Merge tag 'trace-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:

 - kprobes: Restructured stack unwinder to show properly on x86 when a
   stack dump happens from a kretprobe callback.

 - Fix to bootconfig parsing

 - Have tracefs allow owner and group permissions by default (only
   denying others). There's been pressure to allow non root to tracefs
   in a controlled fashion, and using groups is probably the safest.

 - Bootconfig memory managament updates.

 - Bootconfig clean up to have the tools directory be less dependent on
   changes in the kernel tree.

 - Allow perf to be traced by function tracer.

 - Rewrite of function graph tracer to be a callback from the function
   tracer instead of having its own trampoline (this change will happen
   on an arch by arch basis, and currently only x86_64 implements it).

 - Allow multiple direct trampolines (bpf hooks to functions) be batched
   together in one synchronization.

 - Allow histogram triggers to add variables that can perform
   calculations against the event's fields.

 - Use the linker to determine architecture callbacks from the ftrace
   trampoline to allow for proper parameter prototypes and prevent
   warnings from the compiler.

 - Extend histogram triggers to key off of variables.

 - Have trace recursion use bit magic to determine preempt context over
   if branches.

 - Have trace recursion disable preemption as all use cases do anyway.

 - Added testing for verification of tracing utilities.

 - Various small clean ups and fixes.

* tag 'trace-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (101 commits)
  tracing/histogram: Fix semicolon.cocci warnings
  tracing/histogram: Fix documentation inline emphasis warning
  tracing: Increase PERF_MAX_TRACE_SIZE to handle Sentinel1 and docker together
  tracing: Show size of requested perf buffer
  bootconfig: Initialize ret in xbc_parse_tree()
  ftrace: do CPU checking after preemption disabled
  ftrace: disable preemption when recursion locked
  tracing/histogram: Document expression arithmetic and constants
  tracing/histogram: Optimize division by a power of 2
  tracing/histogram: Covert expr to const if both operands are constants
  tracing/histogram: Simplify handling of .sym-offset in expressions
  tracing: Fix operator precedence for hist triggers expression
  tracing: Add division and multiplication support for hist triggers
  tracing: Add support for creating hist trigger variables from literal
  selftests/ftrace: Stop tracing while reading the trace file by default
  MAINTAINERS: Update KPROBES and TRACING entries
  test_kprobes: Move it from kernel/ to lib/
  docs, kprobes: Remove invalid URL and add new reference
  samples/kretprobes: Fix return value if register_kretprobe() failed
  lib/bootconfig: Fix the xbc_get_info kerneldoc
  ...

5 files changed, 517 insertions, 92 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 1b99aead800c..6fdbf9613aec 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2080,9 +2080,10 @@ config TEST_DIV64
 	  If unsure, say N.
 
 config KPROBES_SANITY_TEST
-	bool "Kprobes sanity tests"
+	tristate "Kprobes sanity tests"
 	depends on DEBUG_KERNEL
 	depends on KPROBES
+	depends on KUNIT
 	help
 	  This option provides for testing basic kprobes functionality on
 	  boot. Samples of kprobe and kretprobe are inserted and
diff --git a/lib/Makefile b/lib/Makefile
index b0cb89451cd3..364c23f15578 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -100,6 +100,7 @@ obj-$(CONFIG_TEST_MEMINIT) += test_meminit.o
 obj-$(CONFIG_TEST_LOCKUP) += test_lockup.o
 obj-$(CONFIG_TEST_HMM) += test_hmm.o
 obj-$(CONFIG_TEST_FREE_PAGES) += test_free_pages.o
+obj-$(CONFIG_KPROBES_SANITY_TEST) += test_kprobes.o
 
 #
 # CFLAGS for compiling floating point code inside the kernel. x86/Makefile turns
diff --git a/lib/bootconfig.c b/lib/bootconfig.c
index 5ae248b29373..70e0d52ffd24 100644
--- a/lib/bootconfig.c
+++ b/lib/bootconfig.c
@@ -4,16 +4,24 @@
  * Masami Hiramatsu <mhiramat@kernel.org>
  */
 
