Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 8b05c7e6 authored by FUJITA Tomonori's avatar FUJITA Tomonori Committed by Linus Torvalds
Browse files

add a helper function to test if an object is on the stack 



lib/debugobjects.c has a function to test if an object is on the stack.
The block layer and ide needs it (they need to avoid DMA from/to stack
buffers).  This patch moves the function to include/linux/sched.h so that
everyone can use it.

lib/debugobjects.c uses current->stack but this patch uses a
task_stack_page() accessor, which is a preferable way to access the stack.

Signed-off-by: default avatarFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 68ad8df4

include/linux/sched.h

+7 −0
Original line number Diff line number Diff line
@@ -1983,6 +1983,13 @@ static inline unsigned long *end_of_stack(struct task_struct *p) 


#endif



static inline int object_is_on_stack(void *obj)

{

	void *stack = task_stack_page(current);



	return (obj >= stack) && (obj < (stack + THREAD_SIZE));

}



extern void thread_info_cache_init(void);



/* set thread flags in other task's structures

lib/debugobjects.c

+1 −3
Original line number Diff line number Diff line
@@ -226,15 +226,13 @@ debug_object_fixup(int (*fixup)(void *addr, enum debug_obj_state state), 


static void debug_object_is_on_stack(void *addr, int onstack)

{

	void *stack = current->stack;

	int is_on_stack;

	static int limit;



	if (limit > 4)

		return;



	is_on_stack = (addr >= stack && addr < (stack + THREAD_SIZE));



	is_on_stack = object_is_on_stack(addr);

	if (is_on_stack == onstack)

		return;