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
|
/* -*- linux-c -*-
* Stack tracing functions
* Copyright (C) 2005, 2006, 2007 Red Hat Inc.
* Copyright (C) 2005 Intel Corporation.
*
* This file is part of systemtap, and is free software. You can
* redistribute it and/or modify it under the terms of the GNU General
* Public License (GPL); either version 2, or (at your option) any
* later version.
*/
#ifndef _STACK_C_
#define _STACK_C_
/** @file stack.c
* @brief Stack Tracing Functions
*/
/** @addtogroup stack Stack Tracing Functions
*
* @{
*/
#include "sym.c"
#include "regs.h"
static int _stp_kta(unsigned long addr);
#define MAXBACKTRACE 20
#if defined (__x86_64__)
#include "stack-x86_64.c"
#elif defined (__ia64__)
#include "stack-ia64.c"
#elif defined (__i386__)
#include "stack-i386.c"
#elif defined (__powerpc64__)
#include "stack-ppc64.c"
#elif defined (__s390__) || defined (__s390x__)
#include "stack-s390.c"
#else
#error "Unsupported architecture"
#endif
/* our copy of kernel_text_address() */
static int _stp_kta(unsigned long addr)
{
static unsigned long stext, etext, sinittext, einittext;
static int init = 0;
if (init == 0) {
init = 1;
etext = _stp_kallsyms_lookup_name("_etext");
stext = _stp_kallsyms_lookup_name("_stext");
sinittext = _stp_kallsyms_lookup_name("_sinittext");
einittext = _stp_kallsyms_lookup_name("_einittext");
}
if (addr >= stext && addr <= etext)
return 1;
if (addr >= sinittext && addr <= einittext)
return 1;
return 0;
}
/** Prints the stack backtrace
* @param regs A pointer to the struct pt_regs.
*/
void _stp_stack_print(struct pt_regs *regs, int verbose, struct kretprobe_instance *pi)
{
if (verbose) {
/* print the current address */
if (pi) {
_stp_print("Returning from: ");
_stp_symbol_print((unsigned long)_stp_probe_addr_r(pi));
_stp_print("\nReturning to : ");
_stp_symbol_print((unsigned long)_stp_ret_addr_r(pi));
} else {
_stp_print_char(' ');
_stp_symbol_print (REG_IP(regs));
}
_stp_print_char('\n');
} else
_stp_printf ("%p ", (int64_t)REG_IP(regs));
__stp_stack_print (regs, verbose, 0);
}
/** Writes stack backtrace to a string
*
* @param str string
* @param regs A pointer to the struct pt_regs.
* @returns void
*/
void _stp_stack_snprint (char *str, int size, struct pt_regs *regs, int verbose, struct kretprobe_instance *pi)
{
/* To get a string, we use a simple trick. First flush the print buffer, */
/* then call _stp_stack_print, then copy the result into the output string */
/* and clear the print buffer. */
_stp_pbuf *pb = per_cpu_ptr(Stp_pbuf, smp_processor_id());
_stp_print_flush();
_stp_stack_print(regs, verbose, pi);
strlcpy(str, pb->buf, size < (int)pb->len ? size : (int)pb->len);
pb->len = 0;
}
/** Prints the user stack backtrace
* @param str string
* @returns Same string as was input with trace info appended,
* @note Currently limited to a depth of two. Works from jprobes and kprobes.
*/
#if 0
void _stp_ustack_print (char *str)
{
struct pt_regs *nregs = ((struct pt_regs *) (THREAD_SIZE + (unsigned long) current->thread_info)) - 1;
_stp_printf ("%p : [user]\n", (int64_t)REG_IP(nregs));
if (REG_SP(nregs))
_stp_printf ("%p : [user]\n", (int64_t)(*(unsigned long *)REG_SP(nregs)));
}
#endif /* 0 */
/** @} */
#endif /* _STACK_C_ */
|
