Merge tag 'trace-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "The majority of the changes are for fixes and clean ups.

  Notable changes:

   - Rework trace event triggers code to be easier to interact with.

   - Support for embedding bootconfig with the kernel (as suppose to
     having it embedded in initram). This is useful for embedded boards
     without initram disks.

   - Speed up boot by parallelizing the creation of tracefs files.

   - Allow absolute ring buffer timestamps handle timestamps that use
     more than 59 bits.

   - Added new tracing clock "TAI" (International Atomic Time)

   - Have weak functions show up in available_filter_function list as:
     __ftrace_invalid_address___<invalid-offset> instead of using the
     name of the function before it"

* tag 'trace-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (52 commits)
  ftrace: Add FTRACE_MCOUNT_MAX_OFFSET to avoid adding weak function
  tracing: Fix comments for event_trigger_separate_filter()
  x86/traceponit: Fix comment about irq vector tracepoints
  x86,tracing: Remove unused headers
  ftrace: Clean up hash direct_functions on register failures
  tracing: Fix comments of create_filter()
  tracing: Disable kcov on trace_preemptirq.c
  tracing: Initialize integer variable to prevent garbage return value
  ftrace: Fix typo in comment
  ftrace: Remove return value of ftrace_arch_modify_*()
  tracing: Cleanup code by removing init "char *name"
  tracing: Change "char *" string form to "char []"
  tracing/timerlat: Do not wakeup the thread if the trace stops at the IRQ
  tracing/timerlat: Print stacktrace in the IRQ handler if needed
  tracing/timerlat: Notify IRQ new max latency only if stop tracing is set
  kprobes: Fix build errors with CONFIG_KRETPROBES=n
  tracing: Fix return value of trace_pid_write()
  tracing: Fix potential double free in create_var_ref()
  tracing: Use strim() to remove whitespace instead of doing it manually
  ftrace: Deal with error return code of the ftrace_process_locs() function
  ...

40 files changed, 822 insertions, 646 deletions

diff --git a/Documentation/admin-guide/bootconfig.rst b/Documentation/admin-guide/bootconfig.rst
index a1860fc0ca88..d99994345d41 100644
--- a/Documentation/admin-guide/bootconfig.rst
+++ b/Documentation/admin-guide/bootconfig.rst
@@ -158,9 +158,15 @@ Each key-value pair is shown in each line with following style::
 Boot Kernel With a Boot Config
 ==============================
 
-Since the boot configuration file is loaded with initrd, it will be added
-to the end of the initrd (initramfs) image file with padding, size,
-checksum and 12-byte magic word as below.
+There are two options to boot the kernel with bootconfig: attaching the
+bootconfig to the initrd image or embedding it in the kernel itself.
+
+Attaching a Boot Config to Initrd
+---------------------------------
+
+Since the boot configuration file is loaded with initrd by default,
+it will be added to the end of the initrd (initramfs) image file with
+padding, size, checksum and 12-byte magic word as below.
 
 [initrd][bootconfig][padding][size(le32)][checksum(le32)][#BOOTCONFIG\n]
 
@@ -196,6 +202,25 @@ To remove the config from the image, you can use -d option as below::
 Then add "bootconfig" on the normal kernel command line to tell the
 kernel to look for the bootconfig at the end of the initrd file.
 
+Embedding a Boot Config into Kernel
+-----------------------------------
+
+If you can not use initrd, you can also embed the bootconfig file in the
+kernel by Kconfig options. In this case, you need to recompile the kernel
+with the following configs::
+
+ CONFIG_BOOT_CONFIG_EMBED=y
+ CONFIG_BOOT_CONFIG_EMBED_FILE="/PATH/TO/BOOTCONFIG/FILE"
+
+``CONFIG_BOOT_CONFIG_EMBED_FILE`` requires an absolute path or a relative
+path to the bootconfig file from source tree or object tree.
+The kernel will embed it as the default bootconfig.
+
+Just as when attaching the bootconfig to the initrd, you need ``bootconfig``
+option on the kernel command line to enable the embedded bootconfig.
+
+Note that even if you set this option, you can override the embedded
+bootconfig by another bootconfig which attached to the initrd.
 
