Merge branch 'tip/tracing/ftrace' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/ftrace

arch/x86/kernel/ftrace.c

@@ -79,11 +79,11 @@ static unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
  *
  * 1) Put the instruction pointer into the IP buffer
  *    and the new code into the "code" buffer.
- * 2) Set a flag that says we are modifying code
- * 3) Wait for any running NMIs to finish.
- * 4) Write the code
- * 5) clear the flag.
- * 6) Wait for any running NMIs to finish.
+ * 2) Wait for any running NMIs to finish and set a flag that says
+ *    we are modifying code, it is done in an atomic operation.
+ * 3) Write the code
+ * 4) clear the flag.
+ * 5) Wait for any running NMIs to finish.
  *
  * If an NMI is executed, the first thing it does is to call
  * "ftrace_nmi_enter". This will check if the flag is set to write
@@ -95,9 +95,9 @@ static unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
  * are the same as what exists.
  */
 
+#define MOD_CODE_WRITE_FLAG (1 << 31)	/* set when NMI should do the write */
 static atomic_t nmi_running = ATOMIC_INIT(0);
 static int mod_code_status;		/* holds return value of text write */
-static int mod_code_write;		/* set when NMI should do the write */
 static void *mod_code_ip;		/* holds the IP to write to */
 static void *mod_code_newcode;		/* holds the text to write to the IP */
 
@@ -114,6 +114,20 @@ int ftrace_arch_read_dyn_info(char *buf, int size)
 	return r;
 }
 
+static void clear_mod_flag(void)
+{
+	int old = atomic_read(&nmi_running);
+
+	for (;;) {
+		int new = old & ~MOD_CODE_WRITE_FLAG;
+
+		if (old == new)
+			break;
+
+		old = atomic_cmpxchg(&nmi_running, old, new);
+	}
+}
+
 static void ftrace_mod_code(void)
 {
 	/*
@@ -127,27 +141,39 @@ static void ftrace_mod_code(void)
 
 	/* if we fail, then kill any new writers */
 	if (mod_code_status)
-		mod_code_write = 0;
+		clear_mod_flag();
 }
 
 void ftrace_nmi_enter(void)
 {
-	atomic_inc(&nmi_running);
-	/* Must have nmi_running seen before reading write flag */
-	smp_mb();
-	if (mod_code_write) {
+	if (atomic_inc_return(&nmi_running) & MOD_CODE_WRITE_FLAG) {
+		smp_rmb();
 		ftrace_mod_code();
 		atomic_inc(&nmi_update_count);
 	}
+	/* Must have previous changes seen before executions */
+	smp_mb();
 }
 
 void ftrace_nmi_exit(void)
 {
 	/* Finish all executions before clearing nmi_running */
-	smp_wmb();
+	smp_mb();
 	atomic_dec(&nmi_running);
 }
 
+static void wait_for_nmi_and_set_mod_flag(void)
+{
+	if (!atomic_cmpxchg(&nmi_running, 0, MOD_CODE_WRITE_FLAG))
+		return;
+
+	do {
+		cpu_relax();
+	} while (atomic_cmpxchg(&nmi_running, 0, MOD_CODE_WRITE_FLAG));
+
+	nmi_wait_count++;
+}
+
 static void wait_for_nmi(void)
 {
 	if (!atomic_read(&nmi_running))
@@ -167,14 +193,9 @@ do_ftrace_mod_code(unsigned long ip, void *new_code)
 	mod_code_newcode = new_code;
 
 	/* The buffers need to be visible before we let NMIs write them */
-	smp_wmb();
-
-	mod_code_write = 1;
-
-	/* Make sure write bit is visible before we wait on NMIs */
 	smp_mb();
 
-	wait_for_nmi();
+	wait_for_nmi_and_set_mod_flag();
 
 	/* Make sure all running NMIs have finished before we write the code */
 	smp_mb();
@@ -182,13 +203,9 @@ do_ftrace_mod_code(unsigned long ip, void *new_code)
 	ftrace_mod_code();
 
 	/* Make sure the write happens before clearing the bit */
-	smp_wmb();
-
-	mod_code_write = 0;
-
-	/* make sure NMIs see the cleared bit */
 	smp_mb();
 
