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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 int save_stack_stack(void *data, char *name) |
21b32bbf | 13 | { |
29a67975 | 14 | return 0; |
c0b766f1 | 15 | } |
21b32bbf | 16 | |
018378c5 ON |
17 | static void |
18 | __save_stack_address(void *data, unsigned long addr, bool reliable, bool nosched) | |
c0b766f1 | 19 | { |
ade1af77 | 20 | struct stack_trace *trace = data; |
147ec4d2 | 21 | #ifdef CONFIG_FRAME_POINTER |
1650743c VN |
22 | if (!reliable) |
23 | return; | |
147ec4d2 | 24 | #endif |
018378c5 ON |
25 | if (nosched && in_sched_functions(addr)) |
26 | return; | |
c0b766f1 AK |
27 | if (trace->skip > 0) { |
28 | trace->skip--; | |
29 | return; | |
21b32bbf | 30 | } |
006e84ee | 31 | if (trace->nr_entries < trace->max_entries) |
c0b766f1 | 32 | trace->entries[trace->nr_entries++] = addr; |
21b32bbf IM |
33 | } |
34 | ||
018378c5 ON |
35 | static void save_stack_address(void *data, unsigned long addr, int reliable) |
36 | { | |
37 | return __save_stack_address(data, addr, reliable, false); | |
38 | } | |
39 | ||
5bc27dc2 AV |
40 | static void |
41 | save_stack_address_nosched(void *data, unsigned long addr, int reliable) | |
9745512c | 42 | { |
018378c5 | 43 | return __save_stack_address(data, addr, reliable, true); |
9745512c AV |
44 | } |
45 | ||
9689ba8a | 46 | static const struct stacktrace_ops save_stack_ops = { |
61c1917f FW |
47 | .stack = save_stack_stack, |
48 | .address = save_stack_address, | |
49 | .walk_stack = print_context_stack, | |
c0b766f1 | 50 | }; |
21b32bbf | 51 | |
9745512c | 52 | static const struct stacktrace_ops save_stack_ops_nosched = { |
61c1917f FW |
53 | .stack = save_stack_stack, |
54 | .address = save_stack_address_nosched, | |
55 | .walk_stack = print_context_stack, | |
9745512c AV |
56 | }; |
57 | ||
21b32bbf IM |
58 | /* |
59 | * Save stack-backtrace addresses into a stack_trace buffer. | |
21b32bbf | 60 | */ |
ab1b6f03 | 61 | void save_stack_trace(struct stack_trace *trace) |
21b32bbf | 62 | { |
e8e999cf | 63 | dump_trace(current, NULL, NULL, 0, &save_stack_ops, trace); |
006e84ee CM |
64 | if (trace->nr_entries < trace->max_entries) |
65 | trace->entries[trace->nr_entries++] = ULONG_MAX; | |
21b32bbf | 66 | } |
8594698e | 67 | EXPORT_SYMBOL_GPL(save_stack_trace); |
9745512c | 68 | |
39581062 | 69 | void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace) |
acc6be54 | 70 | { |
e8e999cf | 71 | dump_trace(current, regs, NULL, 0, &save_stack_ops, trace); |
acc6be54 VN |
72 | if (trace->nr_entries < trace->max_entries) |
73 | trace->entries[trace->nr_entries++] = ULONG_MAX; | |
74 | } | |
75 | ||
9745512c AV |
76 | void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) |
77 | { | |
e8e999cf | 78 | dump_trace(tsk, NULL, NULL, 0, &save_stack_ops_nosched, trace); |
9745512c AV |
79 | if (trace->nr_entries < trace->max_entries) |
80 | trace->entries[trace->nr_entries++] = ULONG_MAX; | |
81 | } | |
8594698e | 82 | EXPORT_SYMBOL_GPL(save_stack_trace_tsk); |
02b67518 TE |
83 | |
84 | /* Userspace stacktrace - based on kernel/trace/trace_sysprof.c */ | |
85 | ||
c9cf4dbb | 86 | struct stack_frame_user { |
02b67518 | 87 | const void __user *next_fp; |
8d7c6a96 | 88 | unsigned long ret_addr; |
02b67518 TE |
89 | }; |
90 | ||
c9cf4dbb FW |
91 | static int |
92 | copy_stack_frame(const void __user *fp, struct stack_frame_user *frame) | |
02b67518 TE |
93 | { |
94 | int ret; | |
95 | ||
96 | if (!access_ok(VERIFY_READ, fp, sizeof(*frame))) | |
97 | return 0; | |
98 | ||
99 | ret = 1; | |
100 | pagefault_disable(); | |
101 | if (__copy_from_user_inatomic(frame, fp, sizeof(*frame))) | |
102 | ret = 0; | |
103 | pagefault_enable(); | |
104 | ||
105 | return ret; | |
106 | } | |
107 | ||
8d7c6a96 TE |
108 | static inline void __save_stack_trace_user(struct stack_trace *trace) |
109 | { | |
110 | const struct pt_regs *regs = task_pt_regs(current); | |
111 | const void __user *fp = (const void __user *)regs->bp; | |
112 | ||
113 | if (trace->nr_entries < trace->max_entries) | |
114 | trace->entries[trace->nr_entries++] = regs->ip; | |
115 | ||
116 | while (trace->nr_entries < trace->max_entries) { | |
c9cf4dbb | 117 | struct stack_frame_user frame; |
8d7c6a96 TE |
118 | |
119 | frame.next_fp = NULL; | |
120 | frame.ret_addr = 0; | |
121 | if (!copy_stack_frame(fp, &frame)) | |
122 | break; | |
123 | if ((unsigned long)fp < regs->sp) | |
124 | break; | |
125 | if (frame.ret_addr) { | |
126 | trace->entries[trace->nr_entries++] = | |
127 | frame.ret_addr; | |
128 | } | |
129 | if (fp == frame.next_fp) | |
130 | break; | |
131 | fp = frame.next_fp; | |
132 | } | |
133 | } | |
134 | ||
02b67518 TE |
135 | void save_stack_trace_user(struct stack_trace *trace) |
136 | { | |
137 | /* | |
138 | * Trace user stack if we are not a kernel thread | |
139 | */ | |
140 | if (current->mm) { | |
8d7c6a96 | 141 | __save_stack_trace_user(trace); |
02b67518 TE |
142 | } |
143 | if (trace->nr_entries < trace->max_entries) | |
144 | trace->entries[trace->nr_entries++] = ULONG_MAX; | |
145 | } | |
146 |