Re: mmap() of /dev/kmem issue

Mario Smarduch
2004-05-05T15:53:10Z

Matthew Wilcox wrote:

> On Wed, May 05, 2004 at 08:08:21AM -0700, Luck, Tony wrote:
> > Mapping kernel memory as uncacheable into a user process
> > seems like a recipe for disaster (well at least for an
> > MCA when the processor catches you using mixed attributes).
>
> ... which is why we don't do that.
>
> See drivers/char/mem.c::mmap_mem(). We call uncached_access() which does:
>
> #elif defined(CONFIG_IA64)
> /*
> * On ia64, we ignore O_SYNC because we cannot tolerate memory attribute
> aliases.
> */
> return !(efi_mem_attributes(addr) & EFI_MEMORY_WB);

That's great but what release is that in?

- mario.

>
>
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