tree 41263d573286cae19d99083d57165ffa0412b9e7
parent 96710098ee124951ff2fed7cd8406da92aad011a
author Will Deacon <will.deacon@arm.com> 1353104100 -0800
committer Linus Torvalds <torvalds@linux-foundation.org> 1353105184 -0800

mm: highmem: don't treat PKMAP_ADDR(LAST_PKMAP) as a highmem address

kmap_to_page returns the corresponding struct page for a virtual address
of an arbitrary mapping.  This works by checking whether the address
falls in the pkmap region and using the pkmap page tables instead of the
linear mapping if appropriate.

Unfortunately, the bounds checking means that PKMAP_ADDR(LAST_PKMAP) is
incorrectly treated as a highmem address and we can end up walking off
the end of pkmap_page_table and subsequently passing junk to pte_page.

This patch fixes the bound check to stay within the pkmap tables.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>