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 11714C2D0DD for ; Thu, 2 Jan 2020 04:29:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D8098215A4 for ; Thu, 2 Jan 2020 04:29:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727689AbgABE3m (ORCPT ); Wed, 1 Jan 2020 23:29:42 -0500 Received: from mga09.intel.com ([134.134.136.24]:12925 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726234AbgABE3l (ORCPT ); Wed, 1 Jan 2020 23:29:41 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 01 Jan 2020 20:29:41 -0800 X-IronPort-AV: E=Sophos;i="5.69,385,1571727600"; d="scan'208";a="221785785" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.16]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 01 Jan 2020 20:29:40 -0800 Subject: [PATCH v3 4/4] efi: Fix handling of multiple efi_fake_mem= entries From: Dan Williams To: mingo@redhat.com Cc: Dave Young , Taku Izumi , Michael Weiser , Ard Biesheuvel , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, kexec@lists.infradead.org, x86@kernel.org Date: Wed, 01 Jan 2020 20:13:39 -0800 Message-ID: <157793841895.977550.10417217401147507173.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <157793839827.977550.7845382457971215205.stgit@dwillia2-desk3.amr.corp.intel.com> References: <157793839827.977550.7845382457971215205.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 Dave noticed that when specifying multiple efi_fake_mem= entries only the last entry was successfully being reflected in the efi memory map. This is due to the fact that the efi_memmap_insert() is being called multiple times, but on successive invocations the insertion should be applied to the last new memmap rather than the original map at efi_fake_memmap() entry. Rework efi_fake_memmap() to install the new memory map after each efi_fake_mem= entry is parsed. This also fixes an issue in efi_fake_memmap() that caused it to litter emtpy entries into the end of the efi memory map. The empty entry causes efi_memmap_insert() to attempt more memmap splits / copies than efi_memmap_split_count() accounted for when sizing the new map. BUG: unable to handle page fault for address: ffffffffff281000 [..] RIP: 0010:efi_memmap_insert+0x11d/0x191 [..] Call Trace: ? bgrt_init+0xbe/0xbe ? efi_arch_mem_reserve+0x1cb/0x228 ? acpi_parse_bgrt+0xa/0xd ? acpi_table_parse+0x86/0xb8 ? acpi_boot_init+0x494/0x4e3 ? acpi_parse_x2apic+0x87/0x87 ? setup_acpi_sci+0xa2/0xa2 ? setup_arch+0x8db/0x9e1 ? start_kernel+0x6a/0x547 ? secondary_startup_64+0xb6/0xc0 Commit af1648984828 "x86/efi: Update e820 with reserved EFI boot services data to fix kexec breakage" is listed in Fixes: since it introduces more occurrences where efi_memmap_insert() is invoked after an efi_fake_mem= configuration has been parsed. Previously the side effects of vestigial empty entries were benign, but with commit af1648984828 that follow-on efi_memmap_insert() invocation triggers the above crash signature. Fixes: 0f96a99dab36 ("efi: Add 'efi_fake_mem' boot option") Fixes: af1648984828 ("x86/efi: Update e820 with reserved EFI boot services...") Link: https://lore.kernel.org/r/20191231014630.GA24942@dhcp-128-65.nay.redhat.com Reported-by: Dave Young Cc: Taku Izumi Cc: Michael Weiser Cc: Ard Biesheuvel Cc: Thomas Gleixner Cc: Ingo Molnar Signed-off-by: Dan Williams --- drivers/firmware/efi/fake_mem.c | 32 +++++++++++++++++--------------- drivers/firmware/efi/memmap.c | 2 +- include/linux/efi.h | 2 ++ 3 files changed, 20 insertions(+), 16 deletions(-) diff --git a/drivers/firmware/efi/fake_mem.c b/drivers/firmware/efi/fake_mem.c index 7e53e5520548..68d752d8af21 100644 --- a/drivers/firmware/efi/fake_mem.c +++ b/drivers/firmware/efi/fake_mem.c @@ -34,26 +34,17 @@ static int __init cmp_fake_mem(const void *x1, const void *x2) return 0; } -void __init efi_fake_memmap(void) +static void __init efi_fake_range(struct efi_mem_range *efi_range) { int new_nr_map = efi.memmap.nr_map; efi_memory_desc_t *md; phys_addr_t new_memmap_phy; unsigned long flags = 0; void *new_memmap; - int i; - - if (!efi_enabled(EFI_MEMMAP) || !nr_fake_mem) - return; /* count up the number of EFI memory descriptor */ - for (i = 0; i < nr_fake_mem; i++) { - for_each_efi_memory_desc(md) { - struct range *r = &efi_fake_mems[i].range; - - new_nr_map += efi_memmap_split_count(md, r); - } - } + for_each_efi_memory_desc(md) + new_nr_map += efi_memmap_split_count(md, &efi_range->range); /* allocate memory for new EFI memmap */ new_memmap_phy = efi_memmap_alloc(new_nr_map, &flags); @@ -64,17 +55,28 @@ void __init efi_fake_memmap(void) new_memmap = early_memremap(new_memmap_phy, efi.memmap.desc_size * new_nr_map); if (!new_memmap) { - memblock_free(new_memmap_phy, efi.memmap.desc_size * new_nr_map); + __efi_memmap_free(new_memmap_phy, + efi.memmap.desc_size * new_nr_map, flags); return; } - for (i = 0; i < nr_fake_mem; i++) - efi_memmap_insert(&efi.memmap, new_memmap, &efi_fake_mems[i]); + efi_memmap_insert(&efi.memmap, new_memmap, efi_range); /* swap into new EFI memmap */ early_memunmap(new_memmap, efi.memmap.desc_size * new_nr_map); efi_memmap_install(new_memmap_phy, new_nr_map, flags); +} + +void __init efi_fake_memmap(void) +{ + int i; + + if (!efi_enabled(EFI_MEMMAP) || !nr_fake_mem) + return; + + for (i = 0; i < nr_fake_mem; i++) + efi_fake_range(&efi_fake_mems[i]); /* print new EFI memmap */ efi_print_memmap(); diff --git a/drivers/firmware/efi/memmap.c b/drivers/firmware/efi/memmap.c index 46c8b4056cc1..157b7776caf5 100644 --- a/drivers/firmware/efi/memmap.c +++ b/drivers/firmware/efi/memmap.c @@ -29,7 +29,7 @@ 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) +void __init __efi_memmap_free(u64 phys, unsigned long size, unsigned long flags) { if (flags & EFI_MEMMAP_MEMBLOCK) { if (slab_is_available()) diff --git a/include/linux/efi.h b/include/linux/efi.h index fa2668a992ae..6ae31e064321 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -1061,6 +1061,8 @@ extern void __iomem *efi_lookup_mapped_addr(u64 phys_addr); extern phys_addr_t __init efi_memmap_alloc(unsigned int num_entries, unsigned long *flags); +extern void __efi_memmap_free(u64 phys, unsigned long size, + unsigned long flags); extern int __init efi_memmap_init_early(struct efi_memory_map_data *data); extern int __init efi_memmap_init_late(phys_addr_t addr, unsigned long size); extern void __init efi_memmap_unmap(void);