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
  ...

20 files changed, 606 insertions, 522 deletions

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)
 		}
 	}
 
-	entry = tracefs_create_file("function_profile_enabled",
-				    TRACE_MODE_WRITE, d_tracer, NULL,
-				    &ftrace_profile_fops);
-	if (!entry)
-		pr_warn("Could not create tracefs 'function_profile_enabled' entry\n");
+	trace_create_file("function_profile_enabled",
+			  TRACE_MODE_WRITE, d_tracer, NULL,
+			  &ftrace_profile_fops);
 }
 
 #else /* CONFIG_FUNCTION_PROFILER */
@@ -2707,18 +2706,16 @@ ftrace_nop_initialize(struct module *mod, struct dyn_ftrace *rec)
  * archs can override this function if they must do something
  * before the modifying code is performed.
  */
-int __weak ftrace_arch_code_modify_prepare(void)
+void __weak ftrace_arch_code_modify_prepare(void)
 {
-	return 0;
 }
 
 /*
  * archs can override this function if they must do something
  * after the modifying code is performed.
  */
-int __weak ftrace_arch_code_modify_post_process(void)
+void __weak ftrace_arch_code_modify_post_process(void)
 {
-	return 0;
 }
 
 void ftrace_modify_all_code(int command)
@@ -2804,12 +2801,7 @@ void __weak arch_ftrace_update_code(int command)
 
 static void ftrace_run_update_code(int command)
 {
-	int ret;
-
-	ret = ftrace_arch_code_modify_prepare();
-	FTRACE_WARN_ON(ret);
-	if (ret)
-		return;
+	ftrace_arch_code_modify_prepare();
 
 	/*
 	 * By default we use stop_machine() to modify the code.
@@ -2819,8 +2811,7 @@ static void ftrace_run_update_code(int command)
 	 */
 	arch_ftrace_update_code(command);
 
-	ret = ftrace_arch_code_modify_post_process();
-	FTRACE_WARN_ON(ret);
+	ftrace_arch_code_modify_post_process();
 }
 
 static void ftrace_run_modify_code(struct ftrace_ops *ops, int command,
@@ -3631,6 +3622,105 @@ static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops,
 		seq_printf(m, " ->%pS", ptr);
 }
 
