From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 658B2C433EF for ; Thu, 2 Dec 2021 00:44:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354865AbhLBArk (ORCPT ); Wed, 1 Dec 2021 19:47:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47610 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344340AbhLBArE (ORCPT ); Wed, 1 Dec 2021 19:47:04 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EEE20C061574; Wed, 1 Dec 2021 16:43:41 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id 45E88CE2073; Thu, 2 Dec 2021 00:43:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 76193C00446; Thu, 2 Dec 2021 00:43:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1638405818; bh=FkkjdHi4jMjNVhOZRiQE9voSnpNCSKi5WpXqUkMfxTU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=i+EUqfSjgFtKmkmlfkbwibrDmN53izS2zVH689cu4zYG5vLXYIQmkQGOA0LWrUPAt 9x9796Pj2hqOrcbKIbbXs0eA4rip8cX47jJ/Tu1mToJwOCcI+b1IBvGdH6K+EDBS3+ YiUvtjbJAxi6se7ujvZ1xJiao6uUlL6AGHSCoyIom10sKjEHDRQ+BWrp2YMFIcpyfx fxsVf5pNuxXIg0w72HXp+zWmTvKwOAmTdmoM5R2EuBh/CR8HJpQ9B45UPzRitvmoFR H7nxxUpKsv5UL7Sb/ebeWen8KCbYZ/GHaOe9dliMUyGJKr6Mk404RrDqgsfd2yNUn3 MVRzEvdjXMyow== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 4723E5C0FCD; Wed, 1 Dec 2021 16:43:38 -0800 (PST) From: "Paul E. McKenney" To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com, mingo@kernel.org, jiangshanlai@gmail.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org, "Paul E. McKenney" Subject: [PATCH rcu 01/17] rcutorture: Sanitize RCUTORTURE_RDR_MASK Date: Wed, 1 Dec 2021 16:43:20 -0800 Message-Id: <20211202004337.3130175-1-paulmck@kernel.org> X-Mailer: git-send-email 2.31.1.189.g2e36527f23 In-Reply-To: <20211202004245.GA3129966@paulmck-ThinkPad-P17-Gen-1> References: <20211202004245.GA3129966@paulmck-ThinkPad-P17-Gen-1> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org RCUTORTURE_RDR_MASK is currently not the bit indicated by RCUTORTURE_RDR_SHIFT, but is instead all the bits less significant than that one. This is an accident waiting to happen, so this commit makes RCUTORTURE_RDR_MASK be that one bit and adjusts uses accordingly. Signed-off-by: Paul E. McKenney --- kernel/rcu/rcutorture.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 8b410d982990c..1e03fe681f025 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -54,7 +54,7 @@ MODULE_AUTHOR("Paul E. McKenney and Josh Triplett extendables field, extendables param, and related definitions. */ #define RCUTORTURE_RDR_SHIFT 8 /* Put SRCU index in upper bits. */ -#define RCUTORTURE_RDR_MASK ((1 << RCUTORTURE_RDR_SHIFT) - 1) +#define RCUTORTURE_RDR_MASK (1 << RCUTORTURE_RDR_SHIFT) #define RCUTORTURE_RDR_BH 0x01 /* Extend readers by disabling bh. */ #define RCUTORTURE_RDR_IRQ 0x02 /* ... disabling interrupts. */ #define RCUTORTURE_RDR_PREEMPT 0x04 /* ... disabling preemption. */ @@ -1466,6 +1466,7 @@ static void rcutorture_one_extend(int *readstate, int newstate, if (lockit) raw_spin_lock_irqsave(¤t->pi_lock, flags); cur_ops->readunlock(idxold >> RCUTORTURE_RDR_SHIFT); + idxold = 0; if (lockit) raw_spin_unlock_irqrestore(¤t->pi_lock, flags); } @@ -1476,7 +1477,7 @@ static void rcutorture_one_extend(int *readstate, int newstate, /* Update the reader state. */ if (idxnew == -1) - idxnew = idxold & ~RCUTORTURE_RDR_MASK; + idxnew = idxold & RCUTORTURE_RDR_MASK; WARN_ON_ONCE(idxnew < 0); WARN_ON_ONCE((idxnew >> RCUTORTURE_RDR_SHIFT) > 1); *readstate = idxnew | newstate; @@ -1626,7 +1627,7 @@ static bool rcu_torture_one_read(struct torture_random_state *trsp, long myid) rcu_torture_writer_state, cookie, cur_ops->get_gp_state()); rcutorture_one_extend(&readstate, 0, trsp, rtrsp); - WARN_ON_ONCE(readstate & RCUTORTURE_RDR_MASK); + WARN_ON_ONCE(readstate); // This next splat is expected behavior if leakpointer, especially // for CONFIG_RCU_STRICT_GRACE_PERIOD=y kernels. WARN_ON_ONCE(leakpointer && READ_ONCE(p->rtort_pipe_count) > 1); -- 2.31.1.189.g2e36527f23