Compat performance is not important and simplicity is more appreciated.
Let's not be smart about it and use simpler copy_from_user() instead of
access + __get_user pair.
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
---
io_uring/rw.c | 14 ++++----------
1 file changed, 4 insertions(+), 10 deletions(-)
diff --git a/io_uring/rw.c b/io_uring/rw.c
index 7133029b4396..22612a956e75 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -48,18 +48,12 @@ static bool io_file_supports_nowait(struct io_kiocb *req, __poll_t mask)
static int io_iov_compat_buffer_select_prep(struct io_rw *rw)
{
- struct compat_iovec __user *uiov;
- compat_ssize_t clen;
+ struct compat_iovec __user *uiov = u64_to_user_ptr(rw->addr);
+ struct compat_iovec iov;
- uiov = u64_to_user_ptr(rw->addr);
- if (!access_ok(uiov, sizeof(*uiov)))
- return -EFAULT;
- if (__get_user(clen, &uiov->iov_len))
+ if (copy_from_user(&iov, uiov, sizeof(iov)))
return -EFAULT;
- if (clen < 0)
- return -EINVAL;
-
- rw->len = clen;
+ rw->len = iov.iov_len;
return 0;
}
--
2.48.1
