From nobody Mon Feb 9 16:18:12 2026 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 5E3FF4685 for ; Wed, 30 Apr 2025 01:05:27 +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=1745975127; cv=none; b=qzj1vkqg39uy2IzvtcfFyXL2lubCJtZmne4yC57dt97LpRYKoZYDn9cCut2ShC+Tb7iXebgug+OyYURBxoTGaiB1LW7XVKB814lwk8FzCWvQq1yX3b+O+PR0pjTdQo5SoEo5oF5UzFtbU1M7Feg8UCdinVtp7n5qcbxJw7xq9ec= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745975127; c=relaxed/simple; bh=eAuW+1XsPwY9rkuRnnnWelC3ErbYzxH9EQx5wYh1v9g=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=bTuT5p+c4TMhOT6srpCaAFV4SWYJ9ICiupJA2ZnAlDEjyqa4Y1B1fUM5HkVui5F6ZIg5s3P2IKQGa6ceDAEN2i2mimHlJwU7EpY8uuPCMlUKAYb/U1LFwYrb+DRwDON15BunjlLPBAyrR0Zfbvj+H9KzJ0I6/aBxhLsr+jnsQ8Y= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=m6YjAchR; 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="m6YjAchR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3DE6FC4CEE3; Wed, 30 Apr 2025 01:05:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1745975127; bh=eAuW+1XsPwY9rkuRnnnWelC3ErbYzxH9EQx5wYh1v9g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=m6YjAchRtZqVp0QpuGrQ3iIeQ8+iNXWcIIRSPu3ybnzFq9IzTdYSLuLhAT8CKN3sO jRgSpG3qV43dpCf7Zhiv8BX6M0nEhg85M+Yh8DoEPBOMurXHW6cmv/ab8R9TDqbb3T MOntnXqmiUsX6olHGor6fgBqPSqCiCU/BJ6PfpNVv1YVLa4q91KrDlas8BDajepSkx SutAPiSulHipwFl3MKVnXj6nCt1LszSzz2OOGq6OETLIc6M8df4obi83ZMkR8MbgxT HuSIDhaEQORKbR31K/dcIYN0wwwa3LQJH1A3iEYTUZpzaMOlDHO+pKg2qWYxekVhGr FdYZzrVU+ntdw== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id AF0C0CE10DB; Tue, 29 Apr 2025 18:05:25 -0700 (PDT) From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: kernel-team@meta.com, Andrew Morton , Kuniyuki Iwashima , Mateusz Guzik , Petr Mladek , Steven Rostedt , John Ogness , Sergey Senozhatsky , Jon Pan-Doh , Bjorn Helgaas , Karolina Stolarek , "Paul E. McKenney" Subject: [PATCH v4 11/20] ratelimit: Force re-initialization when rate-limiting re-enabled Date: Tue, 29 Apr 2025 18:05:15 -0700 Message-Id: <20250430010524.3614408-11-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: quoted-printable Content-Type: text/plain; charset="utf-8" Currently, if rate limiting is disabled, ___ratelimit() does an immediate early return with no state changes. This can result in false-positive drops when re-enabling rate limiting. Therefore, mark the ratelimit_state structure "uninitialized" when rate limiting is disabled. [ paulmck: Apply Petr Mladek feedback. ] Link: https://lore.kernel.org/all/fbe93a52-365e-47fe-93a4-44a44547d601@paul= mck-laptop/ Link: https://lore.kernel.org/all/20250423115409.3425-1-spasswolf@web.de/ Signed-off-by: Paul E. McKenney Cc: Petr Mladek Cc: Andrew Morton Cc: Kuniyuki Iwashima Cc: Mateusz Guzik Cc: Steven Rostedt Cc: John Ogness Cc: Sergey Senozhatsky --- lib/ratelimit.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/lib/ratelimit.c b/lib/ratelimit.c index 7a7ba4835639f..7d4f4e241213e 100644 --- a/lib/ratelimit.c +++ b/lib/ratelimit.c @@ -35,11 +35,24 @@ int ___ratelimit(struct ratelimit_state *rs, const char= *func) unsigned long flags; int ret; =20 + /* + * Zero interval says never limit, otherwise, non-positive burst + * says always limit. + */ if (interval <=3D 0 || burst <=3D 0) { ret =3D interval =3D=3D 0 || burst > 0; + if (!(READ_ONCE(rs->flags) & RATELIMIT_INITIALIZED) || (!interval && !bu= rst) || + !raw_spin_trylock_irqsave(&rs->lock, flags)) { + if (!ret) + ratelimit_state_inc_miss(rs); + return ret; + } + + /* Force re-initialization once re-enabled. */ + rs->flags &=3D ~RATELIMIT_INITIALIZED; if (!ret) ratelimit_state_inc_miss(rs); - return ret; + goto unlock_ret; } =20 /* --=20 2.40.1