From: Brendan Jackman <jackmanb@google.com>
Date: Tue, 11 Mar 2025 13:18:23 +0000 (+0000)
Subject: selftests/mm/mlock: print error on failure
X-Git-Tag: v6.15-rc1~81^2~235
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=1ddae9d67ee11886f9a35b78ad837eb26559e9ab;p=thirdparty%2Fkernel%2Flinux.git

selftests/mm/mlock: print error on failure

It's not really possible to start diagnosing this without knowing the
actual error.

Also update the mlock2 helper to behave like libc would by setting errno
and returning -1.

Link: https://lkml.kernel.org/r/20250311-mm-selftests-v4-12-dec210a658f5@google.com
Signed-off-by: Brendan Jackman <jackmanb@google.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/tools/testing/selftests/mm/mlock-random-test.c b/tools/testing/selftests/mm/mlock-random-test.c
index 1cd80b0f76c33..b8d7e966f44c6 100644
--- a/tools/testing/selftests/mm/mlock-random-test.c
+++ b/tools/testing/selftests/mm/mlock-random-test.c
@@ -161,9 +161,9 @@ static void test_mlock_within_limit(char *p, int alloc_size)
 				       MLOCK_ONFAULT);
 
 		if (ret)
-			ksft_exit_fail_msg("%s() failure at |%p(%d)| mlock:|%p(%d)|\n",
+			ksft_exit_fail_msg("%s() failure (%s) at |%p(%d)| mlock:|%p(%d)|\n",
 					   is_mlock ? "mlock" : "mlock2",
-					   p, alloc_size,
+					   strerror(errno), p, alloc_size,
 					   p + start_offset, lock_size);
 	}
 
diff --git a/tools/testing/selftests/mm/mlock2.h b/tools/testing/selftests/mm/mlock2.h
index 4417eaa5cfb78..81e77fa41901a 100644
--- a/tools/testing/selftests/mm/mlock2.h
+++ b/tools/testing/selftests/mm/mlock2.h
@@ -6,7 +6,13 @@
 
 static int mlock2_(void *start, size_t len, int flags)
 {
-	return syscall(__NR_mlock2, start, len, flags);
+	int ret = syscall(__NR_mlock2, start, len, flags);
+
+	if (ret) {
+		errno = ret;
+		return -1;
+	}
+	return 0;
 }
 
 static FILE *seek_to_smaps_entry(unsigned long addr)