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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 | ||
9afc5eee | 10 | #include <linux/time.h> |
6c6bd754 BR |
11 | #include <linux/oprofile.h> |
12 | #include <linux/sched.h> | |
13 | #include <asm/processor.h> | |
0de3b56b | 14 | #include <linux/uaccess.h> |
62034f03 | 15 | #include <asm/compat.h> |
1217d34b | 16 | #include <asm/oprofile_impl.h> |
6c6bd754 BR |
17 | |
18 | #define STACK_SP(STACK) *(STACK) | |
19 | ||
20 | #define STACK_LR64(STACK) *((unsigned long *)(STACK) + 2) | |
21 | #define STACK_LR32(STACK) *((unsigned int *)(STACK) + 1) | |
22 | ||
23 | #ifdef CONFIG_PPC64 | |
24 | #define STACK_LR(STACK) STACK_LR64(STACK) | |
25 | #else | |
26 | #define STACK_LR(STACK) STACK_LR32(STACK) | |
27 | #endif | |
28 | ||
29 | static unsigned int user_getsp32(unsigned int sp, int is_first) | |
30 | { | |
31 | unsigned int stack_frame[2]; | |
62034f03 | 32 | void __user *p = compat_ptr(sp); |
6c6bd754 | 33 | |
96d4f267 | 34 | if (!access_ok(p, sizeof(stack_frame))) |
6c6bd754 BR |
35 | return 0; |
36 | ||
37 | /* | |
38 | * The most likely reason for this is that we returned -EFAULT, | |
39 | * which means that we've done all that we can do from | |
40 | * interrupt context. | |
41 | */ | |
62034f03 | 42 | if (__copy_from_user_inatomic(stack_frame, p, sizeof(stack_frame))) |
6c6bd754 BR |
43 | return 0; |
44 | ||
45 | if (!is_first) | |
46 | oprofile_add_trace(STACK_LR32(stack_frame)); | |
47 | ||
48 | /* | |
49 | * We do not enforce increasing stack addresses here because | |
50 | * we may transition to a different stack, eg a signal handler. | |
51 | */ | |
52 | return STACK_SP(stack_frame); | |
53 | } | |
54 | ||
55 | #ifdef CONFIG_PPC64 | |
56 | static unsigned long user_getsp64(unsigned long sp, int is_first) | |
57 | { | |
58 | unsigned long stack_frame[3]; | |
59 | ||
96d4f267 | 60 | if (!access_ok((void __user *)sp, sizeof(stack_frame))) |
6c6bd754 BR |
61 | return 0; |
62 | ||
62034f03 | 63 | if (__copy_from_user_inatomic(stack_frame, (void __user *)sp, |
6c6bd754 BR |
64 | sizeof(stack_frame))) |
65 | return 0; | |
66 | ||
67 | if (!is_first) | |
68 | oprofile_add_trace(STACK_LR64(stack_frame)); | |
69 | ||
70 | return STACK_SP(stack_frame); | |
71 | } | |
72 | #endif | |
73 | ||
74 | static unsigned long kernel_getsp(unsigned long sp, int is_first) | |
75 | { | |
76 | unsigned long *stack_frame = (unsigned long *)sp; | |
77 | ||
78 | if (!validate_sp(sp, current, STACK_FRAME_OVERHEAD)) | |
79 | return 0; | |
80 | ||
81 | if (!is_first) | |
82 | oprofile_add_trace(STACK_LR(stack_frame)); | |
83 | ||
84 | /* | |
85 | * We do not enforce increasing stack addresses here because | |
86 | * we might be transitioning from an interrupt stack to a kernel | |
87 | * stack. validate_sp() is designed to understand this, so just | |
88 | * use it. | |
89 | */ | |
90 | return STACK_SP(stack_frame); | |
91 | } | |
92 | ||
93 | void op_powerpc_backtrace(struct pt_regs * const regs, unsigned int depth) | |
94 | { | |
95 | unsigned long sp = regs->gpr[1]; | |
96 | int first_frame = 1; | |
97 | ||
98 | /* We ditch the top stackframe so need to loop through an extra time */ | |
99 | depth += 1; | |
100 | ||
101 | if (!user_mode(regs)) { | |
102 | while (depth--) { | |
103 | sp = kernel_getsp(sp, first_frame); | |
104 | if (!sp) | |
105 | break; | |
106 | first_frame = 0; | |
107 | } | |
108 | } else { | |
0de3b56b | 109 | pagefault_disable(); |
6c6bd754 | 110 | #ifdef CONFIG_PPC64 |
cab175f9 | 111 | if (!is_32bit_task()) { |
6c6bd754 BR |
112 | while (depth--) { |
113 | sp = user_getsp64(sp, first_frame); | |
114 | if (!sp) | |
115 | break; | |
116 | first_frame = 0; | |
117 | } | |
0de3b56b | 118 | pagefault_enable(); |
6c6bd754 BR |
119 | return; |
120 | } | |
121 | #endif | |
122 | ||
123 | while (depth--) { | |
124 | sp = user_getsp32(sp, first_frame); | |
125 | if (!sp) | |
126 | break; | |
127 | first_frame = 0; | |
128 | } | |
0de3b56b | 129 | pagefault_enable(); |
6c6bd754 BR |
130 | } |
131 | } |