+	clear_mod_flag();
 	wait_for_nmi();
 
 	return mod_code_status;

kernel/trace/trace.c

@@ -1201,7 +1201,7 @@ void trace_graph_return(struct ftrace_graph_ret *trace)
  * trace_vbprintk - write binary msg to tracing buffer
  *
  */
-int trace_vbprintk(unsigned long ip, int depth, const char *fmt, va_list args)
+int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
 {
 	static raw_spinlock_t trace_buf_lock =
 		(raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
@@ -1243,7 +1243,6 @@ int trace_vbprintk(unsigned long ip, int depth, const char *fmt, va_list args)
 		goto out_unlock;
 	entry = ring_buffer_event_data(event);
 	entry->ip			= ip;
-	entry->depth			= depth;
 	entry->fmt			= fmt;
 
 	memcpy(entry->buf, trace_buf, sizeof(u32) * len);
@@ -1261,7 +1260,7 @@ out:
 }
 EXPORT_SYMBOL_GPL(trace_vbprintk);
 
-int trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args)
+int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
 {
 	static raw_spinlock_t trace_buf_lock = __RAW_SPIN_LOCK_UNLOCKED;
 	static char trace_buf[TRACE_BUF_SIZE];
@@ -1298,7 +1297,6 @@ int trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args)
 		goto out_unlock;
 	entry = ring_buffer_event_data(event);
 	entry->ip			= ip;
-	entry->depth			= depth;
 
 	memcpy(&entry->buf, trace_buf, len);
 	entry->buf[len] = 0;
@@ -1701,38 +1699,6 @@ static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
 	return TRACE_TYPE_HANDLED;
 }
 
-static enum print_line_t print_bprintk_msg_only(struct trace_iterator *iter)
-{
-	struct trace_seq *s = &iter->seq;
-	struct trace_entry *entry = iter->ent;
-	struct bprint_entry *field;
-	int ret;
-
-	trace_assign_type(field, entry);
-
-	ret = trace_seq_bprintf(s, field->fmt, field->buf);
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
-
-	return TRACE_TYPE_HANDLED;
-}
-
-static enum print_line_t print_printk_msg_only(struct trace_iterator *iter)
-{
-	struct trace_seq *s = &iter->seq;
-	struct trace_entry *entry = iter->ent;
-	struct print_entry *field;
-	int ret;
-
-	trace_assign_type(field, entry);
-
-	ret = trace_seq_printf(s, "%s", field->buf);
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
-
-	return TRACE_TYPE_HANDLED;
-}
-
 static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
 {
 	struct trace_seq *s = &iter->seq;
@@ -1794,12 +1760,12 @@ static enum print_line_t print_trace_line(struct trace_iterator *iter)
 	if (iter->ent->type == TRACE_BPRINT &&
 			trace_flags & TRACE_ITER_PRINTK &&
 			trace_flags & TRACE_ITER_PRINTK_MSGONLY)
-		return print_bprintk_msg_only(iter);
+		return trace_print_bprintk_msg_only(iter);
 
 	if (iter->ent->type == TRACE_PRINT &&
 			trace_flags & TRACE_ITER_PRINTK &&
 			trace_flags & TRACE_ITER_PRINTK_MSGONLY)
-		return print_printk_msg_only(iter);
+		return trace_print_printk_msg_only(iter);
 
 	if (trace_flags & TRACE_ITER_BIN)
 		return print_bin_fmt(iter);
@@ -1948,9 +1914,14 @@ int tracing_open_generic(struct inode *inode, struct file *filp)
 static int tracing_release(struct inode *inode, struct file *file)
 {
 	struct seq_file *m = (struct seq_file *)file->private_data;
-	struct trace_iterator *iter = m->private;
+	struct trace_iterator *iter;
 	int cpu;
 
+	if (!(file->f_mode & FMODE_READ))
+		return 0;
+
+	iter = m->private;
+
 	mutex_lock(&trace_types_lock);
 	for_each_tracing_cpu(cpu) {
 		if (iter->buffer_iter[cpu])
@@ -1976,12 +1947,24 @@ static int tracing_open(struct inode *inode, struct file *file)
 	struct trace_iterator *iter;
 	int ret = 0;
 
