1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Copyright (C) 2012 ARM Ltd.
4 */
5 #ifndef __ASM_STACKTRACE_H
6 #define __ASM_STACKTRACE_H
7
8 #include <linux/percpu.h>
9 #include <linux/sched.h>
10 #include <linux/sched/task_stack.h>
11 #include <linux/types.h>
12 #include <linux/llist.h>
13
14 #include <asm/memory.h>
15 #include <asm/ptrace.h>
16 #include <asm/sdei.h>
17
18 enum stack_type {
19 STACK_TYPE_UNKNOWN,
20 STACK_TYPE_TASK,
21 STACK_TYPE_IRQ,
22 STACK_TYPE_OVERFLOW,
23 STACK_TYPE_SDEI_NORMAL,
24 STACK_TYPE_SDEI_CRITICAL,
25 __NR_STACK_TYPES
26 };
27
28 struct stack_info {
29 unsigned long low;
30 unsigned long high;
31 enum stack_type type;
32 };
33
34 extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk,
35 const char *loglvl);
36
37 DECLARE_PER_CPU(unsigned long *, irq_stack_ptr);
38
on_stack(unsigned long sp,unsigned long size,unsigned long low,unsigned long high,enum stack_type type,struct stack_info * info)39 static inline bool on_stack(unsigned long sp, unsigned long size,
40 unsigned long low, unsigned long high,
41 enum stack_type type, struct stack_info *info)
42 {
43 if (!low)
44 return false;
45
46 if (sp < low || sp + size < sp || sp + size > high)
47 return false;
48
49 if (info) {
50 info->low = low;
51 info->high = high;
52 info->type = type;
53 }
54 return true;
55 }
56
on_irq_stack(unsigned long sp,unsigned long size,struct stack_info * info)57 static inline bool on_irq_stack(unsigned long sp, unsigned long size,
58 struct stack_info *info)
59 {
60 unsigned long low = (unsigned long)raw_cpu_read(irq_stack_ptr);
61 unsigned long high = low + IRQ_STACK_SIZE;
62
63 return on_stack(sp, size, low, high, STACK_TYPE_IRQ, info);
64 }
65
on_task_stack(const struct task_struct * tsk,unsigned long sp,unsigned long size,struct stack_info * info)66 static inline bool on_task_stack(const struct task_struct *tsk,
67 unsigned long sp, unsigned long size,
68 struct stack_info *info)
69 {
70 unsigned long low = (unsigned long)task_stack_page(tsk);
71 unsigned long high = low + THREAD_SIZE;
72
73 return on_stack(sp, size, low, high, STACK_TYPE_TASK, info);
74 }
75
76 #ifdef CONFIG_VMAP_STACK
77 DECLARE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack);
78
on_overflow_stack(unsigned long sp,unsigned long size,struct stack_info * info)79 static inline bool on_overflow_stack(unsigned long sp, unsigned long size,
80 struct stack_info *info)
81 {
82 unsigned long low = (unsigned long)raw_cpu_ptr(overflow_stack);
83 unsigned long high = low + OVERFLOW_STACK_SIZE;
84
85 return on_stack(sp, size, low, high, STACK_TYPE_OVERFLOW, info);
86 }
87 #else
on_overflow_stack(unsigned long sp,unsigned long size,struct stack_info * info)88 static inline bool on_overflow_stack(unsigned long sp, unsigned long size,
89 struct stack_info *info) { return false; }
90 #endif
91
92
93 /*
94 * We can only safely access per-cpu stacks from current in a non-preemptible
95 * context.
96 */
on_accessible_stack(const struct task_struct * tsk,unsigned long sp,unsigned long size,struct stack_info * info)97 static inline bool on_accessible_stack(const struct task_struct *tsk,
98 unsigned long sp, unsigned long size,
99 struct stack_info *info)
100 {
101 if (info)
102 info->type = STACK_TYPE_UNKNOWN;
103
104 if (on_task_stack(tsk, sp, size, info))
105 return true;
106 if (tsk != current || preemptible())
107 return false;
108 if (on_irq_stack(sp, size, info))
109 return true;
110 if (on_overflow_stack(sp, size, info))
111 return true;
112 if (on_sdei_stack(sp, size, info))
113 return true;
114
115 return false;
116 }
117
118 #endif /* __ASM_STACKTRACE_H */
119