[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>
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index e97c32c..917b204 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -95,7 +95,7 @@
return 1;
}
-static inline int valid_mmap_phys_addr_range(unsigned long addr, size_t size)
+static inline int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
{
return 1;
}
@@ -242,7 +242,7 @@
{
size_t size = vma->vm_end - vma->vm_start;
- if (!valid_mmap_phys_addr_range(vma->vm_pgoff << PAGE_SHIFT, size))
+ if (!valid_mmap_phys_addr_range(vma->vm_pgoff, size))
return -EINVAL;
vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff,