Root/
1 | #include <linux/kernel.h> |
2 | #include <linux/init.h> |
3 | #include <linux/random.h> |
4 | #include <linux/sched.h> |
5 | #include <linux/stat.h> |
6 | #include <linux/types.h> |
7 | #include <linux/fs.h> |
8 | #include <linux/export.h> |
9 | #include <linux/interrupt.h> |
10 | #include <linux/stacktrace.h> |
11 | #include <linux/fault-inject.h> |
12 | |
13 | /* |
14 | * setup_fault_attr() is a helper function for various __setup handlers, so it |
15 | * returns 0 on error, because that is what __setup handlers do. |
16 | */ |
17 | int setup_fault_attr(struct fault_attr *attr, char *str) |
18 | { |
19 | unsigned long probability; |
20 | unsigned long interval; |
21 | int times; |
22 | int space; |
23 | |
24 | /* "<interval>,<probability>,<space>,<times>" */ |
25 | if (sscanf(str, "%lu,%lu,%d,%d", |
26 | &interval, &probability, &space, ×) < 4) { |
27 | printk(KERN_WARNING |
28 | "FAULT_INJECTION: failed to parse arguments\n"); |
29 | return 0; |
30 | } |
31 | |
32 | attr->probability = probability; |
33 | attr->interval = interval; |
34 | atomic_set(&attr->times, times); |
35 | atomic_set(&attr->space, space); |
36 | |
37 | return 1; |
38 | } |
39 | EXPORT_SYMBOL_GPL(setup_fault_attr); |
40 | |
41 | static void fail_dump(struct fault_attr *attr) |
42 | { |
43 | if (attr->verbose > 0) |
44 | printk(KERN_NOTICE "FAULT_INJECTION: forcing a failure\n"); |
45 | if (attr->verbose > 1) |
46 | dump_stack(); |
47 | } |
48 | |
49 | #define atomic_dec_not_zero(v) atomic_add_unless((v), -1, 0) |
50 | |
51 | static bool fail_task(struct fault_attr *attr, struct task_struct *task) |
52 | { |
53 | return !in_interrupt() && task->make_it_fail; |
54 | } |
55 | |
56 | #define MAX_STACK_TRACE_DEPTH 32 |
57 | |
58 | #ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER |
59 | |
60 | static bool fail_stacktrace(struct fault_attr *attr) |
61 | { |
62 | struct stack_trace trace; |
63 | int depth = attr->stacktrace_depth; |
64 | unsigned long entries[MAX_STACK_TRACE_DEPTH]; |
65 | int n; |
66 | bool found = (attr->require_start == 0 && attr->require_end == ULONG_MAX); |
67 | |
68 | if (depth == 0) |
69 | return found; |
70 | |
71 | trace.nr_entries = 0; |
72 | trace.entries = entries; |
73 | trace.max_entries = depth; |
74 | trace.skip = 1; |
75 | |
76 | save_stack_trace(&trace); |
77 | for (n = 0; n < trace.nr_entries; n++) { |
78 | if (attr->reject_start <= entries[n] && |
79 | entries[n] < attr->reject_end) |
80 | return false; |
81 | if (attr->require_start <= entries[n] && |
82 | entries[n] < attr->require_end) |
83 | found = true; |
84 | } |
85 | return found; |
86 | } |
87 | |
88 | #else |
89 | |
90 | static inline bool fail_stacktrace(struct fault_attr *attr) |
91 | { |
92 | return true; |
93 | } |
94 | |
95 | #endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */ |
96 | |
97 | /* |
98 | * This code is stolen from failmalloc-1.0 |
99 | * http://www.nongnu.org/failmalloc/ |
100 | */ |
101 | |
102 | bool should_fail(struct fault_attr *attr, ssize_t size) |
103 | { |
104 | /* No need to check any other properties if the probability is 0 */ |
105 | if (attr->probability == 0) |
106 | return false; |
107 | |
108 | if (attr->task_filter && !fail_task(attr, current)) |
109 | return false; |
110 | |
111 | if (atomic_read(&attr->times) == 0) |
112 | return false; |
113 | |
114 | if (atomic_read(&attr->space) > size) { |
115 | atomic_sub(size, &attr->space); |
116 | return false; |
117 | } |
118 | |
119 | if (attr->interval > 1) { |
120 | attr->count++; |
121 | if (attr->count % attr->interval) |
122 | return false; |
123 | } |
124 | |
125 | if (attr->probability <= random32() % 100) |
126 | return false; |
