[PATCH v8 8/9] selftests/livepatch: Add state test for provides/obsoletes

@@ -6,6 +6,8 @@
 
 MOD_MEMINFO=test_klp_meminfo_lp
 MOD_CMDLINE=test_klp_cmdline_lp
+MOD_STATE=test_klp_state
+MOD_STATE2=test_klp_state2
 
 setup_config
 detect_provides_attr

@@ -213,4 +215,238 @@ livepatch: '$MOD_CMDLINE': unpatching complete
 % rmmod $MOD_CMDLINE
 % rmmod $MOD_MEMINFO"
 
+
+# - load a livepatch with provides=1 that registers state ID 1
+# - try to load another livepatch with provides=1 that reuses the same
+#   state ID. The second one will replace the first one.
+# - disable and unload the remaining livepatch
+
+start_test "same state, same provides"
+
+load_lp $MOD_STATE state=1 provides=1
+load_lp $MOD_STATE2 state=1 provides=1
+
+disable_lp $MOD_STATE2
+unload_lp $MOD_STATE2
+unload_lp $MOD_STATE
+
+check_result "% insmod test_modules/$MOD_STATE.ko state=1 provides=1
+livepatch: enabling patch '$MOD_STATE'
+livepatch: '$MOD_STATE': initializing patching transition
+$MOD_STATE: pre_patch_callback: vmlinux
+$MOD_STATE: allocate_loglevel_state: allocating space to store console_loglevel
+livepatch: '$MOD_STATE': starting patching transition
+livepatch: '$MOD_STATE': completing patching transition
+$MOD_STATE: post_patch_callback: vmlinux
+$MOD_STATE: fix_console_loglevel: fixing console_loglevel
+livepatch: '$MOD_STATE': patching complete
+% insmod test_modules/$MOD_STATE2.ko state=1 provides=1
+livepatch: enabling patch '$MOD_STATE2'
+livepatch: '$MOD_STATE2': initializing patching transition
+$MOD_STATE2: pre_patch_callback: vmlinux
+$MOD_STATE2: allocate_loglevel_state: space to store console_loglevel already allocated
+livepatch: '$MOD_STATE2': starting patching transition
+livepatch: '$MOD_STATE2': completing patching transition
+$MOD_STATE2: post_patch_callback: vmlinux
+$MOD_STATE2: fix_console_loglevel: taking over the console_loglevel change
+livepatch: '$MOD_STATE2': patching complete
+% echo 0 > $SYSFS_KLP_DIR/$MOD_STATE2/enabled
+livepatch: '$MOD_STATE2': initializing unpatching transition
+$MOD_STATE2: pre_unpatch_callback: vmlinux
+$MOD_STATE2: restore_console_loglevel: restoring console_loglevel
+livepatch: '$MOD_STATE2': starting unpatching transition
+livepatch: '$MOD_STATE2': completing unpatching transition
+$MOD_STATE2: post_unpatch_callback: vmlinux
+$MOD_STATE2: free_loglevel_state: freeing space for the stored console_loglevel
+livepatch: '$MOD_STATE2': unpatching complete
+% rmmod $MOD_STATE2
+% rmmod $MOD_STATE"
+
+
+# - load a livepatch with provides=1 that registers state ID 1
+# - try to load another livepatch with provides=2 that reuses the same
+#   state ID. The second one must be rejected because livepatches with
+#   different provides ids must not share the same state id.
+# - disable and unload the remaining livepatch
+
+start_test "same state, misc provides"
+
+load_lp $MOD_STATE state=1 provides=1
+load_failing_mod $MOD_STATE2 state=1 provides=2
+
+disable_lp $MOD_STATE
+unload_lp $MOD_STATE
+
+check_result "% insmod test_modules/$MOD_STATE.ko state=1 provides=1
+livepatch: enabling patch '$MOD_STATE'
+livepatch: '$MOD_STATE': initializing patching transition
+$MOD_STATE: pre_patch_callback: vmlinux
+$MOD_STATE: allocate_loglevel_state: allocating space to store console_loglevel
+livepatch: '$MOD_STATE': starting patching transition
+livepatch: '$MOD_STATE': completing patching transition
+$MOD_STATE: post_patch_callback: vmlinux
+$MOD_STATE: fix_console_loglevel: fixing console_loglevel
+livepatch: '$MOD_STATE': patching complete
+% insmod test_modules/$MOD_STATE2.ko state=1 provides=2
+livepatch: Livepatch patch ($MOD_STATE2) is not compatible with the already installed livepatches.
+insmod: ERROR: could not insert module test_modules/$MOD_STATE2.ko: Invalid parameters
