1 files changed, 175 insertions, 291 deletions

diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 4de3e57f723c..ba476009e5de 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -15,6 +15,33 @@
 #include "trace.h"
 #include "trace_output.h"
 
+static bool kill_ftrace_graph;
+
+/**
+ * ftrace_graph_is_dead - returns true if ftrace_graph_stop() was called
+ *
+ * ftrace_graph_stop() is called when a severe error is detected in
+ * the function graph tracing. This function is called by the critical
+ * paths of function graph to keep those paths from doing any more harm.
+ */
+bool ftrace_graph_is_dead(void)
+{
+	return kill_ftrace_graph;
+}
+
+/**
+ * ftrace_graph_stop - set to permanently disable function graph tracincg
+ *
+ * In case of an error int function graph tracing, this is called
+ * to try to keep function graph tracing from causing any more harm.
+ * Usually this is pretty severe and this is called to try to at least
+ * get a warning out to the user.
+ */
+void ftrace_graph_stop(void)
+{
+	kill_ftrace_graph = true;
+}
+
 /* When set, irq functions will be ignored */
 static int ftrace_graph_skip_irqs;
 
@@ -80,7 +107,7 @@ enum {
 	FLAGS_FILL_END   = 3 << TRACE_GRAPH_PRINT_FILL_SHIFT,
 };
 
-static enum print_line_t
+static void
 print_graph_duration(unsigned long long duration, struct trace_seq *s,
 		     u32 flags);
 
@@ -92,6 +119,9 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
 	unsigned long long calltime;
 	int index;
 
+	if (unlikely(ftrace_graph_is_dead()))
+		return -EBUSY;
+
 	if (!current->ret_stack)
 		return -EBUSY;
 
@@ -323,7 +353,7 @@ int trace_graph_entry(struct ftrace_graph_ent *trace)
 	return ret;
 }
 
-int trace_graph_thresh_entry(struct ftrace_graph_ent *trace)
+static int trace_graph_thresh_entry(struct ftrace_graph_ent *trace)
 {
 	if (tracing_thresh)
 		return 1;
@@ -412,7 +442,7 @@ void set_graph_array(struct trace_array *tr)
 	smp_mb();
 }
 
-void trace_graph_thresh_return(struct ftrace_graph_ret *trace)
+static void trace_graph_thresh_return(struct ftrace_graph_ret *trace)
 {
 	if (tracing_thresh &&
 	    (trace->rettime - trace->calltime < tracing_thresh))
@@ -445,35 +475,32 @@ static void graph_trace_reset(struct trace_array *tr)
 	unregister_ftrace_graph();
 }
 
+static int graph_trace_update_thresh(struct trace_array *tr)
+{
+	graph_trace_reset(tr);
+	return graph_trace_init(tr);
+}
+
 static int max_bytes_for_cpu;
 
-static enum print_line_t
-print_graph_cpu(struct trace_seq *s, int cpu)
+static void print_graph_cpu(struct trace_seq *s, int cpu)
 {
-	int ret;
-
 	/*
 	 * Start with a space character - to make it stand out
 	 * to the right a bit when trace output is pasted into
 	 * email:
 	 */
-	ret = trace_seq_printf(s, " %*d) ", max_bytes_for_cpu, cpu);
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
-
-	return TRACE_TYPE_HANDLED;
+	trace_seq_printf(s, " %*d) ", max_bytes_for_cpu, cpu);
 }
 
 #define TRACE_GRAPH_PROCINFO_LENGTH	14
 
-static enum print_line_t
-print_graph_proc(struct trace_seq *s, pid_t pid)
+static void print_graph_proc(struct trace_seq *s, pid_t pid)
 {
 	char comm[TASK_COMM_LEN];
 	/* sign + log10(MAX_INT) + '\0' */
 	char pid_str[11];
 	int spaces = 0;
-	int ret;
 	int len;
 	int i;
 
