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Donenfeld" , LKML From: Jens Axboe Subject: [PATCH] random: convert to using fops->write_iter() Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Now that the read side has been converted to fix a regression with splice, convert the write side as well to have some symmetry in the interface used (and help deprecate ->write()). Signed-off-by: Jens Axboe --- Jason, this has only been booted. I did verify that it seems to take a write just fine, but I would appreciate if you could vet this one with your testing. Thanks! diff --git a/drivers/char/random.c b/drivers/char/random.c index 41ca5966aa4f..3da04068c225 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1283,20 +1283,20 @@ static __poll_t random_poll(struct file *file, poll= _table *wait) return crng_ready() ? EPOLLIN | EPOLLRDNORM : EPOLLOUT | EPOLLWRNORM; } =20 -static int write_pool(const char __user *ubuf, size_t len) +static size_t write_pool(struct iov_iter *iter) { size_t block_len; int ret =3D 0; u8 block[BLAKE2S_BLOCK_SIZE]; =20 - while (len) { - block_len =3D min(len, sizeof(block)); - if (copy_from_user(block, ubuf, block_len)) { - ret =3D -EFAULT; + while (iov_iter_count(iter)) { + block_len =3D min(iov_iter_count(iter), sizeof(block)); + if (!copy_from_iter(block, block_len, iter)) { + if (!ret) + ret =3D -EFAULT; goto out; } - len -=3D block_len; - ubuf +=3D block_len; + ret +=3D block_len; mix_pool_bytes(block, block_len); cond_resched(); } @@ -1306,16 +1306,9 @@ static int write_pool(const char __user *ubuf, size_= t len) return ret; } =20 -static ssize_t random_write(struct file *file, const char __user *ubuf, - size_t len, loff_t *ppos) +static ssize_t random_write_iter(struct kiocb *kiocb, struct iov_iter *fro= m) { - int ret; - - ret =3D write_pool(ubuf, len); - if (ret) - return ret; - - return (ssize_t)len; + return write_pool(from); } =20 static ssize_t urandom_read_iter(struct kiocb *kiocb, struct iov_iter *to) @@ -1373,7 +1366,10 @@ static long random_ioctl(struct file *f, unsigned in= t cmd, unsigned long arg) return -EINVAL; credit_init_bits(ent_count); return 0; - case RNDADDENTROPY: + case RNDADDENTROPY: { + struct iov_iter iter; + struct iovec iov; + if (!capable(CAP_SYS_ADMIN)) return -EPERM; if (get_user(ent_count, p++)) @@ -1382,11 +1378,16 @@ static long random_ioctl(struct file *f, unsigned i= nt cmd, unsigned long arg) return -EINVAL; if (get_user(size, p++)) return -EFAULT; - retval =3D write_pool((const char __user *)p, size); + + iov.iov_base =3D p; + iov.iov_len =3D size; + iov_iter_init(&iter, WRITE, &iov, 1, size); + retval =3D write_pool(&iter); if (retval < 0) return retval; credit_init_bits(ent_count); return 0; + } case RNDZAPENTCNT: case RNDCLEARPOOL: /* No longer has any effect. */ @@ -1412,7 +1413,7 @@ static int random_fasync(int fd, struct file *filp, i= nt on) =20 const struct file_operations random_fops =3D { .read_iter =3D random_read_iter, - .write =3D random_write, + .write_iter =3D random_write_iter, .poll =3D random_poll, .unlocked_ioctl =3D random_ioctl, .compat_ioctl =3D compat_ptr_ioctl, @@ -1423,7 +1424,7 @@ const struct file_operations random_fops =3D { =20 const struct file_operations urandom_fops =3D { .read_iter =3D urandom_read_iter, - .write =3D random_write, + .write_iter =3D random_write_iter, .unlocked_ioctl =3D random_ioctl, .compat_ioctl =3D compat_ptr_ioctl, .fasync =3D random_fasync, --=20 Jens Axboe