+% echo 0 > $SYSFS_KLP_DIR/$MOD_STATE/enabled
+livepatch: '$MOD_STATE': initializing unpatching transition
+$MOD_STATE: pre_unpatch_callback: vmlinux
+$MOD_STATE: restore_console_loglevel: restoring console_loglevel
+livepatch: '$MOD_STATE': starting unpatching transition
+livepatch: '$MOD_STATE': completing unpatching transition
+$MOD_STATE: post_unpatch_callback: vmlinux
+$MOD_STATE: free_loglevel_state: freeing space for the stored console_loglevel
+livepatch: '$MOD_STATE': unpatching complete
+% rmmod $MOD_STATE"
+
+
+# Take over system state change by a patch that obsoletes the old one.
+# Although the provides IDs are different, the second patch's obsoletes
+# list includes the first patch's provides ID, so it can replace the
+# first patch and reuse the same state ID.
+
+start_test "same states, replaced by obsoletes"
+
+load_lp $MOD_STATE state=1 provides=1
+load_lp $MOD_STATE2 state=1 provides=2 obsoletes=1
+unload_lp $MOD_STATE
+disable_lp $MOD_STATE2
+unload_lp $MOD_STATE2
+
+check_result "% insmod test_modules/$MOD_STATE.ko state=1 provides=1
+livepatch: enabling patch '$MOD_STATE'
+livepatch: '$MOD_STATE': initializing patching transition
+$MOD_STATE: pre_patch_callback: vmlinux
+$MOD_STATE: allocate_loglevel_state: allocating space to store console_loglevel
+livepatch: '$MOD_STATE': starting patching transition
+livepatch: '$MOD_STATE': completing patching transition
+$MOD_STATE: post_patch_callback: vmlinux
+$MOD_STATE: fix_console_loglevel: fixing console_loglevel
+livepatch: '$MOD_STATE': patching complete
+% insmod test_modules/$MOD_STATE2.ko state=1 provides=2 obsoletes=1
+livepatch: enabling patch '$MOD_STATE2'
+livepatch: '$MOD_STATE2': initializing patching transition
+$MOD_STATE2: pre_patch_callback: vmlinux
+$MOD_STATE2: allocate_loglevel_state: space to store console_loglevel already allocated
+livepatch: '$MOD_STATE2': starting patching transition
+livepatch: '$MOD_STATE2': completing patching transition
+$MOD_STATE2: post_patch_callback: vmlinux
+$MOD_STATE2: fix_console_loglevel: taking over the console_loglevel change
+livepatch: '$MOD_STATE2': patching complete
+% rmmod $MOD_STATE
+% echo 0 > $SYSFS_KLP_DIR/$MOD_STATE2/enabled
+livepatch: '$MOD_STATE2': initializing unpatching transition
+$MOD_STATE2: pre_unpatch_callback: vmlinux
+$MOD_STATE2: restore_console_loglevel: restoring console_loglevel
+livepatch: '$MOD_STATE2': starting unpatching transition
+livepatch: '$MOD_STATE2': completing unpatching transition
+$MOD_STATE2: post_unpatch_callback: vmlinux
+$MOD_STATE2: free_loglevel_state: freeing space for the stored console_loglevel
+livepatch: '$MOD_STATE2': unpatching complete
+% rmmod $MOD_STATE2"
+
+
+# - load a livepatch that modifies system state (state=1) with
+#   provides=1, then another livepatch with the same provides id=1 that declares
+#   a different system state (state=2)
+# - the second livepatch would replace the first one due to the same
+#   provides id, but it does not handle the system state modified by
+#   the first one, therefore it is rejected as incompatible and the
+#   insmod must fail.
+# - verify the first livepatch is still alive, then disable and
+#   unload it.
+
+start_test "misc states, same provides"
+load_lp $MOD_STATE state=1 provides=1
+load_failing_mod $MOD_STATE2 state=2 provides=1
+
+disable_lp $MOD_STATE
+unload_lp $MOD_STATE
+
+check_result "% insmod test_modules/$MOD_STATE.ko state=1 provides=1
+livepatch: enabling patch '$MOD_STATE'
+livepatch: '$MOD_STATE': initializing patching transition
+$MOD_STATE: pre_patch_callback: vmlinux
+$MOD_STATE: allocate_loglevel_state: allocating space to store console_loglevel
+livepatch: '$MOD_STATE': starting patching transition
