On Mon, May 25, 2020 at 11:43:19AM -0500, Gustavo A. R. Silva wrote:

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct hv_dr_state {
	...
        struct hv_pcidev_description func[];
};

struct pci_bus_relations {
	...
        struct pci_function_description func[];
} __packed;

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.

So, replace the following forms:

offsetof(struct hv_dr_state, func) +
	(sizeof(struct hv_pcidev_description) *
	(relations->device_count))

offsetof(struct pci_bus_relations, func) +
	(sizeof(struct pci_function_description) *
	(bus_rel->device_count))

with:

struct_size(dr, func, relations->device_count)

and

struct_size(bus_rel, func, bus_rel->device_count)

respectively.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Reviewed-by: Wei Liu <wei.liu@kernel.org>

FAOD I expect this patch to go through pci tree.