diff options
| -rw-r--r-- | drivers/char/random.c | 50 | ||||
| -rw-r--r-- | include/linux/random.h | 3 | ||||
| -rw-r--r-- | init/main.c | 17 |
3 files changed, 40 insertions, 30 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index e591c6aadca4..1427f66252c6 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -772,18 +772,13 @@ static int random_pm_notification(struct notifier_block *nb, unsigned long actio static struct notifier_block pm_notifier = { .notifier_call = random_pm_notification }; /* - * The first collection of entropy occurs at system boot while interrupts - * are still turned off. Here we push in latent entropy, RDSEED, a timestamp, - * utsname(), and the command line. Depending on the above configuration knob, - * RDSEED may be considered sufficient for initialization. Note that much - * earlier setup may already have pushed entropy into the input pool by the - * time we get here. + * This is called extremely early, before time keeping functionality is + * available, but arch randomness is. Interrupts are not yet enabled. */ -int __init random_init(const char *command_line) +void __init random_init_early(const char *command_line) { - ktime_t now = ktime_get_real(); - size_t i, longs, arch_bits; unsigned long entropy[BLAKE2S_BLOCK_SIZE / sizeof(long)]; + size_t i, longs, arch_bits; #if defined(LATENT_ENTROPY_PLUGIN) static const u8 compiletime_seed[BLAKE2S_BLOCK_SIZE] __initconst __latent_entropy; @@ -803,34 +798,49 @@ int __init random_init(const char *command_line) i += longs; continue; } - entropy[0] = random_get_entropy(); - _mix_pool_bytes(entropy, sizeof(*entropy)); arch_bits -= sizeof(*entropy) * 8; ++i; } - _mix_pool_bytes(&now, sizeof(now)); - _mix_pool_bytes(utsname(), sizeof(*(utsname()))); + _mix_pool_bytes(command_line, strlen(command_line)); + + /* Reseed if already seeded by earlier phases. */ + if (crng_ready()) + crng_reseed(); + else if (trust_cpu) + _credit_init_bits(arch_bits); +} + +/* + * This is called a little bit after the prior function, and now there is + * access to timestamps counters. Interrupts are not yet enabled. + */ +void __init random_init(void) +{ + unsigned long entropy = random_get_entropy(); + ktime_t now = ktime_get_real(); + + _mix_pool_bytes(utsname(), sizeof(*(utsname()))); + _mix_pool_bytes(&now, sizeof(now)); + _mix_pool_bytes(&entropy, sizeof(entropy)); add_latent_entropy(); /* - * If we were initialized by the bootloader before jump labels are - * initialized, then we should enable the static branch here, where + * If we were initialized by the cpu or bootloader before jump labels + * are initialized, then we should enable the static branch here, where * it's guaranteed that jump labels have been initialized. */ if (!static_branch_likely(&crng_is_ready) && crng_init >= CRNG_READY) crng_set_ready(NULL); + /* Reseed if already seeded by earlier phases. */ if (crng_ready()) crng_reseed(); - else if (trust_cpu) - _credit_init_bits(arch_bits); WARN_ON(register_pm_notifier(&pm_notifier)); - WARN(!random_get_entropy(), "Missing cycle counter and fallback timer; RNG " - "entropy collection will consequently suffer."); - return 0; + WARN(!entropy, "Missing cycle counter and fallback timer; RNG " + "entropy collection will consequently suffer."); } /* diff --git a/include/linux/random.h b/include/linux/random.h index 3fec206487f6..a9e6e16f9774 100644 --- a/include/linux/random.h +++ b/include/linux/random.h @@ -72,7 +72,8 @@ static inline unsigned long get_random_canary(void) return get_random_long() & CANARY_MASK; } -int __init random_init(const char *command_line); +void __init random_init_early(const char *command_line); +void __init random_init(void); bool rng_is_initialized(void); int wait_for_random_bytes(void); diff --git a/init/main.c b/init/main.c index 1fe7942f5d4a..0866e5d0d467 100644 --- a/init/main.c +++ b/init/main.c @@ -976,6 +976,9 @@ asmlinkage __visible void __init __no_sanitize_address start_kernel(void) parse_args("Setting extra init args", extra_init_args, NULL, 0, -1, -1, NULL, set_init_arg); + /* Architectural and non-timekeeping rng init, before allocator init */ + random_init_early(command_line); + /* * These use large bootmem allocations and must precede * kmem_cache_init() @@ -1035,17 +1038,13 @@ asmlinkage __visible void __init __no_sanitize_address start_kernel(void) hrtimers_init(); softirq_init(); timekeeping_init(); - kfence_init(); time_init(); - /* - * For best initial stack canary entropy, prepare it after: - * - setup_arch() for any UEFI RNG entropy and boot cmdline access - * - timekeeping_init() for ktime entropy used in random_init() - * - time_init() for making random_get_entropy() work on some platforms - * - random_init() to initialize the RNG from from early entropy sources - */ - random_init(command_line); + /* This must be after timekeeping is initialized */ + random_init(); + + /* These make use of the fully initialized rng */ + kfence_init(); boot_init_stack_canary(); perf_event_init(); |