@@ -488,56 +515,43 @@ print_graph_proc(struct trace_seq *s, pid_t pid)
 		spaces = TRACE_GRAPH_PROCINFO_LENGTH - len;
 
 	/* First spaces to align center */
-	for (i = 0; i < spaces / 2; i++) {
-		ret = trace_seq_putc(s, ' ');
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
+	for (i = 0; i < spaces / 2; i++)
+		trace_seq_putc(s, ' ');
 
-	ret = trace_seq_printf(s, "%s-%s", comm, pid_str);
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
+	trace_seq_printf(s, "%s-%s", comm, pid_str);
 
 	/* Last spaces to align center */
-	for (i = 0; i < spaces - (spaces / 2); i++) {
-		ret = trace_seq_putc(s, ' ');
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
-	return TRACE_TYPE_HANDLED;
+	for (i = 0; i < spaces - (spaces / 2); i++)
+		trace_seq_putc(s, ' ');
 }
 
 
-static enum print_line_t
-print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
+static void print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 {
-	if (!trace_seq_putc(s, ' '))
-		return 0;
-
-	return trace_print_lat_fmt(s, entry);
+	trace_seq_putc(s, ' ');
+	trace_print_lat_fmt(s, entry);
 }
 
 /* If the pid changed since the last trace, output this event */
-static enum print_line_t
+static void
 verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data)
 {
 	pid_t prev_pid;
 	pid_t *last_pid;
-	int ret;
 
 	if (!data)
-		return TRACE_TYPE_HANDLED;
+		return;
 
 	last_pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
 
 	if (*last_pid == pid)
-		return TRACE_TYPE_HANDLED;
+		return;
 
 	prev_pid = *last_pid;
 	*last_pid = pid;
 
 	if (prev_pid == -1)
-		return TRACE_TYPE_HANDLED;
+		return;
 /*
  * Context-switch trace line:
 
@@ -546,33 +560,12 @@ verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data)
  ------------------------------------------
 
  */
-	ret = trace_seq_puts(s,
-		" ------------------------------------------\n");
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
-
-	ret = print_graph_cpu(s, cpu);
-	if (ret == TRACE_TYPE_PARTIAL_LINE)
-		return TRACE_TYPE_PARTIAL_LINE;
-
-	ret = print_graph_proc(s, prev_pid);
-	if (ret == TRACE_TYPE_PARTIAL_LINE)
-		return TRACE_TYPE_PARTIAL_LINE;
-
-	ret = trace_seq_puts(s, " => ");
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
-
-	ret = print_graph_proc(s, pid);
-	if (ret == TRACE_TYPE_PARTIAL_LINE)
-		return TRACE_TYPE_PARTIAL_LINE;
-
-	ret = trace_seq_puts(s,
-		"\n ------------------------------------------\n\n");
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
-
-	return TRACE_TYPE_HANDLED;
+	trace_seq_puts(s, " ------------------------------------------\n");
+	print_graph_cpu(s, cpu);
+	print_graph_proc(s, prev_pid);
+	trace_seq_puts(s, " => ");
+	print_graph_proc(s, pid);
+	trace_seq_puts(s, "\n ------------------------------------------\n\n");
 }
 
 static struct ftrace_graph_ret_entry *
@@ -646,175 +639,122 @@ get_return_for_leaf(struct trace_iterator *iter,
 	return next;
 }
 
-static int print_graph_abs_time(u64 t, struct trace_seq *s)
+static void print_graph_abs_time(u64 t, struct trace_seq *s)
 {
 	unsigned long usecs_rem;
 
 	usecs_rem = do_div(t, NSEC_PER_SEC);
 	usecs_rem /= 1000;
 
-	return trace_seq_printf(s, "%5lu.%06lu |  ",
-			(unsigned long)t, usecs_rem);
+	trace_seq_printf(s, "%5lu.%06lu |  ",
+			 (unsigned long)t, usecs_rem);
 }
 
