diff options
| -rw-r--r-- | drivers/char/random.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index b3ce4201a51f..00b50ccc9fae 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1255,7 +1255,7 @@ static __poll_t random_poll(struct file *file, poll_table *wait) return crng_ready() ? EPOLLIN | EPOLLRDNORM : EPOLLOUT | EPOLLWRNORM; } -static ssize_t write_pool(struct iov_iter *iter) +static ssize_t write_pool_user(struct iov_iter *iter) { u8 block[BLAKE2S_BLOCK_SIZE]; ssize_t ret = 0; @@ -1270,7 +1270,13 @@ static ssize_t write_pool(struct iov_iter *iter) mix_pool_bytes(block, copied); if (!iov_iter_count(iter) || copied != sizeof(block)) break; - cond_resched(); + + BUILD_BUG_ON(PAGE_SIZE % sizeof(block) != 0); + if (ret % PAGE_SIZE == 0) { + if (signal_pending(current)) + break; + cond_resched(); + } } memzero_explicit(block, sizeof(block)); @@ -1279,7 +1285,7 @@ static ssize_t write_pool(struct iov_iter *iter) static ssize_t random_write_iter(struct kiocb *kiocb, struct iov_iter *iter) { - return write_pool(iter); + return write_pool_user(iter); } static ssize_t urandom_read_iter(struct kiocb *kiocb, struct iov_iter *iter) @@ -1346,7 +1352,7 @@ static long random_ioctl(struct file *f, unsigned int cmd, unsigned long arg) ret = import_single_range(WRITE, p, len, &iov, &iter); if (unlikely(ret)) return ret; - ret = write_pool(&iter); + ret = write_pool_user(&iter); if (unlikely(ret < 0)) return ret; /* Since we're crediting, enforce that it was all written into the pool. */ |