-	iter = __tracing_open(inode, file);
-	if (IS_ERR(iter))
-		ret = PTR_ERR(iter);
-	else if (trace_flags & TRACE_ITER_LATENCY_FMT)
-		iter->iter_flags |= TRACE_FILE_LAT_FMT;
+	/* If this file was open for write, then erase contents */
+	if ((file->f_mode & FMODE_WRITE) &&
+	    !(file->f_flags & O_APPEND)) {
+		long cpu = (long) inode->i_private;
 
+		if (cpu == TRACE_PIPE_ALL_CPU)
+			tracing_reset_online_cpus(&global_trace);
+		else
+			tracing_reset(&global_trace, cpu);
+	}
+
+	if (file->f_mode & FMODE_READ) {
+		iter = __tracing_open(inode, file);
+		if (IS_ERR(iter))
+			ret = PTR_ERR(iter);
+		else if (trace_flags & TRACE_ITER_LATENCY_FMT)
+			iter->iter_flags |= TRACE_FILE_LAT_FMT;
+	}
 	return ret;
 }
 
@@ -2056,9 +2039,17 @@ static int show_traces_open(struct inode *inode, struct file *file)
 	return ret;
 }
 
+static ssize_t
+tracing_write_stub(struct file *filp, const char __user *ubuf,
+		   size_t count, loff_t *ppos)
+{
+	return count;
+}
+
 static const struct file_operations tracing_fops = {
 	.open		= tracing_open,
 	.read		= seq_read,
+	.write		= tracing_write_stub,
 	.llseek		= seq_lseek,
 	.release	= tracing_release,
 };
@@ -3154,7 +3145,7 @@ static int mark_printk(const char *fmt, ...)
 	int ret;
 	va_list args;
 	va_start(args, fmt);
-	ret = trace_vprintk(0, -1, fmt, args);
+	ret = trace_vprintk(0, fmt, args);
 	va_end(args);
 	return ret;
 }
@@ -3583,7 +3574,7 @@ static void tracing_init_debugfs_percpu(long cpu)
 		pr_warning("Could not create debugfs 'trace_pipe' entry\n");
 
 	/* per cpu trace */
-	entry = debugfs_create_file("trace", 0444, d_cpu,
+	entry = debugfs_create_file("trace", 0644, d_cpu,
 				(void *) cpu, &tracing_fops);
 	if (!entry)
 		pr_warning("Could not create debugfs 'trace' entry\n");
@@ -3897,7 +3888,7 @@ static __init int tracer_init_debugfs(void)
 	if (!entry)
 		pr_warning("Could not create debugfs 'tracing_cpumask' entry\n");
 
-	entry = debugfs_create_file("trace", 0444, d_tracer,
+	entry = debugfs_create_file("trace", 0644, d_tracer,
 				 (void *) TRACE_PIPE_ALL_CPU, &tracing_fops);
 	if (!entry)
 		pr_warning("Could not create debugfs 'trace' entry\n");

kernel/trace/trace.h

@@ -123,7 +123,6 @@ struct userstack_entry {
 struct bprint_entry {
 	struct trace_entry	ent;
 	unsigned long		ip;
-	int			depth;
 	const char		*fmt;
 	u32			buf[];
 };
@@ -131,7 +130,6 @@ struct bprint_entry {
 struct print_entry {
 	struct trace_entry	ent;
 	unsigned long		ip;
-	int			depth;
 	char			buf[];
 };
 
@@ -598,9 +596,9 @@ extern int trace_selftest_startup_branch(struct tracer *trace,
 extern void *head_page(struct trace_array_cpu *data);
 extern long ns2usecs(cycle_t nsec);
 extern int
-trace_vbprintk(unsigned long ip, int depth, const char *fmt, va_list args);
+trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
 extern int
-trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args);
+trace_vprintk(unsigned long ip, const char *fmt, va_list args);
 
 extern unsigned long trace_flags;
 

