From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794215621; b=qjjsYDi9n9NH80O/cfiXU/j56hQh9BdjzWphwvb2Cbn/dxLVpdcadL88vutmBPnVxbxx uVFWYeNY2OB/N10dCCvNDW1LXQ8OIz1mkMiI5RDU+BXIWipwlsYkUArnJcogN5MAn4RA9 5Wla/jqWQEKcyt/ruGe/e96hVPy3+tqfqx4QyaqjJaQ0PjN1zrfJI6fhE2kyv7FvNkC5R 2iBJBauIs2BPsl7XvXjn1BIeUh5/1GInW6YvXTk+Z26b932HJOOrPSWBWaoPdPON2/Qxc KqjcuAQIDY6CEB1hgwlNIS5mSWksed1Y2s/9jLvt3PO5qdnptkmptWR/mrJhCX4+Nag== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794215621; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=WewbPdXloQFzq7PxEEzYBZGym0dDSEfWIKjsTFPTFGk=; b=h/4UT2Z0lVho1doHBJjasxXQ4y6aZ2jZ6skrLnomGxSrk+wvMeebh+/TSZZEYKgdAl3+ qH2GK+IbIw1gjw53zlRkI39CIYrWA1eWC3XBEq6Y9ZKKHo9YMh/jN4qLmHNcfikTX7lBz NLc5LIextzTgckreAos2Z4FXftp2IeiFSh88it1rwa5BAuYHG0GfcwfGgkx/9Qpzym6GM MdwSSi52YCLhRENi0vxANXXsSB1N1CKU4Z4wcRrB5Zd2WVzYv3KuKWZb1skv5RUnc2UWr GmT983sQsLmVx1qY9SFAGMsrHZpqzEvZH+EHIvHzJqRZzQEcj91FT317qyLW6X9KeRA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=NOZ0F7Sz; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5C1E4606A31C; Mon, 9 Nov 2026 09:13:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=NOZ0F7Sz Received: by smtp.kernel.org (Postfix) with ESMTPSA id EA4C11F0089F; Mon, 9 Nov 2026 09:13:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794215621; bh=WewbPdXloQFzq7PxEEzYBZGym0dDSEfWIKjsTFPTFGk=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=NOZ0F7SzJk9PfMsNlARgiXEIR4TN3eLHPymrOqc17Hg6gYCSHgCMTY/siLKpUXLwG PtGySWokir2nJ9/OVyTHpDcO+k9ORd0fyT3OIqzPu0euhsC2ZQ2J9CtU6gSLMhSmtR hw+Qc3i2ZwYGwqb8FVZVjff2b+oppBMgQCCCTp4diDqXgm2arWMlEMKtnVVoyZf2Us JXTUMKaDfCaVQ4WDEz93/9xvApuY2WP3EwoI/fGfzyiuljc09UCPzcPb07u2eHAIU2 fv6kzYaUAXJ5Bz0wagLvKx9UU2UWRNL+lN1x6988/PDE51tdD4eG9pRfxsXpHteHL7 dxAdg6g89FK4g== Date: Mon, 9 Nov 2026 10:13:33 +0100 From: "Oscar Salvador (SUSE)" To: Chris Down Cc: Dave Hansen , Andy Lutomirski , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , David Hildenbrand , Oscar Salvador , Andrew Morton , Lance Yang , Muchun Song , linux-mm@kvack.org, linux-cxl@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@meta.com Subject: Re: [PATCH] x86/mm: Tear down the direct map when memory hot add fails Message-ID: References: X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Sat, Nov 07, 2026 at 07:00:52PM -0800, Chris Down wrote: > arch_add_memory() sets up the direct map before calling add_pages(). > If add_pages() fails, the range stays mapped and any page tables > allocated for it are leaked. A later hot add can reuse the stale > mapping. > > Remove the direct mapping on failure. > > Fixes: 45e0b78b0532 ("[PATCH] hot-add-mem x86_64: use CONFIG_MEMORY_HOTPLUG_RESERVE") > Signed-off-by: Chris Down Acked-by: Oscar Salvador (SUSE) -- Oscar Salvador SUSE Labs