Merge tag 'livepatching-for-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching

Pull livepatching updates from Petr Mladek:
 "Improvements and cleanups of livepatching selftests"

* tag 'livepatching-for-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching:
  selftests/livepatch: adopt to newer sysctl error format
  selftests/livepatch: Use "comm" instead of "diff" for dmesg
  selftests/livepatch: add test delimiter to dmesg
  selftests/livepatch: refine dmesg 'taints' in dmesg comparison
  selftests/livepatch: Don't clear dmesg when running tests
  selftests/livepatch: fix mem leaks in test-klp-shadow-vars
  selftests/livepatch: more verification in test-klp-shadow-vars
  selftests/livepatch: rework test-klp-shadow-vars
  selftests/livepatch: simplify test-klp-callbacks busy target tests

2 files changed, 160 insertions, 117 deletions

diff --git a/lib/livepatch/test_klp_callbacks_busy.c b/lib/livepatch/test_klp_callbacks_busy.c
index 40beddf8a0e2..7ac845f65be5 100644
--- a/lib/livepatch/test_klp_callbacks_busy.c
+++ b/lib/livepatch/test_klp_callbacks_busy.c
@@ -5,34 +5,53 @@
 
 #include <linux/module.h>
 #include <linux/kernel.h>
+#include <linux/sched.h>
 #include <linux/workqueue.h>
 #include <linux/delay.h>
 
-static int sleep_secs;
-module_param(sleep_secs, int, 0644);
-MODULE_PARM_DESC(sleep_secs, "sleep_secs (default=0)");
+/* load/run-time control from sysfs writer  */
+static bool block_transition;
+module_param(block_transition, bool, 0644);
+MODULE_PARM_DESC(block_transition, "block_transition (default=false)");
 
 static void busymod_work_func(struct work_struct *work);
-static DECLARE_DELAYED_WORK(work, busymod_work_func);
+static DECLARE_WORK(work, busymod_work_func);
 
 static void busymod_work_func(struct work_struct *work)
 {
-	pr_info("%s, sleeping %d seconds ...\n", __func__, sleep_secs);
-	msleep(sleep_secs * 1000);
+	pr_info("%s enter\n", __func__);
+
+	while (READ_ONCE(block_transition)) {
+		/*
+		 * Busy-wait until the sysfs writer has acknowledged a
+		 * blocked transition and clears the flag.
+		 */
+		msleep(20);
+	}
+
 	pr_info("%s exit\n", __func__);
 }
 
 static int test_klp_callbacks_busy_init(void)
 {
 	pr_info("%s\n", __func__);
-	schedule_delayed_work(&work,
-		msecs_to_jiffies(1000 * 0));
+	schedule_work(&work);
+
+	if (!block_transition) {
+		/*
+		 * Serialize output: print all messages from the work
+		 * function before returning from init().
+		 */
+		flush_work(&work);
+	}
+
 	return 0;
 }
 
 static void test_klp_callbacks_busy_exit(void)
 {
-	cancel_delayed_work_sync(&work);
+	WRITE_ONCE(block_transition, false);
+	flush_work(&work);
 	pr_info("%s\n", __func__);
 }
 
diff --git a/lib/livepatch/test_klp_shadow_vars.c b/lib/livepatch/test_klp_shadow_vars.c
index f0b5a1d24e55..b99116490858 100644
--- a/lib/livepatch/test_klp_shadow_vars.c
+++ b/lib/livepatch/test_klp_shadow_vars.c
@@ -109,8 +109,7 @@ static void shadow_free(void *obj, unsigned long id, klp_shadow_dtor_t dtor)
 static void shadow_free_all(unsigned long id, klp_shadow_dtor_t dtor)
 {
 	klp_shadow_free_all(id, dtor);
-	pr_info("klp_%s(id=0x%lx, dtor=PTR%d)\n",
-		__func__, id, ptr_id(dtor));
+	pr_info("klp_%s(id=0x%lx, dtor=PTR%d)\n", __func__, id, ptr_id(dtor));
 }
 
 
@@ -124,12 +123,16 @@ static int shadow_ctor(void *obj, void *shadow_data, void *ctor_data)
 		return -EINVAL;
 
 	*sv = *var;
-	pr_info("%s: PTR%d -> PTR%d\n",
-		__func__, ptr_id(sv), ptr_id(*var));
+	pr_info("%s: PTR%d -> PTR%d\n", __func__, ptr_id(sv), ptr_id(*var));
 
 	return 0;
 }
 
+/*
+ * With more than one item to free in the list, order is not determined and
+ * shadow_dtor will not be passed to shadow_free_all() which would make the
+ * test fail. (see pass 6)
+ */
 static void shadow_dtor(void *obj, void *shadow_data)
 {
 	int **sv = shadow_data;
@@ -138,132 +141,153 @@ static void shadow_dtor(void *obj, void *shadow_data)
 		__func__, ptr_id(obj), ptr_id(sv));
 }
 
-static int test_klp_shadow_vars_init(void)
-{
-	void *obj			= THIS_MODULE;
-	int id			= 0x1234;
-	gfp_t gfp_flags		= GFP_KERNEL;
+/* number of objects we simulate that need shadow vars */
+#define NUM_OBJS 3
 
