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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 37C73C2D0C2 for ; Fri, 3 Jan 2020 11:41:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0CB1921D7D for ; Fri, 3 Jan 2020 11:41:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578051680; bh=Hc6UcQ9UpT/kVsHpfR+qryCfdpE3qLzn7SldrCucIX8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=IIEhyL5xcc2u0nqDAyh1MzO9syizDBFD4zTAn8y6JybFLdqShjd+6Kke35W/VrXSo arpskZVPtJT/5tLjQQIuieVXQnpX2mP4S73az53GrktzDX2q0AOkJ96yAn/Njyq7N+ X2xgFgD27Qg/MJVse+BrEPOCcwS/nio6PVw3Y9tg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727876AbgACLlP (ORCPT ); Fri, 3 Jan 2020 06:41:15 -0500 Received: from mail.kernel.org ([198.145.29.99]:40418 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727841AbgACLkn (ORCPT ); Fri, 3 Jan 2020 06:40:43 -0500 Received: from localhost.localdomain (amontpellier-657-1-18-247.w109-210.abo.wanadoo.fr [109.210.65.247]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 269892464B; Fri, 3 Jan 2020 11:40:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578051642; bh=Hc6UcQ9UpT/kVsHpfR+qryCfdpE3qLzn7SldrCucIX8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ii790vAP0OPeIIlLjwcHHtH/Ks7PQ+Dtw3t1mC4olvTHfFIGuQk++kQWf5SDFCCfn iWmGrQWDHkC+CTqCo8p9hJPSPKZBZz8vigTRj8T3JQu2mfMBy1aC5Y2veux74cl9j1 WGdwYSGVSxkfHU/1PMgBEPCF6kx7e+QknpY6Vahw= From: Ard Biesheuvel To: linux-efi@vger.kernel.org, Ingo Molnar , Thomas Gleixner Cc: Ard Biesheuvel , Ard Biesheuvel , linux-kernel@vger.kernel.org, Andy Lutomirski , Arvind Sankar , Matthew Garrett Subject: [PATCH 13/20] efi/x86: don't panic or BUG() on non-critical error conditions Date: Fri, 3 Jan 2020 12:39:46 +0100 Message-Id: <20200103113953.9571-14-ardb@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200103113953.9571-1-ardb@kernel.org> References: <20200103113953.9571-1-ardb@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-efi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org The logic in __efi_enter_virtual_mode() does a number of steps in sequence, all of which may fail in one way or the other. In most cases, we simply print an error and disable EFI runtime services support, but in some cases, we BUG() or panic() and bring down the system when encountering conditions that we could easily handle in the same way. While at it, replace a pointless page-to-virt-phys conversion with one that goes straight from struct page to physical. Signed-off-by: Ard Biesheuvel --- arch/x86/platform/efi/efi.c | 28 ++++++++++++++-------------- arch/x86/platform/efi/efi_64.c | 9 +++++---- 2 files changed, 19 insertions(+), 18 deletions(-) diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index 53ed0b123641..4f539bfdc051 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -889,16 +889,14 @@ static void __init __efi_enter_virtual_mode(void) if (efi_alloc_page_tables()) { pr_err("Failed to allocate EFI page tables\n"); - clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); - return; + goto err; } efi_merge_regions(); new_memmap = efi_map_regions(&count, &pg_shift); if (!new_memmap) { pr_err("Error reallocating memory, EFI runtime non-functional!\n"); - clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); - return; + goto err; } pa = __pa(new_memmap); @@ -912,8 +910,7 @@ static void __init __efi_enter_virtual_mode(void) if (efi_memmap_init_late(pa, efi.memmap.desc_size * count)) { pr_err("Failed to remap late EFI memory map\n"); - clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); - return; + goto err; } if (efi_enabled(EFI_DBG)) { @@ -921,12 +918,11 @@ static void __init __efi_enter_virtual_mode(void) efi_print_memmap(); } - BUG_ON(!efi.systab); + if (WARN_ON(!efi.systab)) + goto err; - if (efi_setup_page_tables(pa, 1 << pg_shift)) { - clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); - return; - } + if (efi_setup_page_tables(pa, 1 << pg_shift)) + goto err; efi_sync_low_kernel_mappings(); @@ -935,9 +931,9 @@ static void __init __efi_enter_virtual_mode(void) efi.memmap.desc_version, (efi_memory_desc_t *)pa); if (status != EFI_SUCCESS) { - pr_alert("Unable to switch EFI into virtual mode (status=%lx)!\n", - status); - panic("EFI call to SetVirtualAddressMap() failed!"); + pr_err("Unable to switch EFI into virtual mode (status=%lx)!\n", + status); + goto err; } efi_free_boot_services(); @@ -964,6 +960,10 @@ static void __init __efi_enter_virtual_mode(void) /* clean DUMMY object */ efi_delete_dummy_variable(); + return; + +err: + clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); } void __init efi_enter_virtual_mode(void) diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c index 910e9ec03b09..c13fa2150976 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -384,11 +384,12 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) return 0; page = alloc_page(GFP_KERNEL|__GFP_DMA32); - if (!page) - panic("Unable to allocate EFI runtime stack < 4GB\n"); + if (!page) { + pr_err("Unable to allocate EFI runtime stack < 4GB\n"); + return 1; + } - efi_scratch.phys_stack = virt_to_phys(page_address(page)); - efi_scratch.phys_stack += PAGE_SIZE; /* stack grows down */ + efi_scratch.phys_stack = page_to_phys(page + 1); /* stack grows down */ npages = (_etext - _text) >> PAGE_SHIFT; text = __pa(_text); -- 2.20.1