Re: [PATCH -next] selftests/landlock: Fix selftest ptrace_test run fail

[Mickaël Salaün]

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@xxxxxxxxxx

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


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

[...]

> CONFIG_SECURITY_YAMA=y

[...]

> CONFIG_LSM="landlock,lockdown,yama,integrity,apparmor"
[...]
> On 2022/11/29 19:03, Mickaël Salaün wrote:
> > 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:
> > > 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:
> > > > 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:
> > > > > 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 <limin100@xxxxxxxxxx>
> > > > > ---
> > > > >     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) {