[PATCH 3/9] fs: explicitly check for CHECK_IOVEC_ONLY in rw_copy_check_uvector

From: Christoph Hellwig
Date: Fri Sep 18 2020 - 08:46:07 EST


Explicitly check for the magic value insted of implicitly relying on
its number representation.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
fs/read_write.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/fs/read_write.c b/fs/read_write.c
index 5db58b8c78d0dd..f153116bc5399b 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -840,8 +840,7 @@ ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
ret = -EINVAL;
goto out;
}
- if (type >= 0
- && unlikely(!access_ok(buf, len))) {
+ if (type != CHECK_IOVEC_ONLY && unlikely(!access_ok(buf, len))) {
ret = -EFAULT;
goto out;
}
@@ -911,7 +910,7 @@ ssize_t compat_rw_copy_check_uvector(int type,
}
if (len < 0) /* size_t not fitting in compat_ssize_t .. */
goto out;
- if (type >= 0 &&
+ if (type != CHECK_IOVEC_ONLY &&
!access_ok(compat_ptr(buf), len)) {
ret = -EFAULT;
goto out;
--
2.28.0