+#ifdef FTRACE_MCOUNT_MAX_OFFSET
+/*
+ * Weak functions can still have an mcount/fentry that is saved in
+ * the __mcount_loc section. These can be detected by having a
+ * symbol offset of greater than FTRACE_MCOUNT_MAX_OFFSET, as the
+ * symbol found by kallsyms is not the function that the mcount/fentry
+ * is part of. The offset is much greater in these cases.
+ *
+ * Test the record to make sure that the ip points to a valid kallsyms
+ * and if not, mark it disabled.
+ */
+static int test_for_valid_rec(struct dyn_ftrace *rec)
+{
+	char str[KSYM_SYMBOL_LEN];
+	unsigned long offset;
+	const char *ret;
+
+	ret = kallsyms_lookup(rec->ip, NULL, &offset, NULL, str);
+
+	/* Weak functions can cause invalid addresses */
+	if (!ret || offset > FTRACE_MCOUNT_MAX_OFFSET) {
+		rec->flags |= FTRACE_FL_DISABLED;
+		return 0;
+	}
+	return 1;
+}
+
+static struct workqueue_struct *ftrace_check_wq __initdata;
+static struct work_struct ftrace_check_work __initdata;
+
+/*
+ * Scan all the mcount/fentry entries to make sure they are valid.
+ */
+static __init void ftrace_check_work_func(struct work_struct *work)
+{
+	struct ftrace_page *pg;
+	struct dyn_ftrace *rec;
+
+	mutex_lock(&ftrace_lock);
+	do_for_each_ftrace_rec(pg, rec) {
+		test_for_valid_rec(rec);
+	} while_for_each_ftrace_rec();
+	mutex_unlock(&ftrace_lock);
+}
+
+static int __init ftrace_check_for_weak_functions(void)
+{
+	INIT_WORK(&ftrace_check_work, ftrace_check_work_func);
+
+	ftrace_check_wq = alloc_workqueue("ftrace_check_wq", WQ_UNBOUND, 0);
+
+	queue_work(ftrace_check_wq, &ftrace_check_work);
+	return 0;
+}
+
+static int __init ftrace_check_sync(void)
+{
+	/* Make sure the ftrace_check updates are finished */
+	if (ftrace_check_wq)
+		destroy_workqueue(ftrace_check_wq);
+	return 0;
+}
+
+late_initcall_sync(ftrace_check_sync);
+subsys_initcall(ftrace_check_for_weak_functions);
+
+static int print_rec(struct seq_file *m, unsigned long ip)
+{
+	unsigned long offset;
+	char str[KSYM_SYMBOL_LEN];
+	char *modname;
+	const char *ret;
+
+	ret = kallsyms_lookup(ip, NULL, &offset, &modname, str);
+	/* Weak functions can cause invalid addresses */
+	if (!ret || offset > FTRACE_MCOUNT_MAX_OFFSET) {
+		snprintf(str, KSYM_SYMBOL_LEN, "%s_%ld",
+			 FTRACE_INVALID_FUNCTION, offset);
+		ret = NULL;
+	}
+
+	seq_puts(m, str);
+	if (modname)
+		seq_printf(m, " [%s]", modname);
+	return ret == NULL ? -1 : 0;
+}
+#else
+static inline int test_for_valid_rec(struct dyn_ftrace *rec)
+{
+	return 1;
+}
+
+static inline int print_rec(struct seq_file *m, unsigned long ip)
+{
+	seq_printf(m, "%ps", (void *)ip);
+	return 0;
+}
+#endif
+
 static int t_show(struct seq_file *m, void *v)
 {
 	struct ftrace_iterator *iter = m->private;
@@ -3655,7 +3745,13 @@ static int t_show(struct seq_file *m, void *v)
 	if (!rec)
 		return 0;
 
-	seq_printf(m, "%ps", (void *)rec->ip);
+	if (print_rec(m, rec->ip)) {
+		/* This should only happen when a rec is disabled */
+		WARN_ON_ONCE(!(rec->flags & FTRACE_FL_DISABLED));
+		seq_putc(m, '\n');
+		return 0;
+	}
+
 	if (iter->flags & FTRACE_ITER_ENABLED) {
 		struct ftrace_ops *ops;
 
@@ -3973,6 +4069,24 @@ add_rec_by_index(struct ftrace_hash *hash, struct ftrace_glob *func_g,
 	return 0;
 }
 
+#ifdef FTRACE_MCOUNT_MAX_OFFSET
+static int lookup_ip(unsigned long ip, char **modname, char *str)
+{
+	unsigned long offset;
+
+	kallsyms_lookup(ip, NULL, &offset, modname, str);
+	if (offset > FTRACE_MCOUNT_MAX_OFFSET)
+		return -1;
+	return 0;
+}
+#else
+static int lookup_ip(unsigned long ip, char **modname, char *str)
+{
+	kallsyms_lookup(ip, NULL, NULL, modname, str);
+	return 0;
+}
+#endif
+
 static int
 ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g,
 		struct ftrace_glob *mod_g, int exclude_mod)
@@ -3980,7 +4094,12 @@ ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g,
 	char str[KSYM_SYMBOL_LEN];
 	char *modname;
 
