Re: [PATCH 3/3] selftests/livepatch: filter 'taints' from dmesg comparison

[Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>]

On 6/12/20 5:17 PM, Petr Mladek wrote:
> On Thu 2020-06-11 09:10:38, Joe Lawrence wrote:
>> On 6/11/20 3:39 AM, Miroslav Benes wrote:
>>> On Wed, 10 Jun 2020, Joe Lawrence wrote:
>>>
>>>> The livepatch selftests currently filter out "tainting kernel with
>>>> TAINT_LIVEPATCH" messages which may be logged when loading livepatch
>>>> modules.
>>>>
>>>> Further filter the log to drop "loading out-of-tree module taints
>>>> kernel" in the rare case the klp_test modules have been built
>>>> out-of-tree.
>>>>
>>>> Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
>>>> ---
>>>>   tools/testing/selftests/livepatch/functions.sh | 3 ++-
>>>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/tools/testing/selftests/livepatch/functions.sh b/tools/testing/selftests/livepatch/functions.sh
>>>> index 83560c3df2ee..f5d4ef12f1cb 100644
>>>> --- a/tools/testing/selftests/livepatch/functions.sh
>>>> +++ b/tools/testing/selftests/livepatch/functions.sh
>>>> @@ -260,7 +260,8 @@ function check_result {
>>>>   	local result
>>>>   	result=$(dmesg --notime | diff --changed-group-format='%>' --unchanged-group-format='' "$SAVED_DMESG" - | \
>>>> -		 grep -v 'tainting' | grep -e '^livepatch:' -e 'test_klp')
>>>> +		 grep -e '^livepatch:' -e 'test_klp' | \
>>>> +		 grep -ve '\<taints\>' -ve '\<tainting\>')
>>>
>>> or make it just 'grep -v 'taint' ? It does not matter much though.
>>>
>>
>> I don't know of any larger words* that may hit a partial match on "taint",
>> but I figured the two word bounded regexes would be more specific.
> 
> I do not have strong opinion. I am fine with both current and Mirek's proposal.
> 
> I am just curious where \< and \> regexp substitutions are documented.
> I see the following at the very end of "man re_syntax":
> 
>    \< and \> are synonyms for  “[[:<:]]” and “[[:>:]]” respectively
> 
> But I am not able to find documentation for “[[:<:]]” and “[[:>:]].
> Even google looks helpless ;-)
> 

AFAIK, using \< and \> matches exact word.  Whereas when used individually,
\< matches beginning and \> matches end of the word.

-- 
Kamalesh