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Commit | Line | Data |
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21b32bbf | 1 | /* |
21b32bbf IM |
2 | * Stack trace management functions |
3 | * | |
8f47e163 | 4 | * Copyright (C) 2006-2009 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> |
21b32bbf IM |
5 | */ |
6 | #include <linux/sched.h> | |
7 | #include <linux/stacktrace.h> | |
c0b766f1 | 8 | #include <linux/module.h> |
02b67518 | 9 | #include <linux/uaccess.h> |
c0b766f1 | 10 | #include <asm/stacktrace.h> |
21b32bbf | 11 | |
c0b766f1 | 12 | static void save_stack_warning(void *data, char *msg) |
21b32bbf | 13 | { |
21b32bbf IM |
14 | } |
15 | ||
c0b766f1 AK |
16 | static void |
17 | save_stack_warning_symbol(void *data, char *msg, unsigned long symbol) | |
21b32bbf | 18 | { |
21b32bbf IM |
19 | } |
20 | ||
c0b766f1 | 21 | static int save_stack_stack(void *data, char *name) |
21b32bbf | 22 | { |
29a67975 | 23 | return 0; |
c0b766f1 | 24 | } |
21b32bbf | 25 | |
bc850d6b | 26 | static void save_stack_address(void *data, unsigned long addr, int reliable) |
c0b766f1 | 27 | { |
ade1af77 | 28 | struct stack_trace *trace = data; |
147ec4d2 | 29 | #ifdef CONFIG_FRAME_POINTER |
1650743c VN |
30 | if (!reliable) |
31 | return; | |
147ec4d2 | 32 | #endif |
c0b766f1 AK |
33 | if (trace->skip > 0) { |
34 | trace->skip--; | |
35 | return; | |
21b32bbf | 36 | } |
006e84ee | 37 | if (trace->nr_entries < trace->max_entries) |
c0b766f1 | 38 | trace->entries[trace->nr_entries++] = addr; |
21b32bbf IM |
39 | } |
40 | ||
5bc27dc2 AV |
41 | static void |
42 | save_stack_address_nosched(void *data, unsigned long addr, int reliable) | |
9745512c | 43 | { |
147ec4d2 ON |
44 | struct stack_trace *trace = data; |
45 | #ifdef CONFIG_FRAME_POINTER | |
1650743c VN |
46 | if (!reliable) |
47 | return; | |
147ec4d2 | 48 | #endif |
9745512c AV |
49 | if (in_sched_functions(addr)) |
50 | return; | |
51 | if (trace->skip > 0) { | |
52 | trace->skip--; | |
53 | return; | |
54 | } | |
55 | if (trace->nr_entries < trace->max_entries) | |
56 | trace->entries[trace->nr_entries++] = addr; | |
57 | } | |
58 | ||
9689ba8a | 59 | static const struct stacktrace_ops save_stack_ops = { |
61c1917f FW |
60 | .warning = save_stack_warning, |
61 | .warning_symbol = save_stack_warning_symbol, | |
62 | .stack = save_stack_stack, | |
63 | .address = save_stack_address, | |
64 | .walk_stack = print_context_stack, | |
c0b766f1 | 65 | }; |
21b32bbf | 66 | |
9745512c | 67 | static const struct stacktrace_ops save_stack_ops_nosched = { |
61c1917f FW |
68 | .warning = save_stack_warning, |
69 | .warning_symbol = save_stack_warning_symbol, | |
70 | .stack = save_stack_stack, | |
71 | .address = save_stack_address_nosched, | |
72 | .walk_stack = print_context_stack, | |
9745512c AV |
73 | }; |
74 | ||
21b32bbf IM |
75 | /* |
76 | * Save stack-backtrace addresses into a stack_trace buffer. | |
21b32bbf | 77 | */ |
ab1b6f03 | 78 | void save_stack_trace(struct stack_trace *trace) |
21b32bbf | 79 | { |
