[LTP] [PATCH v3 05/11] Add landlock01 test

[Li Wang]

Hi Petr,

On Fri, Jul 12, 2024 at 3:58 PM Petr Vorel <pvorel@suse.cz> wrote:

> Hi Andrea, Li,
>
> ...
> > >> First, this fails at least on various kernel versions (tested:
> Tumbleweed
> > >> 6.10.0-rc7-3.g92abc10-default, and SLE15-SP4 5.14.21 with
> lsm=landlock and
> > >> Debian 6.6.15-amd64):
>
> > >> landlock01.c:49: TFAIL: Size is too small expected EINVAL: ENOMSG (42)
>
> > >> Is it a kernel bug or a test bug?
>
>
> > > You probably need to check the `/usr/include/linux/landlock.h` header
> file
> > > exist,
> > > and to see if 'struct landlock_ruleset_attr' contains the new field
> > > 'handled_access_net'.
>
> > > If not exist or does not contain that, the test defines 'struct
> > > landlock_ruleset_attr'
> > > in lapi/landlock.h which contains handled_access_net directly, this is
> > > likely the
> > > root cause lead test failed on your box.
>
> > And, if the header file does not exist, the macro condition will choose
> to
> > use 'rule_size - 1',
> > and that caused the ENOMSG error during test on the newer kernel.
>
> > #ifdef HAVE_STRUCT_LANDLOCK_RULESET_ATTR_HANDLED_ACCESS_NET
> >     rule_small_size = rule_size - sizeof(uint64_t) - 1;
> > #else
> >     rule_small_size = rule_size - 1;
> > #endif
>
> > So to keep the kernel-headers and running kernel version consistent
> should
> > be required
> > for the landlock01 test. Otherwise the #ifdef possibly won't work
> correctly.
>
> FYI Having inconsistent kernel headers and running kernel would be a
> problem for
> more LTP tests than just landlock01 (basically many tests which have
> autotools
> check). But this can be problematic for some development (e.g. linux-next).
> Therefore we at least assume UAPI headers shouldn't be newer than running
> kernel, see https://lore.kernel.org/ltp/ZJP_qPeJ37H4qhEN@yuki/.
>

Yes, I agree on this.

As landlock01 uses the macro I pointed out in the last email,
it is almost unable to set a correct rule_small_size w/o
variants of kernel-headers.

So I still think just simply set the 'rule_small_size' to 'sizeof(__u64) -
1;'
will make life easier but Andrea has a different perspective on that.

Anyway, I would leave this to Andrea (an excellent black-box tester)
for more struggling. lol~



> > I guess we might have to resolve this on the test side.
>
> Trying to compare versions <linux/version.h> could be used:
>
> #define LINUX_VERSION_CODE 395008
> #define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + ((c) > 255 ? 255
> : (c)))
> #define LINUX_VERSION_MAJOR 6
> #define LINUX_VERSION_PATCHLEVEL 7
> #define LINUX_VERSION_SUBLEVEL 0
>
> We already use KERNEL_VERSION() in kdump and device-drivers tests.
>

It could work by adding more kernel judgment for the macro definition,
but a little bit of a mess IMHO.

-- 
Regards,
Li Wang