diff options
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/random.c | 44 |
1 files changed, 23 insertions, 21 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index e5d9739b81f5..8be3efd65ef2 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1101,25 +1101,30 @@ static DEFINE_PER_CPU(struct fast_pool, irq_randomness) = { * and therefore this has no security on its own. s represents the * four-word SipHash state, while v represents a two-word input. */ -static void fast_mix(unsigned long s[4], const unsigned long v[2]) +static void fast_mix(unsigned long s[4], unsigned long v1, unsigned long v2) { - size_t i; - - for (i = 0; i < 2; ++i) { - s[3] ^= v[i]; #ifdef CONFIG_64BIT - s[0] += s[1]; s[1] = rol64(s[1], 13); s[1] ^= s[0]; s[0] = rol64(s[0], 32); - s[2] += s[3]; s[3] = rol64(s[3], 16); s[3] ^= s[2]; - s[0] += s[3]; s[3] = rol64(s[3], 21); s[3] ^= s[0]; - s[2] += s[1]; s[1] = rol64(s[1], 17); s[1] ^= s[2]; s[2] = rol64(s[2], 32); +#define PERM() do { \ + s[0] += s[1]; s[1] = rol64(s[1], 13); s[1] ^= s[0]; s[0] = rol64(s[0], 32); \ + s[2] += s[3]; s[3] = rol64(s[3], 16); s[3] ^= s[2]; \ + s[0] += s[3]; s[3] = rol64(s[3], 21); s[3] ^= s[0]; \ + s[2] += s[1]; s[1] = rol64(s[1], 17); s[1] ^= s[2]; s[2] = rol64(s[2], 32); \ +} while (0) #else - s[0] += s[1]; s[1] = rol32(s[1], 5); s[1] ^= s[0]; s[0] = rol32(s[0], 16); - s[2] += s[3]; s[3] = rol32(s[3], 8); s[3] ^= s[2]; - s[0] += s[3]; s[3] = rol32(s[3], 7); s[3] ^= s[0]; - s[2] += s[1]; s[1] = rol32(s[1], 13); s[1] ^= s[2]; s[2] = rol32(s[2], 16); +#define PERM() do { \ + s[0] += s[1]; s[1] = rol32(s[1], 5); s[1] ^= s[0]; s[0] = rol32(s[0], 16); \ + s[2] += s[3]; s[3] = rol32(s[3], 8); s[3] ^= s[2]; \ + s[0] += s[3]; s[3] = rol32(s[3], 7); s[3] ^= s[0]; \ + s[2] += s[1]; s[1] = rol32(s[1], 13); s[1] ^= s[2]; s[2] = rol32(s[2], 16); \ +} while (0) #endif - s[0] ^= v[i]; - } + + s[3] ^= v1; + PERM(); + s[0] ^= v1; + s[3] ^= v2; + PERM(); + s[0] ^= v2; } #ifdef CONFIG_SMP @@ -1189,10 +1194,8 @@ void add_interrupt_randomness(int irq) struct pt_regs *regs = get_irq_regs(); unsigned int new_count; - fast_mix(fast_pool->pool, (unsigned long[2]){ - entropy, - (regs ? instruction_pointer(regs) : _RET_IP_) ^ swab(irq) - }); + fast_mix(fast_pool->pool, entropy, + (regs ? instruction_pointer(regs) : _RET_IP_) ^ swab(irq)); new_count = ++fast_pool->count; if (new_count & MIX_INFLIGHT) @@ -1232,8 +1235,7 @@ static void add_timer_randomness(struct timer_rand_state *state, unsigned int nu * sometime after, so mix into the fast pool. */ if (in_hardirq()) { - fast_mix(this_cpu_ptr(&irq_randomness)->pool, - (unsigned long[2]){ entropy, num }); + fast_mix(this_cpu_ptr(&irq_randomness)->pool, entropy, num); } else { spin_lock_irqsave(&input_pool.lock, flags); _mix_pool_bytes(&entropy, sizeof(entropy)); |