On Wed, 10 Nov 2010 11:03:21 +0100 Martin Wilck <martin.wilck@xxxxxxxxxxxxxx> wrote: > The checks for valid mmaps of PCI resources made > through /proc/bus/pci files that were introduced in > 9eff02e2042f96fb2aedd02e032eca1c5333d767 have several problems: > > 1. mmap() calls on /proc/bus/pci files are made with real file > offsets > 0, whereas under /sys/bus/pci/devices, the start of the > resource corresponds to offset 0. This may lead to false negatives in > pci_mmap_fits(), which implicitly assumes the /sys/bus/pci/devices > layout. > > 2. The loop in proc_bus_pci_mmap doesn't skip empty resouces. This > leads to false positives, because pci_mmap_fits() doesn't treat empty > resources correctly (the calculated size is 1 << > (8*sizeof(resource_size_t)-PAGE_SHIFT) in this case!). > > 3. If a user maps resources with BAR > 0, pci_mmap_fits will emit > bogus WARNINGS for the first resources that don't fit until the > correct one is found. > > On many controllers the first 2-4 BARs are used, and the others are > empty. In this case, an mmap attempt will first fail on the non-empty > BARs (including the "right" BAR because of 1.) and emit bogus > WARNINGS because of 3., and finally succeed on the first empty BAR > because of 2. This is certainly not the intended behaviour. > > This patch addresses all 3 issues. > Updated with an enum type for the additional parameter for > pci_mmap_fits(). > > Signed-off-by: Martin Wilck <martin.wilck@xxxxxxxxxxxxxx> Thanks Martin, I'll push this into my for-linus branch for 2.6.37; may as well cc: stable as well, since this is a long standing bug. -- Jesse Barnes, Intel Open Source Technology Center -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
