From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingo Molnar Subject: [GIT PULL] EFI fixes Date: Thu, 2 Feb 2017 21:54:45 +0100 Message-ID: <20170202205444.GA32650@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Linus Torvalds Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Thomas Gleixner , "H. Peter Anvin" , Matt Fleming , Ard Biesheuvel , linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Peter Zijlstra List-Id: linux-efi@vger.kernel.org Linus, Please pull the latest efi-urgent-for-linus git tree from: git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git efi-urgent-for-linus # HEAD: c8f325a59cfc718d13a50fbc746ed9b415c25e92 efi/fdt: Avoid FDT manipulation after ExitBootServices() Two EFI boot fixes, one for arm64 and one for x86 systems with certain firmware versions. Thanks, Ingo ------------------> Ard Biesheuvel (1): efi/fdt: Avoid FDT manipulation after ExitBootServices() Jiri Kosina (1): x86/efi: Always map the first physical page into the EFI pagetables arch/x86/platform/efi/efi_64.c | 16 ++++++++++++++++ drivers/firmware/efi/libstub/fdt.c | 14 +++----------- 2 files changed, 19 insertions(+), 11 deletions(-) diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c index 319148bd4b05..2f25a363068c 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -269,6 +269,22 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) efi_scratch.use_pgd = true; /* + * Certain firmware versions are way too sentimential and still believe + * they are exclusive and unquestionable owners of the first physical page, + * even though they explicitly mark it as EFI_CONVENTIONAL_MEMORY + * (but then write-access it later during SetVirtualAddressMap()). + * + * Create a 1:1 mapping for this page, to avoid triple faults during early + * boot with such firmware. We are free to hand this page to the BIOS, + * as trim_bios_range() will reserve the first page and isolate it away + * from memory allocators anyway. + */ + if (kernel_map_pages_in_pgd(pgd, 0x0, 0x0, 1, _PAGE_RW)) { + pr_err("Failed to create 1:1 mapping for the first page!\n"); + return 1; + } + + /* * When making calls to the firmware everything needs to be 1:1 * mapped and addressable with 32-bit pointers. Map the kernel * text and allocate a new stack because we can't rely on the diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c index 921dfa047202..260c4b4b492e 100644 --- a/drivers/firmware/efi/libstub/fdt.c +++ b/drivers/firmware/efi/libstub/fdt.c @@ -187,6 +187,7 @@ static efi_status_t update_fdt_memmap(void *fdt, struct efi_boot_memmap *map) struct exit_boot_struct { efi_memory_desc_t *runtime_map; int *runtime_entry_count; + void *new_fdt_addr; }; static efi_status_t exit_boot_func(efi_system_table_t *sys_table_arg, @@ -202,7 +203,7 @@ static efi_status_t exit_boot_func(efi_system_table_t *sys_table_arg, efi_get_virtmap(*map->map, *map->map_size, *map->desc_size, p->runtime_map, p->runtime_entry_count); - return EFI_SUCCESS; + return update_fdt_memmap(p->new_fdt_addr, map); } /* @@ -300,22 +301,13 @@ efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table, priv.runtime_map = runtime_map; priv.runtime_entry_count = &runtime_entry_count; + priv.new_fdt_addr = (void *)*new_fdt_addr; status = efi_exit_boot_services(sys_table, handle, &map, &priv, exit_boot_func); if (status == EFI_SUCCESS) { efi_set_virtual_address_map_t *svam; - status = update_fdt_memmap((void *)*new_fdt_addr, &map); - if (status != EFI_SUCCESS) { - /* - * The kernel won't get far without the memory map, but - * may still be able to print something meaningful so - * return success here. - */ - return EFI_SUCCESS; - } - /* Install the new virtual address map */ svam = sys_table->runtime->set_virtual_address_map; status = svam(runtime_entry_count * desc_size, desc_size,