From: Ingo Molnar Date: Fri, 3 Feb 2017 21:59:33 +0000 (+0100) Subject: sched/headers: Move task-stack related APIs from to to Split out the task->stack related functionality, which is not really part of the core scheduler APIs. Only keep task_thread_info() because it's used by sched.h. Update the code that uses those facilities. Acked-by: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar --- diff --git a/arch/mips/kernel/smp-cps.c b/arch/mips/kernel/smp-cps.c index 1d3188c23bb8..6d45f05538c8 100644 --- a/arch/mips/kernel/smp-cps.c +++ b/arch/mips/kernel/smp-cps.c @@ -11,7 +11,7 @@ #include #include #include -#include +#include #include #include #include diff --git a/arch/mips/sibyte/sb1250/smp.c b/arch/mips/sibyte/sb1250/smp.c index 1cf66f5ff23d..0a4a2c3982d8 100644 --- a/arch/mips/sibyte/sb1250/smp.c +++ b/arch/mips/sibyte/sb1250/smp.c @@ -21,7 +21,7 @@ #include #include #include -#include +#include #include #include diff --git a/include/linux/sched.h b/include/linux/sched.h index 3b3e31da416e..af9590c8bfb0 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1450,6 +1450,15 @@ union thread_union { unsigned long stack[THREAD_SIZE/sizeof(long)]; }; +#ifdef CONFIG_THREAD_INFO_IN_TASK +static inline struct thread_info *task_thread_info(struct task_struct *task) +{ + return &task->thread_info; +} +#elif !defined(__HAVE_THREAD_FUNCTIONS) +# define task_thread_info(task) ((struct thread_info *)(task)->stack) +#endif + #ifndef __HAVE_ARCH_KSTACK_END static inline int kstack_end(void *addr) { @@ -1540,112 +1549,6 @@ static inline void task_unlock(struct task_struct *p) spin_unlock(&p->alloc_lock); } -#ifdef CONFIG_THREAD_INFO_IN_TASK - -static inline struct thread_info *task_thread_info(struct task_struct *task) -{ - return &task->thread_info; -} - -/* - * When accessing the stack of a non-current task that might exit, use - * try_get_task_stack() instead. task_stack_page will return a pointer - * that could get freed out from under you. - */ -static inline void *task_stack_page(const struct task_struct *task) -{ - return task->stack; -} - -#define setup_thread_stack(new,old) do { } while(0) - -static inline unsigned long *end_of_stack(const struct task_struct *task) -{ - return task->stack; -} - -#elif !defined(__HAVE_THREAD_FUNCTIONS) - -#define task_thread_info(task) ((struct thread_info *)(task)->stack) -#define task_stack_page(task) ((void *)(task)->stack) - -static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org) -{ - *task_thread_info(p) = *task_thread_info(org); - task_thread_info(p)->task = p; -} - -/* - * Return the address of the last usable long on the stack. - * - * When the stack grows down, this is just above the thread - * info struct. Going any lower will corrupt the threadinfo. - * - * When the stack grows up, this is the highest address. - * Beyond that position, we corrupt data on the next page. - */ -static inline unsigned long *end_of_stack(struct task_struct *p) -{ -#ifdef CONFIG_STACK_GROWSUP - return (unsigned long *)((unsigned long)task_thread_info(p) + THREAD_SIZE) - 1; -#else - return (unsigned long *)(task_thread_info(p) + 1); -#endif -} - -#endif - -#ifdef CONFIG_THREAD_INFO_IN_TASK -static inline void *try_get_task_stack(struct task_struct *tsk) -{ - return atomic_inc_not_zero(&tsk->stack_refcount) ? - task_stack_page(tsk) : NULL; -} - -extern void put_task_stack(struct task_struct *tsk); -#else -static inline void *try_get_task_stack(struct task_struct *tsk) -{ - return task_stack_page(tsk); -} - -static inline void put_task_stack(struct task_struct *tsk) {} -#endif - -#define task_stack_end_corrupted(task) \ - (*(end_of_stack(task)) != STACK_END_MAGIC) - -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_stack_cache_init(void); - -#ifdef CONFIG_DEBUG_STACK_USAGE -static inline unsigned long stack_not_used(struct task_struct *p) -{ - unsigned long *n = end_of_stack(p); - - do { /* Skip over canary */ -# ifdef CONFIG_STACK_GROWSUP - n--; -# else - n++; -# endif - } while (!