Check if the PCI memory starting address is disabled and return -EINVAL.
This will have minimal impact to performance as it is only during the
set up of the mmap and will avoid consequences of a failed load/store.
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
---
arch/sparc/kernel/pci.c | 42 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 42 insertions(+)
diff --git a/arch/sparc/kernel/pci.c b/arch/sparc/kernel/pci.c
index 9c1878f..208d7c0 100644
--- a/arch/sparc/kernel/pci.c
+++ b/arch/sparc/kernel/pci.c
@@ -20,6 +20,7 @@
#include <linux/init.h>
#include <linux/of.h>
#include <linux/of_device.h>
+#include <linux/types.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
@@ -854,6 +855,44 @@ static void __pci_mmap_set_pgprot(struct pci_dev *dev, struct vm_area_struct *vm
/* Our io_remap_pfn_range takes care of this, do nothing. */
}
+/* Ensure the mmap address range is within an enabled resource range. */
+int __pci_mmap_page_invalid(struct pci_dev *dev, unsigned long pfn)
+{
+ int i;
+ unsigned short cmd;
+ phys_addr_t page_start = pfn << PAGE_SHIFT;
+
+ pci_read_config_word(dev, PCI_COMMAND, &cmd);
+ for (i = 0; i < PCI_NUM_RESOURCES; i++) {
+ struct resource *res = &dev->resource[i];
+
+ /* Check if this is the resource in the range.
+ * Note: Size is not checked, so running off the end of an
+ * enabled block into a disabled block will still result in
+ * issues.
+ */
+ if (res->start <= page_start && res->end >= page_start) {
+ /* Not initialized */
+ if (!res->flags)
+ return -EINVAL;
+
+ /* IO Resource disabled */
+ if ((res->flags & IORESOURCE_IO) &&
+ !(cmd & PCI_COMMAND_IO))
+ return -EINVAL;
+
+ /* Memory Resource disabled */
+ if ((res->flags & IORESOURCE_MEM) &&
+ !(cmd & PCI_COMMAND_MEMORY))
+ return -EINVAL;
+
+ /* Looks good */
+ return 0;
+ }
+ }
+ return -EINVAL;
+}
+
/* Perform the actual remap of the pages for a PCI device mapping, as appropriate
* for this architecture. The region in the process to map is described by vm_start
* and vm_end members of VMA, the base physical address is found in vm_pgoff.
@@ -872,6 +911,9 @@ int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
if (ret < 0)
return ret;
+ if (__pci_mmap_page_invalid(dev, vma->vm_pgoff))
+ return -EINVAL;
+
__pci_mmap_set_pgprot(dev, vma, mmap_state);
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
--
2.1.4
--
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