diff options
Diffstat (limited to 'drivers/firmware/efi/libstub/efi-stub-helper.c')
| -rw-r--r-- | drivers/firmware/efi/libstub/efi-stub-helper.c | 571 |
1 files changed, 295 insertions, 276 deletions
diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c index 3d972061c1b0..7aa2f9ad2935 100644 --- a/drivers/firmware/efi/libstub/efi-stub-helper.c +++ b/drivers/firmware/efi/libstub/efi-stub-helper.c @@ -9,10 +9,9 @@ #include <linux/stdarg.h> -#include <linux/ctype.h> #include <linux/efi.h> #include <linux/kernel.h> -#include <linux/printk.h> /* For CONSOLE_LOGLEVEL_* */ +#include <linux/overflow.h> #include <asm/efi.h> #include <asm/setup.h> @@ -20,159 +19,20 @@ bool efi_nochunk; bool efi_nokaslr = !IS_ENABLED(CONFIG_RANDOMIZE_BASE); -int efi_loglevel = CONSOLE_LOGLEVEL_DEFAULT; bool efi_novamap; static bool efi_noinitrd; static bool efi_nosoftreserve; static bool efi_disable_pci_dma = IS_ENABLED(CONFIG_EFI_DISABLE_PCI_DMA); +int efi_mem_encrypt; + bool __pure __efi_soft_reserve_enabled(void) { return !efi_nosoftreserve; } /** - * efi_char16_puts() - Write a UCS-2 encoded string to the console - * @str: UCS-2 encoded string - */ -void efi_char16_puts(efi_char16_t *str) -{ - efi_call_proto(efi_table_attr(efi_system_table, con_out), - output_string, str); -} - -static -u32 utf8_to_utf32(const u8 **s8) -{ - u32 c32; - u8 c0, cx; - size_t clen, i; - - c0 = cx = *(*s8)++; - /* - * The position of the most-significant 0 bit gives us the length of - * a multi-octet encoding. - */ - for (clen = 0; cx & 0x80; ++clen) - cx <<= 1; - /* - * If the 0 bit is in position 8, this is a valid single-octet - * encoding. If the 0 bit is in position 7 or positions 1-3, the - * encoding is invalid. - * In either case, we just return the first octet. - */ - if (clen < 2 || clen > 4) - return c0; - /* Get the bits from the first octet. */ - c32 = cx >> clen--; - for (i = 0; i < clen; ++i) { - /* Trailing octets must have 10 in most significant bits. */ - cx = (*s8)[i] ^ 0x80; - if (cx & 0xc0) - return c0; - c32 = (c32 << 6) | cx; - } - /* - * Check for validity: - * - The character must be in the Unicode range. - * - It must not be a surrogate. - * - It must be encoded using the correct number of octets. - */ - if (c32 > 0x10ffff || - (c32 & 0xf800) == 0xd800 || - clen != (c32 >= 0x80) + (c32 >= 0x800) + (c32 >= 0x10000)) - return c0; - *s8 += clen; - return c32; -} - -/** - * efi_puts() - Write a UTF-8 encoded string to the console - * @str: UTF-8 encoded string - */ -void efi_puts(const char *str) -{ - efi_char16_t buf[128]; - size_t pos = 0, lim = ARRAY_SIZE(buf); - const u8 *s8 = (const u8 *)str; - u32 c32; - - while (*s8) { - if (*s8 == '\n') - buf[pos++] = L'\r'; - c32 = utf8_to_utf32(&s8); - if (c32 < 0x10000) { - /* Characters in plane 0 use a single word. */ - buf[pos++] = c32; - } else { - /* - * Characters in other planes encode into a surrogate - * pair. - */ - buf[pos++] = (0xd800 - (0x10000 >> 10)) + (c32 >> 10); - buf[pos++] = 0xdc00 + (c32 & 0x3ff); - } - if (*s8 == '\0' || pos >= lim - 2) { - buf[pos] = L'\0'; - efi_char16_puts(buf); - pos = 0; - } - } -} - -/** - * efi_printk() - Print a kernel message - * @fmt: format string - * - * The first letter of the format string is used to determine the logging level - * of the message. If the level is less then the current EFI logging level, the - * message is suppressed. The message will be truncated to 255 bytes. - * - * Return: number of printed characters - */ -int efi_printk(const char *fmt, ...) -{ - char printf_buf[256]; - va_list args; - int printed; - int loglevel = printk_get_level(fmt); - - switch (loglevel) { - case '0' ... '9': - loglevel -= '0'; - break; - default: - /* - * Use