Blame view

kernel/linux-imx6_3.14.28/arch/x86/oprofile/backtrace.c 2.72 KB
6b13f685e   김민수   BSP 최초 추가
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
  /**
   * @file backtrace.c
   *
   * @remark Copyright 2002 OProfile authors
   * @remark Read the file COPYING
   *
   * @author John Levon
   * @author David Smith
   */
  
  #include <linux/oprofile.h>
  #include <linux/sched.h>
  #include <linux/mm.h>
  #include <linux/compat.h>
  #include <linux/uaccess.h>
  
  #include <asm/ptrace.h>
  #include <asm/stacktrace.h>
  
  static int backtrace_stack(void *data, char *name)
  {
  	/* Yes, we want all stacks */
  	return 0;
  }
  
  static void backtrace_address(void *data, unsigned long addr, int reliable)
  {
  	unsigned int *depth = data;
  
  	if ((*depth)--)
  		oprofile_add_trace(addr);
  }
  
  static struct stacktrace_ops backtrace_ops = {
  	.stack		= backtrace_stack,
  	.address	= backtrace_address,
  	.walk_stack	= print_context_stack,
  };
  
  #ifdef CONFIG_COMPAT
  static struct stack_frame_ia32 *
  dump_user_backtrace_32(struct stack_frame_ia32 *head)
  {
  	/* Also check accessibility of one struct frame_head beyond: */
  	struct stack_frame_ia32 bufhead[2];
  	struct stack_frame_ia32 *fp;
  	unsigned long bytes;
  
  	bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead));
  	if (bytes != 0)
  		return NULL;
  
  	fp = (struct stack_frame_ia32 *) compat_ptr(bufhead[0].next_frame);
  
  	oprofile_add_trace(bufhead[0].return_address);
  
  	/* frame pointers should strictly progress back up the stack
  	* (towards higher addresses) */
  	if (head >= fp)
  		return NULL;
  
  	return fp;
  }
  
  static inline int
  x86_backtrace_32(struct pt_regs * const regs, unsigned int depth)
  {
  	struct stack_frame_ia32 *head;
  
  	/* User process is IA32 */
  	if (!current || !test_thread_flag(TIF_IA32))
  		return 0;
  
  	head = (struct stack_frame_ia32 *) regs->bp;
  	while (depth-- && head)
  		head = dump_user_backtrace_32(head);
  
  	return 1;
  }
  
  #else
  static inline int
  x86_backtrace_32(struct pt_regs * const regs, unsigned int depth)
  {
  	return 0;
  }
  #endif /* CONFIG_COMPAT */
  
  static struct stack_frame *dump_user_backtrace(struct stack_frame *head)
  {
  	/* Also check accessibility of one struct frame_head beyond: */
  	struct stack_frame bufhead[2];
  	unsigned long bytes;
  
  	bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead));
  	if (bytes != 0)
  		return NULL;
  
  	oprofile_add_trace(bufhead[0].return_address);
  
  	/* frame pointers should strictly progress back up the stack
  	 * (towards higher addresses) */
  	if (head >= bufhead[0].next_frame)
  		return NULL;
  
  	return bufhead[0].next_frame;
  }
  
  void
  x86_backtrace(struct pt_regs * const regs, unsigned int depth)
  {
  	struct stack_frame *head = (struct stack_frame *)frame_pointer(regs);
  
  	if (!user_mode_vm(regs)) {
  		unsigned long stack = kernel_stack_pointer(regs);
  		if (depth)
  			dump_trace(NULL, regs, (unsigned long *)stack, 0,
  				   &backtrace_ops, &depth);
  		return;
  	}
  
  	if (x86_backtrace_32(regs, depth))
  		return;
  
  	while (depth-- && head)
  		head = dump_user_backtrace(head);
  }