Commit cf6a85a8 authored by Will Deacon's avatar Will Deacon
Browse files

Merge branch 'for-next/random' into for-next/core 

Avoid calling arch_get_random_seed_long() from add_interrupt_randomness()
as this can result in a firmware call on some arm64 systems.

* for-next/random:
  random: avoid arch_get_random_seed_long() when collecting IRQ randomness
parents c974a8e5 390596c9

drivers/char/random.c

+1 −14
Original line number Diff line number Diff line
@@ -1261,8 +1261,6 @@ void add_interrupt_randomness(int irq, int irq_flags) 
	cycles_t		cycles = random_get_entropy();

	__u32			c_high, j_high;

	__u64			ip;

	unsigned long		seed;

	int			credit = 0;



	if (cycles == 0)

		cycles = get_reg(fast_pool, regs);
@@ -1298,23 +1296,12 @@ void add_interrupt_randomness(int irq, int irq_flags) 


	fast_pool->last = now;

	__mix_pool_bytes(r, &fast_pool->pool, sizeof(fast_pool->pool));



	/*

	 * If we have architectural seed generator, produce a seed and

	 * add it to the pool.  For the sake of paranoia don't let the

	 * architectural seed generator dominate the input from the

	 * interrupt noise.

	 */

	if (arch_get_random_seed_long(&seed)) {

		__mix_pool_bytes(r, &seed, sizeof(seed));

		credit = 1;

	}

	spin_unlock(&r->lock);



	fast_pool->count = 0;



	/* award one bit for the contents of the fast pool */

	credit_entropy_bits(r, credit + 1);

	credit_entropy_bits(r, 1);

}

EXPORT_SYMBOL_GPL(add_interrupt_randomness);