diff options
| -rw-r--r-- | drivers/char/random.c | 5 | ||||
| -rw-r--r-- | include/linux/random.h | 1 | ||||
| -rw-r--r-- | lib/random32.c | 23 |
3 files changed, 27 insertions, 2 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index 7a744d391756..4fe5609eeb72 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -603,8 +603,11 @@ retry: if (!r->initialized && nbits > 0) { r->entropy_total += nbits; - if (r->entropy_total > 128) + if (r->entropy_total > 128) { r->initialized = 1; + if (r == &nonblocking_pool) + prandom_reseed_late(); + } } trace_credit_entropy_bits(r->name, nbits, entropy_count, diff --git a/include/linux/random.h b/include/linux/random.h index bf9085e89fb5..5117ae348fe8 100644 --- a/include/linux/random.h +++ b/include/linux/random.h @@ -29,6 +29,7 @@ unsigned long randomize_range(unsigned long start, unsigned long end, unsigned l u32 prandom_u32(void); void prandom_bytes(void *buf, int nbytes); void prandom_seed(u32 seed); +void prandom_reseed_late(void); u32 prandom_u32_state(struct rnd_state *); void prandom_bytes_state(struct rnd_state *state, void *buf, int nbytes); diff --git a/lib/random32.c b/lib/random32.c index 12215df701e8..9f2f2fb03dfe 100644 --- a/lib/random32.c +++ b/lib/random32.c @@ -200,9 +200,18 @@ static void prandom_start_seed_timer(void) * Generate better values after random number generator * is fully initialized. */ -static int __init prandom_reseed(void) +static void __prandom_reseed(bool late) { int i; + unsigned long flags; + static bool latch = false; + static DEFINE_SPINLOCK(lock); + + /* only allow initial seeding (late == false) once */ + spin_lock_irqsave(&lock, flags); + if (latch && !late) + goto out; + latch = true; for_each_possible_cpu(i) { struct rnd_state *state = &per_cpu(net_rand_state,i); @@ -216,6 +225,18 @@ static int __init prandom_reseed(void) /* mix it in */ prandom_u32_state(state); } +out: + spin_unlock_irqrestore(&lock, flags); +} + +void prandom_reseed_late(void) +{ + __prandom_reseed(true); +} + +static int __init prandom_reseed(void) +{ + __prandom_reseed(false); prandom_start_seed_timer(); return 0; } |