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
124
125
126
127
|
/**
* Copyright (C) 2005 Brian Rogan <bcr6@cornell.edu>, IBM
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
**/
#include <linux/oprofile.h>
#include <linux/sched.h>
#include <asm/processor.h>
#include <asm/uaccess.h>
#include <asm/compat.h>
#define STACK_SP(STACK) *(STACK)
#define STACK_LR64(STACK) *((unsigned long *)(STACK) + 2)
#define STACK_LR32(STACK) *((unsigned int *)(STACK) + 1)
#ifdef CONFIG_PPC64
#define STACK_LR(STACK) STACK_LR64(STACK)
#else
#define STACK_LR(STACK) STACK_LR32(STACK)
#endif
static unsigned int user_getsp32(unsigned int sp, int is_first)
{
unsigned int stack_frame[2];
void __user *p = compat_ptr(sp);
if (!access_ok(VERIFY_READ, p, sizeof(stack_frame)))
return 0;
/*
* The most likely reason for this is that we returned -EFAULT,
* which means that we've done all that we can do from
* interrupt context.
*/
if (__copy_from_user_inatomic(stack_frame, p, sizeof(stack_frame)))
return 0;
if (!is_first)
oprofile_add_trace(STACK_LR32(stack_frame));
/*
* We do not enforce increasing stack addresses here because
* we may transition to a different stack, eg a signal handler.
*/
return STACK_SP(stack_frame);
}
#ifdef CONFIG_PPC64
static unsigned long user_getsp64(unsigned long sp, int is_first)
{
unsigned long stack_frame[3];
if (!access_ok(VERIFY_READ, (void __user *)sp, sizeof(stack_frame)))
return 0;
if (__copy_from_user_inatomic(stack_frame, (void __user *)sp,
sizeof(stack_frame)))
return 0;
if (!is_first)
oprofile_add_trace(STACK_LR64(stack_frame));
return STACK_SP(stack_frame);
}
#endif
static unsigned long kernel_getsp(unsigned long sp, int is_first)
{
unsigned long *stack_frame = (unsigned long *)sp;
if (!validate_sp(sp, current, STACK_FRAME_OVERHEAD))
return 0;
if (!is_first)
oprofile_add_trace(STACK_LR(stack_frame));
/*
* We do not enforce increasing stack addresses here because
* we might be transitioning from an interrupt stack to a kernel
* stack. validate_sp() is designed to understand this, so just
* use it.
*/
return STACK_SP(stack_frame);
}
void op_powerpc_backtrace(struct pt_regs * const regs, unsigned int depth)
{
unsigned long sp = regs->gpr[1];
int first_frame = 1;
/* We ditch the top stackframe so need to loop through an extra time */
depth += 1;
if (!user_mode(regs)) {
while (depth--) {
sp = kernel_getsp(sp, first_frame);
if (!sp)
break;
first_frame = 0;
}
} else {
#ifdef CONFIG_PPC64
if (!is_32bit_task()) {
while (depth--) {
sp = user_getsp64(sp, first_frame);
if (!sp)
break;
first_frame = 0;
}
return;
}
#endif
while (depth--) {
sp = user_getsp32(sp, first_frame);
if (!sp)
break;
first_frame = 0;
}
}
}
|
