[PATCH] make valid_mmap_phys_addr_range() take a pfn

Newer ARMs have a 40 bit physical address space, but mapping physical
memory above 4G needs a special page table format which we (currently?) do
not use for userspace mappings, so what happens instead is that mapping an
address >= 4G will happily discard the upper bits and wrap.

There is a valid_mmap_phys_addr_range() arch hook where we could check for
>= 4G addresses and deny the mapping, but this hook takes an unsigned long
address:

	static inline int valid_mmap_phys_addr_range(unsigned long addr, size_t size);

And drivers/char/mem.c:mmap_mem() calls it like this:

	static int mmap_mem(struct file * file, struct vm_area_struct * vma)
	{
		size_t size = vma->vm_end - vma->vm_start;

		if (!valid_mmap_phys_addr_range(vma->vm_pgoff << PAGE_SHIFT, size))

So that's not much help either.

This patch makes the hook take a pfn instead of a phys address.

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 2 insertions, 2 deletions

diff --git a/arch/ia64/kernel/efi.c b/arch/ia64/kernel/efi.c
index b13c055..e4bfa9d 100644
--- a/arch/ia64/kernel/efi.c
+++ b/arch/ia64/kernel/efi.c
@@ -759,7 +759,7 @@ valid_phys_addr_range (unsigned long phys_addr, unsigned long size)
 }
 
 int
-valid_mmap_phys_addr_range (unsigned long phys_addr, unsigned long size)
+valid_mmap_phys_addr_range (unsigned long pfn, unsigned long size)
 {
 	/*
 	 * MMIO regions are often missing from the EFI memory map.
diff --git a/arch/ia64/pci/pci.c b/arch/ia64/pci/pci.c
index 276512f..60b45e7 100644
--- a/arch/ia64/pci/pci.c
+++ b/arch/ia64/pci/pci.c
@@ -650,7 +650,7 @@ pci_mmap_legacy_page_range(struct pci_bus *bus, struct vm_area_struct *vma)
 	 * Avoid attribute aliasing.  See Documentation/ia64/aliasing.txt
 	 * for more details.
 	 */
-	if (!valid_mmap_phys_addr_range(vma->vm_pgoff << PAGE_SHIFT, size))
+	if (!valid_mmap_phys_addr_range(vma->vm_pgoff, size))
 		return -EINVAL;
 	prot = phys_mem_access_prot(NULL, vma->vm_pgoff, size,
 				    vma->vm_page_prot);