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-rw-r--r--kernel/trace/ftrace.c50
1 files changed, 48 insertions, 2 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 140699a9a8a7..d6973dfadb36 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -32,6 +32,7 @@
#include <trace/events/sched.h>
#include <asm/ftrace.h>
+#include <asm/setup.h>
#include "trace_output.h"
#include "trace_stat.h"
@@ -598,7 +599,7 @@ function_profile_call(unsigned long ip, unsigned long parent_ip)
local_irq_save(flags);
stat = &__get_cpu_var(ftrace_profile_stats);
- if (!stat->hash)
+ if (!stat->hash || !ftrace_profile_enabled)
goto out;
rec = ftrace_find_profiled_func(stat, ip);
@@ -629,7 +630,7 @@ static void profile_graph_return(struct ftrace_graph_ret *trace)
local_irq_save(flags);
stat = &__get_cpu_var(ftrace_profile_stats);
- if (!stat->hash)
+ if (!stat->hash || !ftrace_profile_enabled)
goto out;
calltime = trace->rettime - trace->calltime;
@@ -723,6 +724,10 @@ ftrace_profile_write(struct file *filp, const char __user *ubuf,
ftrace_profile_enabled = 1;
} else {
ftrace_profile_enabled = 0;
+ /*
+ * unregister_ftrace_profiler calls stop_machine
+ * so this acts like an synchronize_sched.
+ */
unregister_ftrace_profiler();
}
}
@@ -2369,6 +2374,45 @@ void ftrace_set_notrace(unsigned char *buf, int len, int reset)
ftrace_set_regex(buf, len, reset, 0);
}
+/*
+ * command line interface to allow users to set filters on boot up.
+ */
+#define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
+static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
+static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
+
+static int __init set_ftrace_notrace(char *str)
+{
+ strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
+ return 1;
+}
+__setup("ftrace_notrace=", set_ftrace_notrace);
+
+static int __init set_ftrace_filter(char *str)
+{
+ strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
+ return 1;
+}
+__setup("ftrace_filter=", set_ftrace_filter);
+
+static void __init set_ftrace_early_filter(char *buf, int enable)
+{
+ char *func;
+
+ while (buf) {
+ func = strsep(&buf, ",");
+ ftrace_set_regex(func, strlen(func), 0, enable);
+ }
+}
+
+static void __init set_ftrace_early_filters(void)
+{
+ if (ftrace_filter_buf[0])
+ set_ftrace_early_filter(ftrace_filter_buf, 1);
+ if (ftrace_notrace_buf[0])
+ set_ftrace_early_filter(ftrace_notrace_buf, 0);
+}
+
static int
ftrace_regex_release(struct inode *inode, struct file *file, int enable)
{
@@ -2829,6 +2873,8 @@ void __init ftrace_init(void)
if (ret)
pr_warning("Failed to register trace ftrace module notifier\n");
+ set_ftrace_early_filters();
+
return;
failed:
ftrace_disabled = 1;