loglevel -1 for cases where we just want to print to - * the screen. - */ - loglevel = -1; - break; - } - - if (loglevel >= efi_loglevel) - return 0; - - if (loglevel >= 0) - efi_puts("EFI stub: "); - - fmt = printk_skip_level(fmt); - - va_start(args, fmt); - printed = vsnprintf(printf_buf, sizeof(printf_buf), fmt, args); - va_end(args); - - efi_puts(printf_buf); - if (printed >= sizeof(printf_buf)) { - efi_puts("[Message truncated]\n"); - return -1; - } - - return printed; -} - -/** * efi_parse_options() - Parse EFI command line options * @cmdline: kernel command line * @@ -187,9 +47,10 @@ int efi_printk(const char *fmt, ...) */ efi_status_t efi_parse_options(char const *cmdline) { - size_t len; + char *buf __free(efi_pool) = NULL; efi_status_t status; - char *str, *buf; + size_t len; + char *str; if (!cmdline) return EFI_SUCCESS; @@ -216,9 +77,17 @@ efi_status_t efi_parse_options(char const *cmdline) efi_loglevel = CONSOLE_LOGLEVEL_QUIET; } else if (!strcmp(param, "noinitrd")) { efi_noinitrd = true; + } else if (IS_ENABLED(CONFIG_X86_64) && !strcmp(param, "no5lvl")) { + efi_no5lvl = true; + } else if (IS_ENABLED(CONFIG_ARCH_HAS_MEM_ENCRYPT) && + !strcmp(param, "mem_encrypt") && val) { + if (parse_option_str(val, "on")) + efi_mem_encrypt = 1; + else if (parse_option_str(val, "off")) + efi_mem_encrypt = -1; } else if (!strcmp(param, "efi") && val) { efi_nochunk = parse_option_str(val, "nochunk"); - efi_novamap = parse_option_str(val, "novamap"); + efi_novamap |= parse_option_str(val, "novamap"); efi_nosoftreserve = IS_ENABLED(CONFIG_EFI_SOFT_RESERVE) && parse_option_str(val, "nosoftreserve"); @@ -234,7 +103,6 @@ efi_status_t efi_parse_options(char const *cmdline) efi_parse_option_graphics(val + strlen("efifb:")); } } - efi_bs_call(free_pool, buf); return EFI_SUCCESS; } @@ -310,7 +178,7 @@ bool efi_load_option_unpack(efi_load_option_unpacked_t *dest, * * Detect this case and extract OptionalData. */ -void efi_apply_loadoptions_quirk(const void **load_options, int *load_options_size) +void efi_apply_loadoptions_quirk(const void **load_options, u32 *load_options_size) { const efi_load_option_t *load_option = *load_options; efi_load_option_unpacked_t load_option_unpacked; @@ -334,28 +202,152 @@ void efi_apply_loadoptions_quirk(const void **load_options, int *load_options_si *load_options_size = load_option_unpacked.optional_data_size; } +enum efistub_event_type { + EFISTUB_EVT_INITRD, + EFISTUB_EVT_LOAD_OPTIONS, + EFISTUB_EVT_COUNT, +}; + +#define STR_WITH_SIZE(s) sizeof(s), s + +static const struct { + u32 pcr_index; + u32 event_id; + u32 event_data_len; + u8 event_data[52]; +} events[] = { + [EFISTUB_EVT_INITRD] = { + 9, + INITRD_EVENT_TAG_ID, + STR_WITH_SIZE("Linux initrd") + }, + [EFISTUB_EVT_LOAD_OPTIONS] = { + 9, + LOAD_OPTIONS_EVENT_TAG_ID, + STR_WITH_SIZE("LOADED_IMAGE::LoadOptions") + }, +}; + +static_assert(sizeof(efi_tcg2_event_t) == sizeof(efi_cc_event_t)); + +union efistub_event { + efi_tcg2_event_t tcg2_data; + efi_cc_event_t cc_data; +}; + +struct efistub_measured_event { + union efistub_event event_data; + TCG_PCClientTaggedEvent tagged_event __packed; +}; + +static efi_status_t efi_measure_tagged_event(unsigned long load_addr, + unsigned long load_size, + enum efistub_event_type event) +{ + union { + efi_status_t + (__efiapi *hash_log_extend_event)(void *, u64, efi_physical_addr_t, + u64, const union efistub_event *); + struct { u32 hash_log_extend_event; } mixed_mode; + } method; + struct efistub_measured_event *evt __free(efi_pool) = NULL; + int size = struct_size(evt, tagged_event.tagged_event_data, + events[event].event_data_len); + efi_guid_t tcg2_guid = EFI_TCG2_PROTOCOL_GUID; + efi_tcg2_protocol_t *tcg2 = NULL; + union efistub_event ev; + efi_status_t status; + void *protocol; + + efi_bs_call(locate_protocol, &tcg2_guid, NULL, (void **)&tcg2); + if (tcg2) { + ev.tcg2_data = (struct efi_tcg2_event){ + .event_size = size, + .event_header.header_size = sizeof(ev.tcg2_data.event_header), + .event_header.header_version = EFI_TCG2_EVENT_HEADER_VERSION, + .event_header.pcr_index = events[event].pcr_index, + .event_header.event_type = EV_EVENT_TAG, + }; + protocol = tcg2; + method.hash_log_extend_event = + (void *)efi_table_attr(tcg2, hash_log_extend_event); + } else { + efi_guid_t cc_guid = EFI_CC_MEASUREMENT_PROTOCOL_GUID; + efi_cc_protocol_t *cc = NULL; + + efi_bs_call(locate_protocol, &cc_guid, NULL, (void **)&cc); + if (!cc) + return EFI_UNSUPPORTED; + + ev.cc_data = (struct efi_cc_event){ + .event_size = size, + .event_header.header_size = sizeof(ev.cc_data.event_header), + .event_header.header_version = EFI_CC_EVENT_HEADER_VERSION, + .event_header.event_type = EV_EVENT_TAG, + }; + + status = efi_call_proto(cc, map_pcr_to_mr_index, + events[event].pcr_index, + &ev.cc_data.event_header.mr_index); + if (status != EFI_SUCCESS) + goto fail; + + protocol = cc; + method.hash_log_extend_event = + (void *)efi_table_attr(cc, hash_log_extend_event); + } + + status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, (void **)&evt); + if (status != EFI_SUCCESS) + goto fail; + + *evt = (struct efistub_measured_event) { + .event_data = ev, + .tagged_event.tagged_event_id = events[event].event_id, + .tagged_event.tagged_event_data_size = events[event].event_data_len, + }; + + memcpy(evt->tagged_event.tagged_event_data, events[event].event_data, + events[event].event_data_len); + + status = efi_fn_call(&method, hash_log_extend_event, protocol, 0, + load_addr, load_size, &evt->event_data); + + if (status == EFI_SUCCESS) + return EFI_SUCCESS; + +fail: + efi_warn("Failed to measure data for event %d: 0x%lx\n", event, status); + return status; +} + /* * Convert the unicode UEFI command line to ASCII to pass to kernel. * Size of memory allocated return in *cmd_line_len. * Returns NULL on error. */ -char *efi_convert_cmdline(efi_loaded_image_t *image, int *cmd_line_len) +char *efi_convert_cmdline(efi_loaded_image_t *image) { - const u16 *s2; - unsigned long cmdline_addr = 0; - int options_chars = efi_table_attr(image, load_options_size); - const u16 *options = efi_table_attr(image, load_options); + const efi_char16_t *options = efi_table_attr(image, load_options); + u32 options_size = efi_table_attr(image, load_options_size); int options_bytes = 0, safe_options_bytes = 0; /* UTF-8 bytes */ + unsigned long cmdline_addr = 0; + const efi_char16_t *s2; bool in_quote = false; efi_status_t status; + u32 options_chars; - efi_apply_loadoptions_quirk((const void **)&options, &options_chars); - options_chars /= sizeof(*options); + if (options_size > 0) + efi_measure_tagged_event((unsigned long)options, options_size, + EFISTUB_EVT_LOAD_OPTIONS); + + efi_apply_loadoptions_quirk((const void **)&options, &options_size); + options_chars = options_size / sizeof(efi_char16_t); if (options) { s2 = options; while (options_bytes < COMMAND_LINE_SIZE && options_chars--) { - u16 c = *s2++; + efi_char16_t c = *s2++; if (c < 0x80) { if (c == L'\0' || c == L'\n') @@ -412,14 +404,12 @@ char *efi_convert_cmdline(efi_loaded_image_t *image, int *cmd_line_len) snprintf((char *)cmdline_addr, options_bytes, "%.