On 01/08/17 17:04, Punit Agrawal wrote:
[...]
> I think I've figured out what's going wrong. pci_for_each_cap is defined
> as -
>
> #define pci_for_each_cap(pos, cap, hdr) \
> for ((pos) = (hdr)->capabilities & ~3; \
> (cap) = (void *)(hdr) + (pos), (pos) != 0; \
> (pos) = ((struct pci_cap_hdr *)(cap))->next & ~3)
>
> Here cap is being assigned before the pos != 0 check. So in the last
> iteration through the loop, cap will point to the start of the PCI
> header - which is then used to set "last->next = pos".
Ah right, sorry about that. How about moving the pos check in front? Does
the following work for you?
diff --git a/include/kvm/pci.h b/include/kvm/pci.h
index c5fc8254..37a65956 100644
--- a/include/kvm/pci.h
+++ b/include/kvm/pci.h
@@ -142,9 +142,9 @@ struct pci_device_header {
enum irq_type irq_type;
};
-#define pci_for_each_cap(pos, cap, hdr) \
- for ((pos) = (hdr)->capabilities & ~3; \
- (cap) = (void *)(hdr) + (pos), (pos) != 0; \
+#define pci_for_each_cap(pos, cap, hdr) \
+ for ((pos) = (hdr)->capabilities & ~3; \
+ (pos) != 0 && ({ (cap) = (void *)(hdr) + (pos); 1; }); \
(pos) = ((struct pci_cap_hdr *)(cap))->next & ~3)
int pci__init(struct kvm *kvm);