 Kernel parameters via Boot Config
 =================================
diff --git a/Documentation/trace/ftrace.rst b/Documentation/trace/ftrace.rst
index 45b8c56af67a..b37dc19e4d40 100644
--- a/Documentation/trace/ftrace.rst
+++ b/Documentation/trace/ftrace.rst
@@ -517,6 +517,18 @@ of ftrace. Here is a list of some of the key files:
 		processing should be able to handle them. See comments in the
 		ktime_get_boot_fast_ns() function for more information.
 
+	tai:
+		This is the tai clock (CLOCK_TAI) and is derived from the wall-
+		clock time. However, this clock does not experience
+		discontinuities and backwards jumps caused by NTP inserting leap
+		seconds. Since the clock access is designed for use in tracing,
+		side effects are possible. The clock access may yield wrong
+		readouts in case the internal TAI offset is updated e.g., caused
+		by setting the system time or using adjtimex() with an offset.
+		These effects are rare and post processing should be able to
+		handle them. See comments in the ktime_get_tai_fast_ns()
+		function for more information.
+
 	To set a clock, simply echo the clock name into this file::
 
 	  # echo global > trace_clock
diff --git a/Documentation/trace/timerlat-tracer.rst b/Documentation/trace/timerlat-tracer.rst
index 64d1fe6e9b93..d643c95c01eb 100644
--- a/Documentation/trace/timerlat-tracer.rst
+++ b/Documentation/trace/timerlat-tracer.rst
@@ -74,8 +74,9 @@ directory. The timerlat configs are:
  - stop_tracing_total_us: stop the system tracing if a
    timer latency at the *thread* context is higher than the configured
    value happens. Writing 0 disables this option.
- - print_stack: save the stack of the IRQ occurrence, and print
-   it after the *thread context* event".
+ - print_stack: save the stack of the IRQ occurrence. The stack is printed
+   after the *thread context* event, or at the IRQ handler if *stop_tracing_us*
+   is hit.
 
 timerlat and osnoise
 ----------------------------
diff --git a/MAINTAINERS b/MAINTAINERS
index e02f4601f821..a0f251772b79 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7517,6 +7517,7 @@ S:	Maintained
 F:	Documentation/admin-guide/bootconfig.rst
 F:	fs/proc/bootconfig.c
 F:	include/linux/bootconfig.h
+F:	lib/bootconfig-data.S
 F:	lib/bootconfig.c
 F:	tools/bootconfig/*
 F:	tools/bootconfig/scripts/*
@@ -20119,8 +20120,8 @@ M:	Ingo Molnar <mingo@redhat.com>
 S:	Maintained
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
 F:	Documentation/trace/ftrace.rst
-F:	arch/*/*/*/ftrace.h
-F:	arch/*/kernel/ftrace.c
+F:	arch/*/*/*/*ftrace*
+F:	arch/*/*/*ftrace*
 F:	fs/tracefs/
 F:	include/*/ftrace.h
 F:	include/linux/trace*.h
diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c
index 83cc068586bc..a0b6d1e3812f 100644
--- a/arch/arm/kernel/ftrace.c
+++ b/arch/arm/kernel/ftrace.c
@@ -79,16 +79,14 @@ static unsigned long __ref adjust_address(struct dyn_ftrace *rec,
 	return (unsigned long)&ftrace_regs_caller_from_init;
 }
 
-int ftrace_arch_code_modify_prepare(void)
+void ftrace_arch_code_modify_prepare(void)
 {
-	return 0;
 }
 
-int ftrace_arch_code_modify_post_process(void)
+void ftrace_arch_code_modify_post_process(void)
 {
 	/* Make sure any TLB misses during machine stop are cleared. */
 	flush_tlb_all();
-	return 0;
 }
 
 static unsigned long ftrace_call_replace(unsigned long pc, unsigned long addr,
diff --git a/arch/riscv/kernel/ftrace.c b/arch/riscv/kernel/ftrace.c
index 4716f4cdc038..2086f6585773 100644
--- a/arch/riscv/kernel/ftrace.c
+++ b/arch/riscv/kernel/ftrace.c
@@ -12,16 +12,14 @@
 #include <asm/patch.h>
 
 #ifdef CONFIG_DYNAMIC_FTRACE
-int ftrace_arch_code_modify_prepare(void) __acquires(&text_mutex)
+void ftrace_arch_code_modify_prepare(void) __acquires(&text_mutex)
 {
 	mutex_lock(&text_mutex);
-	return 0;
 }
 
