comment.

This also uses the opportunity to add the proper TAP headers, and add one
check for proper error handling (illegal file descriptor).

Link: https://lkml.kernel.org/r/20230821160534.3414911-1-andre.przywara@arm.com
Link: https://lkml.kernel.org/r/20230821160534.3414911-2-andre.przywara@arm.com
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Nhat Pham <nphamcs@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 tools/testing/selftests/cachestat/test_cachestat.c |   20 ++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

--- a/tools/testing/selftests/cachestat/test_cachestat.c~selftests-cachestat-test-for-cachestat-availability
+++ a/tools/testing/selftests/cachestat/test_cachestat.c
@@ -15,6 +15,8 @@
 
 #include "../kselftest.h"
 
+#define NR_TESTS	8
+
 static const char * const dev_files[] = {
 	"/dev/zero", "/dev/null", "/dev/urandom",
 	"/proc/version", "/proc"
@@ -236,7 +238,23 @@ out:
 
 int main(void)
 {
-	int ret = 0;
+	int ret;
+
+	ksft_print_header();
+
+	ret = syscall(__NR_cachestat, -1, NULL, NULL, 0);
+	if (ret == -1 && errno == ENOSYS)
+		ksft_exit_skip("cachestat syscall not available\n");
+
+	ksft_set_plan(NR_TESTS);
+
+	if (ret == -1 && errno == EBADF) {
+		ksft_test_result_pass("bad file descriptor recognized\n");
+		ret = 0;
+	} else {
+		ksft_test_result_fail("bad file descriptor ignored\n");
+		ret = 1;
+	}
 
 	for (int i = 0; i < 5; i++) {
 		const char *dev_filename = dev_files[i];
_

Patches currently in -mm which might be from andre.przywara@arm.com are