1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
|
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Common arm64 stack unwinder code.
*
* Copyright (C) 2012 ARM Ltd.
*/
#ifndef __ASM_STACKTRACE_COMMON_H
#define __ASM_STACKTRACE_COMMON_H
#include <linux/bitmap.h>
#include <linux/bitops.h>
#include <linux/types.h>
enum stack_type {
STACK_TYPE_UNKNOWN,
STACK_TYPE_TASK,
STACK_TYPE_IRQ,
STACK_TYPE_OVERFLOW,
STACK_TYPE_SDEI_NORMAL,
STACK_TYPE_SDEI_CRITICAL,
__NR_STACK_TYPES
};
struct stack_info {
unsigned long low;
unsigned long high;
enum stack_type type;
};
/*
* A snapshot of a frame record or fp/lr register values, along with some
* accounting information necessary for robust unwinding.
*
* @fp: The fp value in the frame record (or the real fp)
* @pc: The lr value in the frame record (or the real lr)
*
* @stacks_done: Stacks which have been entirely unwound, for which it is no
* longer valid to unwind to.
*
* @prev_fp: The fp that pointed to this frame record, or a synthetic value
* of 0. This is used to ensure that within a stack, each
* subsequent frame record is at an increasing address.
* @prev_type: The type of stack this frame record was on, or a synthetic
* value of STACK_TYPE_UNKNOWN. This is used to detect a
* transition from one stack to another.
*
* @kr_cur: When KRETPROBES is selected, holds the kretprobe instance
* associated with the most recently encountered replacement lr
* value.
*
* @task: The task being unwound.
*/
struct unwind_state {
unsigned long fp;
unsigned long pc;
DECLARE_BITMAP(stacks_done, __NR_STACK_TYPES);
unsigned long prev_fp;
enum stack_type prev_type;
#ifdef CONFIG_KRETPROBES
struct llist_node *kr_cur;
#endif
struct task_struct *task;
};
static inline bool on_overflow_stack(unsigned long sp, unsigned long size,
struct stack_info *info);
static inline bool on_stack(unsigned long sp, unsigned long size,
unsigned long low, unsigned long high,
enum stack_type type, struct stack_info *info)
{
if (!low)
return false;
if (sp < low || sp + size < sp || sp + size > high)
return false;
if (info) {
info->low = low;
info->high = high;
info->type = type;
}
return true;
}
static inline bool on_accessible_stack_common(const struct task_struct *tsk,
unsigned long sp,
unsigned long size,
struct stack_info *info)
{
if (info)
info->type = STACK_TYPE_UNKNOWN;
/*
* Both the kernel and nvhe hypervisor make use of
* an overflow_stack
*/
return on_overflow_stack(sp, size, info);
}
static inline void unwind_init_common(struct unwind_state *state,
struct task_struct *task)
{
state->task = task;
#ifdef CONFIG_KRETPROBES
state->kr_cur = NULL;
#endif
/*
* Prime the first unwind.
*
* In unwind_next() we'll check that the FP points to a valid stack,
* which can't be STACK_TYPE_UNKNOWN, and the first unwind will be
* treated as a transition to whichever stack that happens to be. The
* prev_fp value won't be used, but we set it to 0 such that it is
* definitely not an accessible stack address.
*/
bitmap_zero(state->stacks_done, __NR_STACK_TYPES);
state->prev_fp = 0;
state->prev_type = STACK_TYPE_UNKNOWN;
}
#endif /* __ASM_STACKTRACE_COMMON_H */
|
