Merge tag 'random_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel...

Pull random fixes from Ted Ts'o:
 "Fix some locking and gcc optimization issues from the most recent
  random_for_linus_stable pull request"

* tag 'random_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
  random: silence compiler warnings and fix race

diff --git a/drivers/char/random.c b/drivers/char/random.c
index e870f329db888c58e06bb854e7cf55d78a8bd313..01a260f67437488b425372c12d33142fce699f84 100644 (file)
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -803,13 +803,13 @@ static int crng_fast_load(const char *cp, size_t len)
                p[crng_init_cnt % CHACHA20_KEY_SIZE] ^= *cp;
                cp++; crng_init_cnt++; len--;
        }
+       spin_unlock_irqrestore(&primary_crng.lock, flags);
        if (crng_init_cnt >= CRNG_INIT_CNT_THRESH) {
                invalidate_batched_entropy();
                crng_init = 1;
                wake_up_interruptible(&crng_init_wait);
                pr_notice("random: fast init done\n");
        }
-       spin_unlock_irqrestore(&primary_crng.lock, flags);
        return 1;
 }
 
@@ -841,6 +841,7 @@ static void crng_reseed(struct crng_state *crng, struct entropy_store *r)
        }
        memzero_explicit(&buf, sizeof(buf));
        crng->init_time = jiffies;
+       spin_unlock_irqrestore(&primary_crng.lock, flags);
        if (crng == &primary_crng && crng_init < 2) {
                invalidate_batched_entropy();
                crng_init = 2;
@@ -848,7 +849,6 @@ static void crng_reseed(struct crng_state *crng, struct entropy_store *r)
                wake_up_interruptible(&crng_init_wait);
                pr_notice("random: crng init done\n");
        }
-       spin_unlock_irqrestore(&primary_crng.lock, flags);
 }
 
 static inline void crng_wait_ready(void)
@@ -2041,8 +2041,8 @@ static DEFINE_PER_CPU(struct batched_entropy, batched_entropy_u64);
 u64 get_random_u64(void)
 {
        u64 ret;
-       bool use_lock = crng_init < 2;
-       unsigned long flags;
+       bool use_lock = READ_ONCE(crng_init) < 2;
+       unsigned long flags = 0;
        struct batched_entropy *batch;
 
 #if BITS_PER_LONG == 64
@@ -2073,8 +2073,8 @@ static DEFINE_PER_CPU(struct batched_entropy, batched_entropy_u32);
 u32 get_random_u32(void)
 {
        u32 ret;
-       bool use_lock = crng_init < 2;
-       unsigned long flags;
+       bool use_lock = READ_ONCE(crng_init) < 2;
+       unsigned long flags = 0;
        struct batched_entropy *batch;
 
        if (arch_get_random_int(&ret))