kernel/trace/trace_event_types.h

@@ -105,7 +105,6 @@ TRACE_EVENT_FORMAT(user_stack, TRACE_USER_STACK, userstack_entry, ignore,
 TRACE_EVENT_FORMAT(bprint, TRACE_BPRINT, bprint_entry, ignore,
 	TRACE_STRUCT(
 		TRACE_FIELD(unsigned long, ip, ip)
-		TRACE_FIELD(unsigned int, depth, depth)
 		TRACE_FIELD(char *, fmt, fmt)
 		TRACE_FIELD_ZERO_CHAR(buf)
 	),
@@ -115,7 +114,6 @@ TRACE_EVENT_FORMAT(bprint, TRACE_BPRINT, bprint_entry, ignore,
 TRACE_EVENT_FORMAT(print, TRACE_PRINT, print_entry, ignore,
 	TRACE_STRUCT(
 		TRACE_FIELD(unsigned long, ip, ip)
-		TRACE_FIELD(unsigned int, depth, depth)
 		TRACE_FIELD_ZERO_CHAR(buf)
 	),
 	TP_RAW_FMT("%08lx (%d) fmt:%p %s")

kernel/trace/trace_functions_graph.c

@@ -14,6 +14,11 @@
 #include "trace.h"
 #include "trace_output.h"
 
+struct fgraph_data {
+	pid_t		last_pid;
+	int		depth;
+};
+
 #define TRACE_GRAPH_INDENT	2
 
 /* Flag options */
@@ -231,16 +236,16 @@ print_graph_proc(struct trace_seq *s, pid_t pid)
 
 /* If the pid changed since the last trace, output this event */
 static enum print_line_t
-verif_pid(struct trace_seq *s, pid_t pid, int cpu, pid_t *last_pids_cpu)
+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 (!last_pids_cpu)
+	if (!data)
 		return TRACE_TYPE_HANDLED;
 
-	last_pid = per_cpu_ptr(last_pids_cpu, cpu);
+	last_pid = &(per_cpu_ptr(data, cpu)->last_pid);
 
 	if (*last_pid == pid)
 		return TRACE_TYPE_HANDLED;
@@ -471,6 +476,7 @@ print_graph_entry_leaf(struct trace_iterator *iter,
 		struct ftrace_graph_ent_entry *entry,
 		struct ftrace_graph_ret_entry *ret_entry, struct trace_seq *s)
 {
+	struct fgraph_data *data = iter->private;
 	struct ftrace_graph_ret *graph_ret;
 	struct ftrace_graph_ent *call;
 	unsigned long long duration;
@@ -481,6 +487,18 @@ print_graph_entry_leaf(struct trace_iterator *iter,
 	call = &entry->graph_ent;
 	duration = graph_ret->rettime - graph_ret->calltime;
 
+	if (data) {
+		int cpu = iter->cpu;
+		int *depth = &(per_cpu_ptr(data, cpu)->depth);
+
+		/*
+		 * Comments display at + 1 to depth. Since
+		 * this is a leaf function, keep the comments
+		 * equal to this depth.
+		 */
+		*depth = call->depth - 1;
+	}
+
 	/* Overhead */
 	ret = print_graph_overhead(duration, s);
 	if (!ret)
@@ -512,12 +530,21 @@ print_graph_entry_leaf(struct trace_iterator *iter,
 }
 
 static enum print_line_t
-print_graph_entry_nested(struct ftrace_graph_ent_entry *entry,
-			struct trace_seq *s, pid_t pid, int cpu)
+print_graph_entry_nested(struct trace_iterator *iter,
+			 struct ftrace_graph_ent_entry *entry,
+			 struct trace_seq *s, int cpu)
 {
-	int i;
-	int ret;
 	struct ftrace_graph_ent *call = &entry->graph_ent;
+	struct fgraph_data *data = iter->private;
+	int ret;
+	int i;
+
+	if (data) {
+		int cpu = iter->cpu;
+		int *depth = &(per_cpu_ptr(data, cpu)->depth);
+
+		*depth = call->depth;
+	}
 