-	kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
+	if (lookup_ip(rec->ip, &modname, str)) {
+		/* This should only happen when a rec is disabled */
+		WARN_ON_ONCE(system_state == SYSTEM_RUNNING &&
+			     !(rec->flags & FTRACE_FL_DISABLED));
+		return 0;
+	}
 
 	if (mod_g) {
 		int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0;
@@ -4431,7 +4550,7 @@ int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
  * @ip: The instruction pointer address to remove the data from
  *
  * Returns the data if it is found, otherwise NULL.
- * Note, if the data pointer is used as the data itself, (see 
+ * Note, if the data pointer is used as the data itself, (see
  * ftrace_func_mapper_find_ip(), then the return value may be meaningless,
  * if the data pointer was set to zero.
  */
@@ -4526,8 +4645,8 @@ register_ftrace_function_probe(char *glob, struct trace_array *tr,
 			       struct ftrace_probe_ops *probe_ops,
 			       void *data)
 {
+	struct ftrace_func_probe *probe = NULL, *iter;
 	struct ftrace_func_entry *entry;
-	struct ftrace_func_probe *probe;
 	struct ftrace_hash **orig_hash;
 	struct ftrace_hash *old_hash;
 	struct ftrace_hash *hash;
@@ -4546,11 +4665,13 @@ register_ftrace_function_probe(char *glob, struct trace_array *tr,
 
 	mutex_lock(&ftrace_lock);
 	/* Check if the probe_ops is already registered */
-	list_for_each_entry(probe, &tr->func_probes, list) {
-		if (probe->probe_ops == probe_ops)
+	list_for_each_entry(iter, &tr->func_probes, list) {
+		if (iter->probe_ops == probe_ops) {
+			probe = iter;
 			break;
+		}
 	}
-	if (&probe->list == &tr->func_probes) {
+	if (!probe) {
 		probe = kzalloc(sizeof(*probe), GFP_KERNEL);
 		if (!probe) {
 			mutex_unlock(&ftrace_lock);
@@ -4668,9 +4789,9 @@ int
 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
 				      struct ftrace_probe_ops *probe_ops)
 {
+	struct ftrace_func_probe *probe = NULL, *iter;
 	struct ftrace_ops_hash old_hash_ops;
 	struct ftrace_func_entry *entry;
-	struct ftrace_func_probe *probe;
 	struct ftrace_glob func_g;
 	struct ftrace_hash **orig_hash;
 	struct ftrace_hash *old_hash;
@@ -4698,11 +4819,13 @@ unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
 
 	mutex_lock(&ftrace_lock);
 	/* Check if the probe_ops is already registered */
-	list_for_each_entry(probe, &tr->func_probes, list) {
-		if (probe->probe_ops == probe_ops)
+	list_for_each_entry(iter, &tr->func_probes, list) {
+		if (iter->probe_ops == probe_ops) {
+			probe = iter;
 			break;
+		}
 	}
-	if (&probe->list == &tr->func_probes)
+	if (!probe)
 		goto err_unlock_ftrace;
 
 	ret = -EINVAL;
@@ -5161,8 +5284,6 @@ int register_ftrace_direct(unsigned long ip, unsigned long addr)
 		goto out_unlock;
 
 	ret = ftrace_set_filter_ip(&direct_ops, ip, 0, 0);
-	if (ret)
-		remove_hash_entry(direct_functions, entry);
 
 	if (!ret && !(direct_ops.flags & FTRACE_OPS_FL_ENABLED)) {
 		ret = register_ftrace_function(&direct_ops);
@@ -5171,6 +5292,7 @@ int register_ftrace_direct(unsigned long ip, unsigned long addr)
 	}
 
 	if (ret) {
+		remove_hash_entry(direct_functions, entry);
 		kfree(entry);
 		if (!direct->count) {
 			list_del_rcu(&direct->next);
@@ -6793,6 +6915,13 @@ void ftrace_module_enable(struct module *mod)
 		    !within_module_init(rec->ip, mod))
 			break;
 
+		/* Weak functions should still be ignored */
+		if (!test_for_valid_rec(rec)) {
+			/* Clear all other flags. Should not be enabled anyway */
+			rec->flags = FTRACE_FL_DISABLED;
+			continue;
+		}
+
 		cnt = 0;
 
 		/*
@@ -6829,11 +6958,16 @@ void ftrace_module_enable(struct module *mod)
 
 void ftrace_module_init(struct module *mod)
 {
+	int ret;
+
 	if (ftrace_disabled || !mod->num_ftrace_callsites)
 		return;
 
