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From:   Jules Irenge <jbi.octave@gmail.com>
To:     boqun.feng@gmail.com
Cc:     linux-kernel@vger.kernel.org, bpf@vger.kernel.org,
        netdev@vger.kernel.org, Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Martin KaFai Lau <kafai@fb.com>,
        Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
        Andrii Nakryiko <andriin@fb.com>
Subject: [PATCH 1/8] bpf: Add missing annotations for __bpf_prog_enter() and  __bpf_prog_exit()
Date:   Wed, 11 Mar 2020 01:09:01 +0000
Message-Id: <20200311010908.42366-2-jbi.octave@gmail.com>
In-Reply-To: <20200311010908.42366-1-jbi.octave@gmail.com>
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 <20200311010908.42366-1-jbi.octave@gmail.com>
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Sparse reports a warning at __bpf_prog_enter() and __bpf_prog_exit()

warning: context imbalance in __bpf_prog_enter() - wrong count at exit
warning: context imbalance in __bpf_prog_exit() - unexpected unlock

The root cause is the missing annotation at __bpf_prog_enter()
and __bpf_prog_exit()

Add the missing __acquires(RCU) annotation
Add the missing __releases(RCU) annotation

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
---
 kernel/bpf/trampoline.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c
index 6b264a92064b..09bce10ad1cc 100644
--- a/kernel/bpf/trampoline.c
+++ b/kernel/bpf/trampoline.c
@@ -374,6 +374,7 @@ void bpf_trampoline_put(struct bpf_trampoline *tr)
  * call __bpf_prog_exit
  */
 u64 notrace __bpf_prog_enter(void)
+	__acquires(RCU)
 {
 	u64 start = 0;
 
@@ -385,6 +386,7 @@ u64 notrace __bpf_prog_enter(void)
 }
 
 void notrace __bpf_prog_exit(struct bpf_prog *prog, u64 start)
+	__releases(RCU)
 {
 	struct bpf_prog_stats *stats;
 
-- 
2.24.1