[PATCH] iov_iter: Use user_read_access_begin() instead of user_access_begin()

[Christophe Leroy]

copy_compat_iovec_from_user() only do unsafe_get_user(),
it only requires read access.

Signed-off-by: Christophe Leroy <christophe.le...@csgroup.eu>
---
 lib/iov_iter.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index f66c62aa7154..76952a117b47 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -1665,7 +1665,7 @@ static int copy_compat_iovec_from_user(struct iovec *iov,
                (const struct compat_iovec __user *)uvec;
        int ret = -EFAULT, i;
 
-       if (!user_access_begin(uiov, nr_segs * sizeof(*uiov)))
+       if (!user_read_access_begin(uiov, nr_segs * sizeof(*uiov)))
                return -EFAULT;
 
        for (i = 0; i < nr_segs; i++) {
@@ -1686,7 +1686,7 @@ static int copy_compat_iovec_from_user(struct iovec *iov,
 
        ret = 0;
 uaccess_end:
-       user_access_end();
+       user_read_access_end();
        return ret;
 }
 
-- 
2.25.0