[PATCH v6 5/8] selftests: livepatch: Adapt atomic replace tests to provides/obsoletes

@@ -357,6 +357,21 @@ function does_sysfs_exist() {
 	[[ -f "$SYSFS_KLP_DIR/$mod/$attr" ]]
 }
 
+# detect_replace_attr() - detect whether the running kernel still exposes
+# the legacy "replace" sysfs attribute and set HAS_REPLACE_ATTR
+# accordingly. The atomic replace tests are only run when the attribute
+# is present. The provides/obsoletes based tests will be added later.
+function detect_replace_attr() {
+	HAS_REPLACE_ATTR=0
+
+	load_lp test_klp_livepatch
+	if does_sysfs_exist test_klp_livepatch "replace"; then
+		HAS_REPLACE_ATTR=1
+	fi
+	disable_lp test_klp_livepatch
+	unload_lp test_klp_livepatch
+}
+
 # check_sysfs_rights(modname, rel_path, expected_rights) - check sysfs
 # path permissions
 #	modname - livepatch module creating the sysfs interface

@@ -11,6 +11,8 @@ MOD_TARGET_BUSY=test_klp_callbacks_busy
 
 setup_config
 
+detect_replace_attr
+
 
 # Test a combination of loading a kernel module and a livepatch that
 # patches a function in the first module.  Load the target module

@@ -451,6 +453,7 @@ $MOD_TARGET_BUSY: busymod_work_func exit
 $MOD_TARGET_BUSY: ${MOD_TARGET_BUSY}_exit"
 
 
+if [[ "$HAS_REPLACE_ATTR" == "1" ]]; then
 # Test loading multiple livepatches.  This test-case is mainly for comparing
 # with the next test-case.
 #

@@ -499,8 +502,10 @@ $MOD_LIVEPATCH: post_unpatch_callback: vmlinux
 livepatch: '$MOD_LIVEPATCH': unpatching complete
 % rmmod $MOD_LIVEPATCH2
 % rmmod $MOD_LIVEPATCH"
+fi
 
 
+if [[ "$HAS_REPLACE_ATTR" == "1" ]]; then
 # Load multiple livepatches, but the second as an 'atomic-replace'
 # patch.  When the latter loads, the original livepatch should be
 # disabled and *none* of its pre/post-unpatch callbacks executed.  On

@@ -548,6 +553,7 @@ $MOD_LIVEPATCH2: post_unpatch_callback: vmlinux
 livepatch: '$MOD_LIVEPATCH2': unpatching complete
 % rmmod $MOD_LIVEPATCH2
 % rmmod $MOD_LIVEPATCH"
+fi
 
 
 exit 0

@@ -13,6 +13,8 @@ MOD_TARGET_PATCH=test_klp_mod_patch
 
 setup_config
 
+detect_replace_attr
+
 
 # - load a livepatch that modifies the output from /proc/cmdline and
 #   verify correct behavior

@@ -49,6 +51,7 @@ livepatch: '$MOD_LIVEPATCH1': unpatching complete
 % rmmod $MOD_LIVEPATCH1"
 
 
+if [[ "$HAS_REPLACE_ATTR" == "1" ]]; then
 # - load a livepatch that modifies the output from /proc/cmdline and
 #   verify correct behavior
 # - load another livepatch and verify that both livepatches are active

@@ -107,8 +110,10 @@ livepatch: '$MOD_LIVEPATCH1': starting unpatching transition
 livepatch: '$MOD_LIVEPATCH1': completing unpatching transition
 livepatch: '$MOD_LIVEPATCH1': unpatching complete
 % rmmod $MOD_LIVEPATCH1"
+fi
 
 
+if [[ "$HAS_REPLACE_ATTR" == "1" ]]; then
 # - load a livepatch that modifies the output from /proc/cmdline and
 #   verify correct behavior
 # - load two additional livepatches and check the number of livepatch modules

@@ -196,6 +201,7 @@ livepatch: '$MOD_REPLACE': starting unpatching transition
 livepatch: '$MOD_REPLACE': completing unpatching transition
 livepatch: '$MOD_REPLACE': unpatching complete
 % rmmod $MOD_REPLACE"
+fi
 
 
 # - load a target module that provides /proc/test_klp_mod_target with

@@ -16,6 +16,20 @@ obj-m += test_klp_atomic_replace.o \
 	test_klp_state3.o \
 	test_klp_syscall.o
 
