From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-171.mta1.migadu.com (out-171.mta1.migadu.com [95.215.58.171]) (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 CD5FF3845B4 for ; Tue, 21 Apr 2026 09:26:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776763562; cv=none; b=lK0wHkb3PTxweOJozdDBk7GAQIhk7naURouOucw5ncmvvPuNIPeQl3N9U94+DqkfNoR0xcTd99xFCetRF9C6ueSJCr87R/4aEVTNnv8gPgfnAPNnW/+1z0by3iX/VCdvkfPIe68CZk9vBlb2eARrACN/liJsKF664OxvoyBlDYs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776763562; c=relaxed/simple; bh=YTZUZfk7mHLvWQcXJq1bYR21rvAOciFQXxpAMYSmokE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=IfVbPrmzDHINtQbY6TPOQdZQE3h7sX8B+CdZUIhPiyTx7htkLBRl8x1gT45w9Zmta4A/QDV8FuT1Eh9TcBBlx8QnG6zwJ/AZyPPwNUaZV1FeS2ab9+rx09zpBmX8vr+e16XywAabTEIC1gvw/S56xnS21VwD4FAWwT/qz3HkIsI= 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=SD3D3SKU; arc=none smtp.client-ip=95.215.58.171 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="SD3D3SKU" Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1776763558; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=NzaoaMrVPuNqytuMUronCSujODBOvvcOBPL0ZtXO8I8=; b=SD3D3SKUPgIj+qrhNP8UR11PcWh6kw6SdyuhxhuNn0ebQLCWAqlwY98c9XHwiFysnJ8hWq 45aWzk4gKq8Ql94lOUphOrMTtyvXqtK2qVDockgcF0MR/1VbwRPFuk6BFp4vpbW6rtbCme YA/THdxoYQ0wBEvAdX2zDNi8oZWR6cA= Date: Tue, 21 Apr 2026 17:25:38 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH] mm: handle potential NULL return from anon_vma_name_reuse() To: Lorenzo Stoakes , David Hildenbrand Cc: Andrew Morton , "Liam R. Howlett" , Ye Liu , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Kairui Song , Qi Zheng , Shakeel Butt , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Jann Horn , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20260421085056.26033-1-ye.liu@linux.dev> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Ye Liu In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT 在 2026/4/21 17:08, Lorenzo Stoakes 写道: > NAK, expected allocation failures (even if practically impossible) should not > cause arbitrary kernel warnings. Thank you both for the thorough review and explanation. You are absolutely right. I mistakenly assumed that leaving vma->anon_name as NULL could lead to a NULL pointer dereference in some path, but as you pointed out, the code is designed to treat NULL as "no name", which is perfectly valid. I also acknowledge that adding a WARN_ON_ONCE in an allocation failure path is incorrect and harmful under memory pressure. Please disregard this patch. I've learned a valuable lesson about error handling in cosmetic features. Thank you again for the guidance. -- Thanks, Ye Liu