x86/mm: Limit mmap() of /dev/mem to valid physical addresses

[uclinux-h8/linux.git] / arch / x86 / mm / mmap.c

diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c
index a996798..320c623 100644 (file)
--- a/arch/x86/mm/mmap.c
+++ b/arch/x86/mm/mmap.c
@@ -174,3 +174,15 @@ const char *arch_vma_name(struct vm_area_struct *vma)
                return "[mpx]";
        return NULL;
 }
+
+int valid_phys_addr_range(phys_addr_t addr, size_t count)
+{
+       return addr + count <= __pa(high_memory);
+}
+
+int valid_mmap_phys_addr_range(unsigned long pfn, size_t count)
+{
+       phys_addr_t addr = (phys_addr_t)pfn << PAGE_SHIFT;
+
+       return valid_phys_addr_range(addr, count);
+}