[PATCH v3 4/6] selftests: livepatch: Check if patched sysfs attribute exists

[Marcos Paulo de Souza]

The commit bb26cfd9e77e
("livepatch: add sysfs entry "patched" for each klp_object") was merged
in v6.1, introducing a new sysfs attribute.

In order to run the selftests on older kernels, check if given kernel
has support for the attribute. If the attribute is not supported, skip
the checks.

Signed-off-by: Marcos Paulo de Souza <mpdesouza@xxxxxxxx>
---
 tools/testing/selftests/livepatch/test-sysfs.sh | 38 +++++++++++++++----------
 1 file changed, 23 insertions(+), 15 deletions(-)

diff --git a/tools/testing/selftests/livepatch/test-sysfs.sh b/tools/testing/selftests/livepatch/test-sysfs.sh
index 58fe1d96997c..394cf3ff99cd 100755
--- a/tools/testing/selftests/livepatch/test-sysfs.sh
+++ b/tools/testing/selftests/livepatch/test-sysfs.sh
@@ -8,6 +8,8 @@ MOD_LIVEPATCH=test_klp_livepatch
 MOD_LIVEPATCH2=test_klp_callbacks_demo
 MOD_LIVEPATCH3=test_klp_syscall
 
+HAS_PATCH_ATTR=0
+
 setup_config
 
 # - load a livepatch and verifies the sysfs entries work as expected
@@ -25,8 +27,12 @@ check_sysfs_rights "$MOD_LIVEPATCH" "stack_order" "-r--r--r--"
 check_sysfs_value  "$MOD_LIVEPATCH" "stack_order" "1"
 check_sysfs_rights "$MOD_LIVEPATCH" "transition" "-r--r--r--"
 check_sysfs_value  "$MOD_LIVEPATCH" "transition" "0"
-check_sysfs_rights "$MOD_LIVEPATCH" "vmlinux/patched" "-r--r--r--"
-check_sysfs_value  "$MOD_LIVEPATCH" "vmlinux/patched" "1"
+
+if does_sysfs_exist "$MOD_LIVEPATCH/vmlinux" "patched"; then
+	check_sysfs_rights "$MOD_LIVEPATCH" "vmlinux/patched" "-r--r--r--"
+	check_sysfs_value  "$MOD_LIVEPATCH" "vmlinux/patched" "1"
+	HAS_PATCH_ATTR=1
+fi
 
 disable_lp $MOD_LIVEPATCH
 
@@ -45,23 +51,24 @@ livepatch: '$MOD_LIVEPATCH': completing unpatching transition
 livepatch: '$MOD_LIVEPATCH': unpatching complete
 % rmmod $MOD_LIVEPATCH"
 
-start_test "sysfs test object/patched"
+if [[ "$HAS_PATCH_ATTR" == "1" ]]; then
+	start_test "sysfs test object/patched"
 
-MOD_LIVEPATCH=test_klp_callbacks_demo
-MOD_TARGET=test_klp_callbacks_mod
-load_lp $MOD_LIVEPATCH
+	MOD_LIVEPATCH=test_klp_callbacks_demo
+	MOD_TARGET=test_klp_callbacks_mod
+	load_lp $MOD_LIVEPATCH
 
-# check the "patch" file changes as target module loads/unloads
-check_sysfs_value  "$MOD_LIVEPATCH" "$MOD_TARGET/patched" "0"
-load_mod $MOD_TARGET
-check_sysfs_value  "$MOD_LIVEPATCH" "$MOD_TARGET/patched" "1"
-unload_mod $MOD_TARGET
-check_sysfs_value  "$MOD_LIVEPATCH" "$MOD_TARGET/patched" "0"
+	# check the "patch" file changes as target module loads/unloads
+	check_sysfs_value  "$MOD_LIVEPATCH" "$MOD_TARGET/patched" "0"
+	load_mod $MOD_TARGET
+	check_sysfs_value  "$MOD_LIVEPATCH" "$MOD_TARGET/patched" "1"
+	unload_mod $MOD_TARGET
+	check_sysfs_value  "$MOD_LIVEPATCH" "$MOD_TARGET/patched" "0"
 
-disable_lp $MOD_LIVEPATCH
-unload_lp $MOD_LIVEPATCH
+	disable_lp $MOD_LIVEPATCH
+	unload_lp $MOD_LIVEPATCH
 
-check_result "% insmod test_modules/test_klp_callbacks_demo.ko
+	check_result "% insmod test_modules/test_klp_callbacks_demo.ko
 livepatch: enabling patch 'test_klp_callbacks_demo'
 livepatch: 'test_klp_callbacks_demo': initializing patching transition
 test_klp_callbacks_demo: pre_patch_callback: vmlinux
@@ -87,6 +94,7 @@ livepatch: 'test_klp_callbacks_demo': completing unpatching transition
 test_klp_callbacks_demo: post_unpatch_callback: vmlinux
 livepatch: 'test_klp_callbacks_demo': unpatching complete
 % rmmod test_klp_callbacks_demo"
+fi
 
 start_test "sysfs test replace enabled"
 

-- 
2.54.0