diff --git a/drivers/char/random.c b/drivers/char/random.c index 1958475fa19f..555dcb318396 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1842,7 +1842,7 @@ EXPORT_SYMBOL(get_random_bytes_arch); * data into the pool to prepare it for use. The pool is not cleared * as that can only decrease the entropy in the pool. */ -static void init_std_data(struct entropy_store *r) +static void __init init_std_data(struct entropy_store *r) { int i; ktime_t now = ktime_get_real(); @@ -1869,7 +1869,7 @@ static void init_std_data(struct entropy_store *r) * take care not to overwrite the precious per platform data * we were given. */ -static int rand_initialize(void) +int __init rand_initialize(void) { init_std_data(&input_pool); init_std_data(&blocking_pool); @@ -1881,7 +1881,6 @@ static int rand_initialize(void) } return 0; } -early_initcall(rand_initialize); #ifdef CONFIG_BLOCK void rand_initialize_disk(struct gendisk *disk) diff --git a/include/linux/random.h b/include/linux/random.h index 2dcfc73bf476..a91cc07df12f 100644 --- a/include/linux/random.h +++ b/include/linux/random.h @@ -35,6 +35,7 @@ extern void add_interrupt_randomness(int irq, int irq_flags) __latent_entropy; extern void get_random_bytes(void *buf, int nbytes); extern int wait_for_random_bytes(void); +extern int __init rand_initialize(void); extern bool rng_is_initialized(void); extern int add_random_ready_callback(struct random_ready_callback *rdy); extern void del_random_ready_callback(struct random_ready_callback *rdy); diff --git a/init/main.c b/init/main.c index 0a8f294c5345..86789c52f51a 100644 --- a/init/main.c +++ b/init/main.c @@ -570,6 +570,20 @@ asmlinkage __visible void __init start_kernel(void) hrtimers_init(); softirq_init(); timekeeping_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 rand_initialize() + * - rand_initialize() to get any arch-specific entropy like RDRAND + * - add_latent_entropy() to get any latent entropy + * - adding command line entropy + */ + rand_initialize(); + add_latent_entropy(); + add_device_randomness(command_line, strlen(command_line)); + boot_init_stack_canary(); + time_init(); sched_clock_postinit(); printk_nmi_init();