-	ftrace_process_locs(mod, mod->ftrace_callsites,
-			    mod->ftrace_callsites + mod->num_ftrace_callsites);
+	ret = ftrace_process_locs(mod, mod->ftrace_callsites,
+				  mod->ftrace_callsites + mod->num_ftrace_callsites);
+	if (ret)
+		pr_warn("ftrace: failed to allocate entries for module '%s' functions\n",
+			mod->name);
 }
 
 static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map,
@@ -7166,15 +7300,19 @@ void __init ftrace_init(void)
 	pr_info("ftrace: allocating %ld entries in %ld pages\n",
 		count, count / ENTRIES_PER_PAGE + 1);
 
-	last_ftrace_enabled = ftrace_enabled = 1;
-
 	ret = ftrace_process_locs(NULL,
 				  __start_mcount_loc,
 				  __stop_mcount_loc);
+	if (ret) {
+		pr_warn("ftrace: failed to allocate entries for functions\n");
+		goto failed;
+	}
 
 	pr_info("ftrace: allocated %ld pages with %ld groups\n",
 		ftrace_number_of_pages, ftrace_number_of_groups);
 
+	last_ftrace_enabled = ftrace_enabled = 1;
+
 	set_ftrace_early_filters();
 
 	return;
diff --git a/kernel/trace/pid_list.c b/kernel/trace/pid_list.c
index a2ef1d18126a..95106d02b32d 100644
--- a/kernel/trace/pid_list.c
+++ b/kernel/trace/pid_list.c
@@ -118,9 +118,9 @@ static inline unsigned int pid_join(unsigned int upper1,
 /**
  * trace_pid_list_is_set - test if the pid is set in the list
  * @pid_list: The pid list to test
- * @pid: The pid to to see if set in the list.
+ * @pid: The pid to see if set in the list.
  *
- * Tests if @pid is is set in the @pid_list. This is usually called
+ * Tests if @pid is set in the @pid_list. This is usually called
  * from the scheduler when a task is scheduled. Its pid is checked
  * if it should be traced or not.
  *
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 05dfc7a12d3d..d59b6a328b7f 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -29,6 +29,14 @@
 
 #include <asm/local.h>
 
+/*
+ * The "absolute" timestamp in the buffer is only 59 bits.
+ * If a clock has the 5 MSBs set, it needs to be saved and
+ * reinserted.
+ */
+#define TS_MSB		(0xf8ULL << 56)
+#define ABS_TS_MASK	(~TS_MSB)
+
 static void update_pages_handler(struct work_struct *work);
 
 /*
@@ -468,6 +476,7 @@ struct rb_time_struct {
 	local_t		cnt;
 	local_t		top;
 	local_t		bottom;
+	local_t		msb;
 };
 #else
 #include <asm/local64.h>
@@ -569,7 +578,6 @@ struct ring_buffer_iter {
  * For the ring buffer, 64 bit required operations for the time is
  * the following:
  *
- *  - Only need 59 bits (uses 60 to make it even).
  *  - Reads may fail if it interrupted a modification of the time stamp.
  *      It will succeed if it did not interrupt another write even if
  *      the read itself is interrupted by a write.
@@ -594,6 +602,7 @@ struct ring_buffer_iter {
  */
 #define RB_TIME_SHIFT	30
 #define RB_TIME_VAL_MASK ((1 << RB_TIME_SHIFT) - 1)
+#define RB_TIME_MSB_SHIFT	 60
 
 static inline int rb_time_cnt(unsigned long val)
 {
@@ -613,7 +622,7 @@ static inline u64 rb_time_val(unsigned long top, unsigned long bottom)
 
 static inline bool __rb_time_read(rb_time_t *t, u64 *ret, unsigned long *cnt)
 {
-	unsigned long top, bottom;
+	unsigned long top, bottom, msb;
 	unsigned long c;
 
