[lkml]   [2007]   [Feb]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[patch 30/59] Revert "[PATCH] Fix up mmap_kmem"
-stable review patch.  If anyone has any objections, please let us know.

From: Linus Torvalds <>

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 <>
Cc: Franck Bui-Huu <>
Cc: Nadia Derbey <>
Cc: Andi Kleen <>
Cc: Arjan van de Ven <>
Cc: Andrew Morton <>
Signed-off-by: Linus Torvalds <>
Signed-off-by: Chris Wright <>
drivers/char/mem.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- linux-
+++ linux-
@@ -293,8 +293,8 @@ static int mmap_kmem(struct file * file,
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
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2007-02-03 03:53    [W:0.140 / U:2.412 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site