-int ftrace_arch_code_modify_post_process(void) __releases(&text_mutex)
+void ftrace_arch_code_modify_post_process(void) __releases(&text_mutex)
 {
 	mutex_unlock(&text_mutex);
-	return 0;
 }
 
 static int ftrace_check_current_call(unsigned long hook_pos,
diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c
index 1852d46babb1..416b5a94353d 100644
--- a/arch/s390/kernel/ftrace.c
+++ b/arch/s390/kernel/ftrace.c
@@ -225,14 +225,13 @@ void arch_ftrace_update_code(int command)
 	ftrace_modify_all_code(command);
 }
 
-int ftrace_arch_code_modify_post_process(void)
+void ftrace_arch_code_modify_post_process(void)
 {
 	/*
 	 * Flush any pre-fetched instructions on all
 	 * CPUs to make the new code visible.
 	 */
 	text_poke_sync_lock();
-	return 0;
 }
 
 #ifdef CONFIG_MODULES
diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h
index 024d9797646e..b5ef474be858 100644
--- a/arch/x86/include/asm/ftrace.h
+++ b/arch/x86/include/asm/ftrace.h
@@ -9,6 +9,13 @@
 # define MCOUNT_ADDR		((unsigned long)(__fentry__))
 #define MCOUNT_INSN_SIZE	5 /* sizeof mcount call */
 
+/* Ignore unused weak functions which will have non zero offsets */
+#ifdef CONFIG_HAVE_FENTRY
+# include <asm/ibt.h>
+/* Add offset for endbr64 if IBT enabled */
+# define FTRACE_MCOUNT_MAX_OFFSET	ENDBR_INSN_SIZE
+#endif
+
 #ifdef CONFIG_DYNAMIC_FTRACE
 #define ARCH_SUPPORTS_FTRACE_OPS 1
 #endif
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index b09d73c2ba89..5b4efc927d80 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -37,7 +37,7 @@
 
 static int ftrace_poke_late = 0;
 
-int ftrace_arch_code_modify_prepare(void)
+void ftrace_arch_code_modify_prepare(void)
     __acquires(&text_mutex)
 {
 	/*
@@ -47,10 +47,9 @@ int ftrace_arch_code_modify_prepare(void)
 	 */
 	mutex_lock(&text_mutex);
 	ftrace_poke_late = 1;
-	return 0;
 }
 
-int ftrace_arch_code_modify_post_process(void)
+void ftrace_arch_code_modify_post_process(void)
     __releases(&text_mutex)
 {
 	/*
@@ -61,7 +60,6 @@ int ftrace_arch_code_modify_post_process(void)
 	text_poke_finish();
 	ftrace_poke_late = 0;
 	mutex_unlock(&text_mutex);
-	return 0;
 }
 
 static const char *ftrace_nop_replace(void)
diff --git a/arch/x86/kernel/tracepoint.c b/arch/x86/kernel/tracepoint.c
index fcfc077afe2d..03ae1caaa878 100644
--- a/arch/x86/kernel/tracepoint.c
+++ b/arch/x86/kernel/tracepoint.c
@@ -1,17 +1,11 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * Code for supporting irq vector tracepoints.
- *
  * Copyright (C) 2013 Seiji Aguchi <seiji.aguchi@hds.com>
- *
  */
 #include <linux/jump_label.h>
 #include <linux/atomic.h>
 
-#include <asm/hw_irq.h>
-#include <asm/desc.h>
 #include <asm/trace/exceptions.h>
-#include <asm/trace/irq_vectors.h>
 
 DEFINE_STATIC_KEY_FALSE(trace_pagefault_key);
 
diff --git a/include/linux/bootconfig.h b/include/linux/bootconfig.h
index a4665c7ab07c..1611f9db878e 100644
--- a/include/linux/bootconfig.h
+++ b/include/linux/bootconfig.h
@@ -289,4 +289,14 @@ int __init xbc_get_info(int *node_size, size_t *data_size);
 /* XBC cleanup data structures */
 void __init xbc_exit(void);
 
+/* XBC embedded bootconfig data in kernel */
+#ifdef CONFIG_BOOT_CONFIG_EMBED
+const char * __init xbc_get_embedded_bootconfig(size_t *size);
+#else
+static inline const char *xbc_get_embedded_bootconfig(size_t *size)
+{
+	return NULL;
+}
+#endif
+
 #endif
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 3eb03d88320d..979f6bfa2c25 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -452,8 +452,8 @@ static inline void stack_tracer_enable(void) { }
 