 	/*
@@ -625,6 +634,7 @@ static inline bool __rb_time_read(rb_time_t *t, u64 *ret, unsigned long *cnt)
 		c = local_read(&t->cnt);
 		top = local_read(&t->top);
 		bottom = local_read(&t->bottom);
+		msb = local_read(&t->msb);
 	} while (c != local_read(&t->cnt));
 
 	*cnt = rb_time_cnt(top);
@@ -633,7 +643,8 @@ static inline bool __rb_time_read(rb_time_t *t, u64 *ret, unsigned long *cnt)
 	if (*cnt != rb_time_cnt(bottom))
 		return false;
 
-	*ret = rb_time_val(top, bottom);
+	/* The shift to msb will lose its cnt bits */
+	*ret = rb_time_val(top, bottom) | ((u64)msb << RB_TIME_MSB_SHIFT);
 	return true;
 }
 
@@ -649,10 +660,12 @@ static inline unsigned long rb_time_val_cnt(unsigned long val, unsigned long cnt
 	return (val & RB_TIME_VAL_MASK) | ((cnt & 3) << RB_TIME_SHIFT);
 }
 
-static inline void rb_time_split(u64 val, unsigned long *top, unsigned long *bottom)
+static inline void rb_time_split(u64 val, unsigned long *top, unsigned long *bottom,
+				 unsigned long *msb)
 {
 	*top = (unsigned long)((val >> RB_TIME_SHIFT) & RB_TIME_VAL_MASK);
 	*bottom = (unsigned long)(val & RB_TIME_VAL_MASK);
+	*msb = (unsigned long)(val >> RB_TIME_MSB_SHIFT);
 }
 
 static inline void rb_time_val_set(local_t *t, unsigned long val, unsigned long cnt)
@@ -663,15 +676,16 @@ static inline void rb_time_val_set(local_t *t, unsigned long val, unsigned long
 
 static void rb_time_set(rb_time_t *t, u64 val)
 {
-	unsigned long cnt, top, bottom;
+	unsigned long cnt, top, bottom, msb;
 
-	rb_time_split(val, &top, &bottom);
+	rb_time_split(val, &top, &bottom, &msb);
 
 	/* Writes always succeed with a valid number even if it gets interrupted. */
 	do {
 		cnt = local_inc_return(&t->cnt);
 		rb_time_val_set(&t->top, top, cnt);
 		rb_time_val_set(&t->bottom, bottom, cnt);
+		rb_time_val_set(&t->msb, val >> RB_TIME_MSB_SHIFT, cnt);
 	} while (cnt != local_read(&t->cnt));
 }
 
@@ -686,8 +700,8 @@ rb_time_read_cmpxchg(local_t *l, unsigned long expect, unsigned long set)
 
 static int rb_time_cmpxchg(rb_time_t *t, u64 expect, u64 set)
 {
-	unsigned long cnt, top, bottom;
-	unsigned long cnt2, top2, bottom2;
+	unsigned long cnt, top, bottom, msb;
+	unsigned long cnt2, top2, bottom2, msb2;
 	u64 val;
 
 	/* The cmpxchg always fails if it interrupted an update */
@@ -703,16 +717,18 @@ static int rb_time_cmpxchg(rb_time_t *t, u64 expect, u64 set)
 
 	 cnt2 = cnt + 1;
 
-	 rb_time_split(val, &top, &bottom);
+	 rb_time_split(val, &top, &bottom, &msb);
 	 top = rb_time_val_cnt(top, cnt);
 	 bottom = rb_time_val_cnt(bottom, cnt);
 
-	 rb_time_split(set, &top2, &bottom2);
+	 rb_time_split(set, &top2, &bottom2, &msb2);
 	 top2 = rb_time_val_cnt(top2, cnt2);
 	 bottom2 = rb_time_val_cnt(bottom2, cnt2);
 
 	if (!rb_time_read_cmpxchg(&t->cnt, cnt, cnt2))
 		return false;
+	if (!rb_time_read_cmpxchg(&t->msb, msb, msb2))
+		return false;
 	if (!rb_time_read_cmpxchg(&t->top, top, top2))
 		return false;
 	if (!rb_time_read_cmpxchg(&t->bottom, bottom, bottom2))
@@ -783,6 +799,24 @@ static inline void verify_event(struct ring_buffer_per_cpu *cpu_buffer,
 }
 #endif
 
