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
8struct task_struct;
9struct pt_regs;
10
11#ifdef CONFIG_ARCH_STACKWALK
12
13/**
14 * stack_trace_consume_fn - Callback for arch_stack_walk()
15 * @cookie: Caller supplied pointer handed back by arch_stack_walk()
16 * @addr: The stack entry address to consume
17 *
18 * Return: True, if the entry was consumed or skipped
19 * False, if there is no space left to store
20 */
21typedef bool (*stack_trace_consume_fn)(void *cookie, unsigned long addr);
22/**
23 * arch_stack_walk - Architecture specific function to walk the stack
24 * @consume_entry: Callback which is invoked by the architecture code for
25 * each entry.
26 * @cookie: Caller supplied pointer which is handed back to
27 * @consume_entry
28 * @task: Pointer to a task struct, can be NULL
29 * @regs: Pointer to registers, can be NULL
30 *
31 * ============ ======= ============================================
32 * task regs
33 * ============ ======= ============================================
34 * task NULL Stack trace from task (can be current)
35 * current regs Stack trace starting on regs->stackpointer
36 * ============ ======= ============================================
37 */
38void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
39 struct task_struct *task, struct pt_regs *regs);
40
41/**
42 * arch_stack_walk_reliable - Architecture specific function to walk the
43 * stack reliably
44 *
45 * @consume_entry: Callback which is invoked by the architecture code for
46 * each entry.
47 * @cookie: Caller supplied pointer which is handed back to
48 * @consume_entry
49 * @task: Pointer to a task struct, can be NULL
50 *
51 * This function returns an error if it detects any unreliable
52 * features of the stack. Otherwise it guarantees that the stack
53 * trace is reliable.
54 *
55 * If the task is not 'current', the caller *must* ensure the task is
56 * inactive and its stack is pinned.
57 */
58int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry, void *cookie,
59 struct task_struct *task);
60
61void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie,
62 const struct pt_regs *regs);
63#endif /* CONFIG_ARCH_STACKWALK */
64
65#ifdef CONFIG_STACKTRACE
66void stack_trace_print(const unsigned long *trace, unsigned int nr_entries,
67 int spaces);
68int stack_trace_snprint(char *buf, size_t size, const unsigned long *entries,
69 unsigned int nr_entries, int spaces);
70unsigned int stack_trace_save(unsigned long *store, unsigned int size,
71 unsigned int skipnr);
72unsigned int stack_trace_save_tsk(struct task_struct *task,
73 unsigned long *store, unsigned int size,
74 unsigned int skipnr);
75unsigned int stack_trace_save_regs(struct pt_regs *regs, unsigned long *store,
76 unsigned int size, unsigned int skipnr);
77unsigned int stack_trace_save_user(unsigned long *store, unsigned int size);
78unsigned int filter_irq_stacks(unsigned long *entries, unsigned int nr_entries);
79
80#ifndef CONFIG_ARCH_STACKWALK
81/* Internal interfaces. Do not use in generic code */
82struct stack_trace {
83 unsigned int nr_entries, max_entries;
84 unsigned long *entries;
85 unsigned int skip; /* input argument: How many entries to skip */
86};
87
88extern void save_stack_trace(struct stack_trace *trace);
89extern void save_stack_trace_regs(struct pt_regs *regs,
90 struct stack_trace *trace);
91extern void save_stack_trace_tsk(struct task_struct *tsk,
92 struct stack_trace *trace);
93extern int save_stack_trace_tsk_reliable(struct task_struct *tsk,
94 struct stack_trace *trace);
95extern void save_stack_trace_user(struct stack_trace *trace);
96#endif /* !CONFIG_ARCH_STACKWALK */
97#endif /* CONFIG_STACKTRACE */
98
99#if defined(CONFIG_STACKTRACE) && defined(CONFIG_HAVE_RELIABLE_STACKTRACE)
100int stack_trace_save_tsk_reliable(struct task_struct *tsk, unsigned long *store,
101 unsigned int size);
102#else
103static inline int stack_trace_save_tsk_reliable(struct task_struct *tsk,
104 unsigned long *store,
105 unsigned int size)
106{
107 return -ENOSYS;
108}
109#endif
110
111#endif /* __LINUX_STACKTRACE_H */
112