ftrace: add ftrace_off_permanent
Impact: add new API to disable all of ftrace on anomalies
It case of a serious anomaly being detected (like something caught by
lockdep) it is a good idea to disable all tracing immediately, without
grabing any locks.
This patch adds ftrace_off_permanent that disables the tracers, function
tracing and ring buffers without a way to enable them again. This should
only be used when something serious has been detected.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index f7ba4ea..13e9cfc 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -257,6 +257,7 @@
extern void tracing_start(void);
extern void tracing_stop(void);
+extern void ftrace_off_permanent(void);
extern void
ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3);
@@ -290,6 +291,7 @@
static inline void tracing_start(void) { }
static inline void tracing_stop(void) { }
+static inline void ftrace_off_permanent(void) { }
static inline int
ftrace_printk(const char *fmt, ...)
{