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

[Petr Vorel]

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/.

> 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.

Kind regards,
Petr