3 files changed, 23 insertions, 8 deletions

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index b5a7d9bfcb24..25accc9dda3b 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 f5c7c382765f..7d33f6673868 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 297b72c880a1..ea00647f4732 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;
         }