5bc27dc2 | 80 | dump_trace(current, NULL, NULL, 0, &save_stack_ops, trace); |
006e84ee CM |
81 | if (trace->nr_entries < trace->max_entries) |
82 | trace->entries[trace->nr_entries++] = ULONG_MAX; | |
21b32bbf | 83 | } |
8594698e | 84 | EXPORT_SYMBOL_GPL(save_stack_trace); |
9745512c | 85 | |
acc6be54 VN |
86 | void save_stack_trace_bp(struct stack_trace *trace, unsigned long bp) |
87 | { | |
88 | dump_trace(current, NULL, NULL, bp, &save_stack_ops, trace); | |
89 | if (trace->nr_entries < trace->max_entries) | |
90 | trace->entries[trace->nr_entries++] = ULONG_MAX; | |
91 | } | |
92 | ||
9745512c AV |
93 | void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) |
94 | { | |
5bc27dc2 | 95 | dump_trace(tsk, NULL, NULL, 0, &save_stack_ops_nosched, trace); |
9745512c AV |
96 | if (trace->nr_entries < trace->max_entries) |
97 | trace->entries[trace->nr_entries++] = ULONG_MAX; | |
98 | } | |
8594698e | 99 | EXPORT_SYMBOL_GPL(save_stack_trace_tsk); |
02b67518 TE |
100 | |
101 | /* Userspace stacktrace - based on kernel/trace/trace_sysprof.c */ | |
102 | ||
c9cf4dbb | 103 | struct stack_frame_user { |
02b67518 | 104 | const void __user *next_fp; |
8d7c6a96 | 105 | unsigned long ret_addr; |
02b67518 TE |
106 | }; |
107 | ||
c9cf4dbb FW |
108 | static int |
109 | copy_stack_frame(const void __user *fp, struct stack_frame_user *frame) | |
02b67518 TE |
110 | { |
111 | int ret; | |
112 | ||
113 | if (!access_ok(VERIFY_READ, fp, sizeof(*frame))) | |
114 | return 0; | |
115 | ||
116 | ret = 1; | |
117 | pagefault_disable(); | |
118 | if (__copy_from_user_inatomic(frame, fp, sizeof(*frame))) | |
119 | ret = 0; | |
120 | pagefault_enable(); | |
121 | ||
122 | return ret; | |
123 | } | |
124 | ||
8d7c6a96 TE |
125 | static inline void __save_stack_trace_user(struct stack_trace *trace) |
126 | { | |
127 | const struct pt_regs *regs = task_pt_regs(current); | |
128 | const void __user *fp = (const void __user *)regs->bp; | |
129 | ||
130 | if (trace->nr_entries < trace->max_entries) | |
131 | trace->entries[trace->nr_entries++] = regs->ip; | |
132 | ||
133 | while (trace->nr_entries < trace->max_entries) { | |
c9cf4dbb | 134 | struct stack_frame_user frame; |
8d7c6a96 TE |
135 | |
136 | frame.next_fp = NULL; | |
137 | frame.ret_addr = 0; | |
138 | if (!copy_stack_frame(fp, &frame)) | |
139 | break; | |
140 | if ((unsigned long)fp < regs->sp) | |
141 | break; | |
142 | if (frame.ret_addr) { | |
143 | trace->entries[trace->nr_entries++] = | |
144 | frame.ret_addr; | |
145 | } | |
146 | if (fp == frame.next_fp) | |
147 | break; | |
148 | fp = frame.next_fp; | |
149 | } | |
150 | } | |
151 | ||
02b67518 TE |
152 | void save_stack_trace_user(struct stack_trace *trace) |
153 | { | |
154 | /* | |
155 | * Trace user stack if we are not a kernel thread | |
156 | */ | |
157 | if (current->mm) { | |
8d7c6a96 | 158 | __save_stack_trace_user(trace); |
02b67518 TE |
159 | } |
160 | if (trace->nr_entries < trace->max_entries) | |
161 | trace->entries[trace->nr_entries++] = ULONG_MAX; | |
162 | } | |
163 |