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-rw-r--r--drivers/char/random.c19
1 files changed, 12 insertions, 7 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c
index f824ef8a927..b2ced39d76b 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -1665,15 +1665,20 @@ EXPORT_SYMBOL(secure_dccp_sequence_number);
1665 * value is not cryptographically secure but for several uses the cost of 1665 * value is not cryptographically secure but for several uses the cost of
1666 * depleting entropy is too high 1666 * depleting entropy is too high
1667 */ 1667 */
1668DEFINE_PER_CPU(__u32 [4], get_random_int_hash);
1668unsigned int get_random_int(void) 1669unsigned int get_random_int(void)
1669{ 1670{
1670 /* 1671 struct keydata *keyptr;
1671 * Use IP's RNG. It suits our purpose perfectly: it re-keys itself 1672 __u32 *hash = get_cpu_var(get_random_int_hash);
1672 * every second, from the entropy pool (and thus creates a limited 1673 int ret;
1673 * drain on it), and uses halfMD4Transform within the second. We 1674
1674 * also mix it with jiffies and the PID: 1675 keyptr = get_keyptr();
1675 */ 1676 hash[0] += current->pid + jiffies + get_cycles() + (int)(long)&ret;
1676 return secure_ip_id((__force __be32)(current->pid + jiffies)); 1677
1678 ret = half_md4_transform(hash, keyptr->secret);
1679 put_cpu_var(get_random_int_hash);
1680
1681 return ret;
1677} 1682}
1678 1683
1679/* 1684/*