-#define pr_fmt(fmt)    "bootconfig: " fmt
-
+#ifdef __KERNEL__
 #include <linux/bootconfig.h>
 #include <linux/bug.h>
 #include <linux/ctype.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/memblock.h>
-#include <linux/printk.h>
 #include <linux/string.h>
+#else /* !__KERNEL__ */
+/*
+ * NOTE: This is only for tools/bootconfig, because tools/bootconfig will
+ * run the parser sanity test.
+ * This does NOT mean lib/bootconfig.c is available in the user space.
+ * However, if you change this file, please make sure the tools/bootconfig
+ * has no issue on building and running.
+ */
+#include <linux/bootconfig.h>
+#endif
 
 /*
  * Extra Boot Config (XBC) is given as tree-structured ascii text of
@@ -34,6 +42,50 @@ static int xbc_err_pos __initdata;
 static int open_brace[XBC_DEPTH_MAX] __initdata;
 static int brace_index __initdata;
 
+#ifdef __KERNEL__
+static inline void * __init xbc_alloc_mem(size_t size)
+{
+	return memblock_alloc(size, SMP_CACHE_BYTES);
+}
+
+static inline void __init xbc_free_mem(void *addr, size_t size)
+{
+	memblock_free_ptr(addr, size);
+}
+
+#else /* !__KERNEL__ */
+
+static inline void *xbc_alloc_mem(size_t size)
+{
+	return malloc(size);
+}
+
+static inline void xbc_free_mem(void *addr, size_t size)
+{
+	free(addr);
+}
+#endif
+/**
+ * xbc_get_info() - Get the information of loaded boot config
+ * @node_size: A pointer to store the number of nodes.
+ * @data_size: A pointer to store the size of bootconfig data.
+ *
+ * Get the number of used nodes in @node_size if it is not NULL,
+ * and the size of bootconfig data in @data_size if it is not NULL.
+ * Return 0 if the boot config is initialized, or return -ENODEV.
+ */
+int __init xbc_get_info(int *node_size, size_t *data_size)
+{
+	if (!xbc_data)
+		return -ENODEV;
+
+	if (node_size)
+		*node_size = xbc_node_num;
+	if (data_size)
+		*data_size = xbc_data_size;
+	return 0;
+}
+
 static int __init xbc_parse_error(const char *msg, const char *p)
 {
 	xbc_err_msg = msg;
@@ -226,7 +278,7 @@ int __init xbc_node_compose_key_after(struct xbc_node *root,
 				      struct xbc_node *node,
 				      char *buf, size_t size)
 {
-	u16 keys[XBC_DEPTH_MAX];
+	uint16_t keys[XBC_DEPTH_MAX];
 	int depth = 0, ret = 0, total = 0;
 
 	if (!node || node == root)
@@ -341,21 +393,21 @@ const char * __init xbc_node_find_next_key_value(struct xbc_node *root,
 
 /* XBC parse and tree build */
 
-static int __init xbc_init_node(struct xbc_node *node, char *data, u32 flag)
+static int __init xbc_init_node(struct xbc_node *node, char *data, uint32_t flag)
 {
 	unsigned long offset = data - xbc_data;
 
 	if (WARN_ON(offset >= XBC_DATA_MAX))
 		return -EINVAL;
 
-	node->data = (u16)offset | flag;
+	node->data = (uint16_t)offset | flag;
 	node->child = 0;
 	node->next = 0;
 
 	return 0;
 }
 
-static struct xbc_node * __init xbc_add_node(char *data, u32 flag)
+static struct xbc_node * __init xbc_add_node(char *data, uint32_t flag)
 {
 	struct xbc_node *node;
 
@@ -385,7 +437,7 @@ static inline __init struct xbc_node *xbc_last_child(struct xbc_node *node)
 	return node;
 }
 
-static struct xbc_node * __init __xbc_add_sibling(char *data, u32 flag, bool head)
+static struct xbc_node * __init __xbc_add_sibling(char *data, uint32_t flag, bool head)
 {
 	struct xbc_node *sib, *node = xbc_add_node(data, flag);
 
@@ -412,17 +464,17 @@ static struct xbc_node * __init __xbc_add_sibling(char *data, u32 flag, bool hea
 	return node;
 }
 
-static inline struct xbc_node * __init xbc_add_sibling(char *data, u32 flag)
+static inline struct xbc_node * __init xbc_add_sibling(char *data, uint32_t flag)
 {
 	return __xbc_add_sibling(data, flag, false);
 }
 
-static inline struct xbc_node * __init xbc_add_head_sibling(char *data, u32 flag)
+static inline struct xbc_node * __init xbc_add_head_sibling(char *data, uint32_t flag)
 {
 	return __xbc_add_sibling(data, flag, true);
 }
 
