From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.218.175.96 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794195872; b=vowHTQL61s1s7sVnDTObWP0snxoNYyi260M0XmeFt4gh37+nFKNtcRsTnp1qNgotrVOP cJL0E61qU9BxjFJIelGqLviX4ifHnUqMtrGExA2v32VvPil/sUKPPlqDcF5lsEGUVZeaQ CNNHfj6kbhLG7LsA39481NtpJKnLOf7Wl+R7TQsOEEYkZBiobVIqY0mfpGf8LofCd8RQu GMgzkYMSnPaTahPkAAhAkxXQ3G5XXJoDZ4idNmmelYej3Av+wijMiv1e7Y8LU04wzj2ra ZKLzgcEUK/feDAYrXoxFMYORXWO0FRpt7Th9PlW83eXyppEUNliFJl69f6VxjVBYLcg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794195872; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:Content-Type:Mime-Version:Subject:From: In-Reply-To:Date:Cc:Content-Transfer-Encoding:Message-Id:References: To:X-Mailer; bh=JTiv2GRYKop7vCx/gXindWSFmU7+GmHnHjp+oJDyjUQ=; b=4nkpkfpN472fy5unV4I4Dm8SDDfgnah5s2c2QX6GJfsYEWHHIFUtJT0/kq8e+1UaFMZJ QoqYmK7VEncNlQTFBui1hdqTQXcE26y7vpI1X50IQP1aOAy7Hr9PtfRuU0XQY5CnlQWJx ST2t9iLOy3hr7Rizw412t3xQps7B0e9wV+G/TV0A1+AccPR+UEGWYrSN2x1l8CxujS2AF FRBB+xPqaEBJ9tbMdRWs46nncBmm8gM6wlIeeaVsSPDukfdlxVts51TVfzX99Mpn3xLgb RY+BavXsSfQ6uP34Xr1ACXtAs1/AsQX3mbQwqitodCoCMuhGBQ8Fx9bwhjta4/pvmeQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=UL182Ymp; arc=none smtp.remote-ip=91.218.175.96 Received: from mta0.migadu.com (out-96.mta0.migadu.com [91.218.175.96]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2D84C606A31C for ; Mon, 9 Nov 2026 03:44:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 2D84C606A31C 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, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=UL182Ymp X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=JTiv2GRYKop7vCx/gXindWSFmU7+GmHnHjp+oJDyjUQ=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1794195869; v=1; x=1794800669; b=UL182YmpeSX6nFVbBsJ7y8S/IyQUXmitlzi+JbC5w2Ptgjh/cWL19fCg1j4IPVm2/p8G8A3e Zz3G2ydotNN5QvKRbPqEHUQIojBNTXxOPc1QrQFTI7OMGbxmf1kuKdNvyTzu1IW2fadxFyJ1+Lw bRnzGF/XbnueIjXLpDOd5JWI= X-Envelope-To: linux-kernel@vger.kernel.org Received: by mta10.migadu.com with ESMTPS id b7f753fb76ab6eb5; Mon, 09 Nov 2026 03:44:29 +0000 X-Mizu-Trace-ID: b7f753fb76ab6eb5 X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset=us-ascii 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 (Mac OS X Mail 16.0 \(3901.200.71.1.16\)) Subject: Re: [PATCH] x86/mm: Tear down the direct map when memory hot add fails From: Muchun Song In-Reply-To: Date: Mon, 9 Nov 2026 11:44:11 +0800 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 , linux-mm@kvack.org, linux-cxl@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@meta.com Content-Transfer-Encoding: quoted-printable Message-Id: <681A0C48-AA5C-4337-8CD0-57FCB21D8D63@linux.dev> References: To: Chris Down X-Mailer: Apple Mail (2.3901.200.71.1.16) > On Nov 8, 2026, at 11:00, Chris Down wrote: >=20 > 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. >=20 > Remove the direct mapping on failure. >=20 > Fixes: 45e0b78b0532 ("[PATCH] hot-add-mem x86_64: use = CONFIG_MEMORY_HOTPLUG_RESERVE") > Signed-off-by: Chris Down Acked-by: Muchun Song Thanks.