 	/* No overhead */
 	ret = print_graph_overhead(-1, s);
@@ -554,24 +581,24 @@ print_graph_entry_nested(struct ftrace_graph_ent_entry *entry,
 }
 
 static enum print_line_t
-print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
-			struct trace_iterator *iter)
+print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s,
+		     int type, unsigned long addr)
 {
-	int ret;
-	int cpu = iter->cpu;
-	pid_t *last_entry = iter->private;
+	struct fgraph_data *data = iter->private;
 	struct trace_entry *ent = iter->ent;
-	struct ftrace_graph_ent *call = &field->graph_ent;
-	struct ftrace_graph_ret_entry *leaf_ret;
+	int cpu = iter->cpu;
+	int ret;
 
 	/* Pid */
-	if (verif_pid(s, ent->pid, cpu, last_entry) == TRACE_TYPE_PARTIAL_LINE)
+	if (verif_pid(s, ent->pid, cpu, data) == TRACE_TYPE_PARTIAL_LINE)
 		return TRACE_TYPE_PARTIAL_LINE;
 
-	/* Interrupt */
-	ret = print_graph_irq(iter, call->func, TRACE_GRAPH_ENT, cpu, ent->pid);
-	if (ret == TRACE_TYPE_PARTIAL_LINE)
-		return TRACE_TYPE_PARTIAL_LINE;
+	if (type) {
+		/* Interrupt */
+		ret = print_graph_irq(iter, addr, type, cpu, ent->pid);
+		if (ret == TRACE_TYPE_PARTIAL_LINE)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
 
 	/* Absolute time */
 	if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME) {
@@ -598,11 +625,25 @@ print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
 			return TRACE_TYPE_PARTIAL_LINE;
 	}
 
+	return 0;
+}
+
+static enum print_line_t
+print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
+			struct trace_iterator *iter)
+{
+	int cpu = iter->cpu;
+	struct ftrace_graph_ent *call = &field->graph_ent;
+	struct ftrace_graph_ret_entry *leaf_ret;
+
+	if (print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func))
+		return TRACE_TYPE_PARTIAL_LINE;
+
 	leaf_ret = get_return_for_leaf(iter, field);
 	if (leaf_ret)
 		return print_graph_entry_leaf(iter, field, leaf_ret, s);
 	else
-		return print_graph_entry_nested(field, s, iter->ent->pid, cpu);
+		return print_graph_entry_nested(iter, field, s, cpu);
 
 }
 
@@ -610,40 +651,27 @@ static enum print_line_t
 print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
 		   struct trace_entry *ent, struct trace_iterator *iter)
 {
-	int i;
-	int ret;
-	int cpu = iter->cpu;
-	pid_t *last_pid = iter->private, pid = ent->pid;
 	unsigned long long duration = trace->rettime - trace->calltime;
+	struct fgraph_data *data = iter->private;
+	pid_t pid = ent->pid;
+	int cpu = iter->cpu;
+	int ret;
+	int i;
 
-	/* Pid */
-	if (verif_pid(s, pid, cpu, last_pid) == TRACE_TYPE_PARTIAL_LINE)
-		return TRACE_TYPE_PARTIAL_LINE;
-
-	/* Absolute time */
-	if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME) {
-		ret = print_graph_abs_time(iter->ts, s);
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
+	if (data) {
+		int cpu = iter->cpu;
+		int *depth = &(per_cpu_ptr(data, cpu)->depth);
 
-	/* Cpu */
-	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
-		ret = print_graph_cpu(s, cpu);
-		if (ret == TRACE_TYPE_PARTIAL_LINE)
-			return TRACE_TYPE_PARTIAL_LINE;
+		/*
+		 * Comments display at + 1 to depth. This is the
+		 * return from a function, we now want the comments
+		 * to display at the same level of the bracket.
+		 */
+		*depth = trace->depth - 1;
 	}
 
-	/* Proc */
-	if (tracer_flags.val & 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_printf(s, " | ");
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
+	if (print_graph_prologue(iter, s, 0, 0))
+		return TRACE_TYPE_PARTIAL_LINE;
 
