vfio: fix truncated BAR offset for 32-bit

When 32-bit application is built on 64-bit system it is possible that
the offset of the resource is outside of the 32-bit value.

The problem with the unsigned long is, that it is 32-bit and not 64-bit
when using armhf compiler. Although the system is returning u64 value,
we are losing it's value if it's higher than 32-bit in the conversion
process. It can further cause mmap to fail due to offset being 0 or to
map not intended memory region.

To make it more portable, the uint64_t value is now being used for
storing offset instead of unsigned long. The size of being 32-bit seems
to be fine as the 32-bit application won't be able to access bigger
memory and it is further converted to size_t anyway. But for better
readability and to be consistent, it's type was changed to size_t as
well.

Fixes: 0205f873557c ("vfio: fix overflow of BAR region offset and size")
Cc: stable@dpdk.org
Signed-off-by: Michal Krawczyk <mk@semihalf.com>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>

diff --git a/drivers/bus/pci/linux/pci_vfio.c b/drivers/bus/pci/linux/pci_vfio.c
index faf2990..b8faa23 100644 (file)
--- a/drivers/bus/pci/linux/pci_vfio.c
+++ b/drivers/bus/pci/linux/pci_vfio.c
@@ -451,7 +451,8 @@ pci_vfio_mmap_bar(int vfio_dev_fd, struct mapped_pci_resource *vfio_res,
                int bar_index, int additional_flags)
 {
        struct memreg {
-               unsigned long offset, size;
+               uint64_t offset;
+               size_t   size;
        } memreg[2] = {};
        void *bar_addr;
        struct pci_msix_table *msix_table = &vfio_res->msix_table;
@@ -504,7 +505,8 @@ pci_vfio_mmap_bar(int vfio_dev_fd, struct mapped_pci_resource *vfio_res,
                RTE_LOG(DEBUG, EAL,
                        "Trying to map BAR%d that contains the MSI-X "
                        "table. Trying offsets: "
-                       "0x%04lx:0x%04lx, 0x%04lx:0x%04lx\n", bar_index,
+                       "0x%04" PRIx64 ":0x%04zx, 0x%04" PRIx64 ":0x%04zx\n",
+                       bar_index,
                        memreg[0].offset, memreg[0].size,
                        memreg[1].offset, memreg[1].size);
        } else {
@@ -529,8 +531,8 @@ pci_vfio_mmap_bar(int vfio_dev_fd, struct mapped_pci_resource *vfio_res,
                if (map_addr != MAP_FAILED
                        && memreg[1].offset && memreg[1].size) {
                        void *second_addr = RTE_PTR_ADD(bar_addr,
-                                                       memreg[1].offset -
-                                                       (uintptr_t)bar->offset);
+                                               (uintptr_t)(memreg[1].offset -
+                                               bar->offset));
                        map_addr = pci_map_resource(second_addr,
                                                        vfio_dev_fd,
                                                        memreg[1].offset,