[bug report] PCI: Add pci_rebar_size_supported() helper

[Dan Carpenter <dan.carpenter@linaro.org>]

Hello Ilpo Järvinen,

Commit bb1fabd0d94e ("PCI: Add pci_rebar_size_supported() helper")
from Nov 13, 2025 (linux-next), leads to the following Smatch static
checker warning:

	drivers/pci/rebar.c:142 pci_rebar_size_supported()
	error: undefined (user controlled) shift '(((1))) << size'

The problem is this call tree:
__resource_resize_store() <- takes an unsigned long from the user
  -> pci_resize_resource() <- truncates it to int
     -> pci_rebar_size_supported()

drivers/pci/rebar.c
    138 bool pci_rebar_size_supported(struct pci_dev *pdev, int bar, int size)
    139 {
    140         u64 sizes = pci_rebar_get_possible_sizes(pdev, bar);
    141 
--> 142         return BIT(size) & sizes;
    143 }

So here size could be negative or >= BITS_PER_LONG which leads to
shift wrapping.  But also truncating the ulong to int in
__resource_resize_store() is not beautiful.

regards,
dan carpenter