[LTP] [PATCH v1] munlockall: add test case that verifies memory has been unlocked

[LTP] [PATCH v1] munlockall: add test case that verifies memory has been unlocked

[Dennis Brendel]

Adding a munlockall() test case that checks if it has the desired effect,
i.e. after calling munlockall() no more memory is locked.

---
 .../kernel/syscalls/munlockall/munlockall02.c | 55 +++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 testcases/kernel/syscalls/munlockall/munlockall02.c

diff --git a/testcases/kernel/syscalls/munlockall/munlockall02.c b/testcases/kernel/syscalls/munlockall/munlockall02.c
new file mode 100644
index 000000000..53d64d47e
--- /dev/null
+++ b/testcases/kernel/syscalls/munlockall/munlockall02.c
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* 
+ * Copyright Red Hat
+ * Author: Dennis Brendel <dbrendel@redhat.com>
+ */
+
+/*
+ * [Description]
+ *
+ * Verify that munlockall(2) unlocks all previously locked memory
+ */
+
+#include <sys/mman.h>
+
+#include "tst_test.h"
+
+static void verify_munlockall(void)
+{
+    unsigned long int size = 0;
+
+    SAFE_FILE_LINES_SCANF("/proc/self/status", "VmLck: %ld", &size);
+
+    if (size != 0UL) {
+        tst_res(TFAIL, "Locked memory after init should be 0 "
+                       "but is %ld", size);
+    }
+
+    if (mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
+        tst_res(TFAIL, "Could not lock memory using mlockall()");
+    }
+
+    SAFE_FILE_LINES_SCANF("/proc/self/status", "VmLck: %ld", &size);
+
+    if (size == 0UL) {
+        tst_res(TFAIL, "Locked memory after mlockall() should be greater "
+                       "than 0, but is %ld", size);
+    }
+
+    if (munlockall() != 0) {
+        tst_res(TFAIL, "Could not unlock memory using munlockall()");
+    }
+
+    SAFE_FILE_LINES_SCANF("/proc/self/status", "VmLck: %ld", &size);
+
+    if (size != 0UL) {
+        tst_res(TFAIL, "Locked memory after munlockall() should be 0 "
+                       "but is %ld", size);
+    } else {
+        tst_res(TPASS, "Test passed");
+    }
+}
+
+static struct tst_test test = {
+    .test_all = verify_munlockall,
+};
-- 
2.44.0



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Re: [LTP] [PATCH v1] munlockall: add test case that verifies memory has been unlocked

[Cyril Hrubis]

Hi!
Generally this is much better test than the munlockall01.c so it would
make more sense to replace munlockall01.c instead of adding a new test.

> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/* 
> + * Copyright Red Hat
> + * Author: Dennis Brendel <dbrendel@redhat.com>
> + */
> +
> +/*

This should be docparse comment, i.e. start with /*\ so that it's picked
up with the documentation parser.

> + * [Description]
> + *
> + * Verify that munlockall(2) unlocks all previously locked memory
> + */
> +
> +#include <sys/mman.h>
> +
> +#include "tst_test.h"
> +
> +static void verify_munlockall(void)
> +{
> +    unsigned long int size = 0;
> +
> +    SAFE_FILE_LINES_SCANF("/proc/self/status", "VmLck: %ld", &size);
> +
> +    if (size != 0UL) {
> +        tst_res(TFAIL, "Locked memory after init should be 0 "
> +                       "but is %ld", size);
> +    }
> +
> +    if (mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
> +        tst_res(TFAIL, "Could not lock memory using mlockall()");
> +    }
> +
> +    SAFE_FILE_LINES_SCANF("/proc/self/status", "VmLck: %ld", &size);
> +
> +    if (size == 0UL) {
> +        tst_res(TFAIL, "Locked memory after mlockall() should be greater "
> +                       "than 0, but is %ld", size);
> +    }
> +
> +    if (munlockall() != 0) {
> +        tst_res(TFAIL, "Could not unlock memory using munlockall()");
> +    }
> +
> +    SAFE_FILE_LINES_SCANF("/proc/self/status", "VmLck: %ld", &size);
> +
> +    if (size != 0UL) {
> +        tst_res(TFAIL, "Locked memory after munlockall() should be 0 "
> +                       "but is %ld", size);
> +    } else {
> +        tst_res(TPASS, "Test passed");
> +    }

This obviously does not work, you have to either return from the
function after each tst_res(TFAIL, ""); or set a flag and print TPASS
only if the flag wasn't set.

> +}
> +
> +static struct tst_test test = {
> +    .test_all = verify_munlockall,
> +};

Also have you checked the test with 'make check' before sending the
patch?

-- 
Cyril Hrubis
chrubis@suse.cz

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