summaryrefslogtreecommitdiff
path: root/lib
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2008-08-01 11:35:16 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-08-01 11:35:16 -0700
commit9a5467fd600669cda488771dac3e951034fe2b08 (patch)
tree20c3c73ff3571e525193aca20d3602161b4e90be /lib
parent676056132425ac425d7215cdaa8bd25582e07966 (diff)
parent00b1304c4ca81dd893973cc620b87a5c3ff3f660 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (46 commits) tcp: MD5: Fix IPv6 signatures skbuff: add missing kernel-doc for do_not_encrypt net/ipv4/route.c: fix build error tcp: MD5: Fix MD5 signatures on certain ACK packets ipv6: Fix ip6_xmit to send fragments if ipfragok is true ipvs: Move userspace definitions to include/linux/ip_vs.h netdev: Fix lockdep warnings in multiqueue configurations. netfilter: xt_hashlimit: fix race between htable_destroy and htable_gc netfilter: ipt_recent: fix race between recent_mt_destroy and proc manipulations netfilter: nf_conntrack_tcp: decrease timeouts while data in unacknowledged irda: replace __FUNCTION__ with __func__ nsc-ircc: default to dongle type 9 on IBM hardware bluetooth: add quirks for a few hci_usb devices hysdn: remove the packed attribute from PofTimStamp_tag isdn: use the common ascii hex helpers tg3: adapt tg3 to use reworked PCI PM code atm: fix direct casts of pointers to u32 in the InterPhase driver atm: fix const assignment/discard warnings in the ATM networking driver net: use the common ascii hex helpers random32: seeding improvement ...
Diffstat (limited to 'lib')
-rw-r--r--lib/random32.c48
1 files changed, 27 insertions, 21 deletions
diff --git a/lib/random32.c b/lib/random32.c
index ca87d86992b..217d5c4b666 100644
--- a/lib/random32.c
+++ b/lib/random32.c
@@ -56,23 +56,12 @@ static u32 __random32(struct rnd_state *state)
return (state->s1 ^ state->s2 ^ state->s3);
}
-static void __set_random32(struct rnd_state *state, unsigned long s)
+/*
+ * Handle minimum values for seeds
+ */
+static inline u32 __seed(u32 x, u32 m)
{
- if (s == 0)
- s = 1; /* default seed is 1 */
-
-#define LCG(n) (69069 * n)
- state->s1 = LCG(s);
- state->s2 = LCG(state->s1);
- state->s3 = LCG(state->s2);
-
- /* "warm it up" */
- __random32(state);
- __random32(state);
- __random32(state);
- __random32(state);
- __random32(state);
- __random32(state);
+ return (x < m) ? x + m : x;
}
/**
@@ -107,7 +96,7 @@ void srandom32(u32 entropy)
*/
for_each_possible_cpu (i) {
struct rnd_state *state = &per_cpu(net_rand_state, i);
- __set_random32(state, state->s1 ^ entropy);
+ state->s1 = __seed(state->s1 ^ entropy, 1);
}
}
EXPORT_SYMBOL(srandom32);
@@ -122,7 +111,19 @@ static int __init random32_init(void)
for_each_possible_cpu(i) {
struct rnd_state *state = &per_cpu(net_rand_state,i);
- __set_random32(state, i + jiffies);
+
+#define LCG(x) ((x) * 69069) /* super-duper LCG */
+ state->s1 = __seed(LCG(i + jiffies), 1);
+ state->s2 = __seed(LCG(state->s1), 7);
+ state->s3 = __seed(LCG(state->s2), 15);
+
+ /* "warm it up" */
+ __random32(state);
+ __random32(state);
+ __random32(state);
+ __random32(state);
+ __random32(state);
+ __random32(state);
}
return 0;
}
@@ -135,13 +136,18 @@ core_initcall(random32_init);
static int __init random32_reseed(void)
{
int i;
- unsigned long seed;
for_each_possible_cpu(i) {
struct rnd_state *state = &per_cpu(net_rand_state,i);
+ u32 seeds[3];
+
+ get_random_bytes(&seeds, sizeof(seeds));
+ state->s1 = __seed(seeds[0], 1);
+ state->s2 = __seed(seeds[1], 7);
+ state->s3 = __seed(seeds[2], 15);
- get_random_bytes(&seed, sizeof(seed));
- __set_random32(state, seed);
+ /* mix it in */
+ __random32(state);
}
return 0;
}