+/*
+ * The absolute time stamp drops the 5 MSBs and some clocks may
+ * require them. The rb_fix_abs_ts() will take a previous full
+ * time stamp, and add the 5 MSB of that time stamp on to the
+ * saved absolute time stamp. Then they are compared in case of
+ * the unlikely event that the latest time stamp incremented
+ * the 5 MSB.
+ */
+static inline u64 rb_fix_abs_ts(u64 abs, u64 save_ts)
+{
+	if (save_ts & TS_MSB) {
+		abs |= save_ts & TS_MSB;
+		/* Check for overflow */
+		if (unlikely(abs < save_ts))
+			abs += 1ULL << 59;
+	}
+	return abs;
+}
 
 static inline u64 rb_time_stamp(struct trace_buffer *buffer);
 
@@ -811,8 +845,10 @@ u64 ring_buffer_event_time_stamp(struct trace_buffer *buffer,
 	u64 ts;
 
 	/* If the event includes an absolute time, then just use that */
-	if (event->type_len == RINGBUF_TYPE_TIME_STAMP)
-		return rb_event_time_stamp(event);
+	if (event->type_len == RINGBUF_TYPE_TIME_STAMP) {
+		ts = rb_event_time_stamp(event);
+		return rb_fix_abs_ts(ts, cpu_buffer->tail_page->page->time_stamp);
+	}
 
 	nest = local_read(&cpu_buffer->committing);
 	verify_event(cpu_buffer, event);
@@ -2754,8 +2790,15 @@ static void rb_add_timestamp(struct ring_buffer_per_cpu *cpu_buffer,
 		(RB_ADD_STAMP_FORCE | RB_ADD_STAMP_ABSOLUTE);
 
 	if (unlikely(info->delta > (1ULL << 59))) {
+		/*
+		 * Some timers can use more than 59 bits, and when a timestamp
+		 * is added to the buffer, it will lose those bits.
+		 */
+		if (abs && (info->ts & TS_MSB)) {
+			info->delta &= ABS_TS_MASK;
+
 		/* did the clock go backwards */
-		if (info->before == info->after && info->before > info->ts) {
+		} else if (info->before == info->after && info->before > info->ts) {
 			/* not interrupted */
 			static int once;
 
@@ -3304,7 +3347,7 @@ static void dump_buffer_page(struct buffer_data_page *bpage,
 
 		case RINGBUF_TYPE_TIME_STAMP:
 			delta = rb_event_time_stamp(event);
-			ts = delta;
+			ts = rb_fix_abs_ts(delta, ts);
 			pr_warn("  [%lld] absolute:%lld TIME STAMP\n", ts, delta);
 			break;
 
@@ -3380,7 +3423,7 @@ static void check_buffer(struct ring_buffer_per_cpu *cpu_buffer,
 
 		case RINGBUF_TYPE_TIME_STAMP:
 			delta = rb_event_time_stamp(event);
-			ts = delta;
+			ts = rb_fix_abs_ts(delta, ts);
 			break;
 
 		case RINGBUF_TYPE_PADDING:
@@ -4367,6 +4410,7 @@ rb_update_read_stamp(struct ring_buffer_per_cpu *cpu_buffer,
 
 	case RINGBUF_TYPE_TIME_STAMP:
 		delta = rb_event_time_stamp(event);
+		delta = rb_fix_abs_ts(delta, cpu_buffer->read_stamp);
 		cpu_buffer->read_stamp = delta;
 		return;
 
@@ -4397,6 +4441,7 @@ rb_update_iter_read_stamp(struct ring_buffer_iter *iter,
 
 	case RINGBUF_TYPE_TIME_STAMP:
 		delta = rb_event_time_stamp(event);
+		delta = rb_fix_abs_ts(delta, iter->read_stamp);
 		iter->read_stamp = delta;
 		return;
 
