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authorLinus Torvalds <torvalds@linux-foundation.org>2022-04-03 12:26:01 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2022-04-03 12:26:01 -0700
commit09bb8856d4a7cf3128dedd79cd07d75bbf4a9f04 (patch)
treed0ae1e3042793fe397ad65f5fdb05bde32de31e9 /include/linux/ftrace.h
parentMerge tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux (diff)
parenttracing: Move user_events.h temporarily out of include/uapi (diff)
downloadlinux-dev-09bb8856d4a7cf3128dedd79cd07d75bbf4a9f04.tar.xz
linux-dev-09bb8856d4a7cf3128dedd79cd07d75bbf4a9f04.zip
Merge tag 'trace-v5.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull more tracing updates from Steven Rostedt: - Rename the staging files to give them some meaning. Just stage1,stag2,etc, does not show what they are for - Check for NULL from allocation in bootconfig - Hold event mutex for dyn_event call in user events - Mark user events to broken (to work on the API) - Remove eBPF updates from user events - Remove user events from uapi header to keep it from being installed. - Move ftrace_graph_is_dead() into inline as it is called from hot paths and also convert it into a static branch. * tag 'trace-v5.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Move user_events.h temporarily out of include/uapi ftrace: Make ftrace_graph_is_dead() a static branch tracing: Set user_events to BROKEN tracing/user_events: Remove eBPF interfaces tracing/user_events: Hold event_mutex during dyn_event_add proc: bootconfig: Add null pointer check tracing: Rename the staging files for trace_events
Diffstat (limited to 'include/linux/ftrace.h')
-rw-r--r--include/linux/ftrace.h16
1 files changed, 15 insertions, 1 deletions
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index ed8cf433a46a..4816b7e11047 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -9,6 +9,7 @@
#include <linux/trace_recursion.h>
#include <linux/trace_clock.h>
+#include <linux/jump_label.h>
#include <linux/kallsyms.h>
#include <linux/linkage.h>
#include <linux/bitops.h>
@@ -1018,7 +1019,20 @@ unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
extern int register_ftrace_graph(struct fgraph_ops *ops);
extern void unregister_ftrace_graph(struct fgraph_ops *ops);
-extern bool ftrace_graph_is_dead(void);
+/**
+ * ftrace_graph_is_dead - returns true if ftrace_graph_stop() was called
+ *
+ * ftrace_graph_stop() is called when a severe error is detected in
+ * the function graph tracing. This function is called by the critical
+ * paths of function graph to keep those paths from doing any more harm.
+ */
+DECLARE_STATIC_KEY_FALSE(kill_ftrace_graph);
+
+static inline bool ftrace_graph_is_dead(void)
+{
+ return static_branch_unlikely(&kill_ftrace_graph);
+}
+
extern void ftrace_graph_stop(void);
/* The current handlers in use */