Hi limin,

Just to let you know that Jeff's patch was merged and is available since
Linux 6.3:
https://lore.kernel.org/all/20230114020306.1407195-1-jeffxu@google.com/ (local)

Regards,
 Mickaël

On Wed, Nov 30, 2022 at 08:32:41PM +0100, Mickaël Salaün wrote:

I checked and the Landlock ptrace test failed because Yama is enabled, which
is expected. You can check that with /proc/sys/kernel/yama/ptrace_scope

Jeff Xu sent a patch to fix this case but it is not ready yet:
https://lore.kernel.org/r/20220628222941.2642917-1-jeffxu@google.com (local)

Could you please send a new patch Jeff, and add Limin in Cc?


On 29/11/2022 12:26, limin wrote:

quoted

cat /proc/cmdline
BOOT_IMAGE=/vmlinuz-6.1.0-next-20221116
root=UUID=a65b3a79-dc02-4728-8a0c-5cf24f4ae08b ro
systemd.unified_cgroup_hierarchy=1 cgroup_no_v1=all


config

#
# Automatically generated file; DO NOT EDIT.
# Linux/x86 6.1.0-rc6 Kernel Configuration
#

[...]

quoted

CONFIG_SECURITY_YAMA=y

[...]

quoted

CONFIG_LSM="landlock,lockdown,yama,integrity,apparmor"

[...]

quoted

On 2022/11/29 19:03, Mickaël Salaün wrote:

quoted

I tested with next-20221116 and all tests are OK. Could you share your
kernel configuration with a link? What is the content of /proc/cmdline?

On 29/11/2022 02:42, limin wrote:

quoted

I run test on Linux ubuntu2204 6.1.0-next-20221116

I did't use yama.

you can reproduce by this step:

cd kernel_src

cd tools/testing/selftests/landlock/
make
./ptrace_test




On 2022/11/29 3:44, Mickaël Salaün wrote:

quoted

This patch changes the test semantic and then cannot work on my test
environment. On which kernel did you run test? Do you use Yama or
something similar?

On 28/11/2022 03:04, limin wrote:

quoted

Tests PTRACE_ATTACH and PTRACE_MODE_READ on the parent,
trace parent return -1 when child== 0
How to reproduce warning:
$ make -C tools/testing/selftests TARGETS=landlock run_tests

Signed-off-by: limin <redacted>
---
    tools/testing/selftests/landlock/ptrace_test.c | 5 ++---
    1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/landlock/ptrace_test.c

b/tools/testing/selftests/landlock/ptrace_test.c
index c28ef98ff3ac..88c4dc63eea0 100644

--- a/tools/testing/selftests/landlock/ptrace_test.c
+++ b/tools/testing/selftests/landlock/ptrace_test.c

@@ -267,12 +267,11 @@ TEST_F(hierarchy, trace)
            /* Tests PTRACE_ATTACH and PTRACE_MODE_READ on the

parent. */
            err_proc_read = test_ptrace_read(parent);
            ret = ptrace(PTRACE_ATTACH, parent, NULL, 0);
+        EXPECT_EQ(-1, ret);
+        EXPECT_EQ(EPERM, errno);
            if (variant->domain_child) {
-            EXPECT_EQ(-1, ret);
-            EXPECT_EQ(EPERM, errno);
                EXPECT_EQ(EACCES, err_proc_read);
            } else {
-            EXPECT_EQ(0, ret);
                EXPECT_EQ(0, err_proc_read);
            }
            if (ret == 0) {