From 6c0eace6e1499712583b6ee62d95161e8b3449f5 Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Sat, 15 Jan 2022 14:40:04 +0100 Subject: random: access input_pool_data directly rather than through pointer This gets rid of another abstraction we no longer need. It would be nice if we could instead make pool an array rather than a pointer, but the latent entropy plugin won't be able to do its magic in that case. So instead we put all accesses to the input pool's actual data through the input_pool_data array directly. Reviewed-by: Dominik Brodowski Signed-off-by: Jason A. Donenfeld --- drivers/char/random.c | 21 ++++++++------------- 1 file changed, 8 insertions(+), 13 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/random.c b/drivers/char/random.c index ff672be101fc..6e4218f78260 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -496,17 +496,12 @@ MODULE_PARM_DESC(ratelimit_disable, "Disable random ratelimit suppression"); static u32 input_pool_data[POOL_WORDS] __latent_entropy; static struct { - /* read-only data: */ - u32 *pool; - - /* read-write data: */ spinlock_t lock; u16 add_ptr; u16 input_rotate; int entropy_count; } input_pool = { .lock = __SPIN_LOCK_UNLOCKED(input_pool.lock), - .pool = input_pool_data }; static ssize_t extract_entropy(void *buf, size_t nbytes, int min); @@ -544,15 +539,15 @@ static void _mix_pool_bytes(const void *in, int nbytes) i = (i - 1) & POOL_WORDMASK; /* XOR in the various taps */ - w ^= input_pool.pool[i]; - w ^= input_pool.pool[(i + POOL_TAP1) & POOL_WORDMASK]; - w ^= input_pool.pool[(i + POOL_TAP2) & POOL_WORDMASK]; - w ^= input_pool.pool[(i + POOL_TAP3) & POOL_WORDMASK]; - w ^= input_pool.pool[(i + POOL_TAP4) & POOL_WORDMASK]; - w ^= input_pool.pool[(i + POOL_TAP5) & POOL_WORDMASK]; + w ^= input_pool_data[i]; + w ^= input_pool_data[(i + POOL_TAP1) & POOL_WORDMASK]; + w ^= input_pool_data[(i + POOL_TAP2) & POOL_WORDMASK]; + w ^= input_pool_data[(i + POOL_TAP3) & POOL_WORDMASK]; + w ^= input_pool_data[(i + POOL_TAP4) & POOL_WORDMASK]; + w ^= input_pool_data[(i + POOL_TAP5) & POOL_WORDMASK]; /* Mix the result back in with a twist */ - input_pool.pool[i] = (w >> 3) ^ twist_table[w & 7]; + input_pool_data[i] = (w >> 3) ^ twist_table[w & 7]; /* * Normally, we add 7 bits of rotation to the pool. @@ -1369,7 +1364,7 @@ static void extract_buf(u8 *out) /* Generate a hash across the pool */ spin_lock_irqsave(&input_pool.lock, flags); - blake2s_update(&state, (const u8 *)input_pool.pool, POOL_BYTES); + blake2s_update(&state, (const u8 *)input_pool_data, POOL_BYTES); blake2s_final(&state, hash); /* final zeros out state */ /* -- cgit