1 files changed, 29 insertions, 1 deletions

diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 77575b386d97..d4545f49242e 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -13,6 +13,9 @@
 #include <linux/sysctl.h>
 #include <linux/init.h>
 #include <linux/fs.h>
+
+#include <asm/setup.h>
+
 #include "trace.h"
 
 #define STACK_TRACE_ENTRIES 500
@@ -133,7 +136,6 @@ stack_trace_call(unsigned long ip, unsigned long parent_ip)
 static struct ftrace_ops trace_ops __read_mostly =
 {
 	.func = stack_trace_call,
-	.flags = FTRACE_OPS_FL_GLOBAL,
 };
 
 static ssize_t
@@ -311,6 +313,21 @@ static const struct file_operations stack_trace_fops = {
 	.release	= seq_release,
 };
 
+static int
+stack_trace_filter_open(struct inode *inode, struct file *file)
+{
+	return ftrace_regex_open(&trace_ops, FTRACE_ITER_FILTER,
+				 inode, file);
+}
+
+static const struct file_operations stack_trace_filter_fops = {
+	.open = stack_trace_filter_open,
+	.read = seq_read,
+	.write = ftrace_filter_write,
+	.llseek = ftrace_regex_lseek,
+	.release = ftrace_regex_release,
+};
+
 int
 stack_trace_sysctl(struct ctl_table *table, int write,
 		   void __user *buffer, size_t *lenp,
@@ -338,8 +355,13 @@ stack_trace_sysctl(struct ctl_table *table, int write,
 	return ret;
 }
 
+static char stack_trace_filter_buf[COMMAND_LINE_SIZE+1] __initdata;
+
 static __init int enable_stacktrace(char *str)
 {
+	if (strncmp(str, "_filter=", 8) == 0)
+		strncpy(stack_trace_filter_buf, str+8, COMMAND_LINE_SIZE);
+
 	stack_tracer_enabled = 1;
 	last_stack_tracer_enabled = 1;
 	return 1;
@@ -358,6 +380,12 @@ static __init int stack_trace_init(void)
 	trace_create_file("stack_trace", 0444, d_tracer,
 			NULL, &stack_trace_fops);
 
+	trace_create_file("stack_trace_filter", 0444, d_tracer,
+			NULL, &stack_trace_filter_fops);
+
+	if (stack_trace_filter_buf[0])
+		ftrace_set_early_filter(&trace_ops, stack_trace_filter_buf, 1);
+
 	if (stack_tracer_enabled)
 		register_ftrace_function(&trace_ops);