selftests/livepatch: Add selftests for "replace" sysfs attribute

Add selftests for both atomic replace and non atomic replace
livepatches. The result is as follows,

  TEST: sysfs test ... ok
  TEST: sysfs test object/patched ... ok
  TEST: sysfs test replace enabled ... ok
  TEST: sysfs test replace disabled ... ok
Suggested-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Tested-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lore.kernel.org/r/20240625151123.2750-3-laoar.shao@gmail.comSigned-off-by: Petr Mladek <pmladek@suse.com>

tools/testing/selftests/livepatch/test-sysfs.sh

@@ -18,6 +18,7 @@ check_sysfs_rights "$MOD_LIVEPATCH" "" "drwxr-xr-x"
 check_sysfs_rights "$MOD_LIVEPATCH" "enabled" "-rw-r--r--"
 check_sysfs_value  "$MOD_LIVEPATCH" "enabled" "1"
 check_sysfs_rights "$MOD_LIVEPATCH" "force" "--w-------"
+check_sysfs_rights "$MOD_LIVEPATCH" "replace" "-r--r--r--"
 check_sysfs_rights "$MOD_LIVEPATCH" "transition" "-r--r--r--"
 check_sysfs_value  "$MOD_LIVEPATCH" "transition" "0"
 check_sysfs_rights "$MOD_LIVEPATCH" "vmlinux/patched" "-r--r--r--"
@@ -83,4 +84,51 @@ test_klp_callbacks_demo: post_unpatch_callback: vmlinux
 livepatch: 'test_klp_callbacks_demo': unpatching complete
 % rmmod test_klp_callbacks_demo"
 
+start_test "sysfs test replace enabled"
+
+MOD_LIVEPATCH=test_klp_atomic_replace
+load_lp $MOD_LIVEPATCH replace=1
+
+check_sysfs_rights "$MOD_LIVEPATCH" "replace" "-r--r--r--"
+check_sysfs_value  "$MOD_LIVEPATCH" "replace" "1"
+
+disable_lp $MOD_LIVEPATCH
+unload_lp $MOD_LIVEPATCH
+
+check_result "% insmod test_modules/$MOD_LIVEPATCH.ko replace=1
+livepatch: enabling patch '$MOD_LIVEPATCH'
+livepatch: '$MOD_LIVEPATCH': initializing patching transition
+livepatch: '$MOD_LIVEPATCH': starting patching transition
+livepatch: '$MOD_LIVEPATCH': completing patching transition
+livepatch: '$MOD_LIVEPATCH': patching complete
+% echo 0 > /sys/kernel/livepatch/$MOD_LIVEPATCH/enabled
+livepatch: '$MOD_LIVEPATCH': initializing unpatching transition
+livepatch: '$MOD_LIVEPATCH': starting unpatching transition
+livepatch: '$MOD_LIVEPATCH': completing unpatching transition
+livepatch: '$MOD_LIVEPATCH': unpatching complete
+% rmmod $MOD_LIVEPATCH"
+
+start_test "sysfs test replace disabled"
+
+load_lp $MOD_LIVEPATCH replace=0
+
+check_sysfs_rights "$MOD_LIVEPATCH" "replace" "-r--r--r--"
+check_sysfs_value  "$MOD_LIVEPATCH" "replace" "0"
+
+disable_lp $MOD_LIVEPATCH
+unload_lp $MOD_LIVEPATCH
+
+check_result "% insmod test_modules/$MOD_LIVEPATCH.ko replace=0
+livepatch: enabling patch '$MOD_LIVEPATCH'
+livepatch: '$MOD_LIVEPATCH': initializing patching transition
+livepatch: '$MOD_LIVEPATCH': starting patching transition
+livepatch: '$MOD_LIVEPATCH': completing patching transition
+livepatch: '$MOD_LIVEPATCH': patching complete
+% echo 0 > /sys/kernel/livepatch/$MOD_LIVEPATCH/enabled
+livepatch: '$MOD_LIVEPATCH': initializing unpatching transition
+livepatch: '$MOD_LIVEPATCH': starting unpatching transition
+livepatch: '$MOD_LIVEPATCH': completing unpatching transition
+livepatch: '$MOD_LIVEPATCH': unpatching complete
+% rmmod $MOD_LIVEPATCH"
+
 exit 0