-static enum print_line_t
+static void
 print_graph_irq(struct trace_iterator *iter, unsigned long addr,
 		enum trace_type type, int cpu, pid_t pid, u32 flags)
 {
-	int ret;
 	struct trace_seq *s = &iter->seq;
+	struct trace_entry *ent = iter->ent;
 
 	if (addr < (unsigned long)__irqentry_text_start ||
 		addr >= (unsigned long)__irqentry_text_end)
-		return TRACE_TYPE_UNHANDLED;
+		return;
 
 	if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
 		/* Absolute time */
-		if (flags & TRACE_GRAPH_PRINT_ABS_TIME) {
-			ret = print_graph_abs_time(iter->ts, s);
-			if (!ret)
-				return TRACE_TYPE_PARTIAL_LINE;
-		}
+		if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
+			print_graph_abs_time(iter->ts, s);
 
 		/* Cpu */
-		if (flags & TRACE_GRAPH_PRINT_CPU) {
-			ret = print_graph_cpu(s, cpu);
-			if (ret == TRACE_TYPE_PARTIAL_LINE)
-				return TRACE_TYPE_PARTIAL_LINE;
-		}
+		if (flags & TRACE_GRAPH_PRINT_CPU)
+			print_graph_cpu(s, cpu);
 
 		/* Proc */
 		if (flags & TRACE_GRAPH_PRINT_PROC) {
-			ret = print_graph_proc(s, pid);
-			if (ret == TRACE_TYPE_PARTIAL_LINE)
-				return TRACE_TYPE_PARTIAL_LINE;
-			ret = trace_seq_puts(s, " | ");
-			if (!ret)
-				return TRACE_TYPE_PARTIAL_LINE;
+			print_graph_proc(s, pid);
+			trace_seq_puts(s, " | ");
 		}
+
+		/* Latency format */
+		if (trace_flags & TRACE_ITER_LATENCY_FMT)
+			print_graph_lat_fmt(s, ent);
 	}
 
 	/* No overhead */
-	ret = print_graph_duration(0, s, flags | FLAGS_FILL_START);
-	if (ret != TRACE_TYPE_HANDLED)
-		return ret;
+	print_graph_duration(0, s, flags | FLAGS_FILL_START);
 
 	if (type == TRACE_GRAPH_ENT)
-		ret = trace_seq_puts(s, "==========>");
+		trace_seq_puts(s, "==========>");
 	else
-		ret = trace_seq_puts(s, "<==========");
-
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
+		trace_seq_puts(s, "<==========");
 
-	ret = print_graph_duration(0, s, flags | FLAGS_FILL_END);
-	if (ret != TRACE_TYPE_HANDLED)
-		return ret;
-
-	ret = trace_seq_putc(s, '\n');
-
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
-	return TRACE_TYPE_HANDLED;
+	print_graph_duration(0, s, flags | FLAGS_FILL_END);
+	trace_seq_putc(s, '\n');
 }
 
-enum print_line_t
+void
 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s)
 {
 	unsigned long nsecs_rem = do_div(duration, 1000);
 	/* log10(ULONG_MAX) + '\0' */
-	char msecs_str[21];
+	char usecs_str[21];
 	char nsecs_str[5];
-	int ret, len;
+	int len;
 	int i;
 
-	sprintf(msecs_str, "%lu", (unsigned long) duration);
+	sprintf(usecs_str, "%lu", (unsigned long) duration);
 
 	/* Print msecs */
-	ret = trace_seq_printf(s, "%s", msecs_str);
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
+	trace_seq_printf(s, "%s", usecs_str);
 
-	len = strlen(msecs_str);
+	len = strlen(usecs_str);
 
 	/* Print nsecs (we don't want to exceed 7 numbers) */
 	if (len < 7) {
 		size_t slen = min_t(size_t, sizeof(nsecs_str), 8UL - len);
 
 		snprintf(nsecs_str, slen, "%03lu", nsecs_rem);
-		ret = trace_seq_printf(s, ".%s", nsecs_str);
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
+		trace_seq_printf(s, ".%s", nsecs_str);
 		len += strlen(nsecs_str);
 	}
 
-	ret = trace_seq_puts(s, " us ");
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
+	trace_seq_puts(s, " us ");
 
 	/* Print remaining spaces to fit the row's width */
-	for (i = len; i < 7; i++) {
-		ret = trace_seq_putc(s, ' ');
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
-	return TRACE_TYPE_HANDLED;
+	for (i = len; i < 7; i++)
+		trace_seq_putc(s, ' ');
 }
 
-static enum print_line_t
+static void
 print_graph_duration(unsigned long long duration, struct trace_seq *s,
 		     u32 flags)
 {
-	int ret = -1;
-
 	if (!(flags & TRACE_GRAPH_PRINT_DURATION) ||
 	    !(trace_flags & TRACE_ITER_CONTEXT_INFO))
-			return TRACE_TYPE_HANDLED;
+		return;
 
 	/* No real adata, just filling the column with spaces */
 	switch (flags & TRACE_GRAPH_PRINT_FILL_MASK) {
 	case FLAGS_FILL_FULL:
-		ret = trace_seq_puts(s, "              |  ");
-		return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
+		trace_seq_puts(s, "              |  ");
+		return;
 	case FLAGS_FILL_START:
-		ret = trace_seq_puts(s, "  ");
-		return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
+		trace_seq_puts(s, "  ");
+		return;
 	case FLAGS_FILL_END:
-		ret = trace_seq_puts(s, " |");
-		return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
+		trace_seq_puts(s, " |");
+		return;
 	}
 
 	/* Signal a overhead of time execution to the output */
-	if (flags & TRACE_GRAPH_PRINT_OVERHEAD) {
-		/* Duration exceeded 100 msecs */
-		if (duration > 100000ULL)
-			ret = trace_seq_puts(s, "! ");
-		/* Duration exceeded 10 msecs */
-		else if (duration > 10000ULL)
-			ret = trace_seq_puts(s, "+ ");
-	}
-
-	/*
-	 * The -1 means we either did not exceed the duration tresholds
-	 * or we dont want to print out the overhead. Either way we need
-	 * to fill out the space.
-	 */
-	if (ret == -1)
-		ret = trace_seq_puts(s, "  ");
-
-	/* Catching here any failure happenned above */
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
-
-	ret = trace_print_graph_duration(duration, s);
-	if (ret != TRACE_TYPE_HANDLED)
-		return ret;
-
-	ret = trace_seq_puts(s, "|  ");
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
+	if (flags & TRACE_GRAPH_PRINT_OVERHEAD)
+		trace_seq_printf(s, "%c ", trace_find_mark(duration));
+	else
+		trace_seq_puts(s, "  ");
 
-	return TRACE_TYPE_HANDLED;
+	trace_print_graph_duration(duration, s);
+	trace_seq_puts(s, "|  ");
 }
 
 /* Case of a leaf function on its call entry */
@@ -828,7 +768,6 @@ print_graph_entry_leaf(struct trace_iterator *iter,
 	struct ftrace_graph_ret *graph_ret;
 	struct ftrace_graph_ent *call;
 	unsigned long long duration;
-	int ret;
 	int i;
 
 	graph_ret = &ret_entry->ret;
@@ -854,22 +793,15 @@ print_graph_entry_leaf(struct trace_iterator *iter,
 	}
 
 	/* Overhead and duration */
-	ret = print_graph_duration(duration, s, flags);
-	if (ret == TRACE_TYPE_PARTIAL_LINE)
-		return TRACE_TYPE_PARTIAL_LINE;
+	print_graph_duration(duration, s, flags);
 
 	/* Function */
-	for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
-		ret = trace_seq_putc(s, ' ');
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
+	for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++)
+		trace_seq_putc(s, ' ');
 
-	ret = trace_seq_printf(s, "%ps();\n", (void *)call->func);
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
+	trace_seq_printf(s, "%ps();\n", (void *)call->func);
 
-	return TRACE_TYPE_HANDLED;
+	return trace_handle_return(s);
 }
 
 static enum print_line_t
@@ -879,7 +811,6 @@ print_graph_entry_nested(struct trace_iterator *iter,
 {
 	struct ftrace_graph_ent *call = &entry->graph_ent;
 	struct fgraph_data *data = iter->private;
-	int ret;
 	int i;
 
 	if (data) {
@@ -895,19 +826,15 @@ print_graph_entry_nested(struct trace_iterator *iter,
 	}
 
 	/* No time */
-	ret = print_graph_duration(0, s, flags | FLAGS_FILL_FULL);
-	if (ret != TRACE_TYPE_HANDLED)
-		return ret;
+	print_graph_duration(0, s, flags | FLAGS_FILL_FULL);
 
 	/* Function */
-	for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
-		ret = trace_seq_putc(s, ' ');
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
+	for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++)
+		trace_seq_putc(s, ' ');
+
+	trace_seq_printf(s, "%ps() {\n", (void *)call->func);
 
-	ret = trace_seq_printf(s, "%ps() {\n", (void *)call->func);
-	if (!ret)
+	if (trace_seq_has_overflowed(s))
 		return TRACE_TYPE_PARTIAL_LINE;
 
 	/*
@@ -917,62 +844,43 @@ print_graph_entry_nested(struct trace_iterator *iter,
 	return TRACE_TYPE_NO_CONSUME;
 }
 
-static enum print_line_t
+static void
 print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s,
 		     int type, unsigned long addr, u32 flags)
 {
 	struct fgraph_data *data = iter->private;
 	struct trace_entry *ent = iter->ent;
 	int cpu = iter->cpu;
-	int ret;
 
 	/* Pid */
-	if (verif_pid(s, ent->pid, cpu, data) == TRACE_TYPE_PARTIAL_LINE)
-		return TRACE_TYPE_PARTIAL_LINE;
+	verif_pid(s, ent->pid, cpu, data);
 
-	if (type) {
+	if (type)
 		/* Interrupt */
-		ret = print_graph_irq(iter, addr, type, cpu, ent->pid, flags);
-		if (ret == TRACE_TYPE_PARTIAL_LINE)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
+		print_graph_irq(iter, addr, type, cpu, ent->pid, flags);
 
 	if (!(trace_flags & TRACE_ITER_CONTEXT_INFO))
-		return 0;
+		return;
 
 	/* Absolute time */
-	if (flags & TRACE_GRAPH_PRINT_ABS_TIME) {
-		ret = print_graph_abs_time(iter->ts, s);
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
+	if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
+		print_graph_abs_time(iter->ts, s);
 
 	/* Cpu */
-	if (flags & TRACE_GRAPH_PRINT_CPU) {
-		ret = print_graph_cpu(s, cpu);
-		if (ret == TRACE_TYPE_PARTIAL_LINE)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
+	if (flags & TRACE_GRAPH_PRINT_CPU)
+		print_graph_cpu(s, cpu);
 
 	/* Proc */
 	if (flags & TRACE_GRAPH_PRINT_PROC) {
-		ret = print_graph_proc(s, ent->pid);
-		if (ret == TRACE_TYPE_PARTIAL_LINE)
-			return TRACE_TYPE_PARTIAL_LINE;
-
-		ret = trace_seq_puts(s, " | ");
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
+		print_graph_proc(s, ent->pid);
+		trace_seq_puts(s, " | ");
 	}
 
