diff options
Diffstat (limited to 'drivers/char/hw_random/core.c')
| -rw-r--r-- | drivers/char/hw_random/core.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c index bc9f95cbac92..f327f7493585 100644 --- a/drivers/char/hw_random/core.c +++ b/drivers/char/hw_random/core.c @@ -424,6 +424,7 @@ static int __init register_miscdev(void) static int hwrng_fillfn(void *unused) { + size_t entropy, entropy_credit = 0; /* in 1/1024 of a bit */ long rc; while (!kthread_should_stop()) { @@ -445,9 +446,17 @@ static int hwrng_fillfn(void *unused) msleep_interruptible(10000); continue; } + + /* If we cannot credit at least one bit of entropy, + * keep track of the remainder for the next iteration + */ + entropy = rc * current_quality * 8 + entropy_credit; + if ((entropy >> 10) == 0) + entropy_credit = entropy; + /* Outside lock, sure, but y'know: randomness. */ add_hwgenerator_randomness((void *)rng_fillbuf, rc, - rc * current_quality * 8 >> 10); + entropy >> 10); } hwrng_fill = NULL; return 0; |