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>
}
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.
* 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);
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;
}
{
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,
#define ARCH_HAS_VALID_PHYS_ADDR_RANGE
extern u64 kern_mem_attribute (unsigned long phys_addr, unsigned long size);
extern int valid_phys_addr_range (unsigned long addr, size_t count); /* efi.c */
-extern int valid_mmap_phys_addr_range (unsigned long addr, size_t count);
+extern int valid_mmap_phys_addr_range (unsigned long pfn, size_t count);
/*
* The following two macros are deprecated and scheduled for removal.