 	/* Latency format */
-	if (trace_flags & TRACE_ITER_LATENCY_FMT) {
-		ret = print_graph_lat_fmt(s, ent);
-		if (ret == TRACE_TYPE_PARTIAL_LINE)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
+	if (trace_flags & TRACE_ITER_LATENCY_FMT)
+		print_graph_lat_fmt(s, ent);
 
-	return 0;
+	return;
 }
 
 /*
@@ -1090,8 +998,7 @@ print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
 	if (check_irq_entry(iter, flags, call->func, call->depth))
 		return TRACE_TYPE_HANDLED;
 
-	if (print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func, flags))
-		return TRACE_TYPE_PARTIAL_LINE;
+	print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func, flags);
 
 	leaf_ret = get_return_for_leaf(iter, field);
 	if (leaf_ret)
@@ -1124,7 +1031,6 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
 	pid_t pid = ent->pid;
 	int cpu = iter->cpu;
 	int func_match = 1;
-	int ret;
 	int i;
 
 	if (check_irq_return(iter, flags, trace->depth))
@@ -1150,20 +1056,14 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
 		}
 	}
 
-	if (print_graph_prologue(iter, s, 0, 0, flags))
-		return TRACE_TYPE_PARTIAL_LINE;
+	print_graph_prologue(iter, s, 0, 0, flags);
 
 	/* Overhead and duration */
-	ret = print_graph_duration(duration, s, flags);
-	if (ret == TRACE_TYPE_PARTIAL_LINE)
-		return TRACE_TYPE_PARTIAL_LINE;
+	print_graph_duration(duration, s, flags);
 
 	/* Closing brace */
-	for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) {
-		ret = trace_seq_putc(s, ' ');
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
+	for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++)
+		trace_seq_putc(s, ' ');
 
 	/*
 	 * If the return function does not have a matching entry,
@@ -1172,30 +1072,20 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
 	 * belongs to, write out the function name. Always do
 	 * that if the funcgraph-tail option is enabled.
 	 */
-	if (func_match && !(flags & TRACE_GRAPH_PRINT_TAIL)) {
-		ret = trace_seq_puts(s, "}\n");
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-	} else {
-		ret = trace_seq_printf(s, "} /* %ps */\n", (void *)trace->func);
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
+	if (func_match && !(flags & TRACE_GRAPH_PRINT_TAIL))
+		trace_seq_puts(s, "}\n");
+	else
+		trace_seq_printf(s, "} /* %ps */\n", (void *)trace->func);
 
 	/* Overrun */
-	if (flags & TRACE_GRAPH_PRINT_OVERRUN) {
-		ret = trace_seq_printf(s, " (Overruns: %lu)\n",
-					trace->overrun);
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
+	if (flags & TRACE_GRAPH_PRINT_OVERRUN)
+		trace_seq_printf(s, " (Overruns: %lu)\n",
+				 trace->overrun);
 
-	ret = print_graph_irq(iter, trace->func, TRACE_GRAPH_RET,
-			      cpu, pid, flags);
-	if (ret == TRACE_TYPE_PARTIAL_LINE)
-		return TRACE_TYPE_PARTIAL_LINE;
+	print_graph_irq(iter, trace->func, TRACE_GRAPH_RET,
+			cpu, pid, flags);
 
-	return TRACE_TYPE_HANDLED;
+	return trace_handle_return(s);
 }
 
 static enum print_line_t
@@ -1212,26 +1102,18 @@ print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
 	if (data)
 		depth = per_cpu_ptr(data->cpu_data, iter->cpu)->depth;
 
-	if (print_graph_prologue(iter, s, 0, 0, flags))
-		return TRACE_TYPE_PARTIAL_LINE;
+	print_graph_prologue(iter, s, 0, 0, flags);
 
 	/* No time */
-	ret = print_graph_duration(0, s, flags | FLAGS_FILL_FULL);
-	if (ret != TRACE_TYPE_HANDLED)
-		return ret;
+	print_graph_duration(0, s, flags | FLAGS_FILL_FULL);
 
