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