linux-stable.git/drivers/pci, branch v3.2.80

PCI: Disable IO/MEM decoding for devices with non-compliant BARs

2016-04-30T22:05:15+00:00

commit b84106b4e2290c081cdab521fa832596cdfea246 upstream.

The PCI config header (first 64 bytes of each device's config space) is
defined by the PCI spec so generic software can identify the device and
manage its usage of I/O, memory, and IRQ resources.

Some non-spec-compliant devices put registers other than BARs where the
BARs should be.  When the PCI core sizes these "BARs", the reads and writes
it does may have unwanted side effects, and the "BAR" may appear to
describe non-sensical address space.

Add a flag bit to mark non-compliant devices so we don't touch their BARs.
Turn off IO/MEM decoding to prevent the devices from consuming address
space, since we can't read the BARs to find out what that address space
would be.

Signed-off-by: Bjorn Helgaas 
Tested-by: Andi Kleen 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

xen/pcifront: Fix mysterious crashes when NUMA locality information was extracted.

2016-04-01T00:54:32+00:00

commit 4d8c8bd6f2062c9988817183a91fe2e623c8aa5e upstream.

Occasionaly PV guests would crash with:

pciback 0000:00:00.1: Xen PCI mapped GSI0 to IRQ16
BUG: unable to handle kernel paging request at 0000000d1a8c0be0
.. snip..
  ] find_next_bit+0xb/0x10
  [] cpumask_next_and+0x22/0x40
  [] pci_device_probe+0xb8/0x120
  [] ? driver_sysfs_add+0x77/0xa0
  [] driver_probe_device+0x1a4/0x2d0
  [] ? pci_match_device+0xdd/0x110
  [] __device_attach_driver+0xa7/0xb0
  [] ? __driver_attach+0xa0/0xa0
  [] bus_for_each_drv+0x62/0x90
  [] __device_attach+0xbd/0x110
  [] device_attach+0xb/0x10
  [] pci_bus_add_device+0x3c/0x70
  [] pci_bus_add_devices+0x38/0x80
  [] pcifront_scan_root+0x13e/0x1a0
  [] pcifront_backend_changed+0x262/0x60b
  [] ? xenbus_gather+0xd6/0x160
  [] ? put_object+0x2f/0x50
  [] xenbus_otherend_changed+0x9d/0xa0
  [] backend_changed+0xe/0x10
  [] xenwatch_thread+0xc8/0x190
  [] ? woken_wake_function+0x10/0x10

which was the result of two things:

When we call pci_scan_root_bus we would pass in 'sd' (sysdata)
pointer which was an 'pcifront_sd' structure. However in the
pci_device_add it expects that the 'sd' is 'struct sysdata' and
sets the dev->node to what is in sd->node (offset 4):

set_dev_node(&dev->dev, pcibus_to_node(bus));

 __pcibus_to_node(const struct pci_bus *bus)
{
        const struct pci_sysdata *sd = bus->sysdata;

        return sd->node;
}

However our structure was pcifront_sd which had nothing at that
offset:

struct pcifront_sd {
        int                        domain;    /*     0     4 */
        /* XXX 4 bytes hole, try to pack */
        struct pcifront_device *   pdev;      /*     8     8 */
}

That is an hole - filled with garbage as we used kmalloc instead of
kzalloc (the second problem).

This patch fixes the issue by:
 1) Use kzalloc to initialize to a well known state.
 2) Put 'struct pci_sysdata' at the start of 'pcifront_sd'. That
    way access to the 'node' will access the right offset.

Signed-off-by: Konrad Rzeszutek Wilk 
Reviewed-by: Boris Ostrovsky 
Signed-off-by: David Vrabel 
Signed-off-by: Ben Hutchings

PCI/AER: Flush workqueue on device remove to avoid use-after-free

2016-02-27T14:28:43+00:00

commit 4ae2182b1e3407de369f8c5d799543b7db74221b upstream.

A Root Port's AER structure (rpc) contains a queue of events.  aer_irq()
enqueues AER status information and schedules aer_isr() to dequeue and
process it.  When we remove a device, aer_remove() waits for the queue to
be empty, then frees the rpc struct.

