Commit 4bb82551 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Fix up mmap of /dev/kmem 

This leaves the issue of whether we should deprecate the whole thing (or
if we should check the whole mmap range, for that matter) open. Just do
the minimal fix for now.
parent 2da5bf80

drivers/char/mem.c

+8 −4
Original line number Diff line number Diff line
@@ -261,7 +261,11 @@ static int mmap_mem(struct file * file, struct vm_area_struct * vma) 


static int mmap_kmem(struct file * file, struct vm_area_struct * vma)

{

        unsigned long long val;

	unsigned long pfn;



	/* Turn a kernel-virtual address into a physical page frame */

	pfn = __pa((u64)vma->vm_pgoff << PAGE_SHIFT) >> PAGE_SHIFT;



	/*

	 * RED-PEN: on some architectures there is more mapped memory

	 * than available in mem_map which pfn_valid checks
@@ -269,10 +273,10 @@ static int mmap_kmem(struct file * file, struct vm_area_struct * vma) 
	 *

	 * RED-PEN: vmalloc is not supported right now.

	 */

	if (!pfn_valid(vma->vm_pgoff))

	if (!pfn_valid(pfn))

		return -EIO;

	val = (u64)vma->vm_pgoff << PAGE_SHIFT;

	vma->vm_pgoff = __pa(val) >> PAGE_SHIFT;



	vma->vm_pgoff = pfn;

	return mmap_mem(file, vma);

}