diff --git a/arch/arm/include/asm/efi.h b/arch/arm/include/asm/efi.h index 84dc0ba822f5..5dcf3c6011b7 100644 --- a/arch/arm/include/asm/efi.h +++ b/arch/arm/include/asm/efi.h @@ -87,4 +87,11 @@ static inline unsigned long efi_get_max_initrd_addr(unsigned long dram_base, return dram_base + SZ_512M; } +struct efi_arm_entry_state { + u32 cpsr_before_ebs; + u32 sctlr_before_ebs; + u32 cpsr_after_ebs; + u32 sctlr_after_ebs; +}; + #endif /* _ASM_ARM_EFI_H */ diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index e821a7d7d5c4..97d37f0a34f5 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -213,7 +213,6 @@ SYM_FUNC_START(startup_32) * We place all of the values on our mini stack so lret can * used to perform that far jump. */ - pushl $__KERNEL_CS leal startup_64(%ebp), %eax #ifdef CONFIG_EFI_MIXED movl efi32_boot_args(%ebp), %edi @@ -224,11 +223,20 @@ SYM_FUNC_START(startup_32) movl efi32_boot_args+8(%ebp), %edx // saved bootparams pointer cmpl $0, %edx jnz 1f + /* + * efi_pe_entry uses MS calling convention, which requires 32 bytes of + * shadow space on the stack even if all arguments are passed in + * registers. We also need an additional 8 bytes for the space that + * would be occupied by the return address, and this also results in + * the correct stack alignment for entry. + */ + subl $40, %esp leal efi_pe_entry(%ebp), %eax movl %edi, %ecx // MS calling convention movl %esi, %edx 1: #endif + pushl $__KERNEL_CS pushl %eax /* Enter paged protected Mode, activating Long Mode */ @@ -784,6 +792,7 @@ SYM_DATA_LOCAL(boot_heap, .fill BOOT_HEAP_SIZE, 1, 0) SYM_DATA_START_LOCAL(boot_stack) .fill BOOT_STACK_SIZE, 1, 0 + .balign 16 SYM_DATA_END_LABEL(boot_stack, SYM_L_LOCAL, boot_stack_end) /* diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index e6fc022bc87e..3939699e62fe 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -278,3 +278,14 @@ config EFI_EARLYCON depends on SERIAL_EARLYCON && !ARM && !IA64 select FONT_SUPPORT select ARCH_USE_MEMREMAP_PROT + +config EFI_CUSTOM_SSDT_OVERLAYS + bool "Load custom ACPI SSDT overlay from an EFI variable" + depends on EFI_VARS && ACPI + default ACPI_TABLE_UPGRADE + help + Allow loading of an ACPI SSDT overlay from an EFI variable specified + by a kernel command line option. + + See Documentation/admin-guide/acpi/ssdt-overlays.rst for more + information. diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c index c697e70ca7e7..71c445d20258 100644 --- a/drivers/firmware/efi/arm-init.c +++ b/drivers/firmware/efi/arm-init.c @@ -52,9 +52,11 @@ static phys_addr_t __init efi_to_phys(unsigned long addr) } static __initdata unsigned long screen_info_table = EFI_INVALID_TABLE_ADDR; +static __initdata unsigned long cpu_state_table = EFI_INVALID_TABLE_ADDR; static const efi_config_table_type_t arch_tables[] __initconst = { {LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID, &screen_info_table}, + {LINUX_EFI_ARM_CPU_STATE_TABLE_GUID, &cpu_state_table}, {} }; @@ -62,7 +64,8 @@ static void __init init_screen_info(void) { struct screen_info *si; - if (screen_info_table != EFI_INVALID_TABLE_ADDR) { + if (IS_ENABLED(CONFIG_ARM) && + screen_info_table != EFI_INVALID_TABLE_ADDR) { si = early_memremap_ro(screen_info_table, sizeof(*si)); if (!si) { pr_err("Could not map screen_info config table\n"); @@ -116,7 +119,8 @@ static int __init uefi_init(u64 efi_system_table) goto out; } retval = efi_config_parse_tables(config_tables, systab->nr_tables, - arch_tables); + IS_ENABLED(CONFIG_ARM) ? arch_tables + : NULL); early_memunmap(config_tables, table_size); out: @@ -238,9 +242,37 @@ void __init efi_init(void) init_screen_info(); +#ifdef CONFIG_ARM /* ARM does not permit early mappings to persist across paging_init() */ - if (IS_ENABLED(CONFIG_ARM)) - efi_memmap_unmap(); + efi_memmap_unmap(); + + if (cpu_state_table != EFI_INVALID_TABLE_ADDR) { + struct efi_arm_entry_state *state; + bool dump_state = true; + + state = early_memremap_ro(cpu_state_table, + sizeof(struct efi_arm_entry_state)); + if (state == NULL) { + pr_warn("Unable to map CPU entry state table.