On Thu, Jul 11, 2024 at 3:07 PM Andrea Cervesato [off-list ref]
wrote:

Hi,

On 7/11/24 05:16, Li Wang wrote:

Hi Andrea,

On Thu, Jul 11, 2024 at 2:02 AM Andrea Cervesato [off-list ref]
wrote:

quoted

From: Andrea Cervesato <andrea.cervesato@suse.com>

This test verifies that landlock_create_ruleset syscall fails with the
right error codes:

- EINVAL Unknown flags, or unknown access, or too small size
- E2BIG size is too big
- EFAULT attr was not a valid address
- ENOMSG Empty accesses (i.e., attr->handled_access_fs is 0)

Reviewed-by: Li Wang <redacted>
Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
---
 runtest/syscalls                                   |  2 +
 testcases/kernel/syscalls/landlock/.gitignore      |  1 +
 testcases/kernel/syscalls/landlock/Makefile        |  7 ++
 testcases/kernel/syscalls/landlock/landlock01.c    | 92
++++++++++++++++++++++
 .../kernel/syscalls/landlock/landlock_common.h     | 74 +++++++++++++++++
 5 files changed, 176 insertions(+)

diff --git a/runtest/syscalls b/runtest/syscalls
index b6cadb2df..667e419a3 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls

@@ -684,6 +684,8 @@ kill11 kill11
 kill12 kill12
 kill13 kill13

+landlock01 landlock01
+
 lchown01 lchown01
 lchown01_16 lchown01_16
 lchown02  lchown02

diff --git a/testcases/kernel/syscalls/landlock/.gitignore

b/testcases/kernel/syscalls/landlock/.gitignore
new file mode 100644
index 000000000..b69f9b94a

--- /dev/null
+++ b/testcases/kernel/syscalls/landlock/.gitignore

@@ -0,0 +1 @@
+landlock01

diff --git a/testcases/kernel/syscalls/landlock/Makefile

b/testcases/kernel/syscalls/landlock/Makefile
new file mode 100644
index 000000000..8cf1b9024

--- /dev/null
+++ b/testcases/kernel/syscalls/landlock/Makefile

@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (C) 2024 SUSE LLC Andrea Cervesato <

andrea.cervesato@suse.com>
+
+top_srcdir             ?= ../../../..
+
+include $(top_srcdir)/include/mk/testcases.mk
+include $(top_srcdir)/include/mk/generic_leaf_target.mk

diff --git a/testcases/kernel/syscalls/landlock/landlock01.c

b/testcases/kernel/syscalls/landlock/landlock01.c
new file mode 100644
index 000000000..90f338fb0

--- /dev/null
+++ b/testcases/kernel/syscalls/landlock/landlock01.c

@@ -0,0 +1,92 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2024 SUSE LLC Andrea Cervesato <

andrea.cervesato@suse.com>
+ */
+
+/*\
+ * [Description]
+ *
+ * This test verifies that landlock_create_ruleset syscall fails with
the right
+ * error codes:
+ *
+ * - EINVAL Unknown flags, or unknown access, or too small size
+ * - E2BIG size is too big
+ * - EFAULT attr was not a valid address
+ * - ENOMSG Empty accesses (i.e., attr->handled_access_fs is 0)
+ */
+
+#include "landlock_common.h"
+
+static struct landlock_ruleset_attr *ruleset_attr;
+static struct landlock_ruleset_attr *null_attr;
+static size_t rule_size;
+static size_t rule_small_size;
+static size_t rule_big_size;
+
+static struct tcase {
+       struct landlock_ruleset_attr **attr;
+       uint64_t access_fs;
+       size_t *size;
+       uint32_t flags;
+       int exp_errno;
+       char *msg;
+} tcases[] = {
+       {&ruleset_attr, -1, &rule_size, 0, EINVAL, "Unknown access"},
+       {&ruleset_attr, 0, &rule_small_size, 0, EINVAL, "Size is too
small"},
+       {&ruleset_attr, 0, &rule_size, -1, EINVAL, "Unknown flags"},
+       {&ruleset_attr, 0, &rule_big_size, 0, E2BIG, "Size is too big"},
+       {&null_attr,    0, &rule_size, 0, EFAULT, "Invalid attr address"},
+       {&ruleset_attr, 0, &rule_size, 0, ENOMSG, "Empty accesses"},
+};
+
+static void run(unsigned int n)
+{
+       struct tcase *tc = &tcases[n];
+
+       if (*tc->attr)
+               (*tc->attr)->handled_access_fs = tc->access_fs;
+
+       TST_EXP_FAIL(tst_syscall(__NR_landlock_create_ruleset,
+                       *tc->attr, *tc->size, tc->flags),
+               tc->exp_errno,
+               "%s",
+               tc->msg);
+
+       if (TST_RET >= 0)
+               SAFE_CLOSE(TST_RET);
+}
+
+static void setup(void)
+{
+       verify_landlock_is_enabled();
+
+       rule_size = sizeof(struct landlock_ruleset_attr);
+
+#ifdef HAVE_STRUCT_LANDLOCK_RULESET_ATTR_HANDLED_ACCESS_NET
+       rule_small_size = rule_size - sizeof(uint64_t);

This is incorrect, at least decrease 1 more number:
     rule_small_size = rule_size - sizeof(uint64_t) - 1;

But, those are quite unnecessary to add the if macro conditions,
as the kernel code explicitly compares the minimal struct with
handled_access_fs via:

   offsetofend(typeof(ruleset_attr), handled_access_fs)

I usually don't look at the kernel source code to write tests, because for
us it should be a black box that could have wrong documentation.
That's also the way we find bugs.

I would go for still using the macros, but removing 1 more byte from the
size when handled_access_net is defined.

Okay, fine.

We still have to adjust the case if someone introduces one more
new field similar to 'handled_access_net' to the structure in the future.

-- 
Regards,
Li Wang

-- 
Mailing list info: https://lists.linux.it/listinfo/ltp