1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_UNWIND_USER_DEFERRED_H
3 #define _LINUX_UNWIND_USER_DEFERRED_H
4
5 #include <linux/task_work.h>
6 #include <linux/unwind_user.h>
7 #include <linux/unwind_deferred_types.h>
8
9 #ifdef CONFIG_UNWIND_USER
10
11 enum {
12 UNWIND_PENDING_BIT = 0,
13 UNWIND_USED_BIT,
14 };
15
16 enum {
17 UNWIND_PENDING = BIT(UNWIND_PENDING_BIT),
18
19 /* Set if the unwinding was used (directly or deferred) */
20 UNWIND_USED = BIT(UNWIND_USED_BIT)
21 };
22
23 void unwind_task_init(struct task_struct *task);
24 void unwind_task_free(struct task_struct *task);
25
26 int unwind_user_faultable(struct unwind_stacktrace *trace);
27
28 int unwind_deferred_init(struct unwind_work *work, unwind_callback_t func);
29 int unwind_deferred_request(struct unwind_work *work, u64 *cookie);
30 void unwind_deferred_cancel(struct unwind_work *work);
31
32 void unwind_deferred_task_exit(struct task_struct *task);
33
unwind_reset_info(void)34 static __always_inline void unwind_reset_info(void)
35 {
36 struct unwind_task_info *info = ¤t->unwind_info;
37 unsigned long bits = atomic_long_read(&info->unwind_mask);
38
39 /* Was there any unwinding? */
40 if (likely(!bits))
41 return;
42
43 do {
44 /* Is a task_work going to run again before going back */
45 if (bits & UNWIND_PENDING)
46 return;
47 } while (!atomic_long_try_cmpxchg(&info->unwind_mask, &bits, 0UL));
48 current->unwind_info.id.id = 0;
49
50 if (unlikely(info->cache)) {
51 info->cache->nr_entries = 0;
52 info->cache->unwind_completed = 0;
53 }
54 }
55
56 #else /* !CONFIG_UNWIND_USER */
57
unwind_task_init(struct task_struct * task)58 static inline void unwind_task_init(struct task_struct *task) {}
unwind_task_free(struct task_struct * task)59 static inline void unwind_task_free(struct task_struct *task) {}
60
unwind_user_faultable(struct unwind_stacktrace * trace)61 static inline int unwind_user_faultable(struct unwind_stacktrace *trace)
62 { return -ENOSYS; }
63
64 static inline int
unwind_deferred_init(struct unwind_work * work,unwind_callback_t func)65 unwind_deferred_init(struct unwind_work *work, unwind_callback_t func)
66 { return -ENOSYS; }
67
68 static inline int
unwind_deferred_request(struct unwind_work * work,u64 * timestamp)69 unwind_deferred_request(struct unwind_work *work, u64 *timestamp)
70 { return -ENOSYS; }
71
unwind_deferred_cancel(struct unwind_work * work)72 static inline void unwind_deferred_cancel(struct unwind_work *work) {}
73
unwind_deferred_task_exit(struct task_struct * task)74 static inline void unwind_deferred_task_exit(struct task_struct *task) {}
unwind_reset_info(void)75 static inline void unwind_reset_info(void) {}
76
77 #endif /* !CONFIG_UNWIND_USER */
78
79 #endif /* _LINUX_UNWIND_USER_DEFERRED_H */
80