-static inline __init struct xbc_node *xbc_add_child(char *data, u32 flag)
+static inline __init struct xbc_node *xbc_add_child(char *data, uint32_t flag)
 {
 	struct xbc_node *node = xbc_add_sibling(data, flag);
 
@@ -780,41 +832,94 @@ static int __init xbc_verify_tree(void)
 	return 0;
 }
 
+/* Need to setup xbc_data and xbc_nodes before call this. */
+static int __init xbc_parse_tree(void)
+{
+	char *p, *q;
+	int ret = 0, c;
+
+	last_parent = NULL;
+	p = xbc_data;
+	do {
+		q = strpbrk(p, "{}=+;:\n#");
+		if (!q) {
+			p = skip_spaces(p);
+			if (*p != '\0')
+				ret = xbc_parse_error("No delimiter", p);
+			break;
+		}
+
+		c = *q;
+		*q++ = '\0';
+		switch (c) {
+		case ':':
+		case '+':
+			if (*q++ != '=') {
+				ret = xbc_parse_error(c == '+' ?
+						"Wrong '+' operator" :
+						"Wrong ':' operator",
+							q - 2);
+				break;
+			}
+			fallthrough;
+		case '=':
+			ret = xbc_parse_kv(&p, q, c);
+			break;
+		case '{':
+			ret = xbc_open_brace(&p, q);
+			break;
+		case '#':
+			q = skip_comment(q);
+			fallthrough;
+		case ';':
+		case '\n':
+			ret = xbc_parse_key(&p, q);
+			break;
+		case '}':
+			ret = xbc_close_brace(&p, q);
+			break;
+		}
+	} while (!ret);
+
+	return ret;
+}
+
 /**
- * xbc_destroy_all() - Clean up all parsed bootconfig
+ * xbc_exit() - Clean up all parsed bootconfig
  *
  * This clears all data structures of parsed bootconfig on memory.
  * If you need to reuse xbc_init() with new boot config, you can
  * use this.
  */
-void __init xbc_destroy_all(void)
+void __init xbc_exit(void)
 {
+	xbc_free_mem(xbc_data, xbc_data_size);
 	xbc_data = NULL;
 	xbc_data_size = 0;
 	xbc_node_num = 0;
-	memblock_free_ptr(xbc_nodes, sizeof(struct xbc_node) * XBC_NODE_MAX);
+	xbc_free_mem(xbc_nodes, sizeof(struct xbc_node) * XBC_NODE_MAX);
 	xbc_nodes = NULL;
 	brace_index = 0;
 }
 
 /**
  * xbc_init() - Parse given XBC file and build XBC internal tree
- * @buf: boot config text
+ * @data: The boot config text original data
+ * @size: The size of @data
  * @emsg: A pointer of const char * to store the error message
  * @epos: A pointer of int to store the error position
  *
- * This parses the boot config text in @buf. @buf must be a
- * null terminated string and smaller than XBC_DATA_MAX.
+ * This parses the boot config text in @data. @size must be smaller
+ * than XBC_DATA_MAX.
  * Return the number of stored nodes (>0) if succeeded, or -errno
  * if there is any error.
  * In error cases, @emsg will be updated with an error message and
  * @epos will be updated with the error position which is the byte offset
  * of @buf. If the error is not a parser error, @epos will be -1.
  */
-int __init xbc_init(char *buf, const char **emsg, int *epos)
+int __init xbc_init(const char *data, size_t size, const char **emsg, int *epos)
 {
-	char *p, *q;
-	int ret, c;
+	int ret;
 
 	if (epos)
 		*epos = -1;
@@ -824,69 +929,33 @@ int __init xbc_init(char *buf, const char **emsg, int *epos)
 			*emsg = "Bootconfig is already initialized";
 		return -EBUSY;
 	}
-
-	ret = strlen(buf);
-	if (ret > XBC_DATA_MAX - 1 || ret == 0) {
+	if (size > XBC_DATA_MAX || size == 0) {
 		if (emsg)
-			*emsg = ret ? "Config data is too big" :
+			*emsg = size ? "Config data is too big" :
 				"Config data is empty";
 		return -ERANGE;
 	}
 
