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122 lines
2.9 KiB
122 lines
2.9 KiB
/* SPDX-License-Identifier: GPL-2.0 */ |
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#ifndef _LINUX_SCHED_TASK_STACK_H |
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#define _LINUX_SCHED_TASK_STACK_H |
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/* |
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* task->stack (kernel stack) handling interfaces: |
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*/ |
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#include <linux/sched.h> |
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#include <linux/magic.h> |
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#ifdef CONFIG_THREAD_INFO_IN_TASK |
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/* |
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* When accessing the stack of a non-current task that might exit, use |
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* try_get_task_stack() instead. task_stack_page will return a pointer |
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* that could get freed out from under you. |
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*/ |
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static inline void *task_stack_page(const struct task_struct *task) |
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{ |
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return task->stack; |
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} |
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#define setup_thread_stack(new,old) do { } while(0) |
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static inline unsigned long *end_of_stack(const struct task_struct *task) |
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{ |
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return task->stack; |
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} |
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#elif !defined(__HAVE_THREAD_FUNCTIONS) |
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#define task_stack_page(task) ((void *)(task)->stack) |
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static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org) |
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{ |
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*task_thread_info(p) = *task_thread_info(org); |
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task_thread_info(p)->task = p; |
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} |
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/* |
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* Return the address of the last usable long on the stack. |
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* |
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* When the stack grows down, this is just above the thread |
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* info struct. Going any lower will corrupt the threadinfo. |
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* |
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* When the stack grows up, this is the highest address. |
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* Beyond that position, we corrupt data on the next page. |
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*/ |
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static inline unsigned long *end_of_stack(struct task_struct *p) |
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{ |
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#ifdef CONFIG_STACK_GROWSUP |
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return (unsigned long *)((unsigned long)task_thread_info(p) + THREAD_SIZE) - 1; |
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#else |
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return (unsigned long *)(task_thread_info(p) + 1); |
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#endif |
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} |
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#endif |
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#ifdef CONFIG_THREAD_INFO_IN_TASK |
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static inline void *try_get_task_stack(struct task_struct *tsk) |
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{ |
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return refcount_inc_not_zero(&tsk->stack_refcount) ? |
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task_stack_page(tsk) : NULL; |
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} |
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extern void put_task_stack(struct task_struct *tsk); |
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#else |
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static inline void *try_get_task_stack(struct task_struct *tsk) |
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{ |
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return task_stack_page(tsk); |
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} |
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static inline void put_task_stack(struct task_struct *tsk) {} |
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#endif |
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#define task_stack_end_corrupted(task) \ |
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(*(end_of_stack(task)) != STACK_END_MAGIC) |
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static inline int object_is_on_stack(const void *obj) |
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{ |
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void *stack = task_stack_page(current); |
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return (obj >= stack) && (obj < (stack + THREAD_SIZE)); |
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} |
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extern void thread_stack_cache_init(void); |
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#ifdef CONFIG_DEBUG_STACK_USAGE |
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static inline unsigned long stack_not_used(struct task_struct *p) |
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{ |
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unsigned long *n = end_of_stack(p); |
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do { /* Skip over canary */ |
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# ifdef CONFIG_STACK_GROWSUP |
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n--; |
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# else |
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n++; |
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# endif |
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} while (!*n); |
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# ifdef CONFIG_STACK_GROWSUP |
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return (unsigned long)end_of_stack(p) - (unsigned long)n; |
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# else |
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return (unsigned long)n - (unsigned long)end_of_stack(p); |
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# endif |
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} |
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#endif |
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extern void set_task_stack_end_magic(struct task_struct *tsk); |
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#ifndef __HAVE_ARCH_KSTACK_END |
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static inline int kstack_end(void *addr) |
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{ |
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/* Reliable end of stack detection: |
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* Some APM bios versions misalign the stack |
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*/ |
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return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*))); |
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} |
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#endif |
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#endif /* _LINUX_SCHED_TASK_STACK_H */
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