@@ -4650,6 +4695,7 @@ rb_buffer_peek(struct ring_buffer_per_cpu *cpu_buffer, u64 *ts,
 	case RINGBUF_TYPE_TIME_STAMP:
 		if (ts) {
 			*ts = rb_event_time_stamp(event);
+			*ts = rb_fix_abs_ts(*ts, reader->page->time_stamp);
 			ring_buffer_normalize_time_stamp(cpu_buffer->buffer,
 							 cpu_buffer->cpu, ts);
 		}
@@ -4741,6 +4787,7 @@ rb_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
 	case RINGBUF_TYPE_TIME_STAMP:
 		if (ts) {
 			*ts = rb_event_time_stamp(event);
+			*ts = rb_fix_abs_ts(*ts, iter->head_page->page->time_stamp);
 			ring_buffer_normalize_time_stamp(cpu_buffer->buffer,
 							 cpu_buffer->cpu, ts);
 		}
@@ -6011,10 +6058,10 @@ static __init int test_ringbuffer(void)
 		pr_info("        total events:   %ld\n", total_lost + total_read);
 		pr_info("  recorded len bytes:   %ld\n", total_len);
 		pr_info(" recorded size bytes:   %ld\n", total_size);
-		if (total_lost)
+		if (total_lost) {
 			pr_info(" With dropped events, record len and size may not match\n"
 				" alloced and written from above\n");
-		if (!total_lost) {
+		} else {
 			if (RB_WARN_ON(buffer, total_len != total_alloc ||
 				       total_size != total_written))
 				break;
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 124f1897fd56..2c95992e2c71 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -721,13 +721,16 @@ int trace_pid_write(struct trace_pid_list *filtered_pids,
 		pos = 0;
 
 		ret = trace_get_user(&parser, ubuf, cnt, &pos);
-		if (ret < 0 || !trace_parser_loaded(&parser))
+		if (ret < 0)
 			break;
 
 		read += ret;
 		ubuf += ret;
 		cnt -= ret;
 
+		if (!trace_parser_loaded(&parser))
+			break;
+
 		ret = -EINVAL;
 		if (kstrtoul(parser.buffer, 0, &val))
 			break;
@@ -753,7 +756,6 @@ int trace_pid_write(struct trace_pid_list *filtered_pids,
 	if (!nr_pids) {
 		/* Cleared the list of pids */
 		trace_pid_list_free(pid_list);
-		read = ret;
 		pid_list = NULL;
 	}
 
@@ -1174,7 +1176,7 @@ void tracing_snapshot_cond(struct trace_array *tr, void *cond_data)
 EXPORT_SYMBOL_GPL(tracing_snapshot_cond);
 
 /**
- * tracing_snapshot_cond_data - get the user data associated with a snapshot
+ * tracing_cond_snapshot_data - get the user data associated with a snapshot
  * @tr:		The tracing instance
  *
  * When the user enables a conditional snapshot using
@@ -1542,6 +1544,7 @@ static struct {
 	{ ktime_get_mono_fast_ns,	"mono",		1 },
 	{ ktime_get_raw_fast_ns,	"mono_raw",	1 },
 	{ ktime_get_boot_fast_ns,	"boot",		1 },
+	{ ktime_get_tai_fast_ns,	"tai",		1 },
 	ARCH_TRACE_CLOCKS
 };
 
@@ -2835,7 +2838,7 @@ trace_event_buffer_lock_reserve(struct trace_buffer **current_rb,
 }
 EXPORT_SYMBOL_GPL(trace_event_buffer_lock_reserve);
 
-static DEFINE_SPINLOCK(tracepoint_iter_lock);
+static DEFINE_RAW_SPINLOCK(tracepoint_iter_lock);
 static DEFINE_MUTEX(tracepoint_printk_mutex);
 
 static void output_printk(struct trace_event_buffer *fbuffer)
@@ -2863,14 +2866,14 @@ static void output_printk(struct trace_event_buffer *fbuffer)
 
 	event = &fbuffer->trace_file->event_call->event;
 