-	int var1, var2, var3, var4;
-	int *pv1, *pv2, *pv3, *pv4;
-	int **sv1, **sv2, **sv3, **sv4;
+/* dynamically created obj fields have the following shadow var id values */
+#define SV_ID1 0x1234
+#define SV_ID2 0x1235
 
-	int **sv;
+/*
+ * The main test case adds/removes new fields (shadow var) to each of these
+ * test structure instances. The last group of fields in the struct represent
+ * the idea that shadow variables may be added and removed to and from the
+ * struct during execution.
+ */
+struct test_object {
+	 /* add anything here below and avoid to define an empty struct */
+	struct shadow_ptr sp;
 
-	pv1 = &var1;
-	pv2 = &var2;
-	pv3 = &var3;
-	pv4 = &var4;
+	/* these represent shadow vars added and removed with SV_ID{1,2} */
+	/* char nfield1; */
+	/* int  nfield2; */
+};
+
+static int test_klp_shadow_vars_init(void)
+{
+	struct test_object objs[NUM_OBJS];
+	char nfields1[NUM_OBJS], *pnfields1[NUM_OBJS], **sv1[NUM_OBJS];
+	char *pndup[NUM_OBJS];
+	int nfields2[NUM_OBJS], *pnfields2[NUM_OBJS], **sv2[NUM_OBJS];
+	void **sv;
+	int ret;
+	int i;
 
 	ptr_id(NULL);
-	ptr_id(pv1);
-	ptr_id(pv2);
-	ptr_id(pv3);
-	ptr_id(pv4);
 
 	/*
 	 * With an empty shadow variable hash table, expect not to find
 	 * any matches.
 	 */
-	sv = shadow_get(obj, id);
+	sv = shadow_get(&objs[0], SV_ID1);
 	if (!sv)
 		pr_info("  got expected NULL result\n");
 
-	/*
-	 * Allocate a few shadow variables with different <obj> and <id>.
-	 */
-	sv1 = shadow_alloc(obj, id, sizeof(pv1), gfp_flags, shadow_ctor, &pv1);
-	if (!sv1)
-		return -ENOMEM;
-
-	sv2 = shadow_alloc(obj + 1, id, sizeof(pv2), gfp_flags, shadow_ctor, &pv2);
-	if (!sv2)
-		return -ENOMEM;
-
-	sv3 = shadow_alloc(obj, id + 1, sizeof(pv3), gfp_flags, shadow_ctor, &pv3);
-	if (!sv3)
-		return -ENOMEM;
-
-	/*
-	 * Verify we can find our new shadow variables and that they point
-	 * to expected data.
-	 */
-	sv = shadow_get(obj, id);
-	if (!sv)
-		return -EINVAL;
-	if (sv == sv1 && *sv1 == pv1)
-		pr_info("  got expected PTR%d -> PTR%d result\n",
-			ptr_id(sv1), ptr_id(*sv1));
-
-	sv = shadow_get(obj + 1, id);
-	if (!sv)
-		return -EINVAL;
-	if (sv == sv2 && *sv2 == pv2)
-		pr_info("  got expected PTR%d -> PTR%d result\n",
-			ptr_id(sv2), ptr_id(*sv2));
-	sv = shadow_get(obj, id + 1);
-	if (!sv)
-		return -EINVAL;
-	if (sv == sv3 && *sv3 == pv3)
-		pr_info("  got expected PTR%d -> PTR%d result\n",
-			ptr_id(sv3), ptr_id(*sv3));
-
-	/*
-	 * Allocate or get a few more, this time with the same <obj>, <id>.
-	 * The second invocation should return the same shadow var.
-	 */
-	sv4 = shadow_get_or_alloc(obj + 2, id, sizeof(pv4), gfp_flags, shadow_ctor, &pv4);
-	if (!sv4)
-		return -ENOMEM;
-
-	sv = shadow_get_or_alloc(obj + 2, id, sizeof(pv4), gfp_flags, shadow_ctor, &pv4);
-	if (!sv)
-		return -EINVAL;
-	if (sv == sv4 && *sv4 == pv4)
-		pr_info("  got expected PTR%d -> PTR%d result\n",
-			ptr_id(sv4), ptr_id(*sv4));
-
-	/*
-	 * Free the <obj=*, id> shadow variables and check that we can no
-	 * longer find them.
-	 */
-	shadow_free(obj, id, shadow_dtor);			/* sv1 */
-	sv = shadow_get(obj, id);
-	if (!sv)
-		pr_info("  got expected NULL result\n");
+	/* pass 1: init & alloc a char+int pair of svars for each objs */
+	for (i = 0; i < NUM_OBJS; i++) {
+		pnfields1[i] = &nfields1[i];
+		ptr_id(pnfields1[i]);
+
+		if (i % 2) {
+			sv1[i] = shadow_alloc(&objs[i], SV_ID1,
+					sizeof(pnfields1[i]), GFP_KERNEL,
+					shadow_ctor, &pnfields1[i]);
+		} else {
+			sv1[i] = shadow_get_or_alloc(&objs[i], SV_ID1,
+					sizeof(pnfields1[i]), GFP_KERNEL,
+					shadow_ctor, &pnfields1[i]);
+		}
+		if (!sv1[i]) {
+			ret = -ENOMEM;
+			goto out;
+		}
+
+		pnfields2[i] = &nfields2[i];
+		ptr_id(pnfields2[i]);
+		sv2[i] = shadow_alloc(&objs[i], SV_ID2, sizeof(pnfields2[i]),
+					GFP_KERNEL, shadow_ctor, &pnfields2[i]);
+		if (!sv2[i]) {
+			ret = -ENOMEM;
+			goto out;
+		}
+	}
 
