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| author | Franck Bui-Huu <fbuihuu@gmail.com> | 2006-10-12 21:06:33 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-10-13 17:35:38 +0200 |
| commit | 99a10a60ba9bedcf5d70ef81414d3e03816afa3f (patch) | |
| tree | 7ea2c86ddd2bfdab885fe86f1c60d412e5730bb1 | |
| parent | Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-fixes (diff) | |
| download | linux-99a10a60ba9bedcf5d70ef81414d3e03816afa3f.tar.xz linux-99a10a60ba9bedcf5d70ef81414d3e03816afa3f.zip | |
[PATCH] Fix up mmap_kmem
vma->vm_pgoff is an pfn _offset_ relatif to the begining
of the memory start. The previous code was doing at first:
vma->vm_pgoff << PAGE_SHIFT
which results into a wrong physical address since some
platforms have a physical mem start that can be different
from 0. After that the previous call __pa() on this
wrong physical address, however __pa() is used to convert
a _virtual_ address into a physical one.
This patch rewrites this convertion. It calculates the
pfn of PAGE_OFFSET which is the pfn of the mem start
then it adds the vma->vm_pgoff to it.
It also uses virt_to_phys() instead of __pa() since the
latter shouldn't be used by drivers.
Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | drivers/char/mem.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/char/mem.c b/drivers/char/mem.c index 6511012cbdcd..a89cb52228c2 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -292,8 +292,8 @@ static int mmap_kmem(struct file * file, struct vm_area_struct * vma) { unsigned long pfn; - /* Turn a kernel-virtual address into a physical page frame */ - pfn = __pa((u64)vma->vm_pgoff << PAGE_SHIFT) >> PAGE_SHIFT; + /* Turn a pfn offset into an absolute pfn */ + pfn = PFN_DOWN(virt_to_phys((void *)PAGE_OFFSET)) + vma->vm_pgoff; /* * RED-PEN: on some architectures there is more mapped memory |