-	xbc_nodes = memblock_alloc(sizeof(struct xbc_node) * XBC_NODE_MAX,
-				   SMP_CACHE_BYTES);
+	xbc_data = xbc_alloc_mem(size + 1);
+	if (!xbc_data) {
+		if (emsg)
+			*emsg = "Failed to allocate bootconfig data";
+		return -ENOMEM;
+	}
+	memcpy(xbc_data, data, size);
+	xbc_data[size] = '\0';
+	xbc_data_size = size + 1;
+
+	xbc_nodes = xbc_alloc_mem(sizeof(struct xbc_node) * XBC_NODE_MAX);
 	if (!xbc_nodes) {
 		if (emsg)
 			*emsg = "Failed to allocate bootconfig nodes";
+		xbc_exit();
 		return -ENOMEM;
 	}
 	memset(xbc_nodes, 0, sizeof(struct xbc_node) * XBC_NODE_MAX);
-	xbc_data = buf;
-	xbc_data_size = ret + 1;
-	last_parent = NULL;
-
-	p = buf;
-	do {
-		q = strpbrk(p, "{}=+;:\n#");
-		if (!q) {
-			p = skip_spaces(p);
-			if (*p != '\0')
-				ret = xbc_parse_error("No delimiter", p);
-			break;
-		}
-
-		c = *q;
-		*q++ = '\0';
-		switch (c) {
-		case ':':
-		case '+':
-			if (*q++ != '=') {
-				ret = xbc_parse_error(c == '+' ?
-						"Wrong '+' operator" :
-						"Wrong ':' operator",
-							q - 2);
-				break;
-			}
-			fallthrough;
-		case '=':
-			ret = xbc_parse_kv(&p, q, c);
-			break;
-		case '{':
-			ret = xbc_open_brace(&p, q);
-			break;
-		case '#':
-			q = skip_comment(q);
-			fallthrough;
-		case ';':
-		case '\n':
-			ret = xbc_parse_key(&p, q);
-			break;
-		case '}':
-			ret = xbc_close_brace(&p, q);
-			break;
-		}
-	} while (!ret);
 
+	ret = xbc_parse_tree();
 	if (!ret)
 		ret = xbc_verify_tree();
 
@@ -895,27 +964,9 @@ int __init xbc_init(char *buf, const char **emsg, int *epos)
 			*epos = xbc_err_pos;
 		if (emsg)
 			*emsg = xbc_err_msg;
-		xbc_destroy_all();
+		xbc_exit();
 	} else
 		ret = xbc_node_num;
 
 	return ret;
 }
-
-/**
- * xbc_debug_dump() - Dump current XBC node list
- *
- * Dump the current XBC node list on printk buffer for debug.
- */
-void __init xbc_debug_dump(void)
-{
-	int i;
-
-	for (i = 0; i < xbc_node_num; i++) {
-		pr_debug("[%d] %s (%s) .next=%d, .child=%d .parent=%d\n", i,
-			xbc_node_get_data(xbc_nodes + i),
-			xbc_node_is_value(xbc_nodes + i) ? "value" : "key",
-			xbc_nodes[i].next, xbc_nodes[i].child,
-			xbc_nodes[i].parent);
-	}
-}
diff --git a/lib/error-inject.c b/lib/error-inject.c
index c73651b15b76..2ff5ef689d72 100644
--- a/lib/error-inject.c
+++ b/lib/error-inject.c
@@ -8,6 +8,7 @@
 #include <linux/mutex.h>
 #include <linux/list.h>
 #include <linux/slab.h>
+#include <asm/sections.h>
 
 /* Whitelist of symbols that can be overridden for error injection. */
 static LIST_HEAD(error_injection_list);
@@ -64,7 +65,7 @@ static void populate_error_injection_list(struct error_injection_entry *start,
 
 	mutex_lock(&ei_mutex);
 	for (iter = start; iter < end; iter++) {
-		entry = arch_deref_entry_point((void *)iter->addr);
+		entry = (unsigned long)dereference_symbol_descriptor((void *)iter->addr);
 