\n"); + return; + } + + if ((state->sctlr_before_ebs & 1) == 0) + pr_warn(FW_BUG "EFI stub was entered with MMU and Dcache disabled, please fix your firmware!\n"); + else if ((state->sctlr_after_ebs & 1) == 0) + pr_warn(FW_BUG "ExitBootServices() returned with MMU and Dcache disabled, please fix your firmware!\n"); + else + dump_state = false; + + if (dump_state || efi_enabled(EFI_DBG)) { + pr_info("CPSR at EFI stub entry : 0x%08x\n", state->cpsr_before_ebs); + pr_info("SCTLR at EFI stub entry : 0x%08x\n", state->sctlr_before_ebs); + pr_info("CPSR after ExitBootServices() : 0x%08x\n", state->cpsr_after_ebs); + pr_info("SCTLR after ExitBootServices(): 0x%08x\n", state->sctlr_after_ebs); + } + early_memunmap(state, sizeof(struct efi_arm_entry_state)); + } +#endif } static bool efifb_overlaps_pci_range(const struct of_pci_range *range) diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 7f1657b6c30d..5114cae4ec97 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -189,7 +189,7 @@ static void generic_ops_unregister(void) efivars_unregister(&generic_efivars); } -#if IS_ENABLED(CONFIG_ACPI) +#ifdef CONFIG_EFI_CUSTOM_SSDT_OVERLAYS #define EFIVAR_SSDT_NAME_MAX 16 static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata; static int __init efivar_ssdt_setup(char *str) @@ -622,7 +622,8 @@ int __init efi_config_parse_tables(const efi_config_table_t *config_tables, rsv = (void *)(p + prsv % PAGE_SIZE); /* reserve the entry itself */ - memblock_reserve(prsv, EFI_MEMRESERVE_SIZE(rsv->size)); + memblock_reserve(prsv, + struct_size(rsv, entry, rsv->size)); for (i = 0; i < atomic_read(&rsv->count); i++) { memblock_reserve(rsv->entry[i].base, diff --git a/drivers/firmware/efi/esrt.c b/drivers/firmware/efi/esrt.c index e3d692696583..d5915272141f 100644 --- a/drivers/firmware/efi/esrt.c +++ b/drivers/firmware/efi/esrt.c @@ -181,7 +181,7 @@ static int esre_create_sysfs_entry(void *esre, int entry_num) rc = kobject_init_and_add(&entry->kobj, &esre1_ktype, NULL, "entry%d", entry_num); if (rc) { - kfree(entry); + kobject_put(&entry->kobj); return rc; } } diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index 75daaf20374e..4cce372edaf4 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -6,7 +6,8 @@ # enabled, even if doing so doesn't break the build. # cflags-$(CONFIG_X86_32) := -march=i386 -cflags-$(CONFIG_X86_64) := -mcmodel=small +cflags-$(CONFIG_X86_64) := -mcmodel=small \ + $(call cc-option,-maccumulate-outgoing-args) cflags-$(CONFIG_X86) += -m$(BITS) -D__KERNEL__ \ -fPIC -fno-strict-aliasing -mno-red-zone \ -mno-mmx -mno-sse -fshort-wchar \ diff --git a/drivers/firmware/efi/libstub/arm32-stub.c b/drivers/firmware/efi/libstub/arm32-stub.c index 40243f524556..d08e5d55838c 100644 --- a/drivers/firmware/efi/libstub/arm32-stub.c +++ b/drivers/firmware/efi/libstub/arm32-stub.c @@ -7,10 +7,49 @@ #include "efistub.h" +static efi_guid_t cpu_state_guid = LINUX_EFI_ARM_CPU_STATE_TABLE_GUID; + +struct efi_arm_entry_state *efi_entry_state; + +static void get_cpu_state(u32 *cpsr, u32 *sctlr) +{ + asm("mrs %0, cpsr" : "=r"(*cpsr)); + if ((*cpsr & MODE_MASK) == HYP_MODE) + asm("mrc p15, 4, %0, c1, c0, 0" : "=r"(*sctlr)); + else + asm("mrc p15, 