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Commit 13ffd431 authored by Jason A. Donenfeld's avatar Jason A. Donenfeld Committed by Greg Kroah-Hartman
Browse files

random: make consistent usage of crng_ready() 



commit a96cfe2d427064325ecbf56df8816c6b871ec285 upstream.

Rather than sometimes checking `crng_init < 2`, we should always use the
crng_ready() macro, so that should we change anything later, it's
consistent. Additionally, that macro already has a likely() around it,
which means we don't need to open code our own likely() and unlikely()
annotations.

Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: default avatarDominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: default avatarJason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 53af3a69

drivers/char/random.c

+7 −12
Original line number Diff line number Diff line
@@ -125,18 +125,13 @@ static void try_to_generate_entropy(void); 
 */

int wait_for_random_bytes(void)

{

	if (likely(crng_ready()))

		return 0;



	do {

	while (!crng_ready()) {

		int ret;

		ret = wait_event_interruptible_timeout(crng_init_wait, crng_ready(), HZ);

		if (ret)

			return ret > 0 ? 0 : ret;



		try_to_generate_entropy();

	} while (!crng_ready());



	}

	return 0;

}

EXPORT_SYMBOL(wait_for_random_bytes);
@@ -291,7 +286,7 @@ static void crng_reseed(void) 
		++next_gen;

	WRITE_ONCE(base_crng.generation, next_gen);

	WRITE_ONCE(base_crng.birth, jiffies);

	if (crng_init < 2) {

	if (!crng_ready()) {

		crng_init = 2;

		finalize_init = true;

	}
@@ -359,7 +354,7 @@ static void crng_make_state(u32 chacha_state[CHACHA20_BLOCK_SIZE / sizeof(u32)], 
	 * ready, we do fast key erasure with the base_crng directly, because

	 * this is what crng_pre_init_inject() mutates during early init.

	 */

	if (unlikely(!crng_ready())) {

	if (!crng_ready()) {

		bool ready;



		spin_lock_irqsave(&base_crng.lock, flags);
@@ -799,7 +794,7 @@ static void credit_entropy_bits(size_t nbits) 
		entropy_count = min_t(unsigned int, POOL_BITS, orig + add);

	} while (cmpxchg(&input_pool.entropy_count, orig, entropy_count) != orig);



	if (crng_init < 2 && entropy_count >= POOL_MIN_BITS)

	if (!crng_ready() && entropy_count >= POOL_MIN_BITS)

		crng_reseed();

}
@@ -956,7 +951,7 @@ int __init rand_initialize(void) 
	extract_entropy(base_crng.key, sizeof(base_crng.key));

	++base_crng.generation;



	if (arch_init && trust_cpu && crng_init < 2) {

	if (arch_init && trust_cpu && !crng_ready()) {

		crng_init = 2;

		pr_notice("crng init done (trusting CPU's manufacturer)\n");

	}
@@ -1545,7 +1540,7 @@ static long random_ioctl(struct file *f, unsigned int cmd, unsigned long arg) 
	case RNDRESEEDCRNG:

		if (!capable(CAP_SYS_ADMIN))

			return -EPERM;

		if (crng_init < 2)

		if (!crng_ready())

			return -ENODATA;

		crng_reseed();

		return 0;