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Message-Id: <20200213151948.709228320@linuxfoundation.org>
Date: Thu, 13 Feb 2020 07:19:22 -0800
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org, Amol Grover <frextrite@...il.com>,
"Steven Rostedt (VMware)" <rostedt@...dmis.org>,
Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.14 059/173] tracing: Annotate ftrace_graph_notrace_hash pointer with __rcu
From: Amol Grover <frextrite@...il.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@...il.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@...dmis.org>
Signed-off-by: Sasha Levin <sashal@...nel.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 6af28692f0f53..dd9fdb52e24ad 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -5147,7 +5147,7 @@ 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 17f36488d3c84..757bb1bffed99 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -869,7 +869,7 @@ 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)
{
@@ -922,10 +922,14 @@ 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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