From mboxrd@z Thu Jan 1 00:00:00 1970 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 624FF17BD3 for ; Fri, 25 Apr 2025 00:28:28 +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=1745540908; cv=none; b=ppqucQSZEDDUXn7Q6mf4y0k3ETkYqG0NVpiPa8bVAwYhnrql6EtBOnI03ziwH6Dn4Edod60PnFLtOppA6JfnCDHHOFvDS8+0OqYl5PeHqn+WX98Yxl19UTM/4kIhKCTgnXtRl9O7zEk4Xk9Pi+YeM++esWZZvZUT/9hjpmC5+ug= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745540908; c=relaxed/simple; bh=AoiJDX1WRQ1z8ex9aR9Xj2ae6DYdYMrmnnHw0NJSU5U=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=tlxnb0MT5xlHBqxof/ewh9S1Z5DYPcytmR/ZFNgzTJpckl+GJplKX7osM8vbYaIGg+IQz+PHaFAGkmYEQZCFb1NhPXJQjuTeYww0sg7l/ufAcFAR6/n0Labq7eYVmx7TwtORjw3bJVCthARN70Hczsu+a0Yz+wbqLmqqaBqnZoI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=muomQSgc; 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="muomQSgc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E0B9BC4CEF8; Fri, 25 Apr 2025 00:28:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1745540908; bh=AoiJDX1WRQ1z8ex9aR9Xj2ae6DYdYMrmnnHw0NJSU5U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=muomQSgc9VyHupd95LHN2iYNEtZkUlBktLDUE3f6OMPUEq9XaVdYNl29/PEndLfmR PUr4GULMUlSAcPpyATT9C5dPYgXZl0ilIqm6Ferk4yATFJpzmBAizaQhJc2guKP0Kc RUFsBEx0Lmj6LG1xn6GawFARWI9t4vq44jd8N0NwYe7XZG/ITWnH5mbsoBGU2TjfE3 q2IzxUW1fyMPd9zTpI5LgoA3sAPU8UYBBXzWFAzCZ3GQZe9/0LqwoyrP0KpFQ1UHWf PYpYdxwIHkz/bSypeWx+0WHwPR5FiRP0H9TBaEI/81QvfV6RsjVncPkdUpx+bEHgbf qgL0fASq8mv4g== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 3F245CE1CFF; Thu, 24 Apr 2025 17:28:27 -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 v3 11/20] ratelimit: Force re-initialization when rate-limiting re-enabled Date: Thu, 24 Apr 2025 17:28:17 -0700 Message-Id: <20250425002826.3431914-11-paulmck@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <72ee57b8-9e2a-4cad-aaa0-1e3353d146d8@paulmck-laptop> References: <72ee57b8-9e2a-4cad-aaa0-1e3353d146d8@paulmck-laptop> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Currently, rate limiting being disabled results in 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. Link: https://lore.kernel.org/all/fbe93a52-365e-47fe-93a4-44a44547d601@paulmck-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..52aab9229ca50 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; + /* + * Zero interval says never limit, otherwise, non-positive burst + * says always limit. + */ if (interval <= 0 || burst <= 0) { ret = interval == 0 || burst > 0; + if (!(READ_ONCE(rs->flags) & RATELIMIT_INITIALIZED) || + !raw_spin_trylock_irqsave(&rs->lock, flags)) { + if (!ret) + ratelimit_state_inc_miss(rs); + return ret; + } + + /* Force re-initialization once re-enabled. */ + rs->flags &= ~RATELIMIT_INITIALIZED; if (!ret) ratelimit_state_inc_miss(rs); - return ret; + goto unlock_ret; } /* -- 2.40.1