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