On Tue, Nov 3, 2020 at 1:28 PM Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote: > > On Fri, Oct 30, 2020 at 11:08:11AM +0100, Daniel Vetter wrote: > > There's three ways to access PCI BARs from userspace: /dev/mem, sysfs > > files, and the old proc interface. Two check against > > iomem_is_exclusive, proc never did. And with CONFIG_IO_STRICT_DEVMEM, > > this starts to matter, since we don't want random userspace having > > access to PCI BARs while a driver is loaded and using it. > > > > Fix this by adding the same iomem_is_exclusive() check we already have > > on the sysfs side in pci_mmap_resource(). > > > > References: 90a545e98126 ("restrict /dev/mem to idle io memory ranges") > > Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx> > > This is OK with me but it looks like IORESOURCE_EXCLUSIVE is currently > only used in a few places: > > e1000_probe() calls pci_request_selected_regions_exclusive(), > ne_pci_probe() calls pci_request_regions_exclusive(), > vmbus_allocate_mmio() calls request_mem_region_exclusive() > > which raises the question of whether it's worth keeping > IORESOURCE_EXCLUSIVE at all. I'm totally fine with removing it > completely. Now that CONFIG_IO_STRICT_DEVMEM upgrades IORESOURCE_BUSY to IORESOURCE_EXCLUSIVE semantics the latter has lost its meaning so I'd be in favor of removing it as well. _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel