From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sai Praneeth Prakhya Subject: [PATCH V2] x86/efi: Add EFI_PGT_DUMP support for x86_32, kexec Date: Thu, 11 May 2017 12:20:33 -0700 Message-ID: <1494530433-19503-1-git-send-email-sai.praneeth.prakhya@intel.com> Return-path: Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: Sai Praneeth , Borislav Petkov , Ricardo Neri , Matt Fleming , Ard Biesheuvel , Ravi Shankar List-Id: linux-efi@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: Matt Fleming Cc: Ard Biesheuvel Cc: Ravi Shankar Changes since v1: 1. Call efi_dump_pagetable() only once from efi_enter_virtual_mode() - as suggested by Boris --- 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 217dc166c649..87835c97611f 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -1011,7 +1011,6 @@ 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(); @@ -1026,6 +1025,8 @@ 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 9b1abcf6e7bb..9477653c78f8 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 76e1cd6b74dd..3bde2589fdb9 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -510,7 +510,10 @@ 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 } -- 2.1.4