diff options
| -rw-r--r-- | drivers/firmware/efi/efi.c | 72 | ||||
| -rw-r--r-- | include/linux/efi.h | 8 |
2 files changed, 80 insertions, 0 deletions
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index a4944e22f294..92914801e388 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -23,7 +23,10 @@ #include <linux/of.h> #include <linux/of_fdt.h> #include <linux/io.h> +#include <linux/kexec.h> #include <linux/platform_device.h> +#include <linux/random.h> +#include <linux/reboot.h> #include <linux/slab.h> #include <linux/acpi.h> #include <linux/ucs2_string.h> @@ -48,6 +51,7 @@ struct efi __read_mostly efi = { .esrt = EFI_INVALID_TABLE_ADDR, .properties_table = EFI_INVALID_TABLE_ADDR, .mem_attr_table = EFI_INVALID_TABLE_ADDR, + .rng_seed = EFI_INVALID_TABLE_ADDR, }; EXPORT_SYMBOL(efi); @@ -440,6 +444,7 @@ static __initdata efi_config_table_type_t common_tables[] = { {EFI_SYSTEM_RESOURCE_TABLE_GUID, "ESRT", &efi.esrt}, {EFI_PROPERTIES_TABLE_GUID, "PROP", &efi.properties_table}, {EFI_MEMORY_ATTRIBUTES_TABLE_GUID, "MEMATTR", &efi.mem_attr_table}, + {LINUX_EFI_RANDOM_SEED_TABLE_GUID, "RNG", &efi.rng_seed}, {NULL_GUID, NULL, NULL}, }; @@ -501,6 +506,29 @@ int __init efi_config_parse_tables(void *config_tables, int count, int sz, pr_cont("\n"); set_bit(EFI_CONFIG_TABLES, &efi.flags); + if (efi.rng_seed != EFI_INVALID_TABLE_ADDR) { + struct linux_efi_random_seed *seed; + u32 size = 0; + + seed = early_memremap(efi.rng_seed, sizeof(*seed)); + if (seed != NULL) { + size = seed->size; + early_memunmap(seed, sizeof(*seed)); + } else { + pr_err("Could not map UEFI random seed!\n"); + } + if (size > 0) { + seed = early_memremap(efi.rng_seed, + sizeof(*seed) + size); + if (seed != NULL) { + add_device_randomness(seed->bits, seed->size); + early_memunmap(seed, sizeof(*seed) + size); + } else { + pr_err("Could not map UEFI random seed!\n"); + } + } + } + /* Parse the EFI Properties table if it exists */ if (efi.properties_table != EFI_INVALID_TABLE_ADDR) { efi_properties_table_t *tbl; @@ -824,3 +852,47 @@ int efi_status_to_err(efi_status_t status) return err; } + +#ifdef CONFIG_KEXEC +static int update_efi_random_seed(struct notifier_block *nb, + unsigned long code, void *unused) +{ + struct linux_efi_random_seed *seed; + u32 size = 0; + + if (!kexec_in_progress) + return NOTIFY_DONE; + + seed = memremap(efi.rng_seed, sizeof(*seed), MEMREMAP_WB); + if (seed != NULL) { + size = min(seed->size, 32U); + memunmap(seed); + } else { + pr_err("Could not map UEFI random seed!\n"); + } + if (size > 0) { + seed = memremap(efi.rng_seed, sizeof(*seed) + size, + MEMREMAP_WB); + if (seed != NULL) { + seed->size = size; + get_random_bytes(seed->bits, seed->size); + memunmap(seed); + } else { + pr_err("Could not map UEFI random seed!\n"); + } + } + return NOTIFY_DONE; +} + +static struct notifier_block efi_random_seed_nb = { + .notifier_call = update_efi_random_seed, +}; + +static int register_update_efi_random_seed(void) +{ + if (efi.rng_seed == EFI_INVALID_TABLE_ADDR) + return 0; + return register_reboot_notifier(&efi_random_seed_nb); +} +late_initcall(register_update_efi_random_seed); +#endif diff --git a/include/linux/efi.h b/include/linux/efi.h index 2d089487d2da..85e28b138cdd 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -599,6 +599,7 @@ void efi_native_runtime_setup(void); */ #define LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID EFI_GUID(0xe03fc20a, 0x85dc, 0x406e, 0xb9, 0x0e, 0x4a, 0xb5, 0x02, 0x37, 0x1d, 0x95) #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) typedef struct { efi_guid_t guid; @@ -872,6 +873,7 @@ extern struct efi { unsigned long esrt; /* ESRT table */ unsigned long properties_table; /* properties table */ unsigned long mem_attr_table; /* memory attributes table */ + unsigned long rng_seed; /* UEFI firmware random seed */ efi_get_time_t *get_time; efi_set_time_t *set_time; efi_get_wakeup_time_t *get_wakeup_time; @@ -1493,4 +1495,10 @@ efi_status_t efi_exit_boot_services(efi_system_table_t *sys_table, struct efi_boot_memmap *map, void *priv, efi_exit_boot_map_processing priv_func); + +struct linux_efi_random_seed { + u32 size; + u8 bits[]; +}; + #endif /* _LINUX_EFI_H */ |