 	/* Indentation */
 	if (depth > 0)
-		for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++) {
-			ret = trace_seq_putc(s, ' ');
-			if (!ret)
-				return TRACE_TYPE_PARTIAL_LINE;
-		}
+		for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++)
+			trace_seq_putc(s, ' ');
 
 	/* The comment */
-	ret = trace_seq_puts(s, "/* ");
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
+	trace_seq_puts(s, "/* ");
 
 	switch (iter->ent->type) {
 	case TRACE_BPRINT:
@@ -1254,17 +1136,18 @@ print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
 			return ret;
 	}
 
+	if (trace_seq_has_overflowed(s))
+		goto out;
+
 	/* Strip ending newline */
-	if (s->buffer[s->len - 1] == '\n') {
-		s->buffer[s->len - 1] = '\0';
-		s->len--;
+	if (s->buffer[s->seq.len - 1] == '\n') {
+		s->buffer[s->seq.len - 1] = '\0';
+		s->seq.len--;
 	}
 
-	ret = trace_seq_puts(s, " */\n");
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
-
-	return TRACE_TYPE_HANDLED;
+	trace_seq_puts(s, " */\n");
+ out:
+	return trace_handle_return(s);
 }
 
 
@@ -1371,35 +1254,35 @@ static void __print_graph_headers_flags(struct seq_file *s, u32 flags)
 		print_lat_header(s, flags);
 
 	/* 1st line */
-	seq_printf(s, "#");
+	seq_putc(s, '#');
 	if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
-		seq_printf(s, "     TIME       ");
+		seq_puts(s, "     TIME       ");
 	if (flags & TRACE_GRAPH_PRINT_CPU)
-		seq_printf(s, " CPU");
+		seq_puts(s, " CPU");
 	if (flags & TRACE_GRAPH_PRINT_PROC)
-		seq_printf(s, "  TASK/PID       ");
+		seq_puts(s, "  TASK/PID       ");
 	if (lat)
-		seq_printf(s, "||||");
+		seq_puts(s, "||||");
 	if (flags & TRACE_GRAPH_PRINT_DURATION)
-		seq_printf(s, "  DURATION   ");
-	seq_printf(s, "               FUNCTION CALLS\n");
+		seq_puts(s, "  DURATION   ");
+	seq_puts(s, "               FUNCTION CALLS\n");
 
 	/* 2nd line */
-	seq_printf(s, "#");
+	seq_putc(s, '#');
 	if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
-		seq_printf(s, "      |         ");
+		seq_puts(s, "      |         ");
 	if (flags & TRACE_GRAPH_PRINT_CPU)
-		seq_printf(s, " |  ");
+		seq_puts(s, " |  ");
 	if (flags & TRACE_GRAPH_PRINT_PROC)
-		seq_printf(s, "   |    |        ");
+		seq_puts(s, "   |    |        ");
 	if (lat)
-		seq_printf(s, "||||");
+		seq_puts(s, "||||");
 	if (flags & TRACE_GRAPH_PRINT_DURATION)
-		seq_printf(s, "   |   |      ");
-	seq_printf(s, "               |   |   |   |\n");
+		seq_puts(s, "   |   |      ");
+	seq_puts(s, "               |   |   |   |\n");
 }
 
-void print_graph_headers(struct seq_file *s)
+static void print_graph_headers(struct seq_file *s)
 {
 	print_graph_headers_flags(s, tracer_flags.val);
 }
@@ -1495,6 +1378,7 @@ static struct trace_event graph_trace_ret_event = {
 
 static struct tracer graph_trace __tracer_data = {
 	.name		= "function_graph",
+	.update_thresh	= graph_trace_update_thresh,
 	.open		= graph_trace_open,
 	.pipe_open	= graph_trace_open,
 	.close		= graph_trace_close,