diff options
authorLinus Torvalds <torvalds@woody.linux-foundation.org>2007-01-22 08:53:24 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-01-22 08:53:24 -0800
commit6d3154cc1143f62c3b80d9929caeaec6db8cb451 (patch)
parenta8b3485287731978899ced11f24628c927890e78 (diff)
Revert "[PATCH] Fix up mmap_kmem"
This reverts commit 99a10a60ba9bedcf5d70ef81414d3e03816afa3f. As per Hugh Dickins: "Nadia Derbey has reported that mmap of /dev/kmem no longer works with the kernel virtual address as offset, and Franck has confirmed that his patch came from a misunderstanding of what an offset means to /dev/kmem - whereas his patch description seems to say that he was correcting the offset on a few plaforms, there was no such problem to correct, and his patch was in fact changing its API on all platforms." Suggested-by: Hugh Dickins <hugh@veritas.com> Cc: Franck Bui-Huu <fbuihuu@gmail.com> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Cc: Andi Kleen <ak@suse.de> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 4f1813e04754..f5c160caf9f4 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -293,8 +293,8 @@ static int mmap_kmem(struct file * file, struct vm_area_struct * vma)
unsigned long pfn;
- /* Turn a pfn offset into an absolute pfn */
- pfn = PFN_DOWN(virt_to_phys((void *)PAGE_OFFSET)) + vma->vm_pgoff;
+ /* 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