Re: [PATCH v2] selftests: livepatch: handle PRINTK_CALLER in check_result()

[Petr Mladek <pmladek@suse.com>]

On Sun 2025-01-19 22:02:38, Madhavan Srinivasan wrote:
> Some arch configs (like ppc64) enable CONFIG_PRINTK_CALLER,
> which adds the caller id as part of the dmesg. With recent
> util-linux's update 467a5b3192f16 ('dmesg: add caller_id support')
> the standard "dmesg" has been enhanced to print PRINTK_CALLER fields.
> 
> Due to this, even though the expected vs observed are same,
> end testcase results are failed.
> 
>  -% insmod test_modules/test_klp_livepatch.ko
>  -livepatch: enabling patch 'test_klp_livepatch'
>  -livepatch: 'test_klp_livepatch': initializing patching transition
>  -livepatch: 'test_klp_livepatch': starting patching transition
>  -livepatch: 'test_klp_livepatch': completing patching transition
>  -livepatch: 'test_klp_livepatch': patching complete
>  -% echo 0 > /sys/kernel/livepatch/test_klp_livepatch/enabled
>  -livepatch: 'test_klp_livepatch': initializing unpatching transition
>  -livepatch: 'test_klp_livepatch': starting unpatching transition
>  -livepatch: 'test_klp_livepatch': completing unpatching transition
>  -livepatch: 'test_klp_livepatch': unpatching complete
>  -% rmmod test_klp_livepatch
>  +[   T3659] % insmod test_modules/test_klp_livepatch.ko
>  +[   T3682] livepatch: enabling patch 'test_klp_livepatch'
>  +[   T3682] livepatch: 'test_klp_livepatch': initializing patching transition
>  +[   T3682] livepatch: 'test_klp_livepatch': starting patching transition
>  +[    T826] livepatch: 'test_klp_livepatch': completing patching transition
>  +[    T826] livepatch: 'test_klp_livepatch': patching complete
>  +[   T3659] % echo 0 > /sys/kernel/livepatch/test_klp_livepatch/enabled
>  +[   T3659] livepatch: 'test_klp_livepatch': initializing unpatching transition
>  +[   T3659] livepatch: 'test_klp_livepatch': starting unpatching transition
>  +[    T789] livepatch: 'test_klp_livepatch': completing unpatching transition
>  +[    T789] livepatch: 'test_klp_livepatch': unpatching complete
>  +[   T3659] % rmmod test_klp_livepatch
> 
>   ERROR: livepatch kselftest(s) failed
>  not ok 1 selftests: livepatch: test-livepatch.sh # exit=1
> 
> Currently the check_result() handles the "[time]" removal from
> the dmesg. Enhance the check to also handle removal of "[Thread Id]"
> or "[CPU Id]".
> 
> Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>

Looks and works well:

Reviewed-by: Petr Mladek <pmladek@suse.com>
Tested-by: Petr Mladek <pmladek@suse.com>

Best Regards,
Petr

PS: The merge window for 6.14 has started yesterday. Every change
    should spend at least few days in linux-next and I have already
    sent a pull request so it is kind of late for 6.14.

    If there is a demand, I could still queue it for 6.14 in the 2nd
    half of the merge window or for rc2. There is only small group
    of people interested into the livepatch selftests anyway.