-	spin_lock_irqsave(&tracepoint_iter_lock, flags);
+	raw_spin_lock_irqsave(&tracepoint_iter_lock, flags);
 	trace_seq_init(&iter->seq);
 	iter->ent = fbuffer->entry;
 	event_call->event.funcs->trace(iter, 0, event);
 	trace_seq_putc(&iter->seq, 0);
 	printk("%s", iter->seq.buffer);
 
-	spin_unlock_irqrestore(&tracepoint_iter_lock, flags);
+	raw_spin_unlock_irqrestore(&tracepoint_iter_lock, flags);
 }
 
 int tracepoint_printk_sysctl(struct ctl_table *table, int write,
@@ -4249,7 +4252,7 @@ static void print_func_help_header_irq(struct array_buffer *buf, struct seq_file
 				       unsigned int flags)
 {
 	bool tgid = flags & TRACE_ITER_RECORD_TGID;
-	const char *space = "            ";
+	static const char space[] = "            ";
 	int prec = tgid ? 12 : 2;
 
 	print_event_info(buf, m);
@@ -4273,9 +4276,7 @@ print_trace_header(struct seq_file *m, struct trace_iterator *iter)
 	struct tracer *type = iter->trace;
 	unsigned long entries;
 	unsigned long total;
-	const char *name = "preemption";
-
-	name = type->name;
+	const char *name = type->name;
 
 	get_total_entries(buf, &total, &entries);
 
@@ -5469,7 +5470,7 @@ static const char readme_msg[] =
 	"  error_log\t- error log for failed commands (that support it)\n"
 	"  buffer_size_kb\t- view and modify size of per cpu buffer\n"
 	"  buffer_total_size_kb  - view total size of all cpu buffers\n\n"
-	"  trace_clock\t\t-change the clock used to order events\n"
+	"  trace_clock\t\t- change the clock used to order events\n"
 	"       local:   Per cpu clock but may not be synced across CPUs\n"
 	"      global:   Synced across CPUs but slows tracing down.\n"
 	"     counter:   Not a clock, but just an increment\n"
@@ -5478,7 +5479,7 @@ static const char readme_msg[] =
 #ifdef CONFIG_X86_64
 	"     x86-tsc:   TSC cycle counter\n"
 #endif
-	"\n  timestamp_mode\t-view the mode used to timestamp events\n"
+	"\n  timestamp_mode\t- view the mode used to timestamp events\n"
 	"       delta:   Delta difference against a buffer-wide timestamp\n"
 	"    absolute:   Absolute (standalone) timestamp\n"
 	"\n  trace_marker\t\t- Writes into this file writes into the kernel buffer\n"
@@ -6326,12 +6327,18 @@ static void tracing_set_nop(struct trace_array *tr)
 	tr->current_trace = &nop_trace;
 }
 
+static bool tracer_options_updated;
+
 static void add_tracer_options(struct trace_array *tr, struct tracer *t)
 {
 	/* Only enable if the directory has been created already. */
 	if (!tr->dir)
 		return;
 
+	/* Only create trace option files after update_tracer_options finish */
+	if (!tracer_options_updated)
+		return;
+
 	create_trace_option_files(tr, t);
 }
 
@@ -6448,7 +6455,7 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
 {
 	struct trace_array *tr = filp->private_data;
 	char buf[MAX_TRACER_SIZE+1];
-	int i;
+	char *name;
 	size_t ret;
 	int err;
 
@@ -6462,11 +6469,9 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
 
 	buf[cnt] = 0;
 
-	/* strip ending whitespace. */
-	for (i = cnt - 1; i > 0 && isspace(buf[i]); i--)
-		buf[i] = 0;
+	name = strim(buf);
 
-	err = tracing_set_tracer(tr, buf);
+	err = tracing_