*n); - -# ifdef CONFIG_STACK_GROWSUP - return (unsigned long)end_of_stack(p) - (unsigned long)n; -# else - return (unsigned long)n - (unsigned long)end_of_stack(p); -# endif -} -#endif -extern void set_task_stack_end_magic(struct task_struct *tsk); - /* set thread flags in other task's structures * - see asm/thread_info.h for TIF_xxxx flags available */ diff --git a/include/linux/sched/task_stack.h b/include/linux/sched/task_stack.h index d2d578e85f7d..aaa5c2a6a0e9 100644 --- a/include/linux/sched/task_stack.h +++ b/include/linux/sched/task_stack.h @@ -1,7 +1,111 @@ #ifndef _LINUX_SCHED_TASK_STACK_H #define _LINUX_SCHED_TASK_STACK_H +/* + * task->stack (kernel stack) handling interfaces: + */ + #include #include +#ifdef CONFIG_THREAD_INFO_IN_TASK + +/* + * When accessing the stack of a non-current task that might exit, use + * try_get_task_stack() instead. task_stack_page will return a pointer + * that could get freed out from under you. + */ +static inline void *task_stack_page(const struct task_struct *task) +{ + return task->stack; +} + +#define setup_thread_stack(new,old) do { } while(0) + +static inline unsigned long *end_of_stack(const struct task_struct *task) +{ + return task->stack; +} + +#elif !defined(__HAVE_THREAD_FUNCTIONS) + +#define task_stack_page(task) ((void *)(task)->stack) + +static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org) +{ + *task_thread_info(p) = *task_thread_info(org); + task_thread_info(p)->task = p; +} + +/* + * Return the address of the last usable long on the stack. + * + * When the stack grows down, this is just above the thread + * info struct. Going any lower will corrupt the threadinfo. + * + * When the stack grows up, this is the highest address. + * Beyond that position, we corrupt data on the next page. + */ +static inline unsigned long *end_of_stack(struct task_struct *p) +{ +#ifdef CONFIG_STACK_GROWSUP + return (unsigned long *)((unsigned long)task_thread_info(p) + THREAD_SIZE) - 1; +#else + return (unsigned long *)(task_thread_info(p) + 1); +#endif +} + +#endif + +#ifdef CONFIG_THREAD_INFO_IN_TASK +static inline void *try_get_task_stack(struct task_struct *tsk) +{ + return atomic_inc_not_zero(&tsk->stack_refcount) ? + task_stack_page(tsk) : NULL; +} + +extern void put_task_stack(struct task_struct *tsk); +#else +static inline void *try_get_task_stack(struct task_struct *tsk) +{ + return task_stack_page(tsk); +} + +static inline void put_task_stack(struct task_struct *tsk) {} +#endif + +#define task_stack_end_corrupted(task) \ + (*(end_of_stack(task)) != STACK_END_MAGIC) + +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_stack_cache_init(void); + +#ifdef CONFIG_DEBUG_STACK_USAGE +static inline unsigned long stack_not_used(struct task_struct *p) +{ + unsigned long *n = end_of_stack(p); + + do { /* Skip over canary */ +# ifdef CONFIG_STACK_GROWSUP + n--; +# else + n++; +# endif + } while (!*n); + +# ifdef CONFIG_STACK_GROWSUP + return (unsigned long)end_of_stack(p) - (unsigned long)n; +# else + return (unsigned long)n - (unsigned long)end_of_stack(p); +# endif +} +#endif +extern void set_task_stack_end_magic(struct task_struct *tsk); + #endif /* _LINUX_SCHED_TASK_STACK_H */