tracing: Annotate ftrace_graph_hash pointer with __rcu (24a9729f) · Commits · 戴 / test

Fix following instances of sparse error kernel/trace/ftrace.c:5664:29: error: incompatible types in comparison kernel/trace/ftrace.c:5785:21: error: incompatible types in comparison kernel/trace/ftrace.c:5864:36: error: incompatible types in comparison kernel/trace/ftrace.c:5866:25: error: incompatible types in comparison Use rcu_dereference_protected to access the __rcu annotated pointer. Link: http://lkml.kernel.org/r/20200201072703.17330-1-frextrite@gmail.com Reviewed-by:

Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by:

Amol Grover <frextrite@gmail.com> Signed-off-by:

Steven Rostedt (VMware) <rostedt@goodmis.org>

kernel/trace/ftrace.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -5591,7 +5591,7 @@ static const struct file_operations ftrace_notrace_fops = {

		static DEFINE_MUTEX(graph_lock);

		struct ftrace_hash *ftrace_graph_hash = EMPTY_HASH;
		struct ftrace_hash __rcu *ftrace_graph_hash = EMPTY_HASH;
		struct ftrace_hash *ftrace_graph_notrace_hash = EMPTY_HASH;

		enum graph_filter_type {

kernel/trace/trace.h

+6 −3

Original line number	Diff line number	Diff line
		@@ -964,22 +964,25 @@ extern void __trace_graph_return(struct trace_array *tr,
		unsigned long flags, int pc);

		#ifdef CONFIG_DYNAMIC_FTRACE
		extern struct ftrace_hash *ftrace_graph_hash;
		extern struct ftrace_hash __rcu *ftrace_graph_hash;
		extern struct ftrace_hash *ftrace_graph_notrace_hash;

		static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
		{
		unsigned long addr = trace->func;
		int ret = 0;
		struct ftrace_hash *hash;

		preempt_disable_notrace();

		if (ftrace_hash_empty(ftrace_graph_hash)) {
		hash = rcu_dereference_protected(ftrace_graph_hash, !preemptible());

		if (ftrace_hash_empty(hash)) {
		ret = 1;
		goto out;
		}

		if (ftrace_lookup_ip(ftrace_graph_hash, addr)) {
		if (ftrace_lookup_ip(hash, addr)) {

		/*
		* This needs to be cleared on the return functions

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