Merge tag 'stable/for-linus-3.15-rc5-tag' of git://git.kernel.org/pub/scm/linux/kerne...

[firefly-linux-kernel-4.4.55.git] / drivers / char / random.c

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 6b75713d953a4e719cd33610f6034bec430c5d95..102c50d38902ca43fed85641618ba202a7251679 100644 (file)
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -995,8 +995,11 @@ retry:
                ibytes = min_t(size_t, ibytes, have_bytes - reserved);
        if (ibytes < min)
                ibytes = 0;
-       entropy_count = max_t(int, 0,
-                             entropy_count - (ibytes << (ENTROPY_SHIFT + 3)));
+       if (have_bytes >= ibytes + reserved)
+               entropy_count -= ibytes << (ENTROPY_SHIFT + 3);
+       else
+               entropy_count = reserved << (ENTROPY_SHIFT + 3);
+
        if (cmpxchg(&r->entropy_count, orig, entropy_count) != orig)
                goto retry;