-	shadow_free(obj + 1, id, shadow_dtor);			/* sv2 */
-	sv = shadow_get(obj + 1, id);
-	if (!sv)
-		pr_info("  got expected NULL result\n");
+	/* pass 2: verify we find allocated svars and where they point to */
+	for (i = 0; i < NUM_OBJS; i++) {
+		/* check the "char" svar for all objects */
+		sv = shadow_get(&objs[i], SV_ID1);
+		if (!sv) {
+			ret = -EINVAL;
+			goto out;
+		}
+		if ((char **)sv == sv1[i] && *sv1[i] == pnfields1[i])
+			pr_info("  got expected PTR%d -> PTR%d result\n",
+				ptr_id(sv1[i]), ptr_id(*sv1[i]));
+
+		/* check the "int" svar for all objects */
+		sv = shadow_get(&objs[i], SV_ID2);
+		if (!sv) {
+			ret = -EINVAL;
+			goto out;
+		}
+		if ((int **)sv == sv2[i] && *sv2[i] == pnfields2[i])
+			pr_info("  got expected PTR%d -> PTR%d result\n",
+				ptr_id(sv2[i]), ptr_id(*sv2[i]));
+	}
 
-	shadow_free(obj + 2, id, shadow_dtor);			/* sv4 */
-	sv = shadow_get(obj + 2, id);
-	if (!sv)
-		pr_info("  got expected NULL result\n");
+	/* pass 3: verify that 'get_or_alloc' returns already allocated svars */
+	for (i = 0; i < NUM_OBJS; i++) {
+		pndup[i] = &nfields1[i];
+		ptr_id(pndup[i]);
+
+		sv = shadow_get_or_alloc(&objs[i], SV_ID1, sizeof(pndup[i]),
+					GFP_KERNEL, shadow_ctor, &pndup[i]);
+		if (!sv) {
+			ret = -EINVAL;
+			goto out;
+		}
+		if ((char **)sv == sv1[i] && *sv1[i] == pnfields1[i])
+			pr_info("  got expected PTR%d -> PTR%d result\n",
+					ptr_id(sv1[i]), ptr_id(*sv1[i]));
+	}
 
-	/*
-	 * We should still find an <id+1> variable.
-	 */
-	sv = shadow_get(obj, id + 1);
-	if (!sv)
-		return -EINVAL;
-	if (sv == sv3 && *sv3 == pv3)
-		pr_info("  got expected PTR%d -> PTR%d result\n",
-			ptr_id(sv3), ptr_id(*sv3));
+	/* pass 4: free <objs[*], SV_ID1> pairs of svars, verify removal */
+	for (i = 0; i < NUM_OBJS; i++) {
+		shadow_free(&objs[i], SV_ID1, shadow_dtor); /* 'char' pairs */
+		sv = shadow_get(&objs[i], SV_ID1);
+		if (!sv)
+			pr_info("  got expected NULL result\n");
+	}
 
-	/*
-	 * Free all the <id+1> variables, too.
-	 */
-	shadow_free_all(id + 1, shadow_dtor);			/* sv3 */
-	sv = shadow_get(obj, id);
-	if (!sv)
-		pr_info("  shadow_get() got expected NULL result\n");
+	/* pass 5: check we still find <objs[*], SV_ID2> svar pairs */
+	for (i = 0; i < NUM_OBJS; i++) {
+		sv = shadow_get(&objs[i], SV_ID2);	/* 'int' pairs */
+		if (!sv) {
+			ret = -EINVAL;
+			goto out;
+		}
+		if ((int **)sv == sv2[i] && *sv2[i] == pnfields2[i])
+			pr_info("  got expected PTR%d -> PTR%d result\n",
+					ptr_id(sv2[i]), ptr_id(*sv2[i]));
+	}
 
+	/* pass 6: free all the <objs[*], SV_ID2> svar pairs too. */
+	shadow_free_all(SV_ID2, NULL);		/* 'int' pairs */
+	for (i = 0; i < NUM_OBJS; i++) {
+		sv = shadow_get(&objs[i], SV_ID2);
+		if (!sv)
+			pr_info("  got expected NULL result\n");
+	}
 
 	free_ptr_list();
 
 	return 0;
+out:
+	shadow_free_all(SV_ID1, NULL);		/* 'char' pairs */
+	shadow_free_all(SV_ID2, NULL);		/* 'int' pairs */
+	free_ptr_list();
+
+	return ret;
 }
 
 static void test_klp_shadow_vars_exit(void)