From: Masami Hiramatsu <mhiramat@kernel.org>
Date: Wed, 23 Mar 2022 07:35:36 +0000 (+0900)
Subject: fprobe: Fix sparse warning for acccessing __rcu ftrace_hash
X-Git-Tag: v6.1-rc5~1659^2~12^2~7^2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=261608f3105ce65e9fd01919f72ead74dcb9f14d;p=platform%2Fkernel%2Flinux-starfive.git

fprobe: Fix sparse warning for acccessing __rcu ftrace_hash

Since ftrace_ops::local_hash::filter_hash field is an __rcu pointer,
we have to use rcu_access_pointer() to access it.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/164802093635.1732982.4938094876018890866.stgit@devnote2
---

diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c
index 63b2321..89d9f99 100644
--- a/kernel/trace/fprobe.c
+++ b/kernel/trace/fprobe.c
@@ -215,7 +215,7 @@ int register_fprobe(struct fprobe *fp, const char *filter, const char *notfilter
 	 * correctly calculate the total number of filtered symbols
 	 * from both filter and notfilter.
 	 */
-	hash = fp->ops.local_hash.filter_hash;
+	hash = rcu_access_pointer(fp->ops.local_hash.filter_hash);
 	if (WARN_ON_ONCE(!hash))
 		goto out;