 		if (!kernel_text_address(entry) ||
 		    !kallsyms_lookup_size_offset(entry, &size, &offset)) {
diff --git a/lib/test_kprobes.c b/lib/test_kprobes.c
new file mode 100644
index 000000000000..a5edc2ebc947
--- /dev/null
+++ b/lib/test_kprobes.c
@@ -0,0 +1,371 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * test_kprobes.c - simple sanity test for *probes
+ *
+ * Copyright IBM Corp. 2008
+ */
+
+#include <linux/kernel.h>
+#include <linux/kprobes.h>
+#include <linux/random.h>
+#include <kunit/test.h>
+
+#define div_factor 3
+
+static u32 rand1, preh_val, posth_val;
+static u32 (*target)(u32 value);
+static u32 (*target2)(u32 value);
+static struct kunit *current_test;
+
+static unsigned long (*internal_target)(void);
+static unsigned long (*stacktrace_target)(void);
+static unsigned long (*stacktrace_driver)(void);
+static unsigned long target_return_address[2];
+
+static noinline u32 kprobe_target(u32 value)
+{
+	return (value / div_factor);
+}
+
+static int kp_pre_handler(struct kprobe *p, struct pt_regs *regs)
+{
+	KUNIT_EXPECT_FALSE(current_test, preemptible());
+	preh_val = (rand1 / div_factor);
+	return 0;
+}
+
+static void kp_post_handler(struct kprobe *p, struct pt_regs *regs,
+		unsigned long flags)
+{
+	KUNIT_EXPECT_FALSE(current_test, preemptible());
+	KUNIT_EXPECT_EQ(current_test, preh_val, (rand1 / div_factor));
+	posth_val = preh_val + div_factor;
+}
+
+static struct kprobe kp = {
+	.symbol_name = "kprobe_target",
+	.pre_handler = kp_pre_handler,
+	.post_handler = kp_post_handler
+};
+
+static void test_kprobe(struct kunit *test)
+{
+	current_test = test;
+	KUNIT_EXPECT_EQ(test, 0, register_kprobe(&kp));
+	target(rand1);
+	unregister_kprobe(&kp);
+	KUNIT_EXPECT_NE(test, 0, preh_val);
+	KUNIT_EXPECT_NE(test, 0, posth_val);
+}
+
+static noinline u32 kprobe_target2(u32 value)
+{
+	return (value / div_factor) + 1;
+}
+
+static noinline unsigned long kprobe_stacktrace_internal_target(void)
+{
+	if (!target_return_address[0])
+		target_return_address[0] = (unsigned long)__builtin_return_address(0);
+	return target_return_address[0];
+}
+
+static noinline unsigned long kprobe_stacktrace_target(void)
+{
+	if (!target_return_address[1])
+		target_return_address[1] = (unsigned long)__builtin_return_address(0);
+
+	if (internal_target)
+		internal_target();
+
+	return target_return_address[1];
+}
+
+static noinline unsigned long kprobe_stacktrace_driver(void)
+{
+	if (stacktrace_target)
+		stacktrace_target();
+
+	/* This is for preventing inlining the function */
+	return (unsigned long)__builtin_return_address(0);
+}
+
+static int kp_pre_handler2(struct kprobe *p, struct pt_regs *regs)
+{
+	preh_val = (rand1 / div_factor) + 1;
+	return 0;
+}
+
+static void kp_post_handler2(struct kprobe *p, struct pt_regs *regs,
+		unsigned long flags)
+{
+	KUNIT_EXPECT_EQ(current_test, preh_val, (rand1 / div_factor) + 1);
+	posth_val = preh_val + div_factor;
+}
+
+static struct kprobe kp2 = {
+	.symbol_name = "kprobe_target2",
+	.pre_handler = kp_pre_handler2,
+	.post_handler = kp_post_handler2
+};
+
+static void test_kprobes(struct kunit *test)
+{
+	struct kprobe *kps[2] = {&kp, &kp2};
+
+	current_test = test;
+
+	/* addr and flags should be cleard for reusing kprobe. */
+	kp.addr = NULL;
+	kp.flags = 0;
+
+	KUNIT_EXPECT_EQ(test, 0, register_kprobes(kps, 2));
+	preh_val = 0;
+	posth_val = 0;
+	target(rand1);
+
+	KUNIT_EXPECT_NE(test, 0, preh_val);
