diff mbox

[4.2.y-ckt,stable] Patch "PCI: Supply CPU physical address (not bus address) to iomem_is_exclusive()" has been added to the 4.2.y-ckt tree

Message ID 1465482996-26621-1-git-send-email-kamal@canonical.com
State New
Headers show

Commit Message

Kamal Mostafa June 9, 2016, 2:36 p.m. UTC
This is a note to let you know that I have just added a patch titled

    PCI: Supply CPU physical address (not bus address) to iomem_is_exclusive()

to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree 
which can be found at:

    https://git.launchpad.net/~canonical-kernel/linux/+git/linux-stable-ckt/log/?h=linux-4.2.y-queue

This patch is scheduled to be released in version 4.2.8-ckt12.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 4.2.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

From 195939642043cacea3292af3e5b7f8f3ba822790 Mon Sep 17 00:00:00 2001
From: Bjorn Helgaas <bhelgaas@google.com>
Date: Thu, 7 Apr 2016 17:15:14 -0700
Subject: PCI: Supply CPU physical address (not bus address) to
 iomem_is_exclusive()

commit ca620723d4ff9ea7ed484eab46264c3af871b9ae upstream.

iomem_is_exclusive() requires a CPU physical address, but on some arches we
supplied a PCI bus address instead.

On most arches, pci_resource_to_user(res) returns "res->start", which is a
CPU physical address.  But on microblaze, mips, powerpc, and sparc, it
returns the PCI bus address corresponding to "res->start".

The result is that pci_mmap_resource() may fail when it shouldn't (if the
bus address happens to match an existing resource), or it may succeed when
it should fail (if the resource is exclusive but the bus address doesn't
match it).

Call iomem_is_exclusive() with "res->start", which is always a CPU physical
address, not the result of pci_resource_to_user().

Fixes: e8de1481fd71 ("resource: allow MMIO exclusivity for device drivers")
Suggested-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
 drivers/pci/pci-sysfs.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

--
2.7.4
diff mbox

Patch

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index eead54c..5f7cbea 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1013,6 +1013,9 @@  static int pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr,
 	if (i >= PCI_ROM_RESOURCE)
 		return -ENODEV;

+	if (res->flags & IORESOURCE_MEM && iomem_is_exclusive(res->start))
+		return -EINVAL;
+
 	if (!pci_mmap_fits(pdev, i, vma, PCI_MMAP_SYSFS)) {
 		WARN(1, "process \"%s\" tried to map 0x%08lx bytes at page 0x%08lx on %s BAR %d (start 0x%16Lx, size 0x%16Lx)\n",
 			current->comm, vma->vm_end-vma->vm_start, vma->vm_pgoff,
@@ -1029,10 +1032,6 @@  static int pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr,
 	pci_resource_to_user(pdev, i, res, &start, &end);
 	vma->vm_pgoff += start >> PAGE_SHIFT;
 	mmap_type = res->flags & IORESOURCE_MEM ? pci_mmap_mem : pci_mmap_io;
-
-	if (res->flags & IORESOURCE_MEM && iomem_is_exclusive(start))
-		return -EINVAL;
-
 	return pci_mmap_page_range(pdev, vma, mmap_type, write_combine);
 }