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path: root/drivers/firmware/efi/libstub/efi-stub-helper.c
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Diffstat (limited to 'drivers/firmware/efi/libstub/efi-stub-helper.c')
-rw-r--r--drivers/firmware/efi/libstub/efi-stub-helper.c571
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");
+ }
+}