 	/* Overhead */
 	ret = print_graph_overhead(duration, s);
@@ -684,42 +712,21 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
 }
 
 static enum print_line_t
-print_graph_comment(struct bprint_entry *trace, struct trace_seq *s,
-		   struct trace_entry *ent, struct trace_iterator *iter)
+print_graph_comment(struct trace_seq *s,  struct trace_entry *ent,
+		    struct trace_iterator *iter)
 {
-	int i;
+	unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
+	struct fgraph_data *data = iter->private;
+	struct trace_event *event;
+	int depth = 0;
 	int ret;
-	int cpu = iter->cpu;
-	pid_t *last_pid = iter->private;
-
-	/* Pid */
-	if (verif_pid(s, ent->pid, cpu, last_pid) == TRACE_TYPE_PARTIAL_LINE)
-		return TRACE_TYPE_PARTIAL_LINE;
-
-	/* Absolute time */
-	if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME) {
-		ret = print_graph_abs_time(iter->ts, s);
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
-
-	/* Cpu */
-	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
-		ret = print_graph_cpu(s, cpu);
-		if (ret == TRACE_TYPE_PARTIAL_LINE)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
+	int i;
 
-	/* Proc */
-	if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) {
-		ret = print_graph_proc(s, ent->pid);
-		if (ret == TRACE_TYPE_PARTIAL_LINE)
-			return TRACE_TYPE_PARTIAL_LINE;
+	if (data)
+		depth = per_cpu_ptr(data, iter->cpu)->depth;
 
-		ret = trace_seq_printf(s, " | ");
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
+	if (print_graph_prologue(iter, s, 0, 0))
+		return TRACE_TYPE_PARTIAL_LINE;
 
 	/* No overhead */
 	ret = print_graph_overhead(-1, s);
@@ -734,8 +741,8 @@ print_graph_comment(struct bprint_entry *trace, struct trace_seq *s,
 	}
 
 	/* Indentation */
-	if (trace->depth > 0)
-		for (i = 0; i < (trace->depth + 1) * TRACE_GRAPH_INDENT; i++) {
+	if (depth > 0)
+		for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++) {
 			ret = trace_seq_printf(s, " ");
 			if (!ret)
 				return TRACE_TYPE_PARTIAL_LINE;
@@ -746,9 +753,26 @@ print_graph_comment(struct bprint_entry *trace, struct trace_seq *s,
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
 
-	ret = trace_seq_bprintf(s, trace->fmt, trace->buf);
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
+	switch (iter->ent->type) {
+	case TRACE_BPRINT:
+		ret = trace_print_bprintk_msg_only(iter);
+		if (ret != TRACE_TYPE_HANDLED)
+			return ret;
+		break;
+	case TRACE_PRINT:
+		ret = trace_print_printk_msg_only(iter);
+		if (ret != TRACE_TYPE_HANDLED)
+			return ret;
+		break;
+	default:
+		event = ftrace_find_event(ent->type);
+		if (!event)
+			return TRACE_TYPE_UNHANDLED;
+
+		ret = event->trace(iter, sym_flags);
+		if (ret != TRACE_TYPE_HANDLED)
+			return ret;
+	}
 
 	/* Strip ending newline */
 	if (s->buffer[s->len - 1] == '\n') {
@@ -767,8 +791,8 @@ print_graph_comment(struct bprint_entry *trace, struct trace_seq *s,
 enum print_line_t
 print_graph_function(struct trace_iterator *iter)
 {
-	struct trace_seq *s = &iter->seq;
 	struct trace_entry *entry = iter->ent;
+	struct trace_seq *s = &iter->seq;
 
 	switch (entry->type) {
 	case TRACE_GRAPH_ENT: {
@@ -781,14 +805,11 @@ print_graph_function(struct trace_iterator *iter)
 		trace_assign_type(field, entry);
 		return print_graph_return(&field->ret, s, entry, iter);
 	}
-	case TRACE_BPRINT: {
-		struct bprint_entry *field;
-		trace_assign_type(field, entry);
-		return print_graph_comment(field, s, entry, iter);
-	}
 	default:
-		return TRACE_TYPE_UNHANDLED;
+		return print_graph_comment(s, entry, iter);
 	}
+
+	return TRACE_TYPE_HANDLED;
 }
 
 static void print_graph_headers(struct seq_file *s)
@@ -820,19 +841,21 @@ static void print_graph_headers(struct seq_file *s)
 
 static void graph_trace_open(struct trace_iterator *iter)
 {
-	/* pid on the last trace processed */
-	pid_t *last_pid = alloc_percpu(pid_t);
+	/* pid and depth on the last trace processed */
+	struct fgraph_data *data = alloc_percpu(struct fgraph_data);
 	int cpu;
 
