[PATCH v3 5/6] selftests: livepatch: Check if replace sysfs attribute exists

[Marcos Paulo de Souza]

The commit adb68ed26a3e ("livepatch: Add "replace" sysfs attribute"),
merged in v6.11, introduced 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 | 39 +++++++++++++++----------
 1 file changed, 23 insertions(+), 16 deletions(-)

diff --git a/tools/testing/selftests/livepatch/test-sysfs.sh b/tools/testing/selftests/livepatch/test-sysfs.sh
index 394cf3ff99cd..744c612a90d3 100755
--- a/tools/testing/selftests/livepatch/test-sysfs.sh
+++ b/tools/testing/selftests/livepatch/test-sysfs.sh
@@ -9,6 +9,7 @@ MOD_LIVEPATCH2=test_klp_callbacks_demo
 MOD_LIVEPATCH3=test_klp_syscall
 
 HAS_PATCH_ATTR=0
+HAS_REPLACE_ATTR=0
 
 setup_config
 
@@ -22,7 +23,6 @@ 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" "stack_order" "-r--r--r--"
 check_sysfs_value  "$MOD_LIVEPATCH" "stack_order" "1"
 check_sysfs_rights "$MOD_LIVEPATCH" "transition" "-r--r--r--"
@@ -34,6 +34,11 @@ if does_sysfs_exist "$MOD_LIVEPATCH/vmlinux" "patched"; then
 	HAS_PATCH_ATTR=1
 fi
 
+if does_sysfs_exist "$MOD_LIVEPATCH" "replace"; then
+	check_sysfs_rights "$MOD_LIVEPATCH" "replace" "-r--r--r--"
+	HAS_REPLACE_ATTR=1
+fi
+
 disable_lp $MOD_LIVEPATCH
 
 unload_lp $MOD_LIVEPATCH
@@ -96,18 +101,19 @@ livepatch: 'test_klp_callbacks_demo': unpatching complete
 % rmmod test_klp_callbacks_demo"
 fi
 
-start_test "sysfs test replace enabled"
+if [[ "$HAS_REPLACE_ATTR" == "1" ]]; then
+	start_test "sysfs test replace enabled"
 
-MOD_LIVEPATCH=test_klp_atomic_replace
-load_lp $MOD_LIVEPATCH replace=1
+	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"
+	check_sysfs_rights "$MOD_LIVEPATCH" "replace" "-r--r--r--"
+	check_sysfs_value  "$MOD_LIVEPATCH" "replace" "1"
 
-disable_lp $MOD_LIVEPATCH
-unload_lp $MOD_LIVEPATCH
+	disable_lp $MOD_LIVEPATCH
+	unload_lp $MOD_LIVEPATCH
 
-check_result "% insmod test_modules/$MOD_LIVEPATCH.ko replace=1
+	check_result "% insmod test_modules/$MOD_LIVEPATCH.ko replace=1
 livepatch: enabling patch '$MOD_LIVEPATCH'
 livepatch: '$MOD_LIVEPATCH': initializing patching transition
 livepatch: '$MOD_LIVEPATCH': starting patching transition
@@ -120,17 +126,17 @@ livepatch: '$MOD_LIVEPATCH': completing unpatching transition
 livepatch: '$MOD_LIVEPATCH': unpatching complete
 % rmmod $MOD_LIVEPATCH"
 
-start_test "sysfs test replace disabled"
+	start_test "sysfs test replace disabled"
 
-load_lp $MOD_LIVEPATCH replace=0
+	load_lp $MOD_LIVEPATCH replace=0
 
-check_sysfs_rights "$MOD_LIVEPATCH" "replace" "-r--r--r--"
-check_sysfs_value  "$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
+	disable_lp $MOD_LIVEPATCH
+	unload_lp $MOD_LIVEPATCH
 
-check_result "% insmod test_modules/$MOD_LIVEPATCH.ko replace=0
+	check_result "% insmod test_modules/$MOD_LIVEPATCH.ko replace=0
 livepatch: enabling patch '$MOD_LIVEPATCH'
 livepatch: '$MOD_LIVEPATCH': initializing patching transition
 livepatch: '$MOD_LIVEPATCH': starting patching transition
@@ -142,6 +148,7 @@ livepatch: '$MOD_LIVEPATCH': starting unpatching transition
 livepatch: '$MOD_LIVEPATCH': completing unpatching transition
 livepatch: '$MOD_LIVEPATCH': unpatching complete
 % rmmod $MOD_LIVEPATCH"
+fi
 
 start_test "sysfs test stack_order value"
 

-- 
2.54.0