+# The legacy "replace" field was replaced by provides/obsoletes. When the
+# kernel (KDIR) still supports "replace", pass KLP_HAS_REPLACE to the
+# modules so that they can #ifdef the legacy "replace" code. Otherwise
+# the modules are built with the provides/obsoletes based code (to be
+# added later).
+KLP_SRC := $(if $(wildcard $(srctree)/include/linux/livepatch.h), \
+		 $(srctree), $(KDIR))
+KLP_HAS_REPLACE := $(shell grep -q 'bool replace' \
+		 $(KLP_SRC)/include/linux/livepatch.h 2>/dev/null \
+		 && echo y)
+ifeq ($(KLP_HAS_REPLACE),y)
+ccflags-y += -DKLP_HAS_REPLACE
+endif
+
 # Ensure that KDIR exists, otherwise skip the compilation
 modules:
 ifneq ("$(wildcard $(KDIR))", "")

@@ -7,9 +7,16 @@
 #include <linux/kernel.h>
 #include <linux/livepatch.h>
 
+#ifdef KLP_HAS_REPLACE
 static int replace;
 module_param(replace, int, 0644);
 MODULE_PARM_DESC(replace, "replace (default=0)");
+#else
+/*
+ * TODO: Add provides/obsoletes module parameters for the
+ * provides/obsoletes based tests (to be added later).
+ */
+#endif
 
 #include <linux/seq_file.h>
 static int livepatch_meminfo_proc_show(struct seq_file *m, void *v)

@@ -36,12 +43,21 @@ static struct klp_object objs[] = {
 static struct klp_patch patch = {
 	.mod = THIS_MODULE,
 	.objs = objs,
+#ifdef KLP_HAS_REPLACE
 	/* set .replace in the init function below for demo purposes */
+#endif
 };
 
 static int test_klp_atomic_replace_init(void)
 {
+#ifdef KLP_HAS_REPLACE
 	patch.replace = replace;
+#else
+	/*
+	 * TODO: Set provides/obsoletes from the module parameters
+	 * for the provides/obsoletes based tests (to be added later).
+	 */
+#endif
 	return klp_enable_patch(&patch);
 }
 

@@ -7,9 +7,16 @@
 #include <linux/kernel.h>
 #include <linux/livepatch.h>
 
+#ifdef KLP_HAS_REPLACE
 static int replace;
 module_param(replace, int, 0644);
 MODULE_PARM_DESC(replace, "replace (default=0)");
+#else
+/*
+ * TODO: Add provides/obsoletes module parameters for the
+ * provides/obsoletes based tests (to be added later).
+ */
+#endif
 
 static const char *const module_state[] = {
 	[MODULE_STATE_LIVE]	= "[MODULE_STATE_LIVE] Normal state",

@@ -72,12 +79,21 @@ static struct klp_object objs[] = {
 static struct klp_patch patch = {
 	.mod = THIS_MODULE,
 	.objs = objs,
+#ifdef KLP_HAS_REPLACE
 	/* set .replace in the init function below for demo purposes */
+#endif
 };
 
 static int test_klp_callbacks_demo2_init(void)
 {
+#ifdef KLP_HAS_REPLACE
 	patch.replace = replace;
+#else
+	/*
+	 * TODO: Set provides/obsoletes from the module parameters
+	 * for the provides/obsoletes based tests (to be added later).
+	 */
+#endif
 	return klp_enable_patch(&patch);
 }
 

@@ -142,7 +142,14 @@ static struct klp_patch patch = {
 	.mod = THIS_MODULE,
 	.objs = objs,
 	.states = states,
+#ifdef KLP_HAS_REPLACE
 	.replace = true,
+#else
+/*
+ * TODO: Add provides/obsoletes module parameters for the
+ * provides/obsoletes based tests (to be added later).
+ */
+#endif
 };
 
 static int test_klp_callbacks_demo_init(void)

@@ -171,7 +171,14 @@ static struct klp_patch patch = {
 	.mod = THIS_MODULE,
 	.objs = objs,
 	.states = states,
+#ifdef KLP_HAS_REPLACE
 	.replace = true,
+#else
+/*
+ * TODO: Add provides/obsoletes module parameters for the
+ * provides/obsoletes based tests (to be added later).
+ */
+#endif
 };
 
 static int test_klp_callbacks_demo_init(void)