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| author | Jason A. Donenfeld <Jason@zx2c4.com> | 2022-01-15 14:40:04 +0100 |
|---|---|---|
| committer | Jason A. Donenfeld <Jason@zx2c4.com> | 2022-01-18 13:03:56 +0100 |
| commit | 6c0eace6e1499712583b6ee62d95161e8b3449f5 (patch) | |
| tree | 3e1327052bf302aa9d69a99ded5acc73095ec798 /drivers/char | |
| parent | 18263c4e8e62f7329f38f5eadc568751242ca89c (diff) | |
| download | linux-6c0eace6e1499712583b6ee62d95161e8b3449f5.tar.gz linux-6c0eace6e1499712583b6ee62d95161e8b3449f5.tar.bz2 linux-6c0eace6e1499712583b6ee62d95161e8b3449f5.zip | |
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 <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/random.c | 21 |
1 files changed, 8 insertions, 13 deletions
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 */ /* |