crng_init is protected by primary_crng->lock. Therefore, we need to hold this lock when increasing crng_init to 2. As we shouldn't hold this lock for too long, only hold it for crng_finalize_init(), and split out the parts which can be delayed to crng_late_init(). If crng_finalize_init() cannot proceed due to workqueues not yet being available, it is called again in rand_initialize(). Then, we do not need to call crng_late_init(): At this time, the boot process is still so early that there are no other processes to wake up. Signed-off-by: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx> --- drivers/char/random.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/drivers/char/random.c b/drivers/char/random.c index 2df08d05e850..c70a9abbd8cb 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -557,19 +557,24 @@ static void __init crng_initialize_primary(void) primary_crng.init_time = jiffies - CRNG_RESEED_INTERVAL - 1; } -static void crng_finalize_init(void) +static bool crng_finalize_init(void) { if (!system_wq) { /* We can't call numa_crng_init until we have workqueues, * so mark this for processing later. */ crng_need_final_init = true; - return; + return false; } invalidate_batched_entropy(); numa_crng_init(); crng_init = 2; crng_need_final_init = false; + return true; +} + +static void crng_late_init(void) +{ process_random_ready_list(); wake_up_interruptible(&crng_init_wait); kill_fasync(&fasync, SIGIO, POLL_IN); @@ -710,6 +715,7 @@ static int crng_slow_load(const u8 *cp, size_t len) static void crng_reseed(struct crng_state *crng) { + bool needs_late_init = false; unsigned long flags; int i; union { @@ -744,9 +750,11 @@ static void crng_reseed(struct crng_state *crng) } memzero_explicit(&buf, sizeof(buf)); WRITE_ONCE(crng->init_time, jiffies); - spin_unlock_irqrestore(&crng->lock, flags); if (crng == &primary_crng && crng_init < 2) - crng_finalize_init(); + needs_late_init = crng_finalize_init(); + spin_unlock_irqrestore(&crng->lock, flags); + if (needs_late_init) + crng_late_init(); } static void _extract_crng(struct crng_state *crng, u8 out[CHACHA_BLOCK_SIZE]) @@ -1383,8 +1391,10 @@ static void __init init_std_data(void) int __init rand_initialize(void) { init_std_data(); - if (crng_need_final_init) + if (crng_need_final_init) { crng_finalize_init(); + pr_notice("crng init done\n"); + } crng_initialize_primary(); crng_global_init_time = jiffies; if (ratelimit_disable) { -- 2.35.1