But aer_isr() references the rpc struct after dequeueing and possibly
emptying the queue, which can cause a use-after-free error as in the
following scenario with two threads, aer_isr() on the left and a
concurrent aer_remove() on the right:

  Thread A                      Thread B
  --------                      --------
  aer_irq():
    rpc->prod_idx++
                                aer_remove():
                                  wait_event(rpc->prod_idx == rpc->cons_idx)
                                  # now blocked until queue becomes empty
  aer_isr():                      # ...
    rpc->cons_idx++               # unblocked because queue is now empty
    ...                           kfree(rpc)
    mutex_unlock(&rpc->rpc_mutex)

To prevent this problem, use flush_work() to wait until the last scheduled
instance of aer_isr() has completed before freeing the rpc struct in
aer_remove().

I reproduced this use-after-free by flashing a device FPGA and
re-enumerating the bus to find the new device.  With SLUB debug, this
crashes with 0x6b bytes (POISON_FREE, the use-after-free magic number) in
GPR25:

  pcieport 0000:00:00.0: AER: Multiple Corrected error received: id=0000
  Unable to handle kernel paging request for data at address 0x27ef9e3e
  Workqueue: events aer_isr
  GPR24: dd6aa000 6b6b6b6b 605f8378 605f8360 d99b12c0 604fc674 606b1704 d99b12c0
  NIP [602f5328] pci_walk_bus+0xd4/0x104

[bhelgaas: changelog, stable tag]
Signed-off-by: Sebastian Andrzej Siewior 
Signed-off-by: Bjorn Helgaas 
Signed-off-by: Ben Hutchings

PCI: Use function 0 VPD for identical functions, regular VPD for others

2015-11-27T12:48:19+00:00

commit da2d03ea27f6ed9d2005a67b20dd021ddacf1e4d upstream.

932c435caba8 ("PCI: Add dev_flags bit to access VPD through function 0")
added PCI_DEV_FLAGS_VPD_REF_F0.  Previously, we set the flag on every
non-zero function of quirked devices.  If a function turned out to be
different from function 0, i.e., it had a different class, vendor ID, or
device ID, the flag remained set but we didn't make VPD accessible at all.

Flip this around so we only set PCI_DEV_FLAGS_VPD_REF_F0 for functions that
are identical to function 0, and allow regular VPD access for any other
functions.

[bhelgaas: changelog, stable tag]
Fixes: 932c435caba8 ("PCI: Add dev_flags bit to access VPD through function 0")
Signed-off-by: Alex Williamson 
Signed-off-by: Bjorn Helgaas 
Acked-by: Myron Stowe 
Acked-by: Mark Rustad 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

PCI: Fix devfn for VPD access through function 0

2015-11-27T12:48:19+00:00

commit 9d9240756e63dd87d6cbf5da8b98ceb8f8192b55 upstream.

Commit 932c435caba8 ("PCI: Add dev_flags bit to access VPD through function
0") passes PCI_SLOT(devfn) for the devfn parameter of pci_get_slot().
Generally this works because we're fairly well guaranteed that a PCIe
device is at slot address 0, but for the general case, including
conventional PCI, it's incorrect.  We need to get the slot and then convert
it back into a devfn.

Fixes: 932c435caba8 ("PCI: Add dev_flags bit to access VPD through function 0")
Signed-off-by: Alex Williamson 
Signed-off-by: Bjorn Helgaas 
Acked-by: Myron Stowe 
Acked-by: Mark Rustad 
Signed-off-by: Ben Hutchings

PCI: Add VPD function 0 quirk for Intel Ethernet devices

2015-10-13T02:46:05+00:00

commit 7aa6ca4d39edf01f997b9e02cf6d2fdeb224f351 upstream.

Set the PCI_DEV_FLAGS_VPD_REF_F0 flag on all Intel Ethernet device
functions other than function 0, so that on multi-function devices, we will
always read VPD from function 0 instead of from the other functions.

