On Sat, May 25, 2024 at 11:34:08AM -0300, Marcos Paulo de Souza wrote:
> Adapt the current test-livepatch.sh script to account the number of
> applied livepatches and ensure that an atomic replace livepatch disables
> all previously applied livepatches.
>
> Signed-off-by: Marcos Paulo de Souza <mpdesouza@xxxxxxxx>
> ---
> Changes since v1:
> * Added checks in the existing test-livepatch.sh instead of creating a
> new test file. (Joe)
> * Fixed issues reported by ShellCheck (Joe)
> ---
> .../testing/selftests/livepatch/test-livepatch.sh | 46 ++++++++++++++++++++--
> 1 file changed, 42 insertions(+), 4 deletions(-)
>
> diff --git a/tools/testing/selftests/livepatch/test-livepatch.sh b/tools/testing/selftests/livepatch/test-livepatch.sh
> index e3455a6b1158..d85405d18e54 100755
> --- a/tools/testing/selftests/livepatch/test-livepatch.sh
> +++ b/tools/testing/selftests/livepatch/test-livepatch.sh
> @@ -107,9 +107,12 @@ livepatch: '$MOD_LIVEPATCH': unpatching complete
>
> # - load a livepatch that modifies the output from /proc/cmdline and
> # verify correct behavior
> -# - load an atomic replace livepatch and verify that only the second is active
> -# - remove the first livepatch and verify that the atomic replace livepatch
> -# is still active
> +# - load two addtional livepatches and check the number of livepatch modules
> +# applied
> +# - load an atomic replace livepatch and check that the other three modules were
> +# disabled
> +# - remove all livepatches besides the atomic replace one and verify that the
> +# atomic replace livepatch is still active
> # - remove the atomic replace livepatch and verify that none are active
>
> start_test "atomic replace livepatch"
> @@ -119,12 +122,31 @@ load_lp $MOD_LIVEPATCH
> grep 'live patched' /proc/cmdline > /dev/kmsg
> grep 'live patched' /proc/meminfo > /dev/kmsg
>
> +for mod in test_klp_syscall test_klp_callbacks_demo; do
Slightly nitpicky here, but the tests were originally written with the
livepatch module names via variables like $MOD_LIVEPATCH. Would using
$MOD_LIVEPATCH{1,2,3} help indicate that their specifics aren't really
interesting, that we just need 3 of them?
> + load_lp $mod
> +done
> +
> +mods=(/sys/kernel/livepatch/*)
> +nmods=${#mods[@]}
> +if [ "$nmods" -ne 3 ]; then
> + die "Expecting three modules listed, found $nmods"
> +fi
> +
I was going to suggest that we might protect against a situation where
other livepatch modules were active, that a simple count wouldn't be
sufficient. But then I thought about this test, atomic replace!
Anything previously loaded is going to be pushed aside anyway.
So maybe (in another patch or set) it would be worth enhancing
functions.sh :: start_test() do a quick sanity check to see that the
initial conditions are safe? That might also prevent some collateral
damage when test A fails and leaves the world a strange place for tests
B, C, etc.
> load_lp $MOD_REPLACE replace=1
>
> grep 'live patched' /proc/cmdline > /dev/kmsg
> grep 'live patched' /proc/meminfo > /dev/kmsg
>
> -unload_lp $MOD_LIVEPATCH
> +mods=(/sys/kernel/livepatch/*)
> +nmods=${#mods[@]}
> +if [ "$nmods" -ne 1 ]; then
> + die "Expecting only one moduled listed, found $nmods"
> +fi
> +
> +# These modules were disabled by the atomic replace
> +for mod in test_klp_callbacks_demo test_klp_syscall $MOD_LIVEPATCH; do
> + unload_lp "$mod"
> +done
>
> grep 'live patched' /proc/cmdline > /dev/kmsg
> grep 'live patched' /proc/meminfo > /dev/kmsg
> @@ -142,6 +164,20 @@ livepatch: '$MOD_LIVEPATCH': starting patching transition
> livepatch: '$MOD_LIVEPATCH': completing patching transition
> livepatch: '$MOD_LIVEPATCH': patching complete
> $MOD_LIVEPATCH: this has been live patched
> +% insmod test_modules/test_klp_syscall.ko
Similar minor nit here, too. If we think copy/pasting all the $MOD_FOO
is annoying, I am fine with leaving this as is. I don't have a strong
opinion other than following some convention.
With that, I'm happy to ack as-is or with variable names.
Acked-by: Joe Lawrence <joe.lawrence@xxxxxxxxxx>
--
Joe
