Re: Possible shared mapping bug in 2.4.23 (at least MIPS/Sparc)

[Ralf Baechle <ralf@linux-mips.org>]

On Sat, Dec 13, 2003 at 11:41:34AM +0000, Peter Horton wrote:

> The current MIPS 2.4 kernel (from CVS) currently allows fixed shared
> mappings to violate D-cache aliasing constraints.
> 
> The check for illegal fixed mappings is done in
> arch_get_unmapped_area(), but these mappings are granted in
> get_unmapped_area() and arch_get_unmapped_area() is never called.
> 
> A quick look at sparc and sparc64 seem to show the same problem.

Ehh...  <asm/pgtable.h> defines HAVE_ARCH_UNMAPPED_AREA therefore
get_unmapped_area calls the arch's version of arch_get_unmapped_area
instead of the generic version in mm/mmap.c

  Ralf