+	KUNIT_EXPECT_NE(test, 0, posth_val);
+
+	preh_val = 0;
+	posth_val = 0;
+	target2(rand1);
+
+	KUNIT_EXPECT_NE(test, 0, preh_val);
+	KUNIT_EXPECT_NE(test, 0, posth_val);
+	unregister_kprobes(kps, 2);
+}
+
+#ifdef CONFIG_KRETPROBES
+static u32 krph_val;
+
+static int entry_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
+{
+	KUNIT_EXPECT_FALSE(current_test, preemptible());
+	krph_val = (rand1 / div_factor);
+	return 0;
+}
+
+static int return_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
+{
+	unsigned long ret = regs_return_value(regs);
+
+	KUNIT_EXPECT_FALSE(current_test, preemptible());
+	KUNIT_EXPECT_EQ(current_test, ret, rand1 / div_factor);
+	KUNIT_EXPECT_NE(current_test, krph_val, 0);
+	krph_val = rand1;
+	return 0;
+}
+
+static struct kretprobe rp = {
+	.handler	= return_handler,
+	.entry_handler  = entry_handler,
+	.kp.symbol_name = "kprobe_target"
+};
+
+static void test_kretprobe(struct kunit *test)
+{
+	current_test = test;
+	KUNIT_EXPECT_EQ(test, 0, register_kretprobe(&rp));
+	target(rand1);
+	unregister_kretprobe(&rp);
+	KUNIT_EXPECT_EQ(test, krph_val, rand1);
+}
+
+static int return_handler2(struct kretprobe_instance *ri, struct pt_regs *regs)
+{
+	unsigned long ret = regs_return_value(regs);
+
+	KUNIT_EXPECT_EQ(current_test, ret, (rand1 / div_factor) + 1);
+	KUNIT_EXPECT_NE(current_test, krph_val, 0);
+	krph_val = rand1;
+	return 0;
+}
+
+static struct kretprobe rp2 = {
+	.handler	= return_handler2,
+	.entry_handler  = entry_handler,
+	.kp.symbol_name = "kprobe_target2"
+};
+
+static void test_kretprobes(struct kunit *test)
+{
+	struct kretprobe *rps[2] = {&rp, &rp2};
+
+	current_test = test;
+	/* addr and flags should be cleard for reusing kprobe. */
+	rp.kp.addr = NULL;
+	rp.kp.flags = 0;
+	KUNIT_EXPECT_EQ(test, 0, register_kretprobes(rps, 2));
+
+	krph_val = 0;
+	target(rand1);
+	KUNIT_EXPECT_EQ(test, krph_val, rand1);
+
+	krph_val = 0;
+	target2(rand1);
+	KUNIT_EXPECT_EQ(test, krph_val, rand1);
+	unregister_kretprobes(rps, 2);
+}
+
+#ifdef CONFIG_ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
+#define STACK_BUF_SIZE 16
+static unsigned long stack_buf[STACK_BUF_SIZE];
+
+static int stacktrace_return_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
+{
+	unsigned long retval = regs_return_value(regs);
+	int i, ret;
+
+	KUNIT_EXPECT_FALSE(current_test, preemptible());
+	KUNIT_EXPECT_EQ(current_test, retval, target_return_address[1]);
+
+	/*
+	 * Test stacktrace inside the kretprobe handler, this will involves
+	 * kretprobe trampoline, but must include correct return address
+	 * of the target function.
+	 */
+	ret = stack_trace_save(stack_buf, STACK_BUF_SIZE, 0);
+	KUNIT_EXPECT_NE(current_test, ret, 0);
+
+	for (i = 0; i < ret; i++) {
+		if (stack_buf[i] == target_return_address[1])
+			break;
+	}
+	KUNIT_EXPECT_NE(current_test, i, ret);
+
+#if !IS_MODULE(CONFIG_KPROBES_SANITY_TEST)
+	/*
+	 * Test stacktrace from pt_regs at the return address. Thus the stack
+	 * trace must start from the target return address.
+	 */
+	ret = stack_trace_save_regs(regs, stack_buf, STACK_BUF_SIZE, 0);
+	KUNIT_EXPECT_NE(current_test, ret, 0);
+	KUNIT_EXPECT_EQ(current_test, stack_buf[0], target_return_address[1]);
+#endif
+
+	return 0;
+}
+
+static struct kretprobe rp3 = {
+	.handler	= stacktrace_return_handler,
+	.kp.symbol_name = "kprobe_stacktrace_target"
+};
+
+static void test_stacktrace_on_kretprobe(struct kunit *test)
+{
+	unsigned long myretaddr = (unsigned long)__builtin_return_address(0);
+
+	current_test = test;
+	rp3.kp.addr = NULL;
+	rp3.kp.flags = 0;
+
+	/*
+	 * Run the stacktrace_driver() to record correct return address in
+	 * stacktrace_target() and ensure stacktrace_driver() call is not
+	 * inlined by checking the return address of stacktrace_driver()
+	 * and the return address of this function is different.
+	 */
+	KUNIT_ASSERT_NE(test, myretaddr, stacktrace_driver());
+
+	KUNIT_ASSERT_EQ(test, 0, register_kretprobe(&rp3));
+	KUNIT_ASSERT_NE(test, myretaddr, stacktrace_driver());
+	unregister_kretprobe(&rp3);
+}
+
+static int stacktrace_internal_return_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
+{
+	unsigned long retval = regs_return_value(regs);
+	int i, ret;
+
+	KUNIT_EXPECT_FALSE(current_test, preemptible());
+	KUNIT_EXPECT_EQ(current_test, retval, target_return_address[0]);
+
+	/*
+	 * Test stacktrace inside the kretprobe handler for nested case.
+	 * The unwinder will find the kretprobe_trampoline address on the
+	 * return address, and kretprobe must solve that.
+	 */
+	ret = stack_trace_save(stack_buf, STACK_BUF_SIZE, 0);
+	KUNIT_EXPECT_NE(current_test, ret, 0);
+
+	for (i = 0; i < ret - 1; i++) {
+		if (stack_buf[i] == target_return_address[0]) {
+			KUNIT_EXPECT_EQ(current_test, stack_buf[i + 1], target_return_address[1]);
+			break;
+		}
+	}
+	KUNIT_EXPECT_NE(current_test, i, ret);
+
+#if !IS_MODULE(CONFIG_KPROBES_SANITY_TEST)
+	/* Ditto for the regs version. */
+	ret = stack_trace_save_regs(regs, stack_buf, STACK_BUF_SIZE, 0);
+	KUNIT_EXPECT_NE(current_test, ret, 0);
+	KUNIT_EXPECT_EQ(current_test, stack_buf[0], target_return_address[0]);
+	KUNIT_EXPECT_EQ(current_test, stack_buf[1], target_return_address[1]);
+#endif
+
+	return 0;
+}
+
+static struct kretprobe rp4 = {
+	.handler	= stacktrace_internal_return_handler,
+	.kp.symbol_name = "kprobe_stacktrace_internal_target"
+};
+
+static void test_stacktrace_on_nested_kretprobe(struct kunit *test)
+{
+	unsigned long myretaddr = (unsigned long)__builtin_return_address(0);
+	struct kretprobe *rps[2] = {&rp3, &rp4};
+
+	current_test = test;
+	rp3.kp.addr = NULL;
+	rp3.kp.flags = 0;
+
+	//KUNIT_ASSERT_NE(test, myretaddr, stacktrace_driver());
+
+	KUNIT_ASSERT_EQ(test, 0, register_kretprobes(rps, 2));
+	KUNIT_ASSERT_NE(test, myretaddr, stacktrace_driver());
+	unregister_kretprobes(rps, 2);
+}
+#endif /* CONFIG_ARCH_CORRECT_STACKTRACE_ON_KRETPROBE */
+
+#endif /* CONFIG_KRETPROBES */
+
+static int kprobes_test_init(struct kunit *test)
+{
+	target = kprobe_target;
+	target2 = kprobe_target2;
+	stacktrace_target = kprobe_stacktrace_target;
+	internal_target = kprobe_stacktrace_internal_target;
+	stacktrace_driver = kprobe_stacktrace_driver;
+
+	do {
+		rand1 = prandom_u32();
+	} while (rand1 <= div_factor);
+	return 0;
+}
+
+static struct kunit_case kprobes_testcases[] = {
+	KUNIT_CASE(test_kprobe),
+	KUNIT_CASE(test_kprobes),
+#ifdef CONFIG_KRETPROBES
+	KUNIT_CASE(test_kretprobe),
+	KUNIT_CASE(test_kretprobes),
+#ifdef CONFIG_ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
+	KUNIT_CASE(test_stacktrace_on_kretprobe),
+	KUNIT_CASE(test_stacktrace_on_nested_kretprobe),
+#endif
+#endif
+	{}
+};
+
+static struct kunit_suite kprobes_test_suite = {
+	.name = "kprobes_test",
+	.init = kprobes_test_init,
+	.test_cases = kprobes_testcases,
+};
+
+kunit_test_suites(&kprobes_test_suite);
+
+MODULE_LICENSE("GPL");