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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/firmware/efi/libstub/file.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/firmware/efi/libstub/file.c')
-rw-r--r-- | drivers/firmware/efi/libstub/file.c | 309 |
1 files changed, 309 insertions, 0 deletions
diff --git a/drivers/firmware/efi/libstub/file.c b/drivers/firmware/efi/libstub/file.c new file mode 100644 index 0000000000..d6a025df07 --- /dev/null +++ b/drivers/firmware/efi/libstub/file.c @@ -0,0 +1,309 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Helper functions used by the EFI stub on multiple + * architectures. This should be #included by the EFI stub + * implementation files. + * + * Copyright 2011 Intel Corporation; author Matt Fleming + */ + +#include <linux/efi.h> +#include <asm/efi.h> + +#include "efistub.h" + +#define MAX_FILENAME_SIZE 256 + +/* + * Some firmware implementations have problems reading files in one go. + * A read chunk size of 1MB seems to work for most platforms. + * + * Unfortunately, reading files in chunks triggers *other* bugs on some + * platforms, so we provide a way to disable this workaround, which can + * be done by passing "efi=nochunk" on the EFI boot stub command line. + * + * If you experience issues with initrd images being corrupt it's worth + * trying efi=nochunk, but chunking is enabled by default on x86 because + * there are far more machines that require the workaround than those that + * break with it enabled. + */ +#define EFI_READ_CHUNK_SIZE SZ_1M + +struct finfo { + efi_file_info_t info; + efi_char16_t filename[MAX_FILENAME_SIZE]; +}; + +static efi_status_t efi_open_file(efi_file_protocol_t *volume, + struct finfo *fi, + efi_file_protocol_t **handle, + unsigned long *file_size) +{ + efi_guid_t info_guid = EFI_FILE_INFO_ID; + efi_file_protocol_t *fh; + unsigned long info_sz; + efi_status_t status; + efi_char16_t *c; + + /* Replace UNIX dir separators with EFI standard ones */ + for (c = fi->filename; *c != L'\0'; c++) { + if (*c == L'/') + *c = L'\\'; + } + + status = efi_call_proto(volume, open, &fh, fi->filename, + EFI_FILE_MODE_READ, 0); + if (status != EFI_SUCCESS) { + efi_err("Failed to open file: %ls\n", fi->filename); + return status; + } + + info_sz = sizeof(struct finfo); + status = efi_call_proto(fh, get_info, &info_guid, &info_sz, fi); + if (status != EFI_SUCCESS) { + efi_err("Failed to get file info\n"); + efi_call_proto(fh, close); + return status; + } + + *handle = fh; + *file_size = fi->info.file_size; + return EFI_SUCCESS; +} + +static efi_status_t efi_open_volume(efi_loaded_image_t *image, + efi_file_protocol_t **fh) +{ + efi_guid_t fs_proto = EFI_FILE_SYSTEM_GUID; + efi_simple_file_system_protocol_t *io; + efi_status_t status; + + status = efi_bs_call(handle_protocol, efi_table_attr(image, device_handle), + &fs_proto, (void **)&io); + if (status != EFI_SUCCESS) { + efi_err("Failed to handle fs_proto\n"); + return status; + } + + status = efi_call_proto(io, open_volume, fh); + if (status != EFI_SUCCESS) + efi_err("Failed to open volume\n"); + + return status; +} + +static int find_file_option(const efi_char16_t *cmdline, int cmdline_len, + const efi_char16_t *prefix, int prefix_size, + efi_char16_t *result, int result_len) +{ + int prefix_len = prefix_size / 2; + bool found = false; + int i; + + for (i = prefix_len; i < cmdline_len; i++) { + if (!memcmp(&cmdline[i - prefix_len], prefix, prefix_size)) { + found = true; + break; + } + } + + if (!found) + return 0; + + /* Skip any leading slashes */ + while (i < cmdline_len && (cmdline[i] == L'/' || cmdline[i] == L'\\')) + i++; + + while (--result_len > 0 && i < cmdline_len) { + efi_char16_t c = cmdline[i++]; + + if (c == L'\0' || c == L'\n' || c == L' ') + break; + *result++ = c; + } + *result = L'\0'; + return i; +} + +static efi_status_t efi_open_device_path(efi_file_protocol_t **volume, + struct finfo *fi) +{ + efi_guid_t text_to_dp_guid = EFI_DEVICE_PATH_FROM_TEXT_PROTOCOL_GUID; + static efi_device_path_from_text_protocol_t *text_to_dp = NULL; + efi_guid_t fs_proto = EFI_FILE_SYSTEM_GUID; + efi_device_path_protocol_t *initrd_dp; + efi_simple_file_system_protocol_t *io; + struct efi_file_path_dev_path *fpath; + efi_handle_t handle; + efi_status_t status; + + /* See if the text to device path protocol exists */ + if (!text_to_dp && + efi_bs_call(locate_protocol, &text_to_dp_guid, NULL, + (void **)&text_to_dp) != EFI_SUCCESS) + return EFI_UNSUPPORTED; + + + /* Convert