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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 7C4B5C52D22 for ; Thu, 27 Feb 2020 13:56:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5169720801 for ; Thu, 27 Feb 2020 13:56:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582811809; bh=65POcJFp0QtikRJMJrWeAydJ2XT6KUTDHap55AKMNRs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=d7d1GmoXt4Uak1hidee+liJmNBCOjM7Pj+DlB2iNBPXwjUYwB/oVKQNmDIKgS9hQN joTGzpyYI0psCZpvkt0X6u8k11nZjmrjXk3V+wUp8nbriGRuPG0+EwcaIlu+hx17CK NUrHIxc5vk4fA2oST1v25PosNeBvAshg/ByxYoU8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732205AbgB0N4s (ORCPT ); Thu, 27 Feb 2020 08:56:48 -0500 Received: from mail.kernel.org ([198.145.29.99]:57356 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732190AbgB0N4p (ORCPT ); Thu, 27 Feb 2020 08:56:45 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8821820578; Thu, 27 Feb 2020 13:56:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582811804; bh=65POcJFp0QtikRJMJrWeAydJ2XT6KUTDHap55AKMNRs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2QzplRNPW7b2PZT0uDvB0S1PXRyvX7LFOIHlsVdpRcYaYB+SBwBh6BMkdXzcgnWxc lIGRxv5LpmO/1DoogAcbyq8gqq2Hh+10Y+pb+WjDGQGWtAhdeGPTjLAuxVQv90JJ4+ O50S3wZBOC74R3kIA2kqtVXFk0AMJUo84axaur0s= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ard Biesheuvel , Andy Lutomirski , Ard Biesheuvel , Arvind Sankar , Matthew Garrett , linux-efi@vger.kernel.org, Ingo Molnar , Sasha Levin Subject: [PATCH 4.14 106/237] efi/x86: Dont panic or BUG() on non-critical error conditions Date: Thu, 27 Feb 2020 14:35:20 +0100 Message-Id: <20200227132304.718102165@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200227132255.285644406@linuxfoundation.org> References: <20200227132255.285644406@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ard Biesheuvel [ Upstream commit e2d68a955e49d61fd0384f23e92058dc9b79be5e ] 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 Cc: Andy Lutomirski Cc: Ard Biesheuvel Cc: Arvind Sankar Cc: Matthew Garrett Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20200103113953.9571-14-ardb@kernel.org Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin --- 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 5b0275310070e..e7f19dec16b97 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -930,16 +930,14 @@ 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); @@ -953,8 +951,7 @@ 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)) { @@ -962,12 +959,11 @@ 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(); @@ -987,9 +983,9 @@ static void __init __efi_enter_virtual_mode(void) } 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; } /* @@ -1016,6 +1012,10 @@ 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 ae369c2bbc3eb..0ebb7f94fd518 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -390,11 +390,12 @@ 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