mirror of
https://github.com/FEX-Emu/linux.git
synced 2024-12-21 17:00:01 +00:00
8c05cd08a7
I just loaded 2.6.37-rc2 on my machines, and I noticed that X no longer starts.
Running an strace of the X server shows that it's doing this:
open("/sys/bus/pci/devices/0000:07:00.0/resource0", O_RDWR) = 10
mmap(NULL, 16777216, PROT_READ|PROT_WRITE, MAP_SHARED, 10, 0) = -1 EINVAL (Invalid argument)
This code seems to be asking for a shared read/write mapping of 16MB worth of
BAR0 starting at file offset 0, and letting the kernel assign a starting
address. Unfortunately, this -EINVAL causes X not to start. Looking into
dmesg, there's a complaint like so:
process "Xorg" tried to map 0x01000000 bytes at page 0x00000000 on 0000:07:00.0 BAR 0 (start 0x 96000000, size 0x 1000000)
...with the following code in pci_mmap_fits:
pci_start = (mmap_api == PCI_MMAP_SYSFS) ?
pci_resource_start(pdev, resno) >> PAGE_SHIFT : 0;
if (start >= pci_start && start < pci_start + size &&
start + nr <= pci_start + size)
It looks like the logic here is set up such that when the mmap call comes via
sysfs, the check in pci_mmap_fits wants vma->vm_pgoff to be between the
resource's start and end address, and the end of the vma to be no farther than
the end. However, the sysfs PCI resource files always start at offset zero,
which means that this test always fails for programs that mmap the sysfs files.
Given the comment in the original commit
|
||
|---|---|---|
| .. | ||
| hotplug | ||
| pcie | ||
| .gitignore | ||
| access.c | ||
| bus.c | ||
| dmar.c | ||
| hotplug-pci.c | ||
| hotplug.c | ||
| htirq.c | ||
| intel-iommu.c | ||
| intr_remapping.c | ||
| intr_remapping.h | ||
| ioapic.c | ||
| iov.c | ||
| iova.c | ||
| irq.c | ||
| Kconfig | ||
| Makefile | ||
| msi.c | ||
| msi.h | ||
| pci-acpi.c | ||
| pci-driver.c | ||
| pci-label.c | ||
| pci-stub.c | ||
| pci-sysfs.c | ||
| pci.c | ||
| pci.h | ||
| probe.c | ||
| proc.c | ||
| quirks.c | ||
| remove.c | ||
| rom.c | ||
| search.c | ||
| setup-bus.c | ||
| setup-irq.c | ||
| setup-res.c | ||
| slot.c | ||
| syscall.c | ||
| vpd.c | ||
| xen-pcifront.c | ||