tree 4f23a06244f7cb6689bd7ded80843c481968a283
parent 90ed52ebe48181d3c5427b3bd1d24f659e7575ad
author Carsten Otte <cotte@de.ibm.com> 1175156439 -0700
committer Linus Torvalds <torvalds@woody.linux-foundation.org> 1175181746 -0700

[PATCH] mm: fix xip issue with /dev/zero

Fix the bug, that reading into xip mapping from /dev/zero fills the user
page table with ZERO_PAGE() entries.  Later on, xip cannot tell which pages
have been ZERO_PAGE() filled by access to a sparse mapping, and which ones
origin from /dev/zero.  It will unmap ZERO_PAGE from all mappings when
filling the sparse hole with data.  xip does now use its own zeroed page
for its sparse mappings.  Please apply.

Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>