 #ifdef CONFIG_DYNAMIC_FTRACE
 
-int ftrace_arch_code_modify_prepare(void);
-int ftrace_arch_code_modify_post_process(void);
+void ftrace_arch_code_modify_prepare(void);
+void ftrace_arch_code_modify_post_process(void);
 
 enum ftrace_bug_type {
 	FTRACE_BUG_UNKNOWN,
diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h
index 157168769fc2..55041d2f884d 100644
--- a/include/linux/kprobes.h
+++ b/include/linux/kprobes.h
@@ -424,7 +424,7 @@ void unregister_kretprobe(struct kretprobe *rp);
 int register_kretprobes(struct kretprobe **rps, int num);
 void unregister_kretprobes(struct kretprobe **rps, int num);
 
-#ifdef CONFIG_KRETPROBE_ON_RETHOOK
+#if defined(CONFIG_KRETPROBE_ON_RETHOOK) || !defined(CONFIG_KRETPROBES)
 #define kprobe_flush_task(tk)	do {} while (0)
 #else
 void kprobe_flush_task(struct task_struct *tk);
diff --git a/init/Kconfig b/init/Kconfig
index 583675727b85..251aac1c0ccd 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1338,7 +1338,7 @@ endif
 
 config BOOT_CONFIG
 	bool "Boot config support"
-	select BLK_DEV_INITRD
+	select BLK_DEV_INITRD if !BOOT_CONFIG_EMBED
 	help
 	  Extra boot config allows system admin to pass a config file as
 	  complemental extension of kernel cmdline when booting.
@@ -1348,6 +1348,25 @@ config BOOT_CONFIG
 
 	  If unsure, say Y.
 
+config BOOT_CONFIG_EMBED
+	bool "Embed bootconfig file in the kernel"
+	depends on BOOT_CONFIG
+	help
+	  Embed a bootconfig file given by BOOT_CONFIG_EMBED_FILE in the
+	  kernel. Usually, the bootconfig file is loaded with the initrd
+	  image. But if the system doesn't support initrd, this option will
+	  help you by embedding a bootconfig file while building the kernel.
+
+	  If unsure, say N.
+
+config BOOT_CONFIG_EMBED_FILE
+	string "Embedded bootconfig file path"
+	depends on BOOT_CONFIG_EMBED
+	help
+	  Specify a bootconfig file which will be embedded to the kernel.
+	  This bootconfig will be used if there is no initrd or no other
+	  bootconfig in the initrd.
+
 config INITRAMFS_PRESERVE_MTIME
 	bool "Preserve cpio archive mtimes in initramfs"
 	default y
diff --git a/init/main.c b/init/main.c
index f057c49f1d9d..02eb533018f6 100644
--- a/init/main.c
+++ b/init/main.c
@@ -266,7 +266,7 @@ static int __init loglevel(char *str)
 early_param("loglevel", loglevel);
 
 #ifdef CONFIG_BLK_DEV_INITRD
-static void * __init get_boot_config_from_initrd(u32 *_size, u32 *_csum)
+static void * __init get_boot_config_from_initrd(size_t *_size)
 {
 	u32 size, csum;
 	char *data;
@@ -300,17 +300,20 @@ found:
 		return NULL;
 	}
 
+	if (xbc_calc_checksum(data, size) != csum) {
+		pr_err("bootconfig checksum failed\n");
+		return NULL;
+	}
+
 	/* Remove bootconfig from initramfs/initrd */
 	initrd_end = (unsigned long)data;
 	if (_size)
 		*_size = size;
-	if (_csum)
-		*_csum = csum;
 
 	return data;
 }
 #else
-static void * __init get_boot_config_from_initrd(u32 *_size, u32 *_csum)
+static void * __init get_boot_config_from_initrd(size_t *_size)
 {
 	return NULL;
 }
@@ -407,14 +410,16 @@ static int __init warn_bootconfig(char *str)
 static void __init setup_boot_config(void)
 {
 	static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
-	const char *msg;
-	int pos;
-	u32 size, csum;
-	char *data, *err;
-	int ret;
+	const char *msg, *data;
+	int pos, ret;
+	size_t size;
+	char *err;
 
