From 4fc8e738ff3e6a208855bb69783280870c7cf251 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Fri, 16 Sep 2022 18:51:36 +0200 Subject: efi: libstub: remove DT dependency from generic stub Refactor the generic EFI stub entry code so that all the dependencies on device tree are abstracted and hidden behind a generic efi_boot_kernel() routine that can also be implemented in other ways. This allows users of the generic stub to avoid using FDT for passing information to the core kernel. Signed-off-by: Ard Biesheuvel --- drivers/firmware/efi/libstub/efi-stub.c | 53 +--------------------------- drivers/firmware/efi/libstub/efistub.h | 7 ++-- drivers/firmware/efi/libstub/fdt.c | 61 ++++++++++++++++++++++++++++++--- 3 files changed, 60 insertions(+), 61 deletions(-) (limited to 'drivers/firmware/efi') diff --git a/drivers/firmware/efi/libstub/efi-stub.c b/drivers/firmware/efi/libstub/efi-stub.c index 72826bc82cb7..80a1c72c4566 100644 --- a/drivers/firmware/efi/libstub/efi-stub.c +++ b/drivers/firmware/efi/libstub/efi-stub.c @@ -10,7 +10,6 @@ */ #include -#include #include #include "efistub.h" @@ -132,14 +131,11 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, unsigned long image_addr; unsigned long image_size = 0; /* addr/point and size pairs for memory management*/ - unsigned long fdt_addr = 0; /* Original DTB */ - unsigned long fdt_size = 0; char *cmdline_ptr = NULL; int cmdline_size = 0; efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID; unsigned long reserve_addr = 0; unsigned long reserve_size = 0; - enum efi_secureboot_mode secure_boot; struct screen_info *si; efi_properties_table_t *prop_tbl; @@ -215,38 +211,6 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, /* Ask the firmware to clear memory on unclean shutdown */ efi_enable_reset_attack_mitigation(); - secure_boot = efi_get_secureboot(); - - /* - * Unauthenticated device tree data is a security hazard, so ignore - * 'dtb=' unless UEFI Secure Boot is disabled. We assume that secure - * boot is enabled if we can't determine its state. - */ - if (!IS_ENABLED(CONFIG_EFI_ARMSTUB_DTB_LOADER) || - secure_boot != efi_secureboot_mode_disabled) { - if (strstr(cmdline_ptr, "dtb=")) - efi_err("Ignoring DTB from command line.\n"); - } else { - status = efi_load_dtb(image, &fdt_addr, &fdt_size); - - if (status != EFI_SUCCESS && status != EFI_NOT_READY) { - efi_err("Failed to load device tree!\n"); - goto fail_free_image; - } - } - - if (fdt_addr) { - efi_info("Using DTB from command line\n"); - } else { - /* Look for a device tree configuration table entry. */ - fdt_addr = (uintptr_t)get_fdt(&fdt_size); - if (fdt_addr) - efi_info("Using DTB from configuration table\n"); - } - - if (!fdt_addr) - efi_info("Generating empty DTB\n"); - efi_load_initrd(image, ULONG_MAX, efi_get_max_initrd_addr(image_addr), NULL); @@ -290,23 +254,8 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, install_memreserve_table(); - status = allocate_new_fdt_and_exit_boot(handle, &fdt_addr, cmdline_ptr, - fdt_addr, fdt_size); - if (status != EFI_SUCCESS) - goto fail_free_fdt; - - if (IS_ENABLED(CONFIG_ARM)) - efi_handle_post_ebs_state(); - - efi_enter_kernel(image_addr, fdt_addr, fdt_totalsize((void *)fdt_addr)); - /* not reached */ - -fail_free_fdt: - efi_err("Failed to update FDT and exit boot services\n"); - - efi_free(fdt_size, fdt_addr); + status = efi_boot_kernel(handle, image, image_addr, cmdline_ptr); -fail_free_image: efi_free(image_size, image_addr); efi_free(reserve_size, reserve_addr); fail_free_screeninfo: diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h index 38ec809aa962..f06d753a1ec9 100644 --- a/drivers/firmware/efi/libstub/efistub.h +++ b/drivers/firmware/efi/libstub/efistub.h @@ -844,11 +844,8 @@ typedef efi_status_t (*efi_exit_boot_map_processing)( efi_status_t efi_exit_boot_services(void *handle, void *priv, efi_exit_boot_map_processing priv_func); -efi_status_t allocate_new_fdt_and_exit_boot(void *handle, - unsigned long *new_fdt_addr, - char *cmdline_ptr, - unsigned long fdt_addr, - unsigned long fdt_size); +efi_status_t efi_boot_kernel(void *handle, efi_loaded_image_t *image, + unsigned long kernel_addr, char *cmdline_ptr); void *get_fdt(unsigned long *fdt_size); diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c index afed0aa94684..4f4d98e51fbf 100644 --- a/drivers/firmware/efi/libstub/fdt.c +++ b/drivers/firmware/efi/libstub/fdt.c @@ -219,17 +219,18 @@ static efi_status_t exit_boot_func(struct efi_boot_memmap *map, void *priv) * exit_boot_services() call, so the exiting of boot services is very tightly * tied to the creation of the FDT with the final memory map in it. */ - +static efi_status_t allocate_new_fdt_and_exit_boot(void *handle, + efi_loaded_image_t *image, unsigned long *new_fdt_addr, - char *cmdline_ptr, - unsigned long fdt_addr, - unsigned long fdt_size) + char *cmdline_ptr) { unsigned long desc_size; u32 desc_ver; efi_status_t status; struct exit_boot_struct priv; + unsigned long fdt_addr = 0; + unsigned long fdt_size = 0; if (!efi_novamap) { status = efi_alloc_virtmap(&priv.runtime_map, &desc_size, @@ -240,6 +241,36 @@ efi_status_t allocate_new_fdt_and_exit_boot(void *handle, } } + /* + * Unauthenticated device tree data is a security hazard, so ignore + * 'dtb=' unless UEFI Secure Boot is disabled. We assume that secure + * boot is enabled if we can't determine its state. + */ + if (!IS_ENABLED(CONFIG_EFI_ARMSTUB_DTB_LOADER) || + efi_get_secureboot() != efi_secureboot_mode_disabled) { + if (strstr(cmdline_ptr, "dtb=")) + efi_err("Ignoring DTB from command line.\n"); + } else { + status = efi_load_dtb(image, &fdt_addr, &fdt_size); + + if (status != EFI_SUCCESS && status != EFI_NOT_READY) { + efi_err("Failed to load device tree!\n"); + goto fail; + } + } + + if (fdt_addr) { + efi_info("Using DTB from command line\n"); + } else { + /* Look for a device tree configuration table entry. */ + fdt_addr = (uintptr_t)get_fdt(&fdt_size); + if (fdt_addr) + efi_info("Using DTB from configuration table\n"); + } + + if (!fdt_addr) + efi_info("Generating empty DTB\n"); + efi_info("Exiting boot services...\n"); status = efi_allocate_pages(MAX_FDT_SIZE, new_fdt_addr, ULONG_MAX); @@ -303,11 +334,33 @@ fail_free_new_fdt: efi_free(MAX_FDT_SIZE, *new_fdt_addr); fail: + efi_free(fdt_size, fdt_addr); + efi_bs_call(free_pool, priv.runtime_map); return EFI_LOAD_ERROR; } +efi_status_t efi_boot_kernel(void *handle, efi_loaded_image_t *image, + unsigned long kernel_addr, char *cmdline_ptr) +{ + unsigned long fdt_addr; + efi_status_t status; + + status = allocate_new_fdt_and_exit_boot(handle, image, &fdt_addr, + cmdline_ptr); + if (status != EFI_SUCCESS) { + efi_err("Failed to update FDT and exit boot services\n"); + return status; + } + + if (IS_ENABLED(CONFIG_ARM)) + efi_handle_post_ebs_state(); + + efi_enter_kernel(kernel_addr, fdt_addr, fdt_totalsize((void *)fdt_addr)); + /* not reached */ +} + void *get_fdt(unsigned long *fdt_size) { void *fdt; -- cgit v1.2.3