uml: clean up TASK_SIZE usage

Clean up the calculation and use of the usable address space size on the host.

task_size is gone, replaced with TASK_SIZE, which is calculated from
CONFIG_TOP_ADDR.  get_kmem_end and set_task_sizes_skas are also gone.

host_task_size, which refers to the entire address space usable by the UML
kernel and which may be larger than the address space usable by a UML process,
since that has to end on a pgdir boundary, is replaced by CONFIG_TOP_ADDR.

STACK_TOP is now TASK_SIZE minus the two stub pages.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 3 deletions

diff --git a/include/asm-um/a.out.h b/include/asm-um/a.out.h
index 9281dd8eb334..f42ff14577fa 100644
--- a/include/asm-um/a.out.h
+++ b/include/asm-um/a.out.h
@@ -13,11 +13,9 @@
 
 extern unsigned long stacksizelim;
 
-extern unsigned long host_task_size;
-
 #define STACK_ROOM (stacksizelim)
 
-#define STACK_TOP task_size
+#define STACK_TOP (TASK_SIZE - 2 * PAGE_SIZE)
 
 #define STACK_TOP_MAX STACK_TOP