From: Masami Hiramatsu <mhiramat@kernel.org>
Date: Thu, 31 Mar 2022 01:11:17 +0000 (+0900)
Subject: rethook: Fix to use WRITE_ONCE() for rethook:: Handler
X-Git-Tag: v6.1-rc5~1602^2~1^2~4
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=a2fb49833cad07a53651c23dce508127085fae2d;p=platform%2Fkernel%2Flinux-starfive.git

rethook: Fix to use WRITE_ONCE() for rethook:: Handler

Since the function pointered by rethook::handler never be removed when
the rethook is alive, it doesn't need to use rcu_assign_pointer() to
update it. Just use WRITE_ONCE().

Reported-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/164868907688.21983.1606862921419988152.stgit@devnote2
---

diff --git a/kernel/trace/rethook.c b/kernel/trace/rethook.c
index ab463a4..b568337 100644
--- a/kernel/trace/rethook.c
+++ b/kernel/trace/rethook.c
@@ -65,7 +65,7 @@ static void rethook_free_rcu(struct rcu_head *head)
  */
 void rethook_free(struct rethook *rh)
 {
-	rcu_assign_pointer(rh->handler, NULL);
+	WRITE_ONCE(rh->handler, NULL);
 
 	call_rcu(&rh->rcu, rethook_free_rcu);
 }