diff options
| -rw-r--r-- | drivers/char/random.c | 43 |
1 files changed, 4 insertions, 39 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index 7d1682ea1e86..6e455bc4a39e 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c | |||
| @@ -910,12 +910,13 @@ void add_interrupt_randomness(int irq, int irq_flags) | |||
| 910 | 910 | ||
| 911 | /* | 911 | /* |
| 912 | * If we have architectural seed generator, produce a seed and | 912 | * If we have architectural seed generator, produce a seed and |
| 913 | * add it to the pool. For the sake of paranoia count it as | 913 | * add it to the pool. For the sake of paranoia don't let the |
| 914 | * 50% entropic. | 914 | * architectural seed generator dominate the input from the |
| 915 | * interrupt noise. | ||
| 915 | */ | 916 | */ |
| 916 | if (arch_get_random_seed_long(&seed)) { | 917 | if (arch_get_random_seed_long(&seed)) { |
| 917 | __mix_pool_bytes(r, &seed, sizeof(seed)); | 918 | __mix_pool_bytes(r, &seed, sizeof(seed)); |
| 918 | credit += sizeof(seed) * 4; | 919 | credit = 1; |
| 919 | } | 920 | } |
| 920 | spin_unlock(&r->lock); | 921 | spin_unlock(&r->lock); |
| 921 | 922 | ||
| @@ -1328,37 +1329,6 @@ void rand_initialize_disk(struct gendisk *disk) | |||
| 1328 | } | 1329 | } |
| 1329 | #endif | 1330 | #endif |
| 1330 | 1331 | ||
| 1331 | /* | ||
| 1332 | * Attempt an emergency refill using arch_get_random_seed_long(). | ||
| 1333 | * | ||
| 1334 | * As with add_interrupt_randomness() be paranoid and only | ||
| 1335 | * credit the output as 50% entropic. | ||
| 1336 | */ | ||
| 1337 | static int arch_random_refill(void) | ||
| 1338 | { | ||
| 1339 | const unsigned int nlongs = 64; /* Arbitrary number */ | ||
| 1340 | unsigned int n = 0; | ||
| 1341 | unsigned int i; | ||
| 1342 | unsigned long buf[nlongs]; | ||
| 1343 | |||
| 1344 | if (!arch_has_random_seed()) | ||
| 1345 | return 0; | ||
| 1346 | |||
| 1347 | for (i = 0; i < nlongs; i++) { | ||
| 1348 | if (arch_get_random_seed_long(&buf[n])) | ||
| 1349 | n++; | ||
| 1350 | } | ||
| 1351 | |||
| 1352 | if (n) { | ||
| 1353 | unsigned int rand_bytes = n * sizeof(unsigned long); | ||
| 1354 | |||
| 1355 | mix_pool_bytes(&input_pool, buf, rand_bytes); | ||
| 1356 | credit_entropy_bits(&input_pool, rand_bytes*4); | ||
| 1357 | } | ||
| 1358 | |||
| 1359 | return n; | ||
| 1360 | } | ||
| 1361 | |||
| 1362 | static ssize_t | 1332 | static ssize_t |
| 1363 | _random_read(int nonblock, char __user *buf, size_t nbytes) | 1333 | _random_read(int nonblock, char __user *buf, size_t nbytes) |
| 1364 | { | 1334 | { |
| @@ -1379,11 +1349,6 @@ _random_read(int nonblock, char __user *buf, size_t nbytes) | |||
| 1379 | return n; | 1349 | return n; |
| 1380 | 1350 | ||
| 1381 | /* Pool is (near) empty. Maybe wait and retry. */ | 1351 | /* Pool is (near) empty. Maybe wait and retry. */ |
| 1382 | |||
| 1383 | /* First try an emergency refill */ | ||
| 1384 | if (arch_random_refill()) | ||
| 1385 | continue; | ||
| 1386 | |||
| 1387 | if (nonblock) | 1352 | if (nonblock) |
| 1388 | return -EAGAIN; | 1353 | return -EAGAIN; |
| 1389 | 1354 | ||
