--- a/src/common_interface.c
+++ b/src/common_interface.c
@@ -290,11 +290,13 @@ pci_device_map_range(struct pci_device *dev, pciaddr_t
base,
/* Make sure that there isn't already a mapping with the same base and
* size.
+ * If there is, use it.
*/
for (i = 0; i < devp->num_mappings; i++) {
if ((devp->mappings[i].base == base)
&& (devp->mappings[i].size == size)) {
- return EINVAL;
+ *addr = devp->mappings[i].memory;
+ return 0;
}
}
I don't think we can just return it. Think of a process that uses
libpciaccess in several components, which happen to use the same
mapping. One will call pci_device_map_range(), the other will call
pci_device_map_range(), at some point the first will call
pci_device_unmap_memory_range() and then oops the second has unexpected
lost access to the mapping.
I don't really know why libpciaccess maintainers thought it should
exclude mapping the same base&size. Maybe you need to confront the rump
usage case with upstream libpciaccess, so they perhaps just drop that
check entirely, and thus allow *several* mappings of the region?
Samuel
