From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-178.mta0.migadu.com (out-178.mta0.migadu.com [91.218.175.178]) (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 7620135AC01 for ; Tue, 11 Aug 2026 06:03:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.178 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786428183; cv=none; b=s5dF+qVka4Va42c+aXo7s6AoZlP9nRh8dtaai/ugDFtZ/cEYzK3j46zS8jHBP/gRG4O1Hn0EujGYmABbj5yYt8562JymE2Gd5vjyRFekpm1O1GOVh5RJVvN3E/FeDELsEXWsFDOWZDaXZLjDZpVCGC0RZEUQm2ugGs9wPIHTG4c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786428183; c=relaxed/simple; bh=z5M1iQBHWGNYPKU2rWv5GB+ulrPmwzpYzCQQIEGjsLg=; h=From:To:Subject:Date:Message-ID:MIME-Version; b=R8oLZ3txxwGxd5diJJPFt2ZNGeYGDVx/VB1YFMhzxLj/mrKcMaBE8uPhIEww4zchYsA6j1xu5K5eZ4VqYWr9+JgHVTAuMGx69TS+ReZfjZ6/ksEK+gpKxko2UD9FxzctSDwzFzR+xE3O7UAIs2CVJJYTHhIM5KTVeIhdTJvtsjQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=LjHWgp7H; arc=none smtp.client-ip=91.218.175.178 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="LjHWgp7H" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1786428169; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=OLDa6A0YWiRXYrThzPVgL6POAMWtNwIFEcHWM4ceiiI=; b=LjHWgp7Hm/hxqNArnnmJRrQpcKJCbDdw7c0TmebmXe5ka83LFFA3ThG0WglGRIJFo8+wPs EmdtnA1xelKwUK27qswu7BJJ1nzqUdMnWLg4fYemuR7l42N/9I7EMypV0GeZGnD540PA3h Ck0J2AUo49kHtOEh9Mp9nFepcO43ie8= From: Qingfang Deng To: Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Qingfang Deng , Breno Leitao , Norbert Szetei , Taegu Ha , linux-ppp@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH net] ppp: annotate lockless queue empty check Date: Tue, 11 Aug 2026 14:02:29 +0800 Message-ID: <20260811060236.322284-1-qingfang.deng@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT ppp_poll() checks whether pf->rq contains a packet without holding the queue lock. skb_peek() requires appropriate locking or a private queue, neither of which applies because ppp_input() can enqueue concurrently. Only queue emptiness is needed, so use skb_queue_empty_lockless() instead. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Qingfang Deng --- drivers/net/ppp/ppp_generic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c index e1013621eb1d..1a610a18893b 100644 --- a/drivers/net/ppp/ppp_generic.c +++ b/drivers/net/ppp/ppp_generic.c @@ -556,7 +556,7 @@ static __poll_t ppp_poll(struct file *file, poll_table *wait) return 0; poll_wait(file, &pf->rwait, wait); mask = EPOLLOUT | EPOLLWRNORM; - if (skb_peek(&pf->rq)) + if (!skb_queue_empty_lockless(&pf->rq)) mask |= EPOLLIN | EPOLLRDNORM; if (pf->dead) mask |= EPOLLHUP; -- 2.43.0