tree 85d056d9a718f69c7242a8bb6cde17fc928fa4cc
parent 8a3a0ee736b9a0150c9d894f2c6cc836a62125a1
author KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> 1174619866 +0900
committer Tony Luck <tony.luck@intel.com> 1175206524 -0700

[IA64] bugfix stack layout upside-down

ia64 expects following vm layout:

== low memory
[register-stack grows up]
[memory-stack grows down]
== high memory

But the code assigns the base of the register stack at the
maximum stack size offset from the fixed address where the
stack *might* start.  Stack randomization will result in the
memory stack starting at a lower address than this, and if the
user has set a low stack limit with "ulimit -s", then you can
end up with the register stack above the memory stack (or if
you were very unlucky right on top of it!).

Fix: Calculate the base address for the register stack starting
from the actual address of the memory stack.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>