*ls", options_bytes - 1, options); - *cmd_line_len = options_bytes; return (char *)cmdline_addr; } /** * efi_exit_boot_services() - Exit boot services * @handle: handle of the exiting image - * @map: pointer to receive the memory map * @priv: argument to be passed to @priv_func * @priv_func: function to process the memory map before exiting boot services * @@ -432,26 +422,26 @@ char *efi_convert_cmdline(efi_loaded_image_t *image, int *cmd_line_len) * * Return: status code */ -efi_status_t efi_exit_boot_services(void *handle, - struct efi_boot_memmap *map, - void *priv, +efi_status_t efi_exit_boot_services(void *handle, void *priv, efi_exit_boot_map_processing priv_func) { + struct efi_boot_memmap *map; efi_status_t status; - status = efi_get_memory_map(map); + if (efi_disable_pci_dma) + efi_pci_disable_bridge_busmaster(); + status = efi_get_memory_map(&map, true); if (status != EFI_SUCCESS) - goto fail; + return status; status = priv_func(map, priv); - if (status != EFI_SUCCESS) - goto free_map; - - if (efi_disable_pci_dma) - efi_pci_disable_bridge_busmaster(); + if (status != EFI_SUCCESS) { + efi_bs_call(free_pool, map); + return status; + } - status = efi_bs_call(exit_boot_services, handle, *map->key_ptr); + status = efi_bs_call(exit_boot_services, handle, map->map_key); if (status == EFI_INVALID_PARAMETER) { /* @@ -467,35 +457,26 @@ efi_status_t efi_exit_boot_services(void *handle, * buffer should account for any changes in the map so the call * to get_memory_map() is expected to succeed here. */ - *map->map_size = *map->buff_size; + map->map_size = map->buff_size; status = efi_bs_call(get_memory_map, - map->map_size, - *map->map, - map->key_ptr, - map->desc_size, - map->desc_ver); + &map->map_size, + &map->map, + &map->map_key, + &map->desc_size, + &map->desc_ver); /* exit_boot_services() was called, thus cannot free */ if (status != EFI_SUCCESS) - goto fail; + return status; status = priv_func(map, priv); /* exit_boot_services() was called, thus cannot free */ if (status != EFI_SUCCESS) - goto fail; + return status; - status = efi_bs_call(exit_boot_services, handle, *map->key_ptr); + status = efi_bs_call(exit_boot_services, handle, map->map_key); } - /* exit_boot_services() was called, thus cannot free */ - if (status != EFI_SUCCESS) - goto fail; - - return EFI_SUCCESS; - -free_map: - efi_bs_call(free_pool, *map->map); -fail: return status; } @@ -552,28 +533,24 @@ static const struct { /** * efi_load_initrd_dev_path() - load the initrd from the Linux initrd device path - * @load_addr: pointer to store the address where the initrd was loaded - * @load_size: pointer to store the size of the loaded initrd + * @initrd: pointer of struct to store the address where the initrd was loaded + * and the size of the loaded initrd * @max: upper limit for the initrd memory allocation * * Return: * * %EFI_SUCCESS if the initrd was loaded successfully, in which * case @load_addr and @load_size are assigned accordingly * * %EFI_NOT_FOUND if no LoadFile2 protocol exists on the initrd device path - * * %EFI_INVALID_PARAMETER if load_addr == NULL or load_size == NULL * * %EFI_OUT_OF_RESOURCES if memory allocation failed * * %EFI_LOAD_ERROR in all other cases */ static -efi_status_t efi_load_initrd_dev_path(unsigned long *load_addr, - unsigned long *load_size, +efi_status_t efi_load_initrd_dev_path(struct linux_efi_initrd *initrd, unsigned long max) { efi_guid_t lf2_proto_guid = EFI_LOAD_FILE2_PROTOCOL_GUID; efi_device_path_protocol_t *dp; efi_load_file2_protocol_t *lf2; - unsigned long initrd_addr; - unsigned long initrd_size; efi_handle_t handle; efi_status_t status; @@ -587,124 +564,99 @@ efi_status_t efi_load_initrd_dev_path(unsigned long *load_addr, if (status != EFI_SUCCESS) return status; - status = efi_call_proto(lf2, load_file, dp, false, &initrd_size, NULL); + initrd->size = 0; + status = efi_call_proto(lf2, load_file, dp, false, &initrd->size, NULL); if (status != EFI_BUFFER_TOO_SMALL) return