the filename wide string into a device path */ + initrd_dp = efi_fn_call(text_to_dp, convert_text_to_device_path, + fi->filename); + + /* Check whether the device path in question implements simple FS */ + if ((efi_bs_call(locate_device_path, &fs_proto, &initrd_dp, &handle) ?: + efi_bs_call(handle_protocol, handle, &fs_proto, (void **)&io)) + != EFI_SUCCESS) + return EFI_NOT_FOUND; + + /* Check whether the remaining device path is a file device path */ + if (initrd_dp->type != EFI_DEV_MEDIA || + initrd_dp->sub_type != EFI_DEV_MEDIA_FILE) { + efi_warn("Unexpected device path node type: (%x, %x)\n", + initrd_dp->type, initrd_dp->sub_type); + return EFI_LOAD_ERROR; + } + + /* Copy the remaining file path into the fi structure */ + fpath = (struct efi_file_path_dev_path *)initrd_dp; + memcpy(fi->filename, fpath->filename, + min(sizeof(fi->filename), + fpath->header.length - sizeof(fpath->header))); + + status = efi_call_proto(io, open_volume, volume); + if (status != EFI_SUCCESS) + efi_err("Failed to open volume\n"); + + return status; +} + +/* + * Check the cmdline for a LILO-style file= arguments. + * + * We only support loading a file from the same filesystem as + * the kernel image. + */ +efi_status_t handle_cmdline_files(efi_loaded_image_t *image, + const efi_char16_t *optstr, + int optstr_size, + unsigned long soft_limit, + unsigned long hard_limit, + unsigned long *load_addr, + unsigned long *load_size) +{ + const efi_char16_t *cmdline = efi_table_attr(image, load_options); + u32 cmdline_len = efi_table_attr(image, load_options_size); + unsigned long efi_chunk_size = ULONG_MAX; + efi_file_protocol_t *volume = NULL; + efi_file_protocol_t *file; + unsigned long alloc_addr; + unsigned long alloc_size; + efi_status_t status; + int offset; + + if (!load_addr || !load_size) + return EFI_INVALID_PARAMETER; + + efi_apply_loadoptions_quirk((const void **)&cmdline, &cmdline_len); + cmdline_len /= sizeof(*cmdline); + + if (IS_ENABLED(CONFIG_X86) && !efi_nochunk) + efi_chunk_size = EFI_READ_CHUNK_SIZE; + + alloc_addr = alloc_size = 0; + do { + struct finfo fi; + unsigned long size; + void *addr; + + offset = find_file_option(cmdline, cmdline_len, + optstr, optstr_size, + fi.filename, ARRAY_SIZE(fi.filename)); + + if (!offset) + break; + + cmdline += offset; + cmdline_len -= offset; + + status = efi_open_device_path(&volume, &fi); + if (status == EFI_UNSUPPORTED || status == EFI_NOT_FOUND) + /* try the volume that holds the kernel itself */ + status = efi_open_volume(image, &volume); + + if (status != EFI_SUCCESS) + goto err_free_alloc; + + status = efi_open_file(volume, &fi, &file, &size); + if (status != EFI_SUCCESS) + goto err_close_volume; + + /* + * Check whether the existing allocation can contain the next + * file. This condition will also trigger naturally during the + * first (and typically only) iteration of the loop, given that + * alloc_size == 0 in that case. + */ + if (round_up(alloc_size + size, EFI_ALLOC_ALIGN) > + round_up(alloc_size, EFI_ALLOC_ALIGN)) { + unsigned long old_addr = alloc_addr; + + status = EFI_OUT_OF_RESOURCES; + if (soft_limit < hard_limit) + status = efi_allocate_pages(alloc_size + size, + &alloc_addr, + soft_limit); + if (status == EFI_OUT_OF_RESOURCES) + status = efi_allocate_pages(alloc_size + size, + &alloc_addr, + hard_limit); + if (status != EFI_SUCCESS) { + efi_err("Failed to allocate memory for files\n"); + goto err_close_file; + } + + if (old_addr != 0) { + /* + * This is not the first time we've gone + * around this loop, and so we are loading + * multiple files that need to be concatenated + * and returned in a single buffer. + */ + memcpy((void *)alloc_addr, (void *)old_addr, alloc_size); + efi_free(alloc_size, old_addr); + } + } + + addr = (void *)alloc_addr + alloc_size; + alloc_size += size; + + while (size) { + unsigned long chunksize = min(size, efi_chunk_size); + + status = efi_call_proto(file, read, &chunksize, addr); + if (status != EFI_SUCCESS) { + efi_err("Failed to read file\n"); + goto err_close_file; + } + addr += chunksize; + size -= chunksize; + } + efi_call_proto(file, close); + efi_call_proto(volume, close); + } while (offset > 0); + + *load_addr = alloc_addr; + *load_size = alloc_size; + + if (*load_size == 0) + return EFI_NOT_READY; + return EFI_SUCCESS; + +err_close_file: + efi_call_proto(file, close); + +err_close_volume: + efi_call_proto(volume, close); + +err_free_alloc: + efi_free(alloc_size, alloc_addr); + return status; +} |