Merge tag 'pinctrl-v4.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw...
[linux-2.6-block.git] / arch / x86 / oprofile / backtrace.c
CommitLineData
1da177e4
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1/**
2 * @file backtrace.c
3 *
4 * @remark Copyright 2002 OProfile authors
5 * @remark Read the file COPYING
6 *
7 * @author John Levon
8 * @author David Smith
9 */
10
11#include <linux/oprofile.h>
12#include <linux/sched.h>
13#include <linux/mm.h>
a0e3e702 14#include <linux/compat.h>
1ac2e6ca 15#include <linux/uaccess.h>
a0e3e702 16
1da177e4 17#include <asm/ptrace.h>
574a6042 18#include <asm/stacktrace.h>
ec2ad9cc 19#include <asm/unwind.h>
574a6042 20
f6dedecc
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21#ifdef CONFIG_COMPAT
22static struct stack_frame_ia32 *
23dump_user_backtrace_32(struct stack_frame_ia32 *head)
24{
a0e3e702 25 /* Also check accessibility of one struct frame_head beyond: */
f6dedecc
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26 struct stack_frame_ia32 bufhead[2];
27 struct stack_frame_ia32 *fp;
a0e3e702 28 unsigned long bytes;
f6dedecc 29
a0e3e702 30 bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead));
0a196848 31 if (bytes != 0)
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32 return NULL;
33
34 fp = (struct stack_frame_ia32 *) compat_ptr(bufhead[0].next_frame);
35
36 oprofile_add_trace(bufhead[0].return_address);
37
38 /* frame pointers should strictly progress back up the stack
39 * (towards higher addresses) */
40 if (head >= fp)
41 return NULL;
42
43 return fp;
44}
45
46static inline int
47x86_backtrace_32(struct pt_regs * const regs, unsigned int depth)
48{
49 struct stack_frame_ia32 *head;
50
6bd33008 51 /* User process is IA32 */
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52 if (!current || !test_thread_flag(TIF_IA32))
53 return 0;
54
55 head = (struct stack_frame_ia32 *) regs->bp;
56 while (depth-- && head)
57 head = dump_user_backtrace_32(head);
58
59 return 1;
60}
61
62#else
63static inline int
64x86_backtrace_32(struct pt_regs * const regs, unsigned int depth)
65{
66 return 0;
67}
68#endif /* CONFIG_COMPAT */
69
40c6b3cb 70static struct stack_frame *dump_user_backtrace(struct stack_frame *head)
1da177e4 71{
a0e3e702 72 /* Also check accessibility of one struct frame_head beyond: */
40c6b3cb 73 struct stack_frame bufhead[2];
a0e3e702 74 unsigned long bytes;
1da177e4 75
a0e3e702 76 bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead));
0a196848 77 if (bytes != 0)
1da177e4
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78 return NULL;
79
40c6b3cb 80 oprofile_add_trace(bufhead[0].return_address);
1da177e4 81
c34d1b4d
HD
82 /* frame pointers should strictly progress back up the stack
83 * (towards higher addresses) */
40c6b3cb 84 if (head >= bufhead[0].next_frame)
c34d1b4d 85 return NULL;
1da177e4 86
40c6b3cb 87 return bufhead[0].next_frame;
1da177e4
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88}
89
1da177e4
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90void
91x86_backtrace(struct pt_regs * const regs, unsigned int depth)
92{
40c6b3cb 93 struct stack_frame *head = (struct stack_frame *)frame_pointer(regs);
1da177e4 94
f39b6f0e 95 if (!user_mode(regs)) {
ec2ad9cc
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96 struct unwind_state state;
97 unsigned long addr;
98
3e344a0d
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99 if (!depth)
100 return;
101
102 oprofile_add_trace(regs->ip);
ec2ad9cc 103
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104 if (!--depth)
105 return;
106
ec2ad9cc
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107 for (unwind_start(&state, current, regs, NULL);
108 !unwind_done(&state); unwind_next_frame(&state)) {
109 addr = unwind_get_return_address(&state);
110 if (!addr)
111 break;
112
113 oprofile_add_trace(addr);
114
115 if (!--depth)
116 break;
117 }
118
1da177e4
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119 return;
120 }
121
f6dedecc
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122 if (x86_backtrace_32(regs, depth))
123 return;
124
c34d1b4d 125 while (depth-- && head)
30379440 126 head = dump_user_backtrace(head);
1da177e4 127}