mirror of
https://github.com/torvalds/linux.git
synced 2024-12-04 18:13:04 +00:00
278294798a
PCI config space access from user space has traditionally been unrestricted with writes being an understood risk for device operation. Unfortunately, device breakage or odd behavior from config writes lacks indicators that can leave driver writers confused when evaluating failures. This is especially true with the new PCIe Data Object Exchange (DOE) mailbox protocol where backdoor shenanigans from user space through things such as vendor defined protocols may affect device operation without complete breakage. A prior proposal restricted read and writes completely.[1] Greg and Bjorn pointed out that proposal is flawed for a couple of reasons. First, lspci should always be allowed and should not interfere with any device operation. Second, setpci is a valuable tool that is sometimes necessary and it should not be completely restricted.[2] Finally methods exist for full lock of device access if required. Even though access should not be restricted it would be nice for driver writers to be able to flag critical parts of the config space such that interference from user space can be detected. Introduce pci_request_config_region_exclusive() to mark exclusive config regions. Such regions trigger a warning and kernel taint if accessed via user space. Create pci_warn_once() to restrict the user from spamming the log. [1] https://lore.kernel.org/all/161663543465.1867664.5674061943008380442.stgit@dwillia2-desk3.amr.corp.intel.com/ [2] https://lore.kernel.org/all/YF8NGeGv9vYcMfTV@kroah.com/ Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Suggested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://lore.kernel.org/r/20220926215711.2893286-2-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> |
||
|---|---|---|
| .. | ||
| controller | ||
| endpoint | ||
| hotplug | ||
| msi | ||
| pcie | ||
| switch | ||
| access.c | ||
| ats.c | ||
| bus.c | ||
| doe.c | ||
| ecam.c | ||
| host-bridge.c | ||
| iov.c | ||
| irq.c | ||
| Kconfig | ||
| Makefile | ||
| mmap.c | ||
| of.c | ||
| p2pdma.c | ||
| pci-acpi.c | ||
| pci-bridge-emul.c | ||
| pci-bridge-emul.h | ||
| pci-driver.c | ||
| pci-label.c | ||
| pci-mid.c | ||
| pci-pf-stub.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 | ||
| vc.c | ||
| vgaarb.c | ||
| vpd.c | ||
| xen-pcifront.c | ||