 	/* Cut out the bootconfig data even if we have no bootconfig option */
-	data = get_boot_config_from_initrd(&size, &csum);
+	data = get_boot_config_from_initrd(&size);
+	/* If there is no bootconfig in initrd, try embedded one. */
+	if (!data)
+		data = xbc_get_embedded_bootconfig(&size);
 
 	strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
 	err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL,
@@ -433,13 +438,8 @@ static void __init setup_boot_config(void)
 	}
 
 	if (size >= XBC_DATA_MAX) {
-		pr_err("bootconfig size %d greater than max size %d\n",
-			size, XBC_DATA_MAX);
-		return;
-	}
-
-	if (xbc_calc_checksum(data, size) != csum) {
-		pr_err("bootconfig checksum failed\n");
+		pr_err("bootconfig size %ld greater than max size %d\n",
+			(long)size, XBC_DATA_MAX);
 		return;
 	}
 
@@ -452,7 +452,7 @@ static void __init setup_boot_config(void)
 				msg, pos);
 	} else {
 		xbc_get_info(&ret, NULL);
-		pr_info("Load bootconfig: %d bytes %d nodes\n", size, ret);
+		pr_info("Load bootconfig: %ld bytes %d nodes\n", (long)size, ret);
 		/* keys starting with "kernel." are passed via cmdline */
 		extra_command_line = xbc_make_cmdline("kernel");
 		/* Also, "init." keys are init arguments */
@@ -471,7 +471,7 @@ static void __init exit_boot_config(void)
 static void __init setup_boot_config(void)
 {
 	/* Remove bootconfig data from initrd */
-	get_boot_config_from_initrd(NULL, NULL);
+	get_boot_config_from_initrd(NULL);
 }
 
 static int __init warn_bootconfig(char *str)
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index dd58c0be9ce2..f214f8c088ed 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1257,79 +1257,6 @@ void kprobe_busy_end(void)
 	preempt_enable();
 }
 
-#if !defined(CONFIG_KRETPROBE_ON_RETHOOK)
-static void free_rp_inst_rcu(struct rcu_head *head)
-{
-	struct kretprobe_instance *ri = container_of(head, struct kretprobe_instance, rcu);
-
-	if (refcount_dec_and_test(&ri->rph->ref))
-		kfree(ri->rph);
-	kfree(ri);
-}
-NOKPROBE_SYMBOL(free_rp_inst_rcu);
-
-static void recycle_rp_inst(struct kretprobe_instance *ri)
-{
-	struct kretprobe *rp = get_kretprobe(ri);
-
-	if (likely(rp))
-		freelist_add(&ri->freelist, &rp->freelist);
-	else
-		call_rcu(&ri->rcu, free_rp_inst_rcu);
-}
-NOKPROBE_SYMBOL(recycle_rp_inst);
-
-/*
- * This function is called from delayed_put_task_struct() when a task is
- * dead and cleaned up to recycle any kretprobe instances associated with
- * this task. These left over instances represent probed functions that
- * have been called but will never return.
- */
-void kprobe_flush_task(struct task_struct *tk)
-{
-	struct kretprobe_instance *ri;
-	struct llist_node *node;
-
-	/* Early boot, not yet initialized. */
-	if (unlikely(!kprobes_initialized))
-		return;
-
-	kprobe_busy_begin();
-
-	node = __llist_del_all(&tk->kretprobe_instances);
-	while (node) {
-		ri = container_of(node, struct kretprobe_instance, llist);
-		node = node->next;
-
-		recycle_rp_inst(ri);
-	}
-
-	kprobe_busy_end();
-}
-NOKPROBE_SYMBOL(kprobe_flush_task);
-
-static inline void free_rp_inst(struct kretprobe *rp)
-{
-	struct kretprobe_instance *ri;
-	struct freelist_node *node;
-	int count = 0;
-
-	node = rp->freelist.head;
-	while (node) {
-		ri = container_of(node, struct kretprobe_instance, freelist);
-		node = node->next;
-
-		kfree(ri);
-		count++;
-	}
-
-	if (refcount_sub_and_test(count, &rp->rph->ref)) {
-		kfree(rp->rph);
-		rp->rph = NULL;
-	}
-}
-#endif	/* !CONFIG_KRETPROBE_ON_RETHOOK */
-
 /* Add the new probe to 'ap->list'. */
 static int add_new_kprobe(struct kprobe *ap, struct kprobe *p)
 {
@@ -1928,6 +1855,77 @@ static struct notifier_block kprobe_exceptions_nb = {
 #ifdef CONFIG_KRETPROBES
 
