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();