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-rw-r--r--kernel/trace/trace_stack.c30
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);
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