Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 5.4 138/309] tracing: Annotate ftrace_graph_notrace_hash pointer with __rcu | Date | Mon, 10 Feb 2020 04:31:34 -0800 |
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From: Amol Grover <frextrite@gmail.com>
[ Upstream commit fd0e6852c407dd9aefc594f54ddcc21d84803d3b ]
Fix following instances of sparse error kernel/trace/ftrace.c:5667:29: error: incompatible types in comparison kernel/trace/ftrace.c:5813:21: error: incompatible types in comparison kernel/trace/ftrace.c:5868:36: error: incompatible types in comparison kernel/trace/ftrace.c:5870:25: error: incompatible types in comparison
Use rcu_dereference_protected to dereference the newly annotated pointer.
Link: http://lkml.kernel.org/r/20200205055701.30195-1-frextrite@gmail.com
Signed-off-by: Amol Grover <frextrite@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- kernel/trace/ftrace.c | 2 +- kernel/trace/trace.h | 8 ++++++-- 2 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index b38c6af10da5b..d297a8bdc681a 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -5103,7 +5103,7 @@ static const struct file_operations ftrace_notrace_fops = { static DEFINE_MUTEX(graph_lock); struct ftrace_hash __rcu *ftrace_graph_hash = EMPTY_HASH; -struct ftrace_hash *ftrace_graph_notrace_hash = EMPTY_HASH; +struct ftrace_hash __rcu *ftrace_graph_notrace_hash = EMPTY_HASH; enum graph_filter_type { GRAPH_FILTER_NOTRACE = 0, diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index f8fb3786af72a..c4fd5731d6b37 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -933,7 +933,7 @@ extern void __trace_graph_return(struct trace_array *tr, #ifdef CONFIG_DYNAMIC_FTRACE extern struct ftrace_hash __rcu *ftrace_graph_hash; -extern struct ftrace_hash *ftrace_graph_notrace_hash; +extern struct ftrace_hash __rcu *ftrace_graph_notrace_hash; static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace) { @@ -986,10 +986,14 @@ static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace) static inline int ftrace_graph_notrace_addr(unsigned long addr) { int ret = 0; + struct ftrace_hash *notrace_hash; preempt_disable_notrace(); - if (ftrace_lookup_ip(ftrace_graph_notrace_hash, addr)) + notrace_hash = rcu_dereference_protected(ftrace_graph_notrace_hash, + !preemptible()); + + if (ftrace_lookup_ip(notrace_hash, addr)) ret = 1; preempt_enable_notrace(); -- 2.20.1
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