From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794531480; b=J8RgcBqhn/jhkAOFUKdLtdKz95rEjR4fcAN+jrUTc8XDj05zGdH6NlFX9NK96I4UNCyX uSvXqrMFoZEHE5CVUsDqIt/GOL73sZuHiN32PuVCT2uFtyjTZgeVC5SSJQioDVLE02jdi oppeOB/CHMe8vHvdwd+hbwOprCEhxYzFrJBJ8jczYqvu4UZKQ7BJCs1VnbUzQ4s6GYNmz qf6gIlmh2noNHJP3AVd+3IpJRqk/CIjYYwY4furTl0t1tcXxvcRf1qk49YJNZZGak4FMt GMNsbGKubmxBMXL3HQlCcQY8wonC49g+JYmFF9czuEmEDnRt1rJwt5j8UyC2aUujZvg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794531480; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=bI+P9eu3oNiojT6bm9h/aMCHW0G1BPXS5GriVMNV+ic=; b=kqTToUaIT0ALjW2P5T83uAmD7pjjYCxT/B3Pg7nr7jtfnZmascsJmQ9whoqSF8IVnJq+ DOZvwdQc5TMjQ2861/MfvyCp9BOp304klIKjh6lMowKcPktc5mw0hACguRg4vYGz2fX5C hiu58IhF2z2XVgVcHbZfdYcWnp/cEvCDxsPZHaX7Hzdth7YXLjDN++FBJ1fa+wzqxS2zP XWEqVO7jQQoaAki70UeBE1hi1YsCSz6RooJzOcPvmdggj6GRy45AZTFwKDmLyupk0mlN7 Ym5hMwG72g5v9adGKuGrvg0WMBiufn+oEl7wQ1iMFb9ZPU/0iFFrl9Ya/YXsR1lLB/g== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=KSnGt324; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with UTF8SMTPS id 6A2E1606A8B9; Fri, 13 Nov 2026 00:58:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=KSnGt324 Received: by smtp.kernel.org (Postfix) with UTF8SMTPSA id A7E951F000CE; Fri, 13 Nov 2026 00:57:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794531480; bh=bI+P9eu3oNiojT6bm9h/aMCHW0G1BPXS5GriVMNV+ic=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=KSnGt324bhPaCnE/6f8LT/N6U2xPNsr7T6Fpf9rojxiRWY8kmnqIr+Tz1D1MIcxwe LhLH0tb6TqmmW/c9mr2ZZUfXDk0ceCyeba4olFZNHJYK9atSynvEe+3FbAHy/oqk8l OlluOXSsp/uN0JU7KweSck/rDpmAZQUfCtsToe4x6xnlYpT36NtJS4fmjNKoUmVZHn sUFrYJ+HGgqizzhBB94cjsLnf1Fv6POzKkVw0hFvwC8uAW6jSTxmIn1C/blqExsUeS K2yxcvQaIKlm83/Gs4vdPo61HC6R/sMSjyeqGgT1zR7LwuxPxIVeY4hRqsbcLA/ExI mNY6PvXnWRksA== From: Joel Fernandes To: linux-kernel@vger.kernel.org, "Paul E . McKenney" , Frederic Weisbecker , Neeraj Upadhyay , Joel Fernandes , Josh Triplett , Boqun Feng , Uladzislau Rezki , Steven Rostedt , Mathieu Desnoyers , Lai Jiangshan , Zqiang , Davidlohr Bueso Cc: rcu@vger.kernel.org, Bradley Morgan , Joel Fernandes Subject: [PATCH for-v7.5 05/14] rcutorture: Fix suspicious rcu_dereference_check() usage for trivial-preempt Date: Thu, 12 Nov 2026 19:57:32 -0500 Message-ID: <20261113005747.2977123-6-jfern@kernel.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20261113005747.2977123-1-jfern@kernel.org> References: <20261113005747.2977123-1-jfern@kernel.org> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Zqiang Running the trivial-preempt flavor triggers a lockdep "suspicious RCU usage" warning from rcu_torture_one_read_start(): WARNING: suspicious RCU usage kernel/rcu/rcutorture.c:2581 suspicious rcu_dereference_check() usage! ... lockdep_rcu_suspicious rcu_torture_one_read_start rcu_torture_one_read rcu_torture_reader The trivial-preempt flavor .readlock_held is set to torture_readlock_not_held(), which check RCU-bh/RCU-sched critical sections. however, it's read lock just increments current->rcu_trivial_preempt_nesting, it's not also RCU read critical sections. the rcu_dereference_check() condition is therefore false, and lockdep report warnings. this commit therefore drop .readlock_held callback to avoid this lockdep warnings. Fixes: c6f4e552e1ea ("rcutorture: Add a textbook-style trivial preemptible RCU") Signed-off-by: Zqiang Reviewed-by: Bradley Morgan Reviewed-by: Paul E. McKenney Tested-by: Paul E. McKenney Link: https://lore.kernel.org/r/20261020094907.15781-1-qiang.zhang@linux.dev Signed-off-by: Joel Fernandes --- kernel/rcu/rcutorture.c | 1 - 1 file changed, 1 deletion(-) diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index e88573b9b7c6..d60d17d14f1c 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -1164,7 +1164,6 @@ static struct rcu_torture_ops trivial_preempt_ops = { .readlock = rcu_torture_read_lock_trivial_preempt, .read_delay = rcu_read_delay, // just reuse rcu's version. .readunlock = rcu_torture_read_unlock_trivial_preempt, - .readlock_held = torture_readlock_not_held, .get_gp_seq = rcu_no_completed, .sync = synchronize_rcu_trivial_preempt, .exp_sync = synchronize_rcu_trivial_preempt, -- 2.54.0