+livepatch: '$MOD_STATE': completing patching transition
+$MOD_STATE: post_patch_callback: vmlinux
+$MOD_STATE: fix_console_loglevel: fixing console_loglevel
+livepatch: '$MOD_STATE': patching complete
+% insmod test_modules/$MOD_STATE2.ko state=2 provides=1
+livepatch: Livepatch patch ($MOD_STATE2) is not compatible with the already installed livepatches.
+insmod: ERROR: could not insert module test_modules/$MOD_STATE2.ko: Invalid parameters
+% echo 0 > $SYSFS_KLP_DIR/$MOD_STATE/enabled
+livepatch: '$MOD_STATE': initializing unpatching transition
+$MOD_STATE: pre_unpatch_callback: vmlinux
+$MOD_STATE: restore_console_loglevel: restoring console_loglevel
+livepatch: '$MOD_STATE': starting unpatching transition
+livepatch: '$MOD_STATE': completing unpatching transition
+$MOD_STATE: post_unpatch_callback: vmlinux
+$MOD_STATE: free_loglevel_state: freeing space for the stored console_loglevel
+livepatch: '$MOD_STATE': unpatching complete
+% rmmod $MOD_STATE"
+
+
+# - load two livepatches with different provides ids (provides=1 and
+#   provides=2) that modify different system states (state=1 and
+#   state=2). Neither of them replaces the other, because their
+#   provides ids differ (and the obsoletes lists are empty), so they
+#   can coexist.
+# - verify the provides sysfs value of both livepatches
+# - disable and unload both livepatches
+
+start_test "misc states, misc provides"
+
+load_lp $MOD_STATE state=1 provides=1
+load_lp $MOD_STATE2 state=2 provides=2
+
+disable_lp $MOD_STATE
+unload_lp $MOD_STATE
+disable_lp $MOD_STATE2
+unload_lp $MOD_STATE2
+
+check_result "% insmod test_modules/$MOD_STATE.ko state=1 provides=1
+livepatch: enabling patch '$MOD_STATE'
+livepatch: '$MOD_STATE': initializing patching transition
+$MOD_STATE: pre_patch_callback: vmlinux
+$MOD_STATE: allocate_loglevel_state: allocating space to store console_loglevel
+livepatch: '$MOD_STATE': starting patching transition
+livepatch: '$MOD_STATE': completing patching transition
+$MOD_STATE: post_patch_callback: vmlinux
+$MOD_STATE: fix_console_loglevel: fixing console_loglevel
+livepatch: '$MOD_STATE': patching complete
+% insmod test_modules/$MOD_STATE2.ko state=2 provides=2
+livepatch: enabling patch '$MOD_STATE2'
+livepatch: '$MOD_STATE2': initializing patching transition
+$MOD_STATE2: pre_patch_callback: vmlinux
+$MOD_STATE2: allocate_loglevel_state: allocating space to store console_loglevel
+livepatch: '$MOD_STATE2': starting patching transition
+livepatch: '$MOD_STATE2': completing patching transition
+$MOD_STATE2: post_patch_callback: vmlinux
+$MOD_STATE2: fix_console_loglevel: fixing console_loglevel
+livepatch: '$MOD_STATE2': patching complete
+% echo 0 > $SYSFS_KLP_DIR/$MOD_STATE/enabled
+livepatch: '$MOD_STATE': initializing unpatching transition
+$MOD_STATE: pre_unpatch_callback: vmlinux
+$MOD_STATE: restore_console_loglevel: restoring console_loglevel
+livepatch: '$MOD_STATE': starting unpatching transition
+livepatch: '$MOD_STATE': completing unpatching transition
+$MOD_STATE: post_unpatch_callback: vmlinux
+$MOD_STATE: free_loglevel_state: freeing space for the stored console_loglevel
+livepatch: '$MOD_STATE': unpatching complete
+% rmmod $MOD_STATE
+% echo 0 > $SYSFS_KLP_DIR/$MOD_STATE2/enabled
+livepatch: '$MOD_STATE2': initializing unpatching transition
+$MOD_STATE2: pre_unpatch_callback: vmlinux
+$MOD_STATE2: restore_console_loglevel: restoring console_loglevel
+livepatch: '$MOD_STATE2': starting unpatching transition
+livepatch: '$MOD_STATE2': completing unpatching transition
+$MOD_STATE2: post_unpatch_callback: vmlinux
+$MOD_STATE2: free_loglevel_state: freeing space for the stored console_loglevel
+livepatch: '$MOD_STATE2': unpatching complete
+% rmmod $MOD_STATE2"
+
 exit 0

