From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C87C8EEB57D for ; Mon, 11 Sep 2023 11:21:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=BhXTphQnIYm72SL0aalkq6mm2E685jBXNnUPN07T48A=; b=nQuYbmtOIEe39r km0DboF2DWvfoaOVipL86nomQ5jOhWUhne2j86fcWfops6cZLSYsT5hbfgnODb8LMA7bOeKSEEJTE zRq0s0KgycP2SMsVTXZiTC3gZFlzM8gMU0i2pbxMg/7Q3eQpghAfARQ7+ZPpJ/oXkPGXI9KiadSxC dyB1jcKURtDST6By7OA4YuMTvzI5JZDzas559XdydlGuKMEWYvXy5K7xmFCWjWGZWC4m1bEnr5mGb 2kawbpTecrmlMs/9PwcEu8mCVILH4+qM7N0ncAkxCvo5KvR0qPO9nXZgPPe7mYAK3IF4jnTLsweJt NidMAGsVTlFmaJc+VlwQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qfez5-000N9s-2s; Mon, 11 Sep 2023 11:21:39 +0000 Received: from mgamail.intel.com ([192.55.52.151]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qfez3-000N93-0h for kexec@lists.infradead.org; Mon, 11 Sep 2023 11:21:38 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1694431297; x=1725967297; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=Zw3TazwdjRU8wNvK9+zXRRn6LyFt0jKcjaf9En8Up90=; b=AJWH2tglzJdSddm09quCgpkVRavZr6ITm1VtkgdMgQSPqkzJKrIDHHN5 R17+ydgic9zXWM2zQXrVtOM4bEPF5vRIkxYj/gEXGHcRQTBz/O69FHVHQ mr2evH/lkUmoLTqxmKin67GQvDPW82J/qK8svrTtWaUrvEqwv6zxJzvTI akQNs/uSlCNOHuxemjAbUBFpvzRoSR53M3nd/DKJAwKCd+M/0h0Gj62sy TbiUUdAX+6tUweiA8tKDq+W1uUyIgCPy3AI0YQpE1H6FQFHVelLVuoadF L4AQ2WtlXS+pIN+Toh3bPSA1C4dlLkEGN+oegqp21p940CrOZidl9LzUx g==; X-IronPort-AV: E=McAfee;i="6600,9927,10829"; a="358358413" X-IronPort-AV: E=Sophos;i="6.02,243,1688454000"; d="scan'208";a="358358413" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Sep 2023 04:21:35 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10829"; a="778356397" X-IronPort-AV: E=Sophos;i="6.02,243,1688454000"; d="scan'208";a="778356397" Received: from ahunter6-mobl1.ger.corp.intel.com (HELO ahunter-VirtualBox.home\044ger.corp.intel.com) ([10.251.216.218]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Sep 2023 04:21:30 -0700 From: Adrian Hunter To: "Kirill A. Shutemov" , Borislav Petkov , Andrew Morton , Ard Biesheuvel Cc: Dave Hansen , Vlastimil Babka , Mike Rapoport , Lorenzo Stoakes , Tom Lendacky , Baoquan He , Vivek Goyal , Dave Young , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev, linux-efi@vger.kernel.org, kexec@lists.infradead.org Subject: [PATCH V2 1/2] efi/unaccepted: Do not let /proc/vmcore try to access unaccepted memory Date: Mon, 11 Sep 2023 14:21:13 +0300 Message-Id: <20230911112114.91323-2-adrian.hunter@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230911112114.91323-1-adrian.hunter@intel.com> References: <20230911112114.91323-1-adrian.hunter@intel.com> MIME-Version: 1.0 Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230911_042137_263435_264DD7CA X-CRM114-Status: GOOD ( 12.85 ) X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org Support for unaccepted memory was added recently, refer commit dcdfdd40fa82 ("mm: Add support for unaccepted memory"), whereby a virtual machine may need to accept memory before it can be used. Do not let /proc/vmcore try to access unaccepted memory because it can cause the guest to fail. For /proc/vmcore, which is read-only, this means a read or mmap of unaccepted memory will return zeros. Signed-off-by: Adrian Hunter --- drivers/firmware/efi/unaccepted_memory.c | 20 ++++++++++++++++++++ include/linux/mm.h | 7 +++++++ 2 files changed, 27 insertions(+) Changes in V2: Change patch subject and commit message Use vmcore_cb->.pfn_is_ram() instead of changing vmcore.c diff --git a/drivers/firmware/efi/unaccepted_memory.c b/drivers/firmware/efi/unaccepted_memory.c index 853f7dc3c21d..79ba576b22e3 100644 --- a/drivers/firmware/efi/unaccepted_memory.c +++ b/drivers/firmware/efi/unaccepted_memory.c @@ -3,6 +3,7 @@ #include #include #include +#include #include /* Protects unaccepted memory bitmap */ @@ -145,3 +146,22 @@ bool range_contains_unaccepted_memory(phys_addr_t start, phys_addr_t end) return ret; } + +#ifdef CONFIG_PROC_VMCORE +static bool unaccepted_memory_vmcore_pfn_is_ram(struct vmcore_cb *cb, + unsigned long pfn) +{ + return !pfn_is_unaccepted_memory(pfn); +} + +static struct vmcore_cb vmcore_cb = { + .pfn_is_ram = unaccepted_memory_vmcore_pfn_is_ram, +}; + +static int __init unaccepted_memory_init_kdump(void) +{ + register_vmcore_cb(&vmcore_cb); + return 0; +} +core_initcall(unaccepted_memory_init_kdump); +#endif /* CONFIG_PROC_VMCORE */ diff --git a/include/linux/mm.h b/include/linux/mm.h index bf5d0b1b16f4..86511150f1d4 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -4062,4 +4062,11 @@ static inline void accept_memory(phys_addr_t start, phys_addr_t end) #endif +static inline bool pfn_is_unaccepted_memory(unsigned long pfn) +{ + phys_addr_t paddr = pfn << PAGE_SHIFT; + + return range_contains_unaccepted_memory(paddr, paddr + PAGE_SIZE); +} + #endif /* _LINUX_MM_H */ -- 2.34.1 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec