diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/firmware/efi/libstub/zboot.c | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/drivers/firmware/efi/libstub/zboot.c b/drivers/firmware/efi/libstub/zboot.c new file mode 100644 index 000000000..ea72c8f27 --- /dev/null +++ b/drivers/firmware/efi/libstub/zboot.c @@ -0,0 +1,302 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/efi.h> +#include <linux/pe.h> +#include <asm/efi.h> +#include <asm/unaligned.h> + +#include "efistub.h" + +static unsigned char zboot_heap[SZ_256K] __aligned(64); +static unsigned long free_mem_ptr, free_mem_end_ptr; + +#define STATIC static +#if defined(CONFIG_KERNEL_GZIP) +#include "../../../../lib/decompress_inflate.c" +#elif defined(CONFIG_KERNEL_LZ4) +#include "../../../../lib/decompress_unlz4.c" +#elif defined(CONFIG_KERNEL_LZMA) +#include "../../../../lib/decompress_unlzma.c" +#elif defined(CONFIG_KERNEL_LZO) +#include "../../../../lib/decompress_unlzo.c" +#elif defined(CONFIG_KERNEL_XZ) +#undef memcpy +#define memcpy memcpy +#undef memmove +#define memmove memmove +#include "../../../../lib/decompress_unxz.c" +#elif defined(CONFIG_KERNEL_ZSTD) +#include "../../../../lib/decompress_unzstd.c" +#endif + +extern char efi_zboot_header[]; +extern char _gzdata_start[], _gzdata_end[]; + +static void log(efi_char16_t str[]) +{ + efi_call_proto(efi_table_attr(efi_system_table, con_out), + output_string, L"EFI decompressor: "); + efi_call_proto(efi_table_attr(efi_system_table, con_out), + output_string, str); + efi_call_proto(efi_table_attr(efi_system_table, con_out), + output_string, L"\n"); +} + +static void error(char *x) +{ + log(L"error() called from decompressor library\n"); +} + +// Local version to avoid pulling in memcmp() +static bool guids_eq(const efi_guid_t *a, const efi_guid_t *b) +{ + const u32 *l = (u32 *)a; + const u32 *r = (u32 *)b; + + return l[0] == r[0] && l[1] == r[1] && l[2] == r[2] && l[3] == r[3]; +} + +static efi_status_t __efiapi +load_file(efi_load_file_protocol_t *this, efi_device_path_protocol_t *rem, + bool boot_policy, unsigned long *bufsize, void *buffer) +{ + unsigned long compressed_size = _gzdata_end - _gzdata_start; + struct efi_vendor_dev_path *vendor_dp; + bool decompress = false; + unsigned long size; + int ret; + + if (rem == NULL || bufsize == NULL) + return EFI_INVALID_PARAMETER; + + if (boot_policy) + return EFI_UNSUPPORTED; + + // Look for our vendor media device node in the remaining file path + if (rem->type == EFI_DEV_MEDIA && + rem->sub_type == EFI_DEV_MEDIA_VENDOR) { + vendor_dp = container_of(rem, struct efi_vendor_dev_path, header); + if (!guids_eq(&vendor_dp->vendorguid, &LINUX_EFI_ZBOOT_MEDIA_GUID)) + return EFI_NOT_FOUND; + + decompress = true; + rem = (void *)(vendor_dp + 1); + } + + if (rem->type != EFI_DEV_END_PATH || + rem->sub_type != EFI_DEV_END_ENTIRE) + return EFI_NOT_FOUND; + + // The uncompressed size of the payload is appended to the raw bit + // stream, and may therefore appear misaligned in memory + size = decompress ? get_unaligned_le32(_gzdata_end - 4) + : compressed_size; + if (buffer == NULL || *bufsize < size) { + *bufsize = size; + return EFI_BUFFER_TOO_SMALL; + } + + if (decompress) { + ret = __decompress(_gzdata_start, compressed_size, NULL, NULL, + buffer, size, NULL, error); + if (ret < 0) { + log(L"Decompression failed"); + return EFI_DEVICE_ERROR; + } + } else { + memcpy(buffer, _gzdata_start, compressed_size); + } + + return EFI_SUCCESS; +} + +// Return the length in bytes of the device path up to the first end node. +static int device_path_length(const efi_device_path_protocol_t *dp) +{ + int len = 0; + + while (dp->type != EFI_DEV_END_PATH) { + len += dp->length; + dp = (void *)((u8 *)dp + dp->length); + } + return len; +} + +static void append_rel_offset_node(efi_device_path_protocol_t **dp, + unsigned long start, unsigned long end) +{ + struct efi_rel_offset_dev_path *rodp = (void *)*dp; + + rodp->header.type = EFI_DEV_MEDIA; + rodp->header.sub_type = EFI_DEV_MEDIA_REL_OFFSET; + rodp->header.length = sizeof(struct efi_rel_offset_dev_path); + rodp->reserved = 0; + rodp->starting_offset = start; + rodp->ending_offset = end; + + *dp = (void *)(rodp + 1); +} + +static void append_ven_media_node(efi_device_path_protocol_t **dp, + efi_guid_t *guid) +{ + struct efi_vendor_dev_path *vmdp = (void *)*dp; + + vmdp->header.type = EFI_DEV_MEDIA; + vmdp->header.sub_type = EFI_DEV_MEDIA_VENDOR; + vmdp->header.length = sizeof(struct efi_vendor_dev_path); + vmdp->vendorguid = *guid; + + *dp = (void *)(vmdp + 1); +} + +static void append_end_node(efi_device_path_protocol_t **dp) +{ + (*dp)->type = EFI_DEV_END_PATH; + (*dp)->sub_type = EFI_DEV_END_ENTIRE; + (*dp)->length = sizeof(struct efi_generic_dev_path); + + ++*dp; +} + +asmlinkage efi_status_t __efiapi +efi_zboot_entry(efi_handle_t handle, efi_system_table_t *systab) +{ + struct efi_mem_mapped_dev_path mmdp = { + .header.type = EFI_DEV_HW, + .header.sub_type = EFI_DEV_MEM_MAPPED, + .header.length = sizeof(struct efi_mem_mapped_dev_path) + }; + efi_device_path_protocol_t *parent_dp, *dpp, *lf2_dp, *li_dp; + efi_load_file2_protocol_t zboot_load_file2; + efi_loaded_image_t *parent, *child; + unsigned long exit_data_size; + efi_handle_t child_handle; + efi_handle_t zboot_handle; + efi_char16_t *exit_data; + efi_status_t status; + void *dp_alloc; + int dp_len; + + WRITE_ONCE(efi_system_table, systab); + + free_mem_ptr = (unsigned long)&zboot_heap; + free_mem_end_ptr = free_mem_ptr + sizeof(zboot_heap); + + exit_data = NULL; + exit_data_size = 0; + + status = efi_bs_call(handle_protocol, handle, + &LOADED_IMAGE_PROTOCOL_GUID, (void **)&parent); + if (status != EFI_SUCCESS) { + log(L"Failed to locate parent's loaded image protocol"); + return status; + } + + status = efi_bs_call(handle_protocol, handle, + &LOADED_IMAGE_DEVICE_PATH_PROTOCOL_GUID, + (void **)&parent_dp); + if (status != EFI_SUCCESS || parent_dp == NULL) { + // Create a MemoryMapped() device path node to describe + // the parent image if no device path was provided. + mmdp.memory_type = parent->image_code_type; + mmdp.starting_addr = (unsigned long)parent->image_base; + mmdp.ending_addr = (unsigned long)parent->image_base + + parent->image_size - 1; + parent_dp = &mmdp.header; + dp_len = sizeof(mmdp); + } else { + dp_len = device_path_length(parent_dp); + } + + // Allocate some pool memory for device path protocol data + status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, + 2 * (dp_len + sizeof(struct efi_rel_offset_dev_path) + + sizeof(struct efi_generic_dev_path)) + + sizeof(struct efi_vendor_dev_path), + (void **)&dp_alloc); + if (status != EFI_SUCCESS) { + log(L"Failed to allocate device path pool memory"); + return status; + } + + // Create a device path describing the compressed payload in this image + // <...parent_dp...>/Offset(<start>, <end>) + lf2_dp = memcpy(dp_alloc, parent_dp, dp_len); + dpp = (void *)((u8 *)lf2_dp + dp_len); + append_rel_offset_node(&dpp, + (unsigned long)(_gzdata_start - efi_zboot_header), + (unsigned long)(_gzdata_end - efi_zboot_header - 1)); + append_end_node(&dpp); + + // Create a device path describing the decompressed payload in this image + // <...parent_dp...>/Offset(<start>, <end>)/VenMedia(ZBOOT_MEDIA_GUID) + dp_len += sizeof(struct efi_rel_offset_dev_path); + li_dp = memcpy(dpp, lf2_dp, dp_len); + dpp = (void *)((u8 *)li_dp + dp_len); + append_ven_media_node(&dpp, &LINUX_EFI_ZBOOT_MEDIA_GUID); + append_end_node(&dpp); + + zboot_handle = NULL; + zboot_load_file2.load_file = load_file; + status = efi_bs_call(install_multiple_protocol_interfaces, + &zboot_handle, + &EFI_DEVICE_PATH_PROTOCOL_GUID, lf2_dp, + &EFI_LOAD_FILE2_PROTOCOL_GUID, &zboot_load_file2, + NULL); + if (status != EFI_SUCCESS) { + log(L"Failed to install LoadFile2 protocol and device path"); + goto free_dpalloc; + } + + status = efi_bs_call(load_image, false, handle, li_dp, NULL, 0, + &child_handle); + if (status != EFI_SUCCESS) { + log(L"Failed to load image"); + goto uninstall_lf2; + } + + status = efi_bs_call(handle_protocol, child_handle, + &LOADED_IMAGE_PROTOCOL_GUID, (void **)&child); + if (status != EFI_SUCCESS) { + log(L"Failed to locate child's loaded image protocol"); + goto unload_image; + } + + // Copy the kernel command line + child->load_options = parent->load_options; + child->load_options_size = parent->load_options_size; + + status = efi_bs_call(start_image, child_handle, &exit_data_size, + &exit_data); + if (status != EFI_SUCCESS) { + log(L"StartImage() returned with error"); + if (exit_data_size > 0) + log(exit_data); + + // If StartImage() returns EFI_SECURITY_VIOLATION, the image is + // not unloaded so we need to do it by hand. + if (status == EFI_SECURITY_VIOLATION) +unload_image: + efi_bs_call(unload_image, child_handle); + } + +uninstall_lf2: + efi_bs_call(uninstall_multiple_protocol_interfaces, + zboot_handle, + &EFI_DEVICE_PATH_PROTOCOL_GUID, lf2_dp, + &EFI_LOAD_FILE2_PROTOCOL_GUID, &zboot_load_file2, + NULL); + +free_dpalloc: + efi_bs_call(free_pool, dp_alloc); + + efi_bs_call(exit, handle, status, exit_data_size, exit_data); + + // Free ExitData in case Exit() returned with a failure code, + // but return the original status code. + log(L"Exit() returned with failure code"); + if (exit_data != NULL) + efi_bs_call(free_pool, exit_data); + return status; +} |