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-rw-r--r--drivers/char/random.c5
-rw-r--r--include/linux/random.h1
-rw-r--r--lib/random32.c23
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;
}