3 files changed, 11 insertions, 16 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 2e8a3fde7104..72ef4dccbcc4 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1967,12 +1967,18 @@ static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
 
 static void print_ip_ins(const char *fmt, const unsigned char *p)
 {
+	char ins[MCOUNT_INSN_SIZE];
 	int i;
 
+	if (copy_from_kernel_nofault(ins, p, MCOUNT_INSN_SIZE)) {
+		printk(KERN_CONT "%s[FAULT] %px\n", fmt, p);
+		return;
+	}
+
 	printk(KERN_CONT "%s", fmt);
 
 	for (i = 0; i < MCOUNT_INSN_SIZE; i++)
-		printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
+		printk(KERN_CONT "%s%02x", i ? ":" : "", ins[i]);
 }
 
 enum ftrace_bug_type ftrace_bug_type;
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index a21ef9cd2aae..d23a09d3eb37 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2198,9 +2198,6 @@ struct saved_cmdlines_buffer {
 };
 static struct saved_cmdlines_buffer *savedcmd;
 
-/* temporary disable recording */
-static atomic_t trace_record_taskinfo_disabled __read_mostly;
-
 static inline char *get_saved_cmdlines(int idx)
 {
 	return &savedcmd->saved_cmdlines[idx * TASK_COMM_LEN];
@@ -2486,8 +2483,6 @@ static bool tracing_record_taskinfo_skip(int flags)
 {
 	if (unlikely(!(flags & (TRACE_RECORD_CMDLINE | TRACE_RECORD_TGID))))
 		return true;
-	if (atomic_read(&trace_record_taskinfo_disabled) || !tracing_is_on())
-		return true;
 	if (!__this_cpu_read(trace_taskinfo_save))
 		return true;
 	return false;
@@ -2736,7 +2731,7 @@ trace_event_buffer_lock_reserve(struct trace_buffer **current_rb,
 	    (entry = this_cpu_read(trace_buffered_event))) {
 		/* Try to use the per cpu buffer first */
 		val = this_cpu_inc_return(trace_buffered_event_cnt);
-		if ((len < (PAGE_SIZE - sizeof(*entry))) && val == 1) {
+		if ((len < (PAGE_SIZE - sizeof(*entry) - sizeof(entry->array[0]))) && val == 1) {
 			trace_event_setup(entry, type, trace_ctx);
 			entry->array[0] = len;
 			return entry;
@@ -3998,9 +3993,6 @@ static void *s_start(struct seq_file *m, loff_t *pos)
 		return ERR_PTR(-EBUSY);
 #endif
 
-	if (!iter->snapshot)
-		atomic_inc(&trace_record_taskinfo_disabled);
-
 	if (*pos != iter->pos) {
 		iter->ent = NULL;
 		iter->cpu = 0;
@@ -4043,9 +4035,6 @@ static void s_stop(struct seq_file *m, void *p)
 		return;
 #endif
 
-	if (!iter->snapshot)
-		atomic_dec(&trace_record_taskinfo_disabled);
-
 	trace_access_unlock(iter->cpu_file);
 	trace_event_read_unlock();
 }
diff --git a/kernel/trace/trace_clock.c b/kernel/trace/trace_clock.c
index c1637f90c8a3..4702efb00ff2 100644
--- a/kernel/trace/trace_clock.c
+++ b/kernel/trace/trace_clock.c
@@ -115,9 +115,9 @@ u64 notrace trace_clock_global(void)
 	prev_time = READ_ONCE(trace_clock_struct.prev_time);
 	now = sched_clock_cpu(this_cpu);
 
-	/* Make sure that now is always greater than prev_time */
+	/* Make sure that now is always greater than or equal to prev_time */
 	if ((s64)(now - prev_time) < 0)
-		now = prev_time + 1;
+		now = prev_time;
 
 	/*
 	 * If in an NMI context then dont risk lockups and simply return
@@ -131,7 +131,7 @@ u64 notrace trace_clock_global(void)
 		/* Reread prev_time in case it was already updated */
 		prev_time = READ_ONCE(trace_clock_struct.prev_time);
 		if ((s64)(now - prev_time) < 0)
-			now = prev_time + 1;
+			now = prev_time;
 
 		trace_clock_struct.prev_time = now;