Re: [PATCH v5 0/6] kselftests: livepatch: Adapt tests to be executed on 4.12 kernels

[Joe Lawrence <joe.lawrence@redhat.com>]

On 5/4/26 2:34 PM, Marcos Paulo de Souza wrote:
> This is the fifth version of the patchset, which fixes the last Sashiko
> comment, about overwriting MOD_LIVEPATCH global variable and using a
> local variable to avoid module load clashing when an older kernel
> don't support some sysfs attributes.
> 
> Original cover-letter:
> These patches don't really change how the patches are run, just skip
> some tests on kernels that don't support a feature (like kprobe and
> livepatched living together) or when a livepatch sysfs attribute is
> missing.
> 
> These patches are based on printk/for-next branch.
> 
> Please review! Thanks!
> 
> Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
> ---
> Changes in v5:
> - Edit the last three patches to avoid overwriting MOD_LIVEPATCH
>   variable, using a local variable. This fixed the last Sashiko report.
> - Link to v4: https://patch.msgid.link/20260429-lp-tests-old-fixes-v4-0-59b9741989d0@suse.com
> 
> Changes in v4:
> - Patch 5 was changed in order to address a comment made by Sashiko, where
>   subsequent tests rewrite the variables that contain the modules being loaded.
> - Link to v3: https://patch.msgid.link/20260427-lp-tests-old-fixes-v3-0-ccf3c90f744c@suse.com
> 
> Changes in v3:
> - Patch 1 was changed to reorganize the ifdeffery to handle multiple archs syscall wrapper (Miroslav)
> - Patch 3 was changed to rework the commit message and to address function naming (Joe)
> - Patches 4, 5 and 6 where had the commit messages to include the kernel version where
>   the given sysfs attributes were included (Petr Mladek)
> - Link to v2: https://patch.msgid.link/20260413-lp-tests-old-fixes-v2-0-367c7cb5006f@suse.com
> 
> Changes in v2:
> - Patch descriptions were changed to remove "test-X", since it was polluting the commit subjects (Miroslav Benes)
> - Patch 8 was dropped since it was checking for a message from an out-of-tree patch. (Petr Mladek)
> - Patch 3 was dropped as should be treated as expected failure for older kernels. (Petr Mladek)
> - Patch 2 was changed to use y/n instead of 1/0, since it's more natural to use it.
> - Patch 1 was changed to handle ppc and loongson, and error out if dealing with a different architecture that sets
>   CONFIG_ARCH_HAS_SYSCALL_WRAPPER and haven't changed the test to include the proper wrapper prefix.
> - Patch 4 was changed to invert the return of the bash function to return 1 in failure, like
>   a normal bash function (Joe Lawrence)
> - Patches 5, 6 an 7 were changed to not split the tests, but to only run the tests
>   when the attribute were present (Miroslav Benes)
> - Link to v1: https://patch.msgid.link/20260313-lp-tests-old-fixes-v1-0-71ac6dfb3253@suse.com
> 
> ---
> Marcos Paulo de Souza (6):
>       selftests: livepatch: Check for ARCH_HAS_SYSCALL_WRAPPER config
>       selftests: livepatch: Replace true/false module parameter by y/n
>       selftests: livepatch: Introduce does_sysfs_exist function
>       selftests: livepatch: Check if patched sysfs attribute exists
>       selftests: livepatch: Check if replace sysfs attribute exists
>       selftests: livepatch: Check if stack_order sysfs attribute exists
> 
>  tools/testing/selftests/livepatch/functions.sh     |  10 +
>  tools/testing/selftests/livepatch/test-kprobe.sh   |   8 +-
>  tools/testing/selftests/livepatch/test-sysfs.sh    | 219 +++++++++++----------
>  .../livepatch/test_modules/test_klp_syscall.c      |  27 ++-
>  4 files changed, 153 insertions(+), 111 deletions(-)
> ---
> base-commit: 712c0756828becbfc629ff8d8b82deff5d1115e4
> change-id: 20260309-lp-tests-old-fixes-f955abc8ec27
> 

Acked-by: Joe Lawrence <joe.lawrence@redhat.com>

FWIW, I tried this out on 4.18.0-372.137.1.el8_6.x86_64, the oldest
kernel we're supporting for livepatching at the momement, and the modern
selftests + Marcos's patchset happily ran without any problems.

-- 
Joe