[PATCH] Add mm->task_size and fix powerpc vdso

This patch adds mm->task_size to keep track of the task size of a given mm
and uses that to fix the powerpc vdso so that it uses the mm task size to
decide what pages to fault in instead of the current thread flags (which
broke when ptracing).

(akpm: I expect that mm_struct.task_size will become the way in which we
finally sort out the confusion between 32-bit processes and 32-bit mm's.  It
may need tweaks, but at this stage this patch is powerpc-only.)

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index b6f51e3a38ec..ff2e09c953b9 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -298,8 +298,9 @@ struct mm_struct {
                                 unsigned long addr, unsigned long len,
                                 unsigned long pgoff, unsigned long flags);
         void (*unmap_area) (struct mm_struct *mm, unsigned long addr);
-        unsigned long mmap_base;                /* base of mmap area */
-        unsigned long cached_hole_size;         /* if non-zero, the largest hole below free_area_cache */
+        unsigned long mmap_base;                /* base of mmap area */
+        unsigned long task_size;                /* size of task vm space */
+        unsigned long cached_hole_size;         /* if non-zero, the largest hole below free_area_cache */
         unsigned long free_area_cache;          /* first hole of size cached_hole_size or larger */
         pgd_t * pgd;
         atomic_t mm_users;                      /* How many users with user space? */