-	if (!last_pid)
+	if (!data)
 		pr_warning("function graph tracer: not enough memory\n");
 	else
 		for_each_possible_cpu(cpu) {
-			pid_t *pid = per_cpu_ptr(last_pid, cpu);
+			pid_t *pid = &(per_cpu_ptr(data, cpu)->last_pid);
+			int *depth = &(per_cpu_ptr(data, cpu)->depth);
 			*pid = -1;
+			*depth = 0;
 		}
 
-	iter->private = last_pid;
+	iter->private = data;
 }
 
 static void graph_trace_close(struct trace_iterator *iter)

kernel/trace/trace_mmiotrace.c

@@ -359,5 +359,5 @@ void mmio_trace_mapping(struct mmiotrace_map *map)
 
 int mmio_trace_printk(const char *fmt, va_list args)
 {
-	return trace_vprintk(0, -1, fmt, args);
+	return trace_vprintk(0, fmt, args);
 }

kernel/trace/trace_output.c

@@ -19,6 +19,38 @@ static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;
 
 static int next_event_type = __TRACE_LAST_TYPE + 1;
 
+enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter)
+{
+	struct trace_seq *s = &iter->seq;
+	struct trace_entry *entry = iter->ent;
+	struct bprint_entry *field;
+	int ret;
+
+	trace_assign_type(field, entry);
+
+	ret = trace_seq_bprintf(s, field->fmt, field->buf);
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	return TRACE_TYPE_HANDLED;
+}
+
+enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter)
+{
+	struct trace_seq *s = &iter->seq;
+	struct trace_entry *entry = iter->ent;
+	struct print_entry *field;
+	int ret;
+
+	trace_assign_type(field, entry);
+
+	ret = trace_seq_printf(s, "%s", field->buf);
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	return TRACE_TYPE_HANDLED;
+}
+
 /**
  * trace_seq_printf - sequence printing of trace information
  * @s: trace sequence descriptor

kernel/trace/trace_output.h

@@ -15,6 +15,11 @@ struct trace_event {
 	trace_print_func	binary;
 };
 
+extern enum print_line_t
+trace_print_bprintk_msg_only(struct trace_iterator *iter);
+extern enum print_line_t
+trace_print_printk_msg_only(struct trace_iterator *iter);
+
 extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
 	__attribute__ ((format (printf, 2, 3)));
 extern int

kernel/trace/trace_printk.c

@@ -112,7 +112,7 @@ int __trace_bprintk(unsigned long ip, const char *fmt, ...)
 		return 0;
 
 	va_start(ap, fmt);
-	ret = trace_vbprintk(ip, task_curr_ret_stack(current), fmt, ap);
+	ret = trace_vbprintk(ip, fmt, ap);
 	va_end(ap);
 	return ret;
 }
@@ -126,7 +126,7 @@ int __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap)
 	if (!(trace_flags & TRACE_ITER_PRINTK))
 		return 0;
 
-	return trace_vbprintk(ip, task_curr_ret_stack(current), fmt, ap);
+	return trace_vbprintk(ip, fmt, ap);
 }
 EXPORT_SYMBOL_GPL(__ftrace_vbprintk);
 
@@ -139,7 +139,7 @@ int __trace_printk(unsigned long ip, const char *fmt, ...)
 		return 0;
 
 	va_start(ap, fmt);
-	ret = trace_vprintk(ip, task_curr_ret_stack(current), fmt, ap);
+	ret = trace_vprintk(ip, fmt, ap);
 	va_end(ap);
 	return ret;
 }
@@ -150,7 +150,7 @@ int __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap)
 	if (!(trace_flags & TRACE_ITER_PRINTK))
 		return 0;
 
-	return trace_vprintk(ip, task_curr_ret_stack(current), fmt, ap);
+	return trace_vprintk(ip, fmt, ap);
 }
 EXPORT_SYMBOL_GPL(__ftrace_vprintk);