Commit | Line | Data |
---|---|---|
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> | |
14 | ||
15 | #define STACK_SP(STACK) *(STACK) | |
16 | ||
17 | #define STACK_LR64(STACK) *((unsigned long *)(STACK) + 2) | |
18 | #define STACK_LR32(STACK) *((unsigned int *)(STACK) + 1) | |
19 | ||
20 | #ifdef CONFIG_PPC64 | |
21 | #define STACK_LR(STACK) STACK_LR64(STACK) | |
22 | #else | |
23 | #define STACK_LR(STACK) STACK_LR32(STACK) | |
24 | #endif | |
25 | ||
26 | static unsigned int user_getsp32(unsigned int sp, int is_first) | |
27 | { | |
28 | unsigned int stack_frame[2]; | |
29 | ||
30 | if (!access_ok(VERIFY_READ, sp, sizeof(stack_frame))) | |
31 | return 0; | |
32 | ||
33 | /* | |
34 | * The most likely reason for this is that we returned -EFAULT, | |
35 | * which means that we've done all that we can do from | |
36 | * interrupt context. | |
37 | */ | |
38 | if (__copy_from_user_inatomic(stack_frame, (void *)(long)sp, | |
39 | sizeof(stack_frame))) | |
40 | return 0; | |
41 | ||
42 | if (!is_first) | |
43 | oprofile_add_trace(STACK_LR32(stack_frame)); | |
44 | ||
45 | /* | |
46 | * We do not enforce increasing stack addresses here because | |
47 | * we may transition to a different stack, eg a signal handler. | |
48 | */ | |
49 | return STACK_SP(stack_frame); | |
50 | } | |
51 | ||
52 | #ifdef CONFIG_PPC64 | |
53 | static unsigned long user_getsp64(unsigned long sp, int is_first) | |
54 | { | |
55 | unsigned long stack_frame[3]; | |
56 | ||
57 | if (!access_ok(VERIFY_READ, sp, sizeof(stack_frame))) | |
58 | return 0; | |
59 | ||
60 | if (__copy_from_user_inatomic(stack_frame, (void *)sp, | |
61 | sizeof(stack_frame))) | |
62 | return 0; | |
63 | ||
64 | if (!is_first) | |
65 | oprofile_add_trace(STACK_LR64(stack_frame)); | |
66 | ||
67 | return STACK_SP(stack_frame); | |
68 | } | |
69 | #endif | |
70 | ||
71 | static unsigned long kernel_getsp(unsigned long sp, int is_first) | |
72 | { | |
73 | unsigned long *stack_frame = (unsigned long *)sp; | |
74 | ||
75 | if (!validate_sp(sp, current, STACK_FRAME_OVERHEAD)) | |
76 | return 0; | |
77 | ||
78 | if (!is_first) | |
79 | oprofile_add_trace(STACK_LR(stack_frame)); | |
80 | ||
81 | /* | |
82 | * We do not enforce increasing stack addresses here because | |
83 | * we might be transitioning from an interrupt stack to a kernel | |
84 | * stack. validate_sp() is designed to understand this, so just | |
85 | * use it. | |
86 | */ | |
87 | return STACK_SP(stack_frame); | |
88 | } | |
89 | ||
90 | void op_powerpc_backtrace(struct pt_regs * const regs, unsigned int depth) | |
91 | { | |
92 | unsigned long sp = regs->gpr[1]; | |
93 | int first_frame = 1; | |
94 | ||
95 | /* We ditch the top stackframe so need to loop through an extra time */ | |
96 | depth += 1; | |
97 | ||
98 | if (!user_mode(regs)) { | |
99 | while (depth--) { | |
100 | sp = kernel_getsp(sp, first_frame); | |
101 | if (!sp) | |
102 | break; | |
103 | first_frame = 0; | |
104 | } | |
105 | } else { | |
106 | #ifdef CONFIG_PPC64 | |
107 | if (!test_thread_flag(TIF_32BIT)) { | |
108 | while (depth--) { | |
109 | sp = user_getsp64(sp, first_frame); | |
110 | if (!sp) | |
111 | break; | |
112 | first_frame = 0; | |
113 | } | |
114 | ||
115 | return; | |
116 | } | |
117 | #endif | |
118 | ||
119 | while (depth--) { | |
120 | sp = user_getsp32(sp, first_frame); | |
121 | if (!sp) | |
122 | break; | |
123 | first_frame = 0; | |
124 | } | |
125 | } | |
126 | } |