From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751647AbdFBNzZ (ORCPT ); Fri, 2 Jun 2017 09:55:25 -0400 Received: from mail-wm0-f52.google.com ([74.125.82.52]:35123 "EHLO mail-wm0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751193AbdFBNzV (ORCPT ); Fri, 2 Jun 2017 09:55:21 -0400 From: Ard Biesheuvel To: linux-efi@vger.kernel.org, Ingo Molnar , Thomas Gleixner , "H . Peter Anvin" Cc: Sai Praneeth , Ard Biesheuvel , linux-kernel@vger.kernel.org, Borislav Petkov , Ricardo Neri , Ravi Shankar , Matt Fleming Subject: [PATCH 12/13] x86/efi: Add EFI_PGT_DUMP support for x86_32 and kexec Date: Fri, 2 Jun 2017 13:52:06 +0000 Message-Id: <20170602135207.21708-13-ard.biesheuvel@linaro.org> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20170602135207.21708-1-ard.biesheuvel@linaro.org> References: <20170602135207.21708-1-ard.biesheuvel@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sai Praneeth EFI_PGT_DUMP, as the name suggests dumps efi page tables to dmesg during kernel boot. This feature is very useful while debugging page faults/null pointer dereferences to efi related addresses. Presently, this feature is limited only to x86_64, so let's extend it to other efi configurations like kexec kernel, efi=old_map and to x86_32 as well. This doesn't effect normal boot path because this config option should be used only for debug purposes. Signed-off-by: Sai Praneeth Prakhya Cc: Borislav Petkov Cc: Ricardo Neri Cc: Ard Biesheuvel Cc: Ravi Shankar Signed-off-by: Matt Fleming --- arch/x86/platform/efi/efi.c | 3 ++- arch/x86/platform/efi/efi_32.c | 9 ++++++++- arch/x86/platform/efi/efi_64.c | 5 ++++- 3 files changed, 14 insertions(+), 3 deletions(-) diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index dc2da5e2c7e4..3cf8536e803b 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -1012,7 +1012,6 @@ static void __init __efi_enter_virtual_mode(void) * necessary relocation fixups for the new virtual addresses. */ efi_runtime_update_mappings(); - efi_dump_pagetable(); /* clean DUMMY object */ efi_delete_dummy_variable(); @@ -1027,6 +1026,8 @@ void __init efi_enter_virtual_mode(void) kexec_enter_virtual_mode(); else __efi_enter_virtual_mode(); + + efi_dump_pagetable(); } /* diff --git a/arch/x86/platform/efi/efi_32.c b/arch/x86/platform/efi/efi_32.c index 403a987d06c7..fe18c5d32bf0 100644 --- a/arch/x86/platform/efi/efi_32.c +++ b/arch/x86/platform/efi/efi_32.c @@ -44,7 +44,14 @@ int __init efi_alloc_page_tables(void) } void efi_sync_low_kernel_mappings(void) {} -void __init efi_dump_pagetable(void) {} + +void __init efi_dump_pagetable(void) +{ +#ifdef CONFIG_EFI_PGT_DUMP + ptdump_walk_pgd_level(NULL, swapper_pg_dir); +#endif +} + int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) { return 0; diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c index 6fbf6c47e603..0d8180811445 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -528,7 +528,10 @@ void __init efi_runtime_update_mappings(void) void __init efi_dump_pagetable(void) { #ifdef CONFIG_EFI_PGT_DUMP - ptdump_walk_pgd_level(NULL, efi_pgd); + if (efi_enabled(EFI_OLD_MEMMAP)) + ptdump_walk_pgd_level(NULL, swapper_pg_dir); + else + ptdump_walk_pgd_level(NULL, efi_pgd); #endif } -- 2.9.3