[bhelgaas: changelog]
Signed-off-by: Mark Rustad 
Signed-off-by: Bjorn Helgaas 
Acked-by: Alexander Duyck 
[bwh: Backported to 3.2:
 - Put the class check in the new function as there is no
   DECLARE_PCI_FIXUP_CLASS_EARLY(
 - Adjust context]
Signed-off-by: Ben Hutchings

PCI: Add dev_flags bit to access VPD through function 0

2015-10-13T02:46:04+00:00

commit 932c435caba8a2ce473a91753bad0173269ef334 upstream.

Add a dev_flags bit, PCI_DEV_FLAGS_VPD_REF_F0, to access VPD through
function 0 to provide VPD access on other functions.  This is for hardware
devices that provide copies of the same VPD capability registers in
multiple functions.  Because the kernel expects that each function has its
own registers, both the locking and the state tracking are affected by VPD
accesses to different functions.

On such devices for example, if a VPD write is performed on function 0,
*any* later attempt to read VPD from any other function of that device will
hang.  This has to do with how the kernel tracks the expected value of the
F bit per function.

Concurrent accesses to different functions of the same device can not only
hang but also corrupt both read and write VPD data.

When hangs occur, typically the error message:

  vpd r/w failed.  This is likely a firmware bug on this device.

will be seen.

Never set this bit on function 0 or there will be an infinite recursion.

Signed-off-by: Mark Rustad 
Signed-off-by: Bjorn Helgaas 
Acked-by: Alexander Duyck 
Signed-off-by: Ben Hutchings

PCI: Fix TI816X class code quirk

2015-10-13T02:46:04+00:00

commit d1541dc977d376406f4584d8eb055488655c98ec upstream.

In fixup_ti816x_class(), we assigned "class = PCI_CLASS_MULTIMEDIA_VIDEO".
But PCI_CLASS_MULTIMEDIA_VIDEO is only the two-byte base class/sub-class
and needs to be shifted to make space for the low-order interface byte.

Shift PCI_CLASS_MULTIMEDIA_VIDEO to set the correct class code.

Fixes: 63c4408074cb ("PCI: Add quirk for setting valid class for TI816X Endpoint")
Signed-off-by: Bjorn Helgaas 
CC: Hemant Pedanekar 
[bwh: Backported to 3.2: the class check is done in this function as there
 is no DECLARE_PCI_FIXUP_CLASS_EARLY()]
Signed-off-by: Ben Hutchings

PCI: Fix infinite loop with ROM image of size 0

2015-05-09T22:16:13+00:00

commit 16b036af31e1456cb69243a5a0c9ef801ecd1f17 upstream.

If the image size would ever read as 0, pci_get_rom_size() could keep
processing the same image over and over again.  Exit the loop if we ever
read a length of zero.

This fixes a soft lockup on boot when the radeon driver calls
pci_get_rom_size() on an AMD Radeon R7 250X PCIe discrete graphics card.

[bhelgaas: changelog, reference]
Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1386973
Reported-by: Federico 
Signed-off-by: Michel Dänzer 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Alex Deucher 
Signed-off-by: Ben Hutchings

PCI: Generate uppercase hex for modalias var in uevent

2015-05-09T22:16:11+00:00

commit 145b3fe579db66fbe999a2bc3fd5b63dffe9636d upstream.

Some implementations of modprobe fail to load the driver for a PCI device
automatically because the "interface" part of the modalias from the kernel
is lowercase, and the modalias from file2alias is uppercase.

The "interface" is the low-order byte of the Class Code, defined in PCI
r3.0, Appendix D.  Most interface types defined in the spec do not use
alpha characters, so they won't be affected.  For example, 00h, 01h, 10h,
20h, etc. are unaffected.

Print the "interface" byte of the Class Code in uppercase hex, as we
already do for the Vendor ID, Device ID, Class, etc.

Commit 89ec3dcf17fd ("PCI: Generate uppercase hex for modalias interface
class") fixed only half of the problem.  Some udev implementations rely on
the uevent file and not the modalias file.

Fixes: d1ded203adf1 ("PCI: add MODALIAS to hotplug event for pci devices")
Fixes: 89ec3dcf17fd ("PCI: Generate uppercase hex for modalias interface class")
Signed-off-by: Ricardo Ribalda Delgado 
Signed-off-by: Bjorn Helgaas 
Acked-by: Greg Kroah-Hartman 
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings