[PATCH v2 4/6] selftests: livepatch: Check if patched sysfs attribute exists

Marcos Paulo de Souza
2026-04-13T17:26:35Z

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@suse.com>
---
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..a2d649404a63 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_exists "$MOD_LIVEPATCH/vmlinux" "patched"; then
+ check_sysfs_rights "$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"

--
2.52.0