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
|
/*
* arch/xtensa/kernel/stacktrace.c
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2001 - 2013 Tensilica Inc.
*/
#include <linux/export.h>
#include <linux/sched.h>
#include <linux/stacktrace.h>
#include <asm/stacktrace.h>
#include <asm/traps.h>
void walk_stackframe(unsigned long *sp,
int (*fn)(struct stackframe *frame, void *data),
void *data)
{
unsigned long a0, a1;
unsigned long sp_end;
a1 = (unsigned long)sp;
sp_end = ALIGN(a1, THREAD_SIZE);
spill_registers();
while (a1 < sp_end) {
struct stackframe frame;
sp = (unsigned long *)a1;
a0 = *(sp - 4);
a1 = *(sp - 3);
if (a1 <= (unsigned long)sp)
break;
frame.pc = MAKE_PC_FROM_RA(a0, a1);
frame.sp = a1;
if (fn(&frame, data))
return;
}
}
#ifdef CONFIG_STACKTRACE
struct stack_trace_data {
struct stack_trace *trace;
unsigned skip;
};
static int stack_trace_cb(struct stackframe *frame, void *data)
{
struct stack_trace_data *trace_data = data;
struct stack_trace *trace = trace_data->trace;
if (trace_data->skip) {
--trace_data->skip;
return 0;
}
if (!kernel_text_address(frame->pc))
return 0;
trace->entries[trace->nr_entries++] = frame->pc;
return trace->nr_entries >= trace->max_entries;
}
void save_stack_trace_tsk(struct task_struct *task, struct stack_trace *trace)
{
struct stack_trace_data trace_data = {
.trace = trace,
.skip = trace->skip,
};
walk_stackframe(stack_pointer(task), stack_trace_cb, &trace_data);
}
EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
void save_stack_trace(struct stack_trace *trace)
{
save_stack_trace_tsk(current, trace);
}
EXPORT_SYMBOL_GPL(save_stack_trace);
#endif
#ifdef CONFIG_FRAME_POINTER
struct return_addr_data {
unsigned long addr;
unsigned skip;
};
static int return_address_cb(struct stackframe *frame, void *data)
{
struct return_addr_data *r = data;
if (r->skip) {
--r->skip;
return 0;
}
if (!kernel_text_address(frame->pc))
return 0;
r->addr = frame->pc;
return 1;
}
unsigned long return_address(unsigned level)
{
struct return_addr_data r = {
.skip = level + 1,
};
walk_stackframe(stack_pointer(NULL), return_address_cb, &r);
return r.addr;
}
EXPORT_SYMBOL(return_address);
#endif
|
