Re: dio_get_page() lockdep complaints

[Peter Zijlstra]

On Mon, 2007-11-12 at 09:45 +0100, Martin Schwidefsky wrote:
> On Sun, 2007-11-11 at 20:49 +0100, Peter Zijlstra wrote:
> > Right, which gets us into all kinds of trouble because some sites need
> > mmap_sem to resolve some races, notably s390 31-bit and shm.
> 
> You are refering to the mmap_sem use in compat_linux.c:do_mmap2, aren't
> you? That check for adresses > 2GB after the call to do_mmap_pgoff can
> be removed since arch_get_unmapped_area already checks against
> TASK_SIZE. The result of the do_mmap_pgoff call will never be out of
> range. This check is a left-over from the early days of the s390 compat
> code.

Correct, that is the one I was referring to. Thanks for the explanation,
I'll clean it up when I take this patch forward.



-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/