0, %0, c1, c0, 0" : "=r"(*sctlr)); +} + efi_status_t check_platform_features(void) { + efi_status_t status; + u32 cpsr, sctlr; int block; + get_cpu_state(&cpsr, &sctlr); + + efi_info("Entering in %s mode with MMU %sabled\n", + ((cpsr & MODE_MASK) == HYP_MODE) ? "HYP" : "SVC", + (sctlr & 1) ? "en" : "dis"); + + status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, + sizeof(*efi_entry_state), + (void **)&efi_entry_state); + if (status != EFI_SUCCESS) { + efi_err("allocate_pool() failed\n"); + return status; + } + + efi_entry_state->cpsr_before_ebs = cpsr; + efi_entry_state->sctlr_before_ebs = sctlr; + + status = efi_bs_call(install_configuration_table, &cpu_state_guid, + efi_entry_state); + if (status != EFI_SUCCESS) { + efi_err("install_configuration_table() failed\n"); + goto free_state; + } + /* non-LPAE kernels can run anywhere */ if (!IS_ENABLED(CONFIG_ARM_LPAE)) return EFI_SUCCESS; @@ -19,9 +58,22 @@ efi_status_t check_platform_features(void) block = cpuid_feature_extract(CPUID_EXT_MMFR0, 0); if (block < 5) { efi_err("This LPAE kernel is not supported by your CPU\n"); - return EFI_UNSUPPORTED; + status = EFI_UNSUPPORTED; + goto drop_table; } return EFI_SUCCESS; + +drop_table: + efi_bs_call(install_configuration_table, &cpu_state_guid, NULL); +free_state: + efi_bs_call(free_pool, efi_entry_state); + return status; +} + +void efi_handle_post_ebs_state(void) +{ + get_cpu_state(&efi_entry_state->cpsr_after_ebs, + &efi_entry_state->sctlr_after_ebs); } static efi_guid_t screen_info_guid = LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID; diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c index 89f075275300..d40fd68c6bb2 100644 --- a/drivers/firmware/efi/libstub/efi-stub-helper.c +++ b/drivers/firmware/efi/libstub/efi-stub-helper.c @@ -32,6 +32,10 @@ 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), @@ -83,6 +87,10 @@ u32 utf8_to_utf32(const u8 **s8) 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]; @@ -113,6 +121,16 @@ void efi_puts(const char *str) } } +/** + * 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]; @@ -154,13 +172,18 @@ int efi_printk(const char *fmt, ...) return printed; } -/* - * Parse the ASCII string 'cmdline' for EFI options, denoted by the efi= +/** + * efi_parse_options() - Parse EFI command line options + * @cmdline: kernel command line + * + * Parse the ASCII string @cmdline for EFI options, denoted by the efi= * option, e.g. efi=nochunk. * * It should be noted that efi= is parsed in two very different * environments, first in the early boot environment of the EFI boot * stub, and subsequently during the kernel boot. + * + * Return: status code */ efi_status_t efi_parse_options(char const *cmdline) { @@ -286,13 +309,21 @@ char *efi_convert_cmdline(efi_loaded_image_t *image, int *cmd_line_len) 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 + * * Handle calling ExitBootServices according to the requirements set out by the * spec. Obtains the current memory map, and returns that info after calling * ExitBootServices. The client must specify a function to perform any * processing of the memory map data prior to ExitBootServices. A client * specific structure may be passed to the function via priv. The client * function may be called multiple times. + * + * Return: status code */ efi_status_t efi_exit_boot_services(void *handle, struct efi_boot_memmap *map, @@ -361,6 +392,11 @@ efi_status_t efi_exit_boot_services(void *handle, return status; } +/** + * get_efi_config_table() - retrieve UEFI configuration table + * @guid: GUID of the configuration table to be retrieved + * Return: pointer to the configuration table or NULL + */ void *get_efi_config_table(efi_guid_t guid) { unsigned long tables = efi_table_attr(efi_system_table, tables); @@ -408,17 +444,18 @@ static const struct { }; /** - * efi_load_initrd_dev_path - load the initrd from the Linux initrd device path + * 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 * @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 + * + * 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, @@ -481,6 +518,16 @@ efi_status_t efi_load_initrd_cmdline(efi_loaded_image_t *image, load_addr, load_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 size of allocated memory for loading the initrd + * @hard_limit: minimum size of allocated memory + * + * Return: status code + */ efi_status_t efi_load_initrd(efi_loaded_image_t *image, unsigned long *load_addr, unsigned long *load_size, @@ -505,6 +552,15 @@ efi_status_t efi_load_initrd(efi_loaded_image_t *image, return status; } +/** + * efi_wait_for_key() - Wait for key stroke + * @usec: number of microseconds to wait for key stroke + * @key: key entered + * + * Wait for up to @usec microseconds for a key stroke. + * + * Return: status code, EFI_SUCCESS if key received + */ efi_status_t efi_wait_for_key(unsigned long usec, efi_input_key_t *key) { efi_event_t events[2], timer; diff --git a/drivers/firmware/efi/libstub/efi-stub.c b/drivers/firmware/efi/libstub/efi-stub.c index e97370bdfdb0..3318ec3f8e5b 100644 --- a/drivers/firmware/efi/libstub/efi-stub.c +++ b/drivers/firmware/efi/libstub/efi-stub.c @@ -329,6 +329,9 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, if (status != EFI_SUCCESS) goto fail_free_initrd; + if (IS_ENABLED(CONFIG_ARM)) + efi_handle_post_ebs_state(); + efi_enter_kernel(image_addr, fdt_addr, fdt_totalsize((void *)fdt_addr)); /* not reached */ diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h index bcd8c0a785f0..2c9d42264c29 100644 --- a/drivers/firmware/efi/libstub/efistub.h +++ b/drivers/firmware/efi/libstub/efistub.h @@ -157,8 +157,14 @@ typedef void (__efiapi *efi_event_notify_t)(efi_event_t, void *); #define EFI_EVT_NOTIFY_WAIT 0x00000100U #define EFI_EVT_NOTIFY_SIGNAL 0x00000200U -/* - * boottime->wait_for_event takes an array of events as input. +/** + * efi_set_event_at() - add event to events array + * + * @events: array of UEFI events + * @ids: index where to put the event in the array + * @event: event to add to the aray + * + * boottime->wait_for_event() takes an array of events as input. * Provide a helper to set it up correctly for mixed mode. */ static inline @@ -771,4 +777,6 @@ efi_status_t efi_load_initrd(efi_loaded_image_t *image, unsigned long soft_limit, unsigned long hard_limit); +void efi_handle_post_ebs_state(void); + #endif diff --git a/drivers/firmware/efi/libstub/file.c b/drivers/firmware/efi/libstub/file.c index 2005e33b33d5..630caa6b1f4c 100644 --- a/drivers/firmware/efi/libstub/file.c +++ b/drivers/firmware/efi/libstub/file.c @@ -102,12 +102,20 @@ static int find_file_option(const efi_char16_t *cmdline, int cmdline_len, if (!found) return 0; + /* Skip any leading slashes */ + while (cmdline[i] == L'/' || cmdline[i] == L'\\') + i++; + while (--result_len > 0 && i < cmdline_len) { - if (cmdline[i] == L'\0' || - cmdline[i] == L'\n' || - cmdline[i] == L' ') + efi_char16_t c = cmdline[i++]; + + if (c == L'\0' || c == L'\n' || c == L' ') break; - *result++ = cmdline[i++]; + else if (c == L'/') + /* Replace UNIX dir separators with EFI standard ones */ + *result++ = L'\\'; + else + *result++ = c; } *result = L'\0'; return i; diff --git a/drivers/firmware/efi/libstub/skip_spaces.c b/drivers/firmware/efi/libstub/skip_spaces.c index a700b3c7f7d0..159fb4e456c6 100644 --- a/drivers/firmware/efi/libstub/skip_spaces.c +++ b/drivers/firmware/efi/libstub/skip_spaces.