diff options
| -rw-r--r-- | drivers/char/random.c | 50 |
1 files changed, 28 insertions, 22 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index a68b4a09327..74eeec58e77 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -584,21 +584,26 @@ struct fast_pool { * collector. It's hardcoded for an 128 bit pool and assumes that any * locks that might be needed are taken by the caller. */ -static void fast_mix(struct fast_pool *f, const void *in, int nbytes) +static void fast_mix(struct fast_pool *f, __u32 input[4]) { - const char *bytes = in; __u32 w; - unsigned i = f->count; unsigned input_rotate = f->rotate; - while (nbytes--) { - w = rol32(*bytes++, input_rotate & 31) ^ f->pool[i & 3] ^ - f->pool[(i + 1) & 3]; - f->pool[i & 3] = (w >> 3) ^ twist_table[w & 7]; - input_rotate += (i++ & 3) ? 7 : 14; - } - f->count = i; + w = rol32(input[0], input_rotate) ^ f->pool[0] ^ f->pool[3]; + f->pool[0] = (w >> 3) ^ twist_table[w & 7]; + input_rotate = (input_rotate + 14) & 31; + w = rol32(input[1], input_rotate) ^ f->pool[1] ^ f->pool[0]; + f->pool[1] = (w >> 3) ^ twist_table[w & 7]; + input_rotate = (input_rotate + 7) & 31; + w = rol32(input[2], input_rotate) ^ f->pool[2] ^ f->pool[1]; + f->pool[2] = (w >> 3) ^ twist_table[w & 7]; + input_rotate = (input_rotate + 7) & 31; + w = rol32(input[3], input_rotate) ^ f->pool[3] ^ f->pool[2]; + f->pool[3] = (w >> 3) ^ twist_table[w & 7]; + input_rotate = (input_rotate + 7) & 31; + f->rotate = input_rotate; + f->count++; } /* @@ -828,20 +833,21 @@ void add_interrupt_randomness(int irq, int irq_flags) struct fast_pool *fast_pool = &__get_cpu_var(irq_randomness); struct pt_regs *regs = get_irq_regs(); unsigned long now = jiffies; - __u32 input[4], cycles = random_get_entropy(); - - input[0] = cycles ^ jiffies; - input[1] = irq; - if (regs) { - __u64 ip = instruction_pointer(regs); - input[2] = ip; - input[3] = ip >> 32; - } + cycles_t cycles = random_get_entropy(); + __u32 input[4], c_high, j_high; + __u64 ip; + + c_high = (sizeof(cycles) > 4) ? cycles >> 32 : 0; + j_high = (sizeof(now) > 4) ? now >> 32 : 0; + input[0] = cycles ^ j_high ^ irq; + input[1] = now ^ c_high; + ip = regs ? instruction_pointer(regs) : _RET_IP_; + input[2] = ip; + input[3] = ip >> 32; - fast_mix(fast_pool, input, sizeof(input)); + fast_mix(fast_pool, input); - if ((fast_pool->count & 1023) && - !time_after(now, fast_pool->last + HZ)) + if ((fast_pool->count & 63) && !time_after(now, fast_pool->last + HZ)) return; fast_pool->last = now; |