1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __LINUX_STACKTRACE_H
3 #define __LINUX_STACKTRACE_H
4
5 #include <linux/types.h>
6 #include <asm/errno.h>
7
8 struct task_struct;
9 struct pt_regs;
10
11 #ifdef CONFIG_STACKTRACE
12 void stack_trace_print(const unsigned long *trace, unsigned int nr_entries,
13 int spaces);
14 int stack_trace_snprint(char *buf, size_t size, const unsigned long *entries,
15 unsigned int nr_entries, int spaces);
16 unsigned int stack_trace_save(unsigned long *store, unsigned int size,
17 unsigned int skipnr);
18 unsigned int stack_trace_save_tsk(struct task_struct *task,
19 unsigned long *store, unsigned int size,
20 unsigned int skipnr);
21 unsigned int stack_trace_save_regs(struct pt_regs *regs, unsigned long *store,
22 unsigned int size, unsigned int skipnr);
23 unsigned int stack_trace_save_user(unsigned long *store, unsigned int size);
24
25 /* Internal interfaces. Do not use in generic code */
26 #ifdef CONFIG_ARCH_STACKWALK
27
28 /**
29 * stack_trace_consume_fn - Callback for arch_stack_walk()
30 * @cookie: Caller supplied pointer handed back by arch_stack_walk()
31 * @addr: The stack entry address to consume
32 * @reliable: True when the stack entry is reliable. Required by
33 * some printk based consumers.
34 *
35 * Return: True, if the entry was consumed or skipped
36 * False, if there is no space left to store
37 */
38 typedef bool (*stack_trace_consume_fn)(void *cookie, unsigned long addr,
39 bool reliable);
40 /**
41 * arch_stack_walk - Architecture specific function to walk the stack
42 * @consume_entry: Callback which is invoked by the architecture code for
43 * each entry.
44 * @cookie: Caller supplied pointer which is handed back to
45 * @consume_entry
46 * @task: Pointer to a task struct, can be NULL
47 * @regs: Pointer to registers, can be NULL
48 *
49 * ============ ======= ============================================
50 * task regs
51 * ============ ======= ============================================
52 * task NULL Stack trace from task (can be current)
53 * current regs Stack trace starting on regs->stackpointer
54 * ============ ======= ============================================
55 */
56 void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
57 struct task_struct *task, struct pt_regs *regs);
58 int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry, void *cookie,
59 struct task_struct *task);
60 void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie,
61 const struct pt_regs *regs);
62
63 #else /* CONFIG_ARCH_STACKWALK */
64 struct stack_trace {
65 unsigned int nr_entries, max_entries;
66 unsigned long *entries;
67 int skip; /* input argument: How many entries to skip */
68 };
69
70 extern void save_stack_trace(struct stack_trace *trace);
71 extern void save_stack_trace_regs(struct pt_regs *regs,
72 struct stack_trace *trace);
73 extern void save_stack_trace_tsk(struct task_struct *tsk,
74 struct stack_trace *trace);
75 extern int save_stack_trace_tsk_reliable(struct task_struct *tsk,
76 struct stack_trace *trace);
77 extern void save_stack_trace_user(struct stack_trace *trace);
78 #endif /* !CONFIG_ARCH_STACKWALK */
79 #endif /* CONFIG_STACKTRACE */
80
81 #if defined(CONFIG_STACKTRACE) && defined(CONFIG_HAVE_RELIABLE_STACKTRACE)
82 int stack_trace_save_tsk_reliable(struct task_struct *tsk, unsigned long *store,
83 unsigned int size);
84 #else
stack_trace_save_tsk_reliable(struct task_struct * tsk,unsigned long * store,unsigned int size)85 static inline int stack_trace_save_tsk_reliable(struct task_struct *tsk,
86 unsigned long *store,
87 unsigned int size)
88 {
89 return -ENOSYS;
90 }
91 #endif
92
93 #endif /* __LINUX_STACKTRACE_H */
94
