From 8b05c7e6e159d2f33c9275281b8b909a89eb7c5d Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Wed, 23 Jul 2008 21:26:53 -0700 Subject: [PATCH] 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: FUJITA Tomonori Cc: Christoph Lameter Cc: Andy Whitcroft Cc: Ingo Molnar Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/sched.h | 7 +++++++ lib/debugobjects.c | 4 +--- 2 files changed, 8 insertions(+), 3 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index dc7e592c473..6aca4a16e37 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -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 diff --git a/lib/debugobjects.c b/lib/debugobjects.c index 85b18d79be8..f86196390cf 100644 --- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -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; -- 2.41.1