From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 44C61606A32C for ; Wed, 4 Nov 2026 14:56:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=RoQXcDVz; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=luMnxL52 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Unsubscribe-Post:List-Owner; bh=rNNVTnTy0cTlwSmGHiRKlZ2iEy2+6bJGyVdMK3sWxNI=; b=RoQXcDVzIhwYHJPI7RKcC9WuVB hY7d/lJ3mXvOxWN71zoyDZNgqgF7ZWgCsDAnj3w0jNR+9U+OlULlEiY/+6GQrvYKrpTeVyPgxF7iO hHf4bH3TuSmrzLOFXNQn6SJ1tCP3qVt3WDUz0tQYvwUJLau/MoVNUKxL5mGqw0xzh5FOBwnF1RZOp FwZbMnaVOpXMXTebYDZRRV+joK+0LFE30H0rvnzC+qOmcOJfEjFado+3sEviwKtLq35L2t5+882V6 QCOdgXI2lcaCwUH4lZd8ptu1iBQZtRtOA9CHgTD/V7hH9V321X5r0eS4VscOwuSnO+Awm3lneC7oY 44sj9EgA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xOcPM-00000005hob-3Q8e; Wed, 04 Nov 2026 14:56:12 +0000 Received: from out-215.mta0.migadu.com ([2001:41d0:1004:224b::d7] helo=mta0.migadu.com) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xOcPJ-00000005hnx-41vp for kexec@lists.infradead.org; Wed, 04 Nov 2026 14:56:11 +0000 X-Envelope-To: kexec@lists.infradead.org DKIM-Signature: a=rsa-sha256; bh=WiQsxdd6QhzAPp2ldpcECaeiN+cck/9lOboIQqVqld8=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793804168; v=1; x=1794408968; b=luMnxL5285DUzIM2AnuE7vWel01YwA/GscQp5xVB+8cHNDMDiOZSJ1K2BKeLcoMm3HYtfixX PC2yI/o6bOXb/2ZmmM/rU7qTaqvh6WDG6BELEtTyoO1wlDlh+yhQfa0VhyGoHUarl54v1XDvkGY 4P/osjJMqUFZVmeWRk762eWU= X-Envelope-To: kexec@lists.infradead.org Received: by mta12.migadu.com with ESMTPS id f8a97d86c29cc177; Wed, 04 Nov 2026 14:56:07 +0000 X-Mizu-Trace-ID: f8a97d86c29cc177 X-Migadu-Flow: FLOW_OUT From: Usama Arif To: 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, leitao@debian.org, 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 Cc: Usama Arif Subject: [PATCH] crash: keep crashkernel CMA pages reserved if activation fails Date: Wed, 4 Nov 2026 06:56:00 -0800 Message-ID: <20261104145600.3708886-1-usama.arif@linux.dev> X-Mailer: git-send-email 2.53.0 X-Archived-By: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261104_065610_357669_026BF2AF X-CRM114-Status: UNSURE ( 9.59 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -2.1 (--) X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" X-Spam-Status: No, score=-18.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 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 --- kernel/crash_reserve.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/crash_reserve.c b/kernel/crash_reserve.c index a03f0a4305a4e..a4b616ed49482 100644 --- a/kernel/crash_reserve.c +++ b/kernel/crash_reserve.c @@ -498,6 +498,7 @@ void __init reserve_crashkernel_cma(unsigned long long cma_size) continue; } + cma_reserve_pages_on_error(res); crashk_cma_ranges[crashk_cma_cnt].start = cma_get_base(res); crashk_cma_ranges[crashk_cma_cnt].end = crashk_cma_ranges[crashk_cma_cnt].start + -- 2.53.0-Meta