@@ -9,10 +9,25 @@
 #include <linux/printk.h>
 #include <linux/livepatch.h>
 
-#define CONSOLE_LOGLEVEL_STATE 1
 /* Version 1 does not support migration. */
 #define CONSOLE_LOGLEVEL_STATE_VERSION 1
 
+static unsigned int state = 1;
+module_param(state, uint, 0644);
+MODULE_PARM_DESC(state, "console loglevel state (default=1)");
+
+#ifdef CONFIG_KLP_HAS_PROVIDES
+static unsigned int provides;
+module_param(provides, uint, 0644);
+MODULE_PARM_DESC(provides, "provides id (default=0)");
+
+#define KLP_MAX_OBSOLETES 16
+static unsigned int obsoletes[KLP_MAX_OBSOLETES];
+static int nr_obsoletes;
+module_param_array(obsoletes, uint, &nr_obsoletes, 0644);
+MODULE_PARM_DESC(obsoletes, "obsoletes provides ids");
+#endif
+
 static const char *const module_state[] = {
 	[MODULE_STATE_LIVE]	= "[MODULE_STATE_LIVE] Normal state",
 	[MODULE_STATE_COMING]	= "[MODULE_STATE_COMING] Full formed, running module_init",

@@ -35,7 +50,7 @@ static int allocate_loglevel_state(void)
 {
 	struct klp_state *loglevel_state;
 
-	loglevel_state = klp_get_state(&patch, CONSOLE_LOGLEVEL_STATE);
+	loglevel_state = klp_get_state(&patch, state);
 	if (!loglevel_state)
 		return -EINVAL;
 

@@ -52,7 +67,7 @@ static void fix_console_loglevel(void)
 {
 	struct klp_state *loglevel_state;
 
-	loglevel_state = klp_get_state(&patch, CONSOLE_LOGLEVEL_STATE);
+	loglevel_state = klp_get_state(&patch, state);
 	if (!loglevel_state)
 		return;
 

@@ -65,7 +80,7 @@ static void restore_console_loglevel(void)
 {
 	struct klp_state *loglevel_state;
 
-	loglevel_state = klp_get_state(&patch, CONSOLE_LOGLEVEL_STATE);
+	loglevel_state = klp_get_state(&patch, state);
 	if (!loglevel_state)
 		return;
 

@@ -77,7 +92,7 @@ static void free_loglevel_state(void)
 {
 	struct klp_state *loglevel_state;
 
-	loglevel_state = klp_get_state(&patch, CONSOLE_LOGLEVEL_STATE);
+	loglevel_state = klp_get_state(&patch, state);
 	if (!loglevel_state)
 		return;
 

@@ -133,7 +148,6 @@ static struct klp_object objs[] = {
 
 static struct klp_state states[] = {
 	{
-		.id = CONSOLE_LOGLEVEL_STATE,
 		.version = CONSOLE_LOGLEVEL_STATE_VERSION,
 	}, { }
 };

@@ -142,15 +156,20 @@ static struct klp_patch patch = {
 	.mod = THIS_MODULE,
 	.objs = objs,
 	.states = states,
-#ifndef CONFIG_KLP_HAS_PROVIDES
-	.replace = true,
-#else
-	/* provides=0 by default, replaces all provides=0 patches */
-#endif
 };
 
 static int test_klp_callbacks_demo_init(void)
 {
+#ifdef CONFIG_KLP_HAS_PROVIDES
+	patch.provides = provides;
+	if (nr_obsoletes > 0) {
+		patch.obsoletes = obsoletes;
+		patch.nr_obsoletes = nr_obsoletes;
+	}
+#else
+	patch.replace = true;
+#endif
+	states[0].id = state;
 	return klp_enable_patch(&patch);
 }
 

@@ -9,10 +9,25 @@
 #include <linux/printk.h>
 #include <linux/livepatch.h>
 
-#define CONSOLE_LOGLEVEL_STATE 1
 /* Version 2 supports migration. */
 #define CONSOLE_LOGLEVEL_STATE_VERSION 2
 
