[PATCH AUTOSEL 4.19 166/219] fork: fix some -Wmissing-prototypes warnings

[Sasha Levin]

From: Yi Wang <wang.yi59@xxxxxxxxxx>

[ Upstream commit fb5bf31722d0805a3f394f7d59f2e8cd07acccb7 ]

We get a warning when building kernel with W=1:

  kernel/fork.c:167:13: warning: no previous prototype for `arch_release_thread_stack' [-Wmissing-prototypes]
  kernel/fork.c:779:13: warning: no previous prototype for `fork_init' [-Wmissing-prototypes]

Add the missing declaration in head file to fix this.

Also, remove arch_release_thread_stack() completely because no arch
seems to implement it since bb9d81264 (arch: remove tile port).

Link: http://lkml.kernel.org/r/1542170087-23645-1-git-send-email-wang.yi59@xxxxxxxxxx
Signed-off-by: Yi Wang <wang.yi59@xxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Acked-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 include/linux/sched/task.h | 2 ++
 init/main.c                | 1 -
 kernel/fork.c              | 5 -----
 3 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h
index 108ede99e5335..44c6f15800ff5 100644
--- a/include/linux/sched/task.h
+++ b/include/linux/sched/task.h
@@ -39,6 +39,8 @@ void __noreturn do_task_dead(void);
 
 extern void proc_caches_init(void);
 
+extern void fork_init(void);
+
 extern void release_task(struct task_struct * p);
 
 #ifdef CONFIG_HAVE_COPY_THREAD_TLS
diff --git a/init/main.c b/init/main.c
index 020972fed1171..38a603f62b7bb 100644
--- a/init/main.c
+++ b/init/main.c
@@ -105,7 +105,6 @@
 static int kernel_init(void *);
 
 extern void init_IRQ(void);
-extern void fork_init(void);
 extern void radix_tree_init(void);
 
 /*
diff --git a/kernel/fork.c b/kernel/fork.c
index aef1430bdce0b..8cb5cd7c97e19 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -163,10 +163,6 @@ static inline void free_task_struct(struct task_struct *tsk)
 }
 #endif
 
-void __weak arch_release_thread_stack(unsigned long *stack)
-{
-}
-
 #ifndef CONFIG_ARCH_THREAD_STACK_ALLOCATOR
 
 /*
@@ -376,7 +372,6 @@ static void release_task_stack(struct task_struct *tsk)
 		return;  /* Better to leak the stack than to free prematurely */
 
 	account_kernel_stack(tsk, -1);
-	arch_release_thread_stack(tsk->stack);
 	free_thread_stack(tsk);
 	tsk->stack = NULL;
 #ifdef CONFIG_VMAP_STACK
-- 
2.20.1