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 #include +#include #include char *skip_spaces(const char *str) diff --git a/fs/efivarfs/file.c b/fs/efivarfs/file.c index e9e27a271af0..feaa5e182b7b 100644 --- a/fs/efivarfs/file.c +++ b/fs/efivarfs/file.c @@ -51,6 +51,7 @@ static ssize_t efivarfs_file_write(struct file *file, } else { inode_lock(inode); i_size_write(inode, datasize + sizeof(attributes)); + inode->i_mtime = current_time(inode); inode_unlock(inode); } @@ -72,10 +73,8 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, ssize_t size = 0; int err; - while (!__ratelimit(&file->f_cred->user->ratelimit)) { - if (!msleep_interruptible(50)) - return -EINTR; - } + while (!__ratelimit(&file->f_cred->user->ratelimit)) + msleep(50); err = efivar_entry_size(var, &datasize); diff --git a/include/linux/efi.h b/include/linux/efi.h index 2c6495f72f79..bb35f3305e55 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -350,6 +350,7 @@ void efi_native_runtime_setup(void); * associated with ConOut */ #define LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID EFI_GUID(0xe03fc20a, 0x85dc, 0x406e, 0xb9, 0x0e, 0x4a, 0xb5, 0x02, 0x37, 0x1d, 0x95) +#define LINUX_EFI_ARM_CPU_STATE_TABLE_GUID EFI_GUID(0xef79e4aa, 0x3c3d, 0x4989, 0xb9, 0x02, 0x07, 0xa9, 0x43, 0xe5, 0x50, 0xd2) #define LINUX_EFI_LOADER_ENTRY_GUID EFI_GUID(0x4a67b082, 0x0a4c, 0x41cf, 0xb6, 0xc7, 0x44, 0x0b, 0x29, 0xbb, 0x8c, 0x4f) #define LINUX_EFI_RANDOM_SEED_TABLE_GUID EFI_GUID(0x1ce1e5bc, 0x7ceb, 0x42f2, 0x81, 0xe5, 0x8a, 0xad, 0xf1, 0x80, 0xf5, 0x7b) #define LINUX_EFI_TPM_EVENT_LOG_GUID EFI_GUID(0xb7799cb0, 0xeca2, 0x4943, 0x96, 0x67, 0x1f, 0xae, 0x07, 0xb7, 0x47, 0xfa) @@ -1236,14 +1237,11 @@ struct linux_efi_memreserve { struct { phys_addr_t base; phys_addr_t size; - } entry[0]; + } entry[]; }; -#define EFI_MEMRESERVE_SIZE(count) (sizeof(struct linux_efi_memreserve) + \ - (count) * sizeof(((struct linux_efi_memreserve *)0)->entry[0])) - #define EFI_MEMRESERVE_COUNT(size) (((size) - sizeof(struct linux_efi_memreserve)) \ - / sizeof(((struct linux_efi_memreserve *)0)->entry[0])) + / sizeof_field(struct linux_efi_memreserve, entry[0])) void __init efi_arch_mem_reserve(phys_addr_t addr, u64 size); diff --git a/include/linux/tpm_eventlog.h b/include/linux/tpm_eventlog.h index 4f8c90c93c29..64356b199e94 100644 --- a/include/linux/tpm_eventlog.h +++ b/include/linux/tpm_eventlog.h @@ -81,6 +81,8 @@ struct tcg_efi_specid_event_algs { u16 digest_size; } __packed; +#define TCG_SPECID_SIG "Spec ID Event03" + struct tcg_efi_specid_event_head { u8 signature[16]; u32 platform_class; @@ -171,6 +173,7 @@ static inline int __calc_tpm2_event_size(struct tcg_pcr_event2_head *event, int i; int j; u32 count, event_type; + const u8 zero_digest[sizeof(event_header->digest)] = {0}; marker = event; marker_start = marker; @@ -198,10 +201,19 @@ static inline int __calc_tpm2_event_size(struct tcg_pcr_event2_head *event, count = READ_ONCE(event->count); event_type = READ_ONCE(event->event_type); + /* Verify that it's the log header */ + if (event_header->pcr_idx != 0 || + event_header->event_type != NO_ACTION || + memcmp(event_header->digest, zero_digest, sizeof(zero_digest))) { + size = 0; + goto out; + } + efispecid = (struct tcg_efi_specid_event_head *)event_header->event; /* Check if event is malformed. */ - if (count > efispecid->num_algs) { + if (memcmp(efispecid->signature, TCG_SPECID_SIG, + sizeof(TCG_SPECID_SIG)) || count > efispecid->num_algs) { size = 0; goto out; }