+static unsigned int state = 1;
+module_param(state, uint, 0644);
+MODULE_PARM_DESC(state, "console loglevel state (default=1)");
+
+#ifdef CONFIG_KLP_HAS_PROVIDES
+static unsigned int provides;
+module_param(provides, uint, 0644);
+MODULE_PARM_DESC(provides, "provides id (default=0)");
+
+#define KLP_MAX_OBSOLETES 16
+static unsigned int obsoletes[KLP_MAX_OBSOLETES];
+static int nr_obsoletes;
+module_param_array(obsoletes, uint, &nr_obsoletes, 0644);
+MODULE_PARM_DESC(obsoletes, "obsoletes provides ids");
+#endif
+
 static const char *const module_state[] = {
 	[MODULE_STATE_LIVE]	= "[MODULE_STATE_LIVE] Normal state",
 	[MODULE_STATE_COMING]	= "[MODULE_STATE_COMING] Full formed, running module_init",

@@ -35,14 +50,14 @@ static int allocate_loglevel_state(void)
 {
 	struct klp_state *loglevel_state, *prev_loglevel_state;
 
-	prev_loglevel_state = klp_get_prev_state(CONSOLE_LOGLEVEL_STATE);
+	prev_loglevel_state = klp_get_prev_state(state);
 	if (prev_loglevel_state) {
 		pr_info("%s: space to store console_loglevel already allocated\n",
 		__func__);
 		return 0;
 	}
 
-	loglevel_state = klp_get_state(&patch, CONSOLE_LOGLEVEL_STATE);
+	loglevel_state = klp_get_state(&patch, state);
 	if (!loglevel_state)
 		return -EINVAL;
 

@@ -59,11 +74,11 @@ static void fix_console_loglevel(void)
 {
 	struct klp_state *loglevel_state, *prev_loglevel_state;
 
-	loglevel_state = klp_get_state(&patch, CONSOLE_LOGLEVEL_STATE);
+	loglevel_state = klp_get_state(&patch, state);
 	if (!loglevel_state)
 		return;
 
-	prev_loglevel_state = klp_get_prev_state(CONSOLE_LOGLEVEL_STATE);
+	prev_loglevel_state = klp_get_prev_state(state);
 	if (prev_loglevel_state) {
 		pr_info("%s: taking over the console_loglevel change\n",
 		__func__);

@@ -80,14 +95,14 @@ static void restore_console_loglevel(void)
 {
 	struct klp_state *loglevel_state, *prev_loglevel_state;
 
-	prev_loglevel_state = klp_get_prev_state(CONSOLE_LOGLEVEL_STATE);
+	prev_loglevel_state = klp_get_prev_state(state);
 	if (prev_loglevel_state) {
 		pr_info("%s: passing the console_loglevel change back to the old livepatch\n",
 		__func__);
 		return;
 	}
 
-	loglevel_state = klp_get_state(&patch, CONSOLE_LOGLEVEL_STATE);
+	loglevel_state = klp_get_state(&patch, state);
 	if (!loglevel_state)
 		return;
 

@@ -99,14 +114,14 @@ static void free_loglevel_state(void)
 {
 	struct klp_state *loglevel_state, *prev_loglevel_state;
 
-	prev_loglevel_state = klp_get_prev_state(CONSOLE_LOGLEVEL_STATE);
+	prev_loglevel_state = klp_get_prev_state(state);
 	if (prev_loglevel_state) {
 		pr_info("%s: keeping space to store console_loglevel\n",
 		__func__);
 		return;
 	}
 
-	loglevel_state = klp_get_state(&patch, CONSOLE_LOGLEVEL_STATE);
+	loglevel_state = klp_get_state(&patch, state);
 	if (!loglevel_state)
 		return;
 

@@ -162,7 +177,6 @@ static struct klp_object objs[] = {
 
 static struct klp_state states[] = {
 	{
-		.id = CONSOLE_LOGLEVEL_STATE,
 		.version = CONSOLE_LOGLEVEL_STATE_VERSION,
 	}, { }
 };

@@ -171,15 +185,20 @@ static struct klp_patch patch = {
 	.mod = THIS_MODULE,
 	.objs = objs,
 	.states = states,
-#ifndef CONFIG_KLP_HAS_PROVIDES
-	.replace = true,
-#else
-	/* provides=0 by default, replaces all provides=0 patches */
-#endif
 };
 
 static int test_klp_callbacks_demo_init(void)
 {
+#ifdef CONFIG_KLP_HAS_PROVIDES
+	patch.provides = provides;
+	if (nr_obsoletes > 0) {
+		patch.obsoletes = obsoletes;
+		patch.nr_obsoletes = nr_obsoletes;
+	}
+#else
+	patch.replace = true;
+#endif
+	states[0].id = state;
 	return klp_enable_patch(&patch);
 }