From 2e8039c656224b4a21e1947f45946d32a59bae53 Mon Sep 17 00:00:00 2001 From: Michael Guralnik Date: Sun, 9 Dec 2018 11:58:04 +0200 Subject: IB/core: uverbs copy to struct or zero helper Add a helper to zero fill fields before copying data to UVERBS_ATTR_STRUCT. As UVERBS_ATTR_STRUCT can be used as an extensible struct, we want to make sure that if the user supplies us with a struct that has new fields that we are not aware of, we return them zeroed to the user. This helper should be used when using UVERBS_ATTR_STRUCT for an extendable data structure and there is a need to make sure that extended members of the struct, that the kernel doesn't handle, are returned zeroed to the user. This is needed due to the fact that UVERBS_ATTR_STRUCT allows non-zero values for members after 'last' member. Signed-off-by: Michael Guralnik Reviewed-by: Majd Dibbiny Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe --- include/rdma/uverbs_ioctl.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/rdma/uverbs_ioctl.h') diff --git a/include/rdma/uverbs_ioctl.h b/include/rdma/uverbs_ioctl.h index bf07cd6336d3..27da906beea7 100644 --- a/include/rdma/uverbs_ioctl.h +++ b/include/rdma/uverbs_ioctl.h @@ -871,6 +871,8 @@ static inline __malloc void *uverbs_zalloc(struct uverbs_attr_bundle *bundle, int _uverbs_get_const(s64 *to, const struct uverbs_attr_bundle *attrs_bundle, size_t idx, s64 lower_bound, u64 upper_bound, s64 *def_val); +int uverbs_copy_to_struct_or_zero(const struct uverbs_attr_bundle *bundle, + size_t idx, const void *from, size_t size); #else static inline int uverbs_get_flags64(u64 *to, const struct uverbs_attr_bundle *attrs_bundle, @@ -906,6 +908,12 @@ _uverbs_get_const(s64 *to, const struct uverbs_attr_bundle *attrs_bundle, { return -EINVAL; } +static inline int +uverbs_copy_to_struct_or_zero(const struct uverbs_attr_bundle *bundle, + size_t idx, const void *from, size_t size) +{ + return -EINVAL; +} #endif #define uverbs_get_const(_to, _attrs_bundle, _idx) \ -- cgit v1.2.3