From patchwork Wed Oct 2 14:57:38 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Frederic Weisbecker X-Patchwork-Id: 13819890 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 58F4C1D0B89; Wed, 2 Oct 2024 14:57:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727881072; cv=none; b=W3tC/W0Kcze5O58FliIzU/yAqqXgwca5OZSPs6gosLC7XgLeEM2E/5BUg+YqvnQWVvgccQWS3mbtD1SwDzYR4tiOOuAORlgNhBo/76J24QAVL9ndQ3TVGB4Jvazs8ixxdRjtAWsH3GgoiV8IBHQihaHROYIPqdQ6fbxhOSLQsRA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727881072; c=relaxed/simple; bh=4jN7m4YdBZpe108+MCUL/gz1eAHliwNklGS/JkzIwho=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=PF77DT2VAL9kg1c5zsWX4LXwNBxm0eBdJuLbGpbUQm8vx7B/uUjrVAUJMXRmoUauaLLxWV8lMNPGAneMDSRoWXZyyT/Oq3xmmut0+y8N3A/dT76kvy9zJHmRtdYSuYYAQMMbt/T2VC2hTxzz7Msk+BPZzf+92NOPO28jOwK5yvQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=qY58D3Kl; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="qY58D3Kl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5FC9CC4CECF; Wed, 2 Oct 2024 14:57:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1727881072; bh=4jN7m4YdBZpe108+MCUL/gz1eAHliwNklGS/JkzIwho=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qY58D3KlK0tRBqsKkUDY1pzUaYqgPGgj7mXMnAMOr2JH2v7LXE3JCU7o6W8gi6Juc JMVrpPX0G0kwPSPLvcbQ2wtUC6YdRjLtqFWRPBJ1m+52f/ICF7E9igm0bE2o0J5BTw jg/7mHZ4EXEhn9StcP3QOLNUn/xlL8pBpY5CdimB34VH6YuqfH1CfQcfb6dZrZu8WY 5FyXZufbzcaHbBQJoQilB04WsZv3XMlw5zwqsU3JnWABQyLFnuLxAMPGVXxoEdDlqB /SeI48Ayq+JvaRqc/lpeMFjTR+3/18N5PwNtsh7lSRnljHgZ0GvX54rlAAg7WdsZL2 SLFjMor11fdIQ== From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , Boqun Feng , Joel Fernandes , Neeraj Upadhyay , "Paul E . McKenney" , Uladzislau Rezki , Zqiang , rcu Subject: [PATCH 3/3] rcu: Report callbacks enqueued on offline CPU blind spot Date: Wed, 2 Oct 2024 16:57:38 +0200 Message-ID: <20241002145738.38226-4-frederic@kernel.org> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20241002145738.38226-1-frederic@kernel.org> References: <20241002145738.38226-1-frederic@kernel.org> Precedence: bulk X-Mailing-List: rcu@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Callbacks enqueued after rcutree_report_cpu_dead() fall into RCU barrier blind spot. Report any potential misuse. Reported-by: Paul E. McKenney Signed-off-by: Frederic Weisbecker Tested-by: Paul E. McKenney Reviewed-by: Joel Fernandes (Google) --- kernel/rcu/tree.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index a60616e69b66..36070b6bf4a1 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -3084,8 +3084,11 @@ __call_rcu_common(struct rcu_head *head, rcu_callback_t func, bool lazy_in) head->func = func; head->next = NULL; kasan_record_aux_stack_noalloc(head); + local_irq_save(flags); rdp = this_cpu_ptr(&rcu_data); + RCU_LOCKDEP_WARN(rcu_rdp_cpu_online(rdp), "Callback enqueued on offline CPU!"); + lazy = lazy_in && !rcu_async_should_hurry(); /* Add the callback to our list. */