selftests/livepatch: Don't clear dmesg when running tests

Inspired by commit f131d9edc29d ("selftests/lkdtm: Don't clear dmesg
when running tests"), keep a reference dmesg copy when beginning each
test.  This way check_result() can compare against the initial copy
rather than relying upon an empty log.

Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Reviewed-by: Yannick Cote <ycote@redhat.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20200618181040.21132-2-joe.lawrence@redhat.com

1 files changed, 3 insertions, 9 deletions

diff --git a/tools/testing/selftests/livepatch/test-livepatch.sh b/tools/testing/selftests/livepatch/test-livepatch.sh
index 493e3df415a1..5fe79ac34be1 100755
--- a/tools/testing/selftests/livepatch/test-livepatch.sh
+++ b/tools/testing/selftests/livepatch/test-livepatch.sh
@@ -10,13 +10,11 @@ MOD_REPLACE=test_klp_atomic_replace
 setup_config
 
 
-# TEST: basic function patching
 # - load a livepatch that modifies the output from /proc/cmdline and
 #   verify correct behavior
 # - unload the livepatch and make sure the patch was removed
 
-echo -n "TEST: basic function patching ... "
-dmesg -C
+start_test "basic function patching"
 
 load_lp $MOD_LIVEPATCH
 
@@ -47,15 +45,13 @@ livepatch: '$MOD_LIVEPATCH': unpatching complete
 % rmmod $MOD_LIVEPATCH"
 
 
-# TEST: multiple livepatches
 # - load a livepatch that modifies the output from /proc/cmdline and
 #   verify correct behavior
 # - load another livepatch and verify that both livepatches are active
 # - unload the second livepatch and verify that the first is still active
 # - unload the first livepatch and verify none are active
 
-echo -n "TEST: multiple livepatches ... "
-dmesg -C
+start_test "multiple livepatches"
 
 load_lp $MOD_LIVEPATCH
 
@@ -109,7 +105,6 @@ livepatch: '$MOD_LIVEPATCH': unpatching complete
 % rmmod $MOD_LIVEPATCH"
 
 
-# TEST: atomic replace livepatch
 # - load a livepatch that modifies the output from /proc/cmdline and
 #   verify correct behavior
 # - load an atomic replace livepatch and verify that only the second is active
@@ -117,8 +112,7 @@ livepatch: '$MOD_LIVEPATCH': unpatching complete
 #   is still active
 # - remove the atomic replace livepatch and verify that none are active
 
-echo -n "TEST: atomic replace livepatch ... "
-dmesg -C
+start_test "atomic replace livepatch"
 
 load_lp $MOD_LIVEPATCH