From ac81d3de03f7d8593a94240d057c8e2e8e869897 Mon Sep 17 00:00:00 2001 From: Sai Praneeth Date: Fri, 2 Jun 2017 13:52:06 +0000 Subject: [PATCH] x86/efi: Extend CONFIG_EFI_PGT_DUMP support to x86_32 and kexec as well CONFIG_EFI_PGT_DUMP=y, as the name suggests, dumps EFI page tables to the kernel log 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 Signed-off-by: Matt Fleming Cc: Ard Biesheuvel Cc: Borislav Petkov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Ravi Shankar Cc: Ricardo Neri Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20170602135207.21708-13-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar --- 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 43b96f5f78ba..f084d8718ac4 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -1014,7 +1014,6 @@ 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(); @@ -1029,6 +1028,8 @@ 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 3481268da3d0..52f7faa1538f 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 eb8dff15a7f6..8ff1f95627f9 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -589,7 +589,10 @@ 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 } -- 2.39.5