[PATCH] powerpc: More hugepage boundary case fixes

Blah.  The patch [0] I recently sent fixing errors with
in_hugepage_area() and prepare_hugepage_range() for powerpc itself has
an off-by-one bug.  Furthermore, the related functions
touches_hugepage_*_range() and within_hugepage_*_range() are also
buggy.  Some of the bugs, like those addressed in [0] originated with
commit 7d24f0b8a53261709938ffabe3e00f88f6498df9 where we tweaked the
semantics of where hugepages are allowed.  Other bugs have been there
essentially forever, and are due to the undefined behaviour of '<<'
with shift counts greater than the type width (LOW_ESID_MASK could
return non-zero for high ranges with the right congruences).

The good news is that I now have a testsuite which should pick up
things like this if they creep in again.

[0] "powerpc-fix-for-hugepage-areas-straddling-4gb-boundary"

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index f867bba893ca..6bc9dbad7dea 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -295,7 +295,7 @@ int prepare_hugepage_range(unsigned long addr, unsigned long len)
         if (addr < 0x100000000UL)
                 err = open_low_hpage_areas(current->mm,
                                           LOW_ESID_MASK(addr, len));
-        if ((addr + len) >= 0x100000000UL)
+        if ((addr + len) > 0x100000000UL)
                 err = open_high_hpage_areas(current->mm,
                                             HTLB_AREA_MASK(addr, len));
         if (err) {