Re: [PATCH v7 for-next 6/8] selftests/livepatch: Add provides/obsoletes test scenarios

[Petr Mladek <pmladek@suse.com>]

On Tue 2026-08-25 19:46:39, Yafang Shao wrote:
> Now that the legacy "replace" field has been replaced by the
> provides/obsoletes mechanism, add test scenarios to verify the new
> behavior.
> 
> Fill in the #else branches of the test modules that were left as
> TODO placeholders in the previous patch:
> 
> - test_klp_atomic_replace.c gains provides and obsoletes module
>   parameters for the provides/obsoletes based tests.
> 
> - test_klp_callbacks_demo2.c gains a provides module parameter.
> 
> - test_klp_livepatch.c gains a provides module parameter so that it
>   can be loaded with a specific provides id for coexistence tests.
> 
> - test_klp_state.c and test_klp_state2.c add a comment in the #else
>   branch noting that provides=0 (the default) is equivalent to the
>   previous .replace=true behavior.
> 
> Add test-provides.sh with four test scenarios:
> 
> 1. provides=0 replaces provides=0: two livepatches with provides=0
>    that modify different functions; the second replaces the first.
> 
> 2. Same provides replaces: two livepatches with provides=1 that
>    modify different functions; the second replaces the first.
> 
> 3. Obsoletes replaces: a livepatch with provides=2 and obsoletes=[1]
>    replaces a livepatch with provides=1. The provides/obsoletes sysfs
>    values are verified.
> 
> 4. provides=0 coexists with provides=1: two livepatches with
>    different provides ids that modify different functions coexist,
>    verifying that provides=0 does not replace a patch with a
>    different provides id.
> 
> The provides/obsoletes based tests only run on kernels that no longer
> support the legacy "replace" attribute.
> 
> Assisted-by: Comagic:DeepSeek-V4-Flash
> Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
> ---
>  tools/testing/selftests/livepatch/Makefile    |   3 +-
>  .../livepatch/test-provides-obsoletes.sh      | 174 ++++++++++++++++++
>  .../test_modules/test_klp_atomic_replace.c    |  22 ++-
>  .../test_modules/test_klp_callbacks_demo2.c   |  12 +-
>  .../test_modules/test_klp_livepatch.c         |   9 +
>  .../livepatch/test_modules/test_klp_state.c   |   5 +-
>  .../livepatch/test_modules/test_klp_state2.c  |   5 +-
>  7 files changed, 205 insertions(+), 25 deletions(-)
>  create mode 100755 tools/testing/selftests/livepatch/test-provides-obsoletes.sh
> 
> diff --git a/tools/testing/selftests/livepatch/Makefile b/tools/testing/selftests/livepatch/Makefile
> index a080eb54a215..38f98594d883 100644
> --- a/tools/testing/selftests/livepatch/Makefile
> +++ b/tools/testing/selftests/livepatch/Makefile
> @@ -11,7 +11,8 @@ TEST_PROGS := \
>  	test-ftrace.sh \
>  	test-sysfs.sh \
>  	test-syscall.sh \
> -	test-kprobe.sh
> +	test-kprobe.sh \
> +	test-provides-obsoletes.sh
>  
>  TEST_FILES := settings
>  
> diff --git a/tools/testing/selftests/livepatch/test-provides-obsoletes.sh b/tools/testing/selftests/livepatch/test-provides-obsoletes.sh
> new file mode 100755
> index 000000000000..2707457b9133
> --- /dev/null
> +++ b/tools/testing/selftests/livepatch/test-provides-obsoletes.sh
> @@ -0,0 +1,174 @@
> +#!/bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (C) 2026 Yafang Shao <laoar.shao@gmail.com>
> +
> +. $(dirname $0)/functions.sh
> +
> +MOD_ATOMIC=test_klp_atomic_replace
> +MOD_LIVEPATCH=test_klp_livepatch

I always get lost in the various test modules and have to look
what is inside. It might help me if the name better describes
the content, for example, rename:

 + test_klp_atomic_replace -> test_klp_proc_memset_livepatch
 + test_klp_livepatch -> test_klp_proc_cmdline_livepatch

So, it is clear that they "livepatch" a given "proc" interface.
And it is rather clear that they livepatch different functions.

The names are long. The following might still be better than
the current state:

   + test_klp_memset_lp
   + test_klp_cmdline_lp

Best Regards,
Petr