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authorLinus Torvalds <torvalds@g5.osdl.org>2005-08-14 01:22:59 +0400
committerLinus Torvalds <torvalds@g5.osdl.org>2005-08-14 01:22:59 +0400
commit4bb82551e165f887448f6f61055d7bcd90aefa2a (patch)
treee52389322e063c5b784ead6ec314503f7646c765 /drivers/char/mem.c
parent2da5bf80f754e28cc153362e5ed1edaa9740897a (diff)
downloadlinux-4bb82551e165f887448f6f61055d7bcd90aefa2a.tar.xz
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.
Diffstat (limited to 'drivers/char/mem.c')
-rw-r--r--drivers/char/mem.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 42187381506b..850a78c9c4bc 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -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);
}