From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 2072528CF5F for ; Fri, 31 Jul 2026 00:40:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785458425; cv=none; b=kGj7AYHxKpKeus3Ljzxf69cIsnfXrwPKcnCOaEqEOYCZtP7/7UDDQ8Ps9tLHO7Kj3S5djEPvSrU7n9JC7pKiIpyJO4JdnVOjKTZ+a5aCfvc5F5GZODfbikS8KMCouVwIl8zYCJOpdZEm6zOO+qEbgwNfiQfx6BiMKGZBdhCvtko= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785458425; c=relaxed/simple; bh=ZS7jUmxVbJs8ExRFdk51tbyoLYaOw4tzxLJwTEUHMLc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=pnioaZzNd2EJJTVD9CcFPyFZQdId1r/3HWLHHqC79er/gNRg5Pl+bhrVOcD8KJ96SSZKBYJEW2fu/eE2V6oYClI1rpDEWNsmE+KrhdD6hLAHN61rj7bmNJc4XOvwvSgCPq59HfggkZUIlYDeWbZtsVS5jImwNrCewC1bWaKOrRU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=eobAuOm8; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="eobAuOm8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A27991F00A3E; Fri, 31 Jul 2026 00:40:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785458421; bh=7z23QR6kFHvnKcbamH/+/thFq5C77hNB10Nqaz6cIjg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=eobAuOm8sheDXsDTt0uwKgxrBQqfJzcI+EZ8I2tqeeAW0TBIGsVNCl9narJ+aWES+ yD5IxogYsAfSEQpsnMUJBb1ORtTEBvoeo01w9v9wlfcJnBOfsR5VTxyOJ3cn8hCw/E 94nyn5KkVFfBYA7OvKxYbhqhUT6Tmc525+uTstHkBoo0hxDACQSea3J+b33AVifHrN v5mFPptcuHUwPsUegeH2td38A3mDMtlmvFwjEL7+1bFhfI5gP4nlnFwjcEXZoV+X6H JJHtgnr481+tgvBKX7tZ9mmj3FkKRZnXIOf/fwGCNif+9I6fbnqPLSWZ61k6ECEbPL FIc7Elz2YwO3g== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 43919CE1018; Thu, 30 Jul 2026 17:40:21 -0700 (PDT) From: "Paul E. McKenney" To: Anna-Maria Behnsen , Frederic Weisbecker , Thomas Gleixner Cc: "Peter Zijlstra (Intel)" , linux-kernel@vger.kernel.org, kernel-team@meta.com, "Paul E. McKenney" Subject: [PATCH RFC 6/9] timers: Use accessor for hrtimer_sleeper ->task field in sleep_timeout.c Date: Thu, 30 Jul 2026 17:40:16 -0700 Message-Id: <20260731004019.3530210-6-paulmck@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The hrtimer_sleeper structure's ->task field is used as a flag to indicate that the associated hrtimer has expired. This means that the hrtimer handler can be storing to this field while other code is loading from it to check for expiry. Note that additional races appear for hrtimers that can be restarted, which could be argued to be a user error. However, that is no reason to let the compiler introduce additional confusion, and to this end, the hrtimer_sleeper_task_get() was introduced, use of which also has the benefit of avoiding open-code access to hrtimer_sleeper innards. Therefore, apply this accessor to schedule_hrtimeout_range_clock(). KCSAN located this issue. Signed-off-by: Paul E. McKenney Cc: Anna-Maria Behnsen Cc: Frederic Weisbecker Cc: Thomas Gleixner --- kernel/time/sleep_timeout.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/time/sleep_timeout.c b/kernel/time/sleep_timeout.c index 3c90574bd904f1..ad8c415851ae19 100644 --- a/kernel/time/sleep_timeout.c +++ b/kernel/time/sleep_timeout.c @@ -212,7 +212,7 @@ int __sched schedule_hrtimeout_range_clock(ktime_t *expires, u64 delta, hrtimer_set_expires_range_ns(&t.timer, *expires, delta); hrtimer_sleeper_start_expires(&t, mode); - if (likely(t.task)) + if (likely(hrtimer_sleeper_task_get(&t))) schedule(); hrtimer_cancel(&t.timer); @@ -220,7 +220,7 @@ int __sched schedule_hrtimeout_range_clock(ktime_t *expires, u64 delta, __set_current_state(TASK_RUNNING); - return !t.task ? 0 : -EINTR; + return !hrtimer_sleeper_task_get(&t) ? 0 : -EINTR; } EXPORT_SYMBOL_GPL(schedule_hrtimeout_range_clock); -- 2.40.1