fix up initial thread stack pointer vs thread_info confusion

The INIT_TASK() initializer was similarly confused about the stack vs
thread_info allocation that the allocators had, and that were fixed in
commit b235beea9e99 ("Clarify naming of thread info/stack allocators").

The task ->stack pointer only incidentally ends up having the same value
as the thread_info, and in fact that will change.

So fix the initial task struct initializer to point to 'init_stack'
instead of 'init_thread_info', and make sure the ia64 definition for
that exists.

This actually makes the ia64 tsk->stack pointer be sensible for the
initial task, but not for any other task.  As mentioned in commit
b235beea9e99, that whole pointer isn't actually used on ia64, since
task_stack_page() there just points to the (single) allocation.

All the other architectures seem to have copied the 'init_stack'
definition, even if it tended to be generally unusued.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 2 insertions, 1 deletions

diff --git a/arch/ia64/kernel/init_task.c b/arch/ia64/kernel/init_task.c
index f9efe9739d3f..0eaa89f3defd 100644
--- a/arch/ia64/kernel/init_task.c
+++ b/arch/ia64/kernel/init_task.c
@@ -26,6 +26,7 @@ static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
  * handled. This is done by having a special ".data..init_task" section...
  */
 #define init_thread_info        init_task_mem.s.thread_info
+#define init_stack              init_task_mem.stack
 
 union {
         struct {
diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index f2cb8d45513d..f8834f820ec2 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -190,7 +190,7 @@ extern struct task_group root_task_group;
 #define INIT_TASK(tsk)  \
 {                                                                       \
         .state          = 0,                                            \
-        .stack          = &init_thread_info,                            \
+        .stack          = init_stack,                                   \
         .usage          = ATOMIC_INIT(2),                               \
         .flags          = PF_KTHREAD,                                   \
         .prio           = MAX_PRIO-20,                                  \