Re: [PATCH] selftests/livepatch: filter 'taints' from dmesg comparison

[Miroslav Benes <mbenes@suse.cz>]

On Wed, 6 Nov 2019, Joe Lawrence wrote:

> The livepatch selftests compare expected dmesg output to verify kernel
> behavior.  They currently filter out "tainting kernel with
> TAINT_LIVEPATCH" messages which may be logged when loading livepatch
> modules.
> 
> Further filter the log to also drop "loading out-of-tree module taints
> kernel" messages in case the klp_test modules have been build without
> the in-tree module flag.

That is true, but "tainting kernel with TAINT_LIVEPATCH" should be printed 
out even in this case. check_modinfo_livepatch() is called for all modules 
and relies on MODINFO(livepatch, Y).

So either the bug is elsewhere or I need one more cup of tea.

Miroslav
 
> Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
> ---
> 
> Note: I stumbled across this in a testing scenario and thought it might
> be generally useful to extend this admittedly fragile mechanism.  Since
> there are no related livepatch-core changes, this can go through Shuah's
> kselftest tree if she prefers.  -- Joe
> 
>  tools/testing/selftests/livepatch/functions.sh | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/livepatch/functions.sh b/tools/testing/selftests/livepatch/functions.sh
> index 79b0affd21fb..57975c323542 100644
> --- a/tools/testing/selftests/livepatch/functions.sh
> +++ b/tools/testing/selftests/livepatch/functions.sh
> @@ -221,7 +221,7 @@ function check_result {
>  	local expect="$*"
>  	local result
>  
> -	result=$(dmesg | grep -v 'tainting' | grep -e 'livepatch:' -e 'test_klp' | sed 's/^\[[ 0-9.]*\] //')
> +	result=$(dmesg | grep -ve '\<taints\>' -ve '\<tainting\>' | grep -e 'livepatch:' -e 'test_klp' | sed 's/^\[[ 0-9.]*\] //')
>  
>  	if [[ "$expect" == "$result" ]] ; then
>  		echo "ok"
> -- 
> 2.21.0
>