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authorMartin Wilck <martin.wilck@ts.fujitsu.com>2010-11-10 11:03:21 +0100
committerJesse Barnes <jbarnes@virtuousgeek.org>2010-11-11 09:34:32 -0800
commit3b519e4ea618b6943a82931630872907f9ac2c2b (patch)
tree55ef8d5305a028dcada03945b3322143446ad9d0
parent4723d0f2f96e6c910f951d595067eb31e0dd2d01 (diff)
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PCI: fix size checks for mmap() on /proc/bus/pci files
The checks for valid mmaps of PCI resources made through /proc/bus/pci files that were introduced in 9eff02e2042f96fb2aedd02e032eca1c5333d767 have several problems: 1. mmap() calls on /proc/bus/pci files are made with real file offsets > 0, whereas under /sys/bus/pci/devices, the start of the resource corresponds to offset 0. This may lead to false negatives in pci_mmap_fits(), which implicitly assumes the /sys/bus/pci/devices layout. 2. The loop in proc_bus_pci_mmap doesn't skip empty resouces. This leads to false positives, because pci_mmap_fits() doesn't treat empty resources correctly (the calculated size is 1 << (8*sizeof(resource_size_t)-PAGE_SHIFT) in this case!). 3. If a user maps resources with BAR > 0, pci_mmap_fits will emit bogus WARNINGS for the first resources that don't fit until the correct one is found. On many controllers the first 2-4 BARs are used, and the others are empty. In this case, an mmap attempt will first fail on the non-empty BARs (including the "right" BAR because of 1.) and emit bogus WARNINGS because of 3., and finally succeed on the first empty BAR because of 2. This is certainly not the intended behaviour. This patch addresses all 3 issues. Updated with an enum type for the additional parameter for pci_mmap_fits(). Cc: stable@kernel.org Signed-off-by: Martin Wilck <martin.wilck@ts.fujitsu.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
-rw-r--r--drivers/pci/pci-sysfs.c22
-rw-r--r--drivers/pci/pci.h7
-rw-r--r--drivers/pci/proc.c2
3 files changed, 23 insertions, 8 deletions
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index b5a7d9bfcb2..25accc9dda3 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -705,17 +705,21 @@ void pci_remove_legacy_files(struct pci_bus *b)
#ifdef HAVE_PCI_MMAP
-int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vma)
+int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vma,
+ enum pci_mmap_api mmap_api)
{
- unsigned long nr, start, size;
+ unsigned long nr, start, size, pci_start;
+ if (pci_resource_len(pdev, resno) == 0)
+ return 0;
nr = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
start = vma->vm_pgoff;
size = ((pci_resource_len(pdev, resno) - 1) >> PAGE_SHIFT) + 1;
- if (start < size && size - start >= nr)
+ 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)
return 1;
- WARN(1, "process \"%s\" tried to map 0x%08lx-0x%08lx on %s BAR %d (size 0x%08lx)\n",
- current->comm, start, start+nr, pci_name(pdev), resno, size);
return 0;
}
@@ -745,8 +749,14 @@ pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr,
if (i >= PCI_ROM_RESOURCE)
return -ENODEV;
- if (!pci_mmap_fits(pdev, i, vma))
+ 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,
+ pci_name(pdev), i,
+ pci_resource_start(pdev, i), pci_resource_len(pdev, i));
return -EINVAL;
+ }
/* pci_mmap_page_range() expects the same kind of entry as coming
* from /proc/bus/pci/ which is a "user visible" value. If this is
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index f5c7c382765..7d33f667386 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -22,8 +22,13 @@ extern void pci_remove_firmware_label_files(struct pci_dev *pdev);
#endif
extern void pci_cleanup_rom(struct pci_dev *dev);
#ifdef HAVE_PCI_MMAP
+enum pci_mmap_api {
+ PCI_MMAP_SYSFS, /* mmap on /sys/bus/pci/devices/<BDF>/resource<N> */
+ PCI_MMAP_PROCFS /* mmap on /proc/bus/pci/<BDF> */
+};
extern int pci_mmap_fits(struct pci_dev *pdev, int resno,
- struct vm_area_struct *vma);
+ struct vm_area_struct *vmai,
+ enum pci_mmap_api mmap_api);
#endif
int pci_probe_reset_function(struct pci_dev *dev);
diff --git a/drivers/pci/proc.c b/drivers/pci/proc.c
index 297b72c880a..ea00647f473 100644
--- a/drivers/pci/proc.c
+++ b/drivers/pci/proc.c
@@ -257,7 +257,7 @@ static int proc_bus_pci_mmap(struct file *file, struct vm_area_struct *vma)
/* Make sure the caller is mapping a real resource for this device */
for (i = 0; i < PCI_ROM_RESOURCE; i++) {
- if (pci_mmap_fits(dev, i, vma))
+ if (pci_mmap_fits(dev, i, vma, PCI_MMAP_PROCFS))
break;
}