EFI_LOAD_ERROR; - status = efi_allocate_pages(initrd_size, &initrd_addr, max); + status = efi_allocate_pages(initrd->size, &initrd->base, max); if (status != EFI_SUCCESS) return status; - status = efi_call_proto(lf2, load_file, dp, false, &initrd_size, - (void *)initrd_addr); + status = efi_call_proto(lf2, load_file, dp, false, &initrd->size, + (void *)initrd->base); if (status != EFI_SUCCESS) { - efi_free(initrd_size, initrd_addr); + efi_free(initrd->size, initrd->base); return EFI_LOAD_ERROR; } - - *load_addr = initrd_addr; - *load_size = initrd_size; return EFI_SUCCESS; } static efi_status_t efi_load_initrd_cmdline(efi_loaded_image_t *image, - unsigned long *load_addr, - unsigned long *load_size, + struct linux_efi_initrd *initrd, unsigned long soft_limit, unsigned long hard_limit) { - if (!IS_ENABLED(CONFIG_EFI_GENERIC_STUB_INITRD_CMDLINE_LOADER) || - (IS_ENABLED(CONFIG_X86) && (!efi_is_native() || image == NULL))) { - *load_addr = *load_size = 0; - return EFI_SUCCESS; - } + if (image == NULL) + return EFI_UNSUPPORTED; return handle_cmdline_files(image, L"initrd=", sizeof(L"initrd=") - 2, soft_limit, hard_limit, - load_addr, load_size); -} - -static const struct { - efi_tcg2_event_t event_data; - efi_tcg2_tagged_event_t tagged_event; - u8 tagged_event_data[]; -} initrd_tcg2_event = { - { - sizeof(initrd_tcg2_event) + sizeof("Linux initrd"), - { - sizeof(initrd_tcg2_event.event_data.event_header), - EFI_TCG2_EVENT_HEADER_VERSION, - 9, - EV_EVENT_TAG, - }, - }, - { - INITRD_EVENT_TAG_ID, - sizeof("Linux initrd"), - }, - { "Linux initrd" }, -}; - -static void efi_measure_initrd(unsigned long load_addr, unsigned long load_size) -{ - efi_guid_t tcg2_guid = EFI_TCG2_PROTOCOL_GUID; - efi_tcg2_protocol_t *tcg2 = NULL; - efi_status_t status; - - efi_bs_call(locate_protocol, &tcg2_guid, NULL, (void **)&tcg2); - if (tcg2) { - status = efi_call_proto(tcg2, hash_log_extend_event, - 0, load_addr, load_size, - &initrd_tcg2_event.event_data); - if (status != EFI_SUCCESS) - efi_warn("Failed to measure initrd data: 0x%lx\n", - status); - else - efi_info("Measured initrd data into PCR %d\n", - initrd_tcg2_event.event_data.event_header.pcr_index); - } + &initrd->base, &initrd->size); } /** * efi_load_initrd() - Load initial RAM disk * @image: EFI loaded image protocol - * @load_addr: pointer to loaded initrd - * @load_size: size of loaded initrd * @soft_limit: preferred address for loading the initrd * @hard_limit: upper limit address for loading the initrd + * @out: pointer to store the address of the initrd table * * Return: status code */ efi_status_t efi_load_initrd(efi_loaded_image_t *image, - unsigned long *load_addr, - unsigned long *load_size, unsigned long soft_limit, - unsigned long hard_limit) + unsigned long hard_limit, + const struct linux_efi_initrd **out) { - efi_status_t status; + efi_guid_t tbl_guid = LINUX_EFI_INITRD_MEDIA_GUID; + efi_status_t status = EFI_SUCCESS; + struct linux_efi_initrd initrd, *tbl; - if (efi_noinitrd) { - *load_addr = *load_size = 0; - status = EFI_SUCCESS; - } else { - status = efi_load_initrd_dev_path(load_addr, load_size, hard_limit); - if (status == EFI_SUCCESS) { - efi_info("Loaded initrd from LINUX_EFI_INITRD_MEDIA_GUID device path\n"); - if (*load_size > 0) - efi_measure_initrd(*load_addr, *load_size); - } else if (status == EFI_NOT_FOUND) { - status = efi_load_initrd_cmdline(image, load_addr, load_size, - soft_limit, hard_limit); - if (status == EFI_SUCCESS && *load_size > 0) - efi_info("Loaded initrd from command line option\n"); - } - if (status != EFI_SUCCESS) { - efi_err("Failed to load initrd: 0x%lx\n", status); - *load_addr = *load_size = 0; - } + if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD) || efi_noinitrd) + return EFI_SUCCESS; + + status = efi_load_initrd_dev_path(&initrd, hard_limit); + if (status == EFI_SUCCESS) { + efi_info("Loaded initrd from LINUX_EFI_INITRD_MEDIA_GUID device path\n"); + } else if (status == EFI_NOT_FOUND) { + status = efi_load_initrd_cmdline(image, &initrd, soft_limit, + hard_limit); + /* command line loader disabled or no initrd= passed? */ + if (status == EFI_UNSUPPORTED || status == EFI_NOT_READY) + return EFI_SUCCESS; + if (status == EFI_SUCCESS) + efi_info("Loaded initrd from command line option\n"); } + if (status != EFI_SUCCESS) + goto failed; + + if (initrd.size > 0 && + efi_measure_tagged_event(initrd.base, initrd.size, + EFISTUB_EVT_INITRD) == EFI_SUCCESS) + efi_info("Measured initrd data into PCR 9\n"); + status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, sizeof(initrd), + (void **)&tbl); + if (status != EFI_SUCCESS) + goto free_initrd; + + *tbl = initrd; + status = efi_bs_call(install_configuration_table, &tbl_guid, tbl); + if (status != EFI_SUCCESS) + goto free_tbl; + + if (out) + *out = tbl; + return EFI_SUCCESS; + +free_tbl: + efi_bs_call(free_pool, tbl); +free_initrd: + efi_free(initrd.size, initrd.base); +failed: + efi_err("Failed to load initrd: 0x%lx\n", status); return status; } @@ -751,3 +703,70 @@ efi_status_t efi_wait_for_key(unsigned long usec, efi_input_key_t *key) return status; } + +/** + * efi_remap_image - Remap a loaded image with the appropriate permissions + * for code and data + * + * @image_base: the base of the image in memory + * @alloc_size: the size of the area in memory occupied by the image + * @code_size: the size of the leading part of the image containing code + * and read-only data + * + * efi_remap_image() uses the EFI memory attribute protocol to remap the code + * region of the loaded image read-only/executable, and the remainder + * read-write/non-executable. The code region is assumed to start at the base + * of the image, and will therefore cover the PE/COFF header as well. + */ +void efi_remap_image(unsigned long image_base, unsigned alloc_size, + unsigned long code_size) +{ + efi_guid_t guid = EFI_MEMORY_ATTRIBUTE_PROTOCOL_GUID; + efi_memory_attribute_protocol_t *memattr; + efi_status_t status; + u64 attr; + + /* + * If the firmware implements the EFI_MEMORY_ATTRIBUTE_PROTOCOL, let's + * invoke it to remap the text/rodata region of the decompressed image + * as read-only and the data/bss region as non-executable. + */ + status = efi_bs_call(locate_protocol, &guid, NULL, (void **)&memattr); + if (status != EFI_SUCCESS) + return; + + // Get the current attributes for the entire region + status = memattr->get_memory_attributes(memattr, image_base, + alloc_size, &attr); + if (status != EFI_SUCCESS) { + efi_warn("Failed to retrieve memory attributes for image region: 0x%lx\n", + status); + return; + } + + // Mark the code region as read-only + status = memattr->set_memory_attributes(memattr, image_base, code_size, + EFI_MEMORY_RO); + if (status != EFI_SUCCESS) { + efi_warn("Failed to remap code region read-only\n"); + return; + } + + // If the entire region was already mapped as non-exec, clear the + // attribute from the code region. Otherwise, set it on the data + // region. + if (attr & EFI_MEMORY_XP) { + status = memattr->clear_memory_attributes(memattr, image_base, + code_size, + EFI_MEMORY_XP); + if (status != EFI_SUCCESS) + efi_warn("Failed to remap code region executable\n"); + } else { + status = memattr->set_memory_attributes(memattr, + image_base + code_size, + alloc_size - code_size, + EFI_MEMORY_XP); + if (status != EFI_SUCCESS) + efi_warn("Failed to remap data region non-executable\n"); + } +} |
