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author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-08-01 11:35:16 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-08-01 11:35:16 -0700 |
commit | 9a5467fd600669cda488771dac3e951034fe2b08 (patch) | |
tree | 20c3c73ff3571e525193aca20d3602161b4e90be /lib | |
parent | 676056132425ac425d7215cdaa8bd25582e07966 (diff) | |
parent | 00b1304c4ca81dd893973cc620b87a5c3ff3f660 (diff) | |
download | lwn-9a5467fd600669cda488771dac3e951034fe2b08.tar.gz lwn-9a5467fd600669cda488771dac3e951034fe2b08.zip |
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.c | 48 |
1 files changed, 27 insertions, 21 deletions
diff --git a/lib/random32.c b/lib/random32.c index ca87d86992bd..217d5c4b666d 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; } |