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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AE9F7C32771 for ; Tue, 7 Jan 2020 00:56:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8CD342073D for ; Tue, 7 Jan 2020 00:56:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727308AbgAGA4l (ORCPT ); Mon, 6 Jan 2020 19:56:41 -0500 Received: from mga17.intel.com ([192.55.52.151]:4836 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727233AbgAGA4l (ORCPT ); Mon, 6 Jan 2020 19:56:41 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 06 Jan 2020 16:56:40 -0800 X-IronPort-AV: E=Sophos;i="5.69,404,1571727600"; d="scan'208";a="210958795" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.16]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 06 Jan 2020 16:56:40 -0800 Subject: [PATCH v4 3/4] efi: Fix efi_memmap_alloc() leaks From: Dan Williams To: mingo@redhat.com Cc: Taku Izumi , Ard Biesheuvel , linux-efi@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, kexec@lists.infradead.org Date: Mon, 06 Jan 2020 16:40:37 -0800 Message-ID: <157835763783.1456824.4013634516855823659.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <157835762222.1456824.290100196815539830.stgit@dwillia2-desk3.amr.corp.intel.com> References: <157835762222.1456824.290100196815539830.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.18-3-g996c MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-efi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org With efi_fake_memmap() and efi_arch_mem_reserve() the efi table may be updated and replaced multiple times. When that happens a previous dynamically allocated efi memory map can be garbage collected. Use the new EFI_MEMMAP_{SLAB,MEMBLOCK} flags to detect when a dynamically allocated memory map is being replaced. Debug statements in efi_memmap_free() reveal: efi: __efi_memmap_free:37: phys: 0x23ffdd580 size: 2688 flags: 0x2 efi: __efi_memmap_free:37: phys: 0x9db00 size: 2640 flags: 0x2 efi: __efi_memmap_free:37: phys: 0x9e580 size: 2640 flags: 0x2 ...a savings of 7968 bytes on a qemu boot with 2 entries specified to efi_fake_mem=. Cc: Taku Izumi Cc: Ard Biesheuvel Signed-off-by: Dan Williams --- drivers/firmware/efi/memmap.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/drivers/firmware/efi/memmap.c b/drivers/firmware/efi/memmap.c index 04dfa56b994b..bffa320d2f9a 100644 --- a/drivers/firmware/efi/memmap.c +++ b/drivers/firmware/efi/memmap.c @@ -29,6 +29,28 @@ static phys_addr_t __init __efi_memmap_alloc_late(unsigned long size) return PFN_PHYS(page_to_pfn(p)); } +static void __init __efi_memmap_free(u64 phys, unsigned long size, unsigned long flags) +{ + if (flags & EFI_MEMMAP_MEMBLOCK) { + if (slab_is_available()) + memblock_free_late(phys, size); + else + memblock_free(phys, size); + } else if (flags & EFI_MEMMAP_SLAB) { + struct page *p = pfn_to_page(PHYS_PFN(phys)); + unsigned int order = get_order(size); + + free_pages((unsigned long) page_address(p), order); + } +} + +static void __init efi_memmap_free(void) +{ + __efi_memmap_free(efi.memmap.phys_map, + efi.memmap.desc_size * efi.memmap.nr_map, + efi.memmap.flags); +} + /** * efi_memmap_alloc - Allocate memory for the EFI memory map * @num_entries: Number of entries in the allocated map. @@ -100,6 +122,8 @@ static int __init __efi_memmap_init(struct efi_memory_map_data *data) return -ENOMEM; } + efi_memmap_free(); + map.phys_map = data->phys_map; map.nr_map = data->size / data->desc_size; map.map_end = map.map + data->size;