IB/uverbs: Use u64_to_user_ptr() not a union
The union approach will get the endianness wrong sometimes if the kernel's
pointer size is 32 bits resulting in EFAULTs when trying to copy to/from
user.
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
diff --git a/include/rdma/uverbs_ioctl.h b/include/rdma/uverbs_ioctl.h
index 32cb147..38287d9 100644
--- a/include/rdma/uverbs_ioctl.h
+++ b/include/rdma/uverbs_ioctl.h
@@ -276,10 +276,7 @@
*/
struct uverbs_ptr_attr {
- union {
- u64 data;
- void __user *ptr;
- };
+ u64 data;
u16 len;
/* Combination of bits from enum UVERBS_ATTR_F_XXXX */
u16 flags;
@@ -361,7 +358,7 @@
return PTR_ERR(attr);
min_size = min_t(size_t, attr->ptr_attr.len, size);
- if (copy_to_user(attr->ptr_attr.ptr, from, min_size))
+ if (copy_to_user(u64_to_user_ptr(attr->ptr_attr.data), from, min_size))
return -EFAULT;
flags = attr->ptr_attr.flags | UVERBS_ATTR_F_VALID_OUTPUT;
@@ -396,7 +393,8 @@
if (uverbs_attr_ptr_is_inline(attr))
memcpy(to, &attr->ptr_attr.data, attr->ptr_attr.len);
- else if (copy_from_user(to, attr->ptr_attr.ptr, attr->ptr_attr.len))
+ else if (copy_from_user(to, u64_to_user_ptr(attr->ptr_attr.data),
+ attr->ptr_attr.len))
return -EFAULT;
return 0;