From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=82.195.75.108 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793979263; b=YMhkFr9yLP+IJ/5ZZG3ebjJEtbE3Mx0VbeHiHKvanp2h2NiDGWFXx6C13rV9qLOL3xZR wd0T03xIIXEJGXERzYnO/5EewDYfc7qyM5TlogvPnNCdD/dGeuvfIrPpXvg33/k2POY/5 89eZ/Icft2nsKsI0uzdoiQLLl9vG92iPxVYc6Vn56rVFvYD7YjH3XxVnFb1o8nqzM3zOs hidQCNiowjGRK3z0d583J/mvY1GlUYd9Cd8/L/Mye5MRdSYsNCqxeX+H8sRzaOdMDRWWR ADhnNifsUM5TfL4fVRAZW86ik4hLMpOdySw5WJIjkaQMcntMO6XurNJtUzVCG7FjYcg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793979263; h=DMARC-Filter:DKIM-Signature:Received:Date:From:To:Cc:Subject: Message-ID:References:MIME-Version:Content-Type:Content-Disposition: In-Reply-To:X-Debian-User; bh=/YxG2ZmZM2e9qBTSySrFx7lsy/MjifUIQN5iXXAUf9Y=; b=P+szj8f+fBJCcXPdFdGiCTrPJLvfDlnhWr7LZIBg70mL/7bJJ0oSny12LEhOtn4WWBHj SokM6qqE7tcoJmGfPfP00I0FPQqzCTLfxCryOqK2Z06oO9y/+cUZFrEd5QAD3gE01g2Yv BQrzTsMomfdSkvWD25/CZeilG5IZTy7HCqJcb68aYlFzcjqLrAeIJm84XDHyaLDQczvNI 9vs3L38YaTuX70zlD02DPCpocaP4AYOzoOKcTr4yzx/ahVPMzdweTpTJjDGkvkGTf7ZpZ Q/Sh/tRCznsEwPcWxSxTT4pVUIcXI2Yn26wd4htbRe7sbts9M56tMVUugWUcyyIgaIg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=debian.org; spf=pass smtp.mailfrom=debian.org; dkim=pass header.d=debian.org header.i=@debian.org header.a=rsa-sha256 header.s=smtpauto.stravinsky header.b=nwQSXUa2; arc=none smtp.remote-ip=82.195.75.108 Received: from stravinsky.debian.org (stravinsky.debian.org [82.195.75.108]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (prime256v1) server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BA0BE606A339 for ; Fri, 6 Nov 2026 15:34:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org BA0BE606A339 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=debian.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=debian.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=debian.org header.i=@debian.org header.a=rsa-sha256 header.s=smtpauto.stravinsky header.b=nwQSXUa2 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=debian.org; s=smtpauto.stravinsky; h=X-Debian-User:In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=/YxG2ZmZM2e9qBTSySrFx7lsy/MjifUIQN5iXXAUf9Y=; b=nwQSXUa2bxKpHSEVGdWaum6xXR 37cQdyep4RT0SyJtpDSFXQKFwmgnl/SHD3v1bS9x8dz+WfGChe4RZlQo6CMksMfLOQjOvd5WIf1Fv FUY32LP0p9GqyFw4JkD6W6/tQouC6mOeunPW5U9N46Yj6ufJNgCch6IxSKxHVu8MbprY3loJygtuf GNNwLKM9kOvePIQeF56CSSltpiSkeNjMUtU48twJPZEnvS4SBrpf84DwTK6sVYY9kCgaWiGoXJliK hyW81dnLOPLA1/gIsMLFSc01fkOvYQ0v519R87UiwMiSJIHcPMnZLxLio1SfVs5EM0FId6L9Gyrqz wdqi8GMA==; Received: from authenticated-user by stravinsky.debian.org with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.96) (envelope-from ) id 1xPLxA-009NnJ-1J; Fri, 06 Nov 2026 15:34:08 +0000 Date: Fri, 6 Nov 2026 07:34:02 -0800 From: Breno Leitao To: Usama Arif Cc: Andrew Morton , baoquan.he@linux.dev, rppt@kernel.org, pasha.tatashin@soleen.com, pratyush@kernel.org, ruirui.yang@linux.dev, jbohac@suse.cz, david@kernel.org, hbathini@linux.ibm.com, kexec@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kas@kernel.org, hannes@cmpxchg.org, riel@surriel.com, shakeel.butt@linux.dev, kernel-team@meta.com Subject: Re: [PATCH] crash: keep crashkernel CMA pages reserved if activation fails Message-ID: References: <20261104145600.3708886-1-usama.arif@linux.dev> 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: <20261104145600.3708886-1-usama.arif@linux.dev> X-Debian-User: leitao On Wed, Nov 04, 2026 at 06:56:00AM -0800, Usama Arif wrote: > reserve_crashkernel_cma() adds each crashkernel CMA area to > crashk_cma_ranges[] as soon as it is declared. If the area later fails > activation, e.g. because movablecore= put the ZONE_MOVABLE boundary > inside it, cma_activate_area() releases the pages to the buddy allocator > as ordinary memory. The range is still handed to the crash kernel and > excluded from the vmcore, so kernel data that lands there is overwritten > by the crash kernel and missing from the dump. > > Mark the areas with cma_reserve_pages_on_error(), so that a failed > activation leaves the pages reserved: lost to the first kernel, but safe > for the crash kernel to use. > > Fixes: ab475510e042 ("kdump: implement reserve_crashkernel_cma") > Signed-off-by: Usama Arif Tested-by: Breno Leitao