Re: [PATCH] selftests/lkdtm: Use "comm" instead of "diff" for dmesg

From: Michael Ellerman
Date: Mon Jun 29 2020 - 16:46:40 EST


Kees Cook <keescook@xxxxxxxxxxxx> writes:
> On Sat, Jun 27, 2020 at 09:51:31PM +1000, Michael Ellerman wrote:
>> Kees Cook <keescook@xxxxxxxxxxxx> writes:
>> > Instead of full GNU diff (which smaller boot environments may not have),
>> > use "comm" which is more available.
>>
>> Although using "comm" requires CONFIG_PRINTK_TIME=y doesn't it?
>
> No, it doesn't seem to. "comm" doesn't carry about the line prefixes.
> AIUI, the only reason for a mention of "sort" is because of how "comm"
> does its line pairing. i.e. as soon as it goes out of sync, it starts
> accounting for the disjunction between files. But that's exactly what we
> want it doing, and the prefix doesn't matter.

OK, if it works.

cheers