From: Masami Hiramatsu <mhiramat@kernel.org>
To: Ingo Molnar <mingo@kernel.org>
Cc: Anders Roxell <anders.roxell@linaro.org>,
paulmck@kernel.org, joel@joelfernandes.org,
"Naveen N . Rao" <naveen.n.rao@linux.ibm.com>,
Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>,
David Miller <davem@davemloft.net>,
Masami Hiramatsu <mhiramat@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Steven Rostedt <rostedt@goodmis.org>
Subject: [PATCH -tip V4 3/4] kprobes: Fix to protect kick_kprobe_optimizer() by kprobe_mutex
Date: Wed, 26 Feb 2020 17:59:51 +0900 [thread overview]
Message-ID: <158270759113.18966.8938334321921933993.stgit@devnote2> (raw)
In-Reply-To: <158270755997.18966.3544449431956918068.stgit@devnote2>
In kprobe_optimizer() kick_kprobe_optimizer() is called
without kprobe_mutex, but this can race with other caller
which is protected by kprobe_mutex.
To fix that, expand kprobe_mutex protected area to protect
kick_kprobe_optimizer() call.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
kernel/kprobes.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 38d9a5d7c8a4..6d76a6e3e1a5 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -592,11 +592,12 @@ static void kprobe_optimizer(struct work_struct *work)
mutex_unlock(&module_mutex);
mutex_unlock(&text_mutex);
cpus_read_unlock();
- mutex_unlock(&kprobe_mutex);
/* Step 5: Kick optimizer again if needed */
if (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list))
kick_kprobe_optimizer();
+
+ mutex_unlock(&kprobe_mutex);
}
/* Wait for completing optimization and unoptimization */
next prev parent reply other threads:[~2020-02-26 8:59 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-26 8:59 [PATCH -tip V4 0/4] kprobes: Fixes and cleanups Masami Hiramatsu
2020-02-26 8:59 ` [PATCH -tip V4 1/4] kprobes: Suppress the suspicious RCU warning on kprobes Masami Hiramatsu
2020-02-26 8:59 ` [PATCH -tip V4 2/4] kprobes: Use non RCU traversal APIs on kprobe_tables if possible Masami Hiramatsu
2020-02-26 8:59 ` Masami Hiramatsu [this message]
2020-03-03 23:52 ` [PATCH -tip V4 3/4] kprobes: Fix to protect kick_kprobe_optimizer() by kprobe_mutex Steven Rostedt
2020-03-04 7:18 ` Masami Hiramatsu
2020-02-26 9:00 ` [PATCH -tip V4 4/4] kprobes: Remove redundant arch_disarm_kprobe() call Masami Hiramatsu
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