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6c6bd754 BR |
1 | /** |
2 | * Copyright (C) 2005 Brian Rogan <bcr6@cornell.edu>, IBM | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
6 | * as published by the Free Software Foundation; either version | |
7 | * 2 of the License, or (at your option) any later version. | |
8 | **/ | |
9 | ||
10 | #include <linux/oprofile.h> | |
11 | #include <linux/sched.h> | |
12 | #include <asm/processor.h> | |
13 | #include <asm/uaccess.h> | |
62034f03 | 14 | #include <asm/compat.h> |
1217d34b | 15 | #include <asm/oprofile_impl.h> |
6c6bd754 BR |
16 | |
17 | #define STACK_SP(STACK) *(STACK) | |
18 | ||
19 | #define STACK_LR64(STACK) *((unsigned long *)(STACK) + 2) | |
20 | #define STACK_LR32(STACK) *((unsigned int *)(STACK) + 1) | |
21 | ||
22 | #ifdef CONFIG_PPC64 | |
23 | #define STACK_LR(STACK) STACK_LR64(STACK) | |
24 | #else | |
25 | #define STACK_LR(STACK) STACK_LR32(STACK) | |
26 | #endif | |
27 | ||
28 | static unsigned int user_getsp32(unsigned int sp, int is_first) | |
29 | { | |
30 | unsigned int stack_frame[2]; | |
62034f03 | 31 | void __user *p = compat_ptr(sp); |
6c6bd754 | 32 | |
62034f03 | 33 | if (!access_ok(VERIFY_READ, p, sizeof(stack_frame))) |
6c6bd754 BR |
34 | return 0; |
35 | ||
36 | /* | |
37 | * The most likely reason for this is that we returned -EFAULT, | |
38 | * which means that we've done all that we can do from | |
39 | * interrupt context. | |
40 | */ | |
62034f03 | 41 | if (__copy_from_user_inatomic(stack_frame, p, sizeof(stack_frame))) |
6c6bd754 BR |
42 | return 0; |
43 | ||
44 | if (!is_first) | |
45 | oprofile_add_trace(STACK_LR32(stack_frame)); | |
46 | ||
47 | /* | |
48 | * We do not enforce increasing stack addresses here because | |
49 | * we may transition to a different stack, eg a signal handler. | |
50 | */ | |
51 | return STACK_SP(stack_frame); | |
52 | } | |
53 | ||
54 | #ifdef CONFIG_PPC64 | |
55 | static unsigned long user_getsp64(unsigned long sp, int is_first) | |
56 | { | |
57 | unsigned long stack_frame[3]; | |
58 | ||
62034f03 | 59 | if (!access_ok(VERIFY_READ, (void __user *)sp, sizeof(stack_frame))) |
6c6bd754 BR |
60 | return 0; |
61 | ||
62034f03 | 62 | if (__copy_from_user_inatomic(stack_frame, (void __user *)sp, |
6c6bd754 BR |
63 | sizeof(stack_frame))) |
64 | return 0; | |
65 | ||
66 | if (!is_first) | |
67 | oprofile_add_trace(STACK_LR64(stack_frame)); | |
68 | ||
69 | return STACK_SP(stack_frame); | |
70 | } | |
71 | #endif | |
72 | ||
73 | static unsigned long kernel_getsp(unsigned long sp, int is_first) | |
74 | { | |
75 | unsigned long *stack_frame = (unsigned long *)sp; | |
76 | ||
77 | if (!validate_sp(sp, current, STACK_FRAME_OVERHEAD)) | |
78 | return 0; | |
79 | ||
80 | if (!is_first) | |
81 | oprofile_add_trace(STACK_LR(stack_frame)); | |
82 | ||
83 | /* | |
84 | * We do not enforce increasing stack addresses here because | |
85 | * we might be transitioning from an interrupt stack to a kernel | |
86 | * stack. validate_sp() is designed to understand this, so just | |
87 | * use it. | |
88 | */ | |
89 | return STACK_SP(stack_frame); | |
90 | } | |
91 | ||
92 | void op_powerpc_backtrace(struct pt_regs * const regs, unsigned int depth) | |
93 | { | |
94 | unsigned long sp = regs->gpr[1]; | |
95 | int first_frame = 1; | |
96 | ||
97 | /* We ditch the top stackframe so need to loop through an extra time */ | |
98 | depth += 1; | |
99 | ||
100 | if (!user_mode(regs)) { | |
101 | while (depth--) { | |
102 | sp = kernel_getsp(sp, first_frame); | |
103 | if (!sp) | |
104 | break; | |
105 | first_frame = 0; | |
106 | } | |
107 | } else { | |
108 | #ifdef CONFIG_PPC64 | |
cab175f9 | 109 | if (!is_32bit_task()) { |
6c6bd754 BR |
110 | while (depth--) { |
111 | sp = user_getsp64(sp, first_frame); | |
112 | if (!sp) | |
113 | break; | |
114 | first_frame = 0; | |
115 | } | |
116 | ||
117 | return; | |
118 | } | |
119 | #endif | |
120 | ||
121 | while (depth--) { | |
122 | sp = user_getsp32(sp, first_frame); | |
123 | if (!sp) | |
124 | break; | |
125 | first_frame = 0; | |
126 | } | |
127 | } | |
128 | } |