 #if !defined(CONFIG_KRETPROBE_ON_RETHOOK)
+static void free_rp_inst_rcu(struct rcu_head *head)
+{
+	struct kretprobe_instance *ri = container_of(head, struct kretprobe_instance, rcu);
+
+	if (refcount_dec_and_test(&ri->rph->ref))
+		kfree(ri->rph);
+	kfree(ri);
+}
+NOKPROBE_SYMBOL(free_rp_inst_rcu);
+
+static void recycle_rp_inst(struct kretprobe_instance *ri)
+{
+	struct kretprobe *rp = get_kretprobe(ri);
+
+	if (likely(rp))
+		freelist_add(&ri->freelist, &rp->freelist);
+	else
+		call_rcu(&ri->rcu, free_rp_inst_rcu);
+}
+NOKPROBE_SYMBOL(recycle_rp_inst);
+
+/*
+ * This function is called from delayed_put_task_struct() when a task is
+ * dead and cleaned up to recycle any kretprobe instances associated with
+ * this task. These left over instances represent probed functions that
+ * have been called but will never return.
+ */
+void kprobe_flush_task(struct task_struct *tk)
+{
+	struct kretprobe_instance *ri;
+	struct llist_node *node;
+
+	/* Early boot, not yet initialized. */
+	if (unlikely(!kprobes_initialized))
+		return;
+
+	kprobe_busy_begin();
+
+	node = __llist_del_all(&tk->kretprobe_instances);
+	while (node) {
+		ri = container_of(node, struct kretprobe_instance, llist);
+		node = node->next;
+
+		recycle_rp_inst(ri);
+	}
+
+	kprobe_busy_end();
+}
+NOKPROBE_SYMBOL(kprobe_flush_task);
+
+static inline void free_rp_inst(struct kretprobe *rp)
+{
+	struct kretprobe_instance *ri;
+	struct freelist_node *node;
+	int count = 0;
+
+	node = rp->freelist.head;
+	while (node) {
+		ri = container_of(node, struct kretprobe_instance, freelist);
+		node = node->next;
+
+		kfree(ri);
+		count++;
+	}
+
+	if (refcount_sub_and_test(count, &rp->rph->ref)) {
+		kfree(rp->rph);
+		rp->rph = NULL;
+	}
+}
+
 /* This assumes the 'tsk' is the current task or the is not running. */
 static kprobe_opcode_t *__kretprobe_find_ret_addr(struct task_struct *tsk,
 						  struct llist_node **cur)
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index d77cd8032213..0d261774d6f3 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -31,6 +31,10 @@ ifdef CONFIG_GCOV_PROFILE_FTRACE
 GCOV_PROFILE := y
 endif
 
+# Functions in this file could be invoked from early interrupt
+# code and produce random code coverage.
+KCOV_INSTRUMENT_trace_preemptirq.o := n
+
 CFLAGS_bpf_trace.o := -I$(src)
 
 CFLAGS_trace_benchmark.o := -I$(src)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index f8db59c3a601..e750fe141a60 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -45,6 +45,8 @@
 #include "trace_output.h"
 #include "trace_stat.h"
 
+#define FTRACE_INVALID_FUNCTION		"__ftrace_invalid_address__"
+
 #define FTRACE_WARN_ON(cond)			\
 	({					\
 		int ___r = cond;		\
@@ -119,7 +121,7 @@ struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = &ftrace_list_end;
 ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
 struct ftrace_ops global_ops;
 
-/* Defined by vmlinux.lds.h see the commment above arch_ftrace_ops_list_func for details */
+/* Defined by vmlinux.lds.h see the comment above arch_ftrace_ops_list_func for details */
 void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
 			  struct ftrace_ops *op, struct ftrace_regs *fregs);
 
@@ -952,7 +954,6 @@ static struct tracer_stat function_stats __initdata = {
 static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
 {
 	struct ftrace_profile_stat *stat;
-	struct dentry *entry;
 	char *name;
 	int ret;
 	int cpu;
@@ -983,11 +984,9 @@ static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
 		}