selftests: livepatch: handle PRINTK_CALLER in check_result()

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 <[email protected]>
Acked-by: Miroslav Benes <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Tested-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>

Author: maddy-kerneldev

tools/testing/selftests/livepatch/functions.sh

@@ -306,7 +306,8 @@ function check_result {
 	result=$(dmesg | awk -v last_dmesg="$LAST_DMESG" 'p; $0 == last_dmesg { p=1 }' | \
 		 grep -e 'livepatch:' -e 'test_klp' | \
 		 grep -v '\(tainting\|taints\) kernel' | \
-		 sed 's/^\[[ 0-9.]*\] //')
+		 sed 's/^\[[ 0-9.]*\] //' | \
+		 sed 's/^\[[ ]*[CT][0-9]*\] //')
 
 	if [[ "$expect" == "$result" ]] ; then
 		echo "ok"