127 | |
128 | if (!fail_stacktrace(attr)) |
129 | return false; |
130 | |
131 | fail_dump(attr); |
132 | |
133 | if (atomic_read(&attr->times) != -1) |
134 | atomic_dec_not_zero(&attr->times); |
135 | |
136 | return true; |
137 | } |
138 | EXPORT_SYMBOL_GPL(should_fail); |
139 | |
140 | #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS |
141 | |
142 | static int debugfs_ul_set(void *data, u64 val) |
143 | { |
144 | *(unsigned long *)data = val; |
145 | return 0; |
146 | } |
147 | |
148 | static int debugfs_ul_get(void *data, u64 *val) |
149 | { |
150 | *val = *(unsigned long *)data; |
151 | return 0; |
152 | } |
153 | |
154 | DEFINE_SIMPLE_ATTRIBUTE(fops_ul, debugfs_ul_get, debugfs_ul_set, "%llu\n"); |
155 | |
156 | static struct dentry *debugfs_create_ul(const char *name, umode_t mode, |
157 | struct dentry *parent, unsigned long *value) |
158 | { |
159 | return debugfs_create_file(name, mode, parent, value, &fops_ul); |
160 | } |
161 | |
162 | #ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER |
163 | |
164 | static int debugfs_stacktrace_depth_set(void *data, u64 val) |
165 | { |
166 | *(unsigned long *)data = |
167 | min_t(unsigned long, val, MAX_STACK_TRACE_DEPTH); |
168 | |
169 | return 0; |
170 | } |
171 | |
172 | DEFINE_SIMPLE_ATTRIBUTE(fops_stacktrace_depth, debugfs_ul_get, |
173 | debugfs_stacktrace_depth_set, "%llu\n"); |
174 | |
175 | static struct dentry *debugfs_create_stacktrace_depth( |
176 | const char *name, umode_t mode, |
177 | struct dentry *parent, unsigned long *value) |
178 | { |
179 | return debugfs_create_file(name, mode, parent, value, |
180 | &fops_stacktrace_depth); |
181 | } |
182 | |
183 | #endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */ |
184 | |
185 | static int debugfs_atomic_t_set(void *data, u64 val) |
186 | { |
187 | atomic_set((atomic_t *)data, val); |
188 | return 0; |
189 | } |
190 | |
191 | static int debugfs_atomic_t_get(void *data, u64 *val) |
192 | { |
193 | *val = atomic_read((atomic_t *)data); |
194 | return 0; |
195 | } |
196 | |
197 | DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t, debugfs_atomic_t_get, |
198 | debugfs_atomic_t_set, "%lld\n"); |
199 | |
200 | static struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode, |
201 | struct dentry *parent, atomic_t *value) |
202 | { |
203 | return debugfs_create_file(name, mode, parent, value, &fops_atomic_t); |
204 | } |
205 | |
206 | struct dentry *fault_create_debugfs_attr(const char *name, |
207 | struct dentry *parent, struct fault_attr *attr) |
208 | { |
209 | umode_t mode = S_IFREG | S_IRUSR | S_IWUSR; |
210 | struct dentry *dir; |
211 | |
212 | dir = debugfs_create_dir(name, parent); |
213 | if (!dir) |
214 | return ERR_PTR(-ENOMEM); |
215 | |
216 | if (!debugfs_create_ul("probability", mode, dir, &attr->probability)) |
217 | goto fail; |
218 | if (!debugfs_create_ul("interval", mode, dir, &attr->interval)) |
219 | goto fail; |
220 | if (!debugfs_create_atomic_t("times", mode, dir, &attr->times)) |
221 | goto fail; |
222 | if (!debugfs_create_atomic_t("space", mode, dir, &attr->space)) |
223 | goto fail; |
224 | if (!debugfs_create_ul("verbose", mode, dir, &attr->verbose)) |
225 | goto fail; |
226 | if (!debugfs_create_bool("task-filter", mode, dir, &attr->task_filter)) |
227 | goto fail; |
228 | |
229 | #ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER |
230 | |
231 | if (!debugfs_create_stacktrace_depth("stacktrace-depth", mode, dir, |
232 | &attr->stacktrace_depth)) |
233 | goto fail; |
234 | if (!debugfs_create_ul("require-start", mode, dir, |
235 | &attr->require_start)) |
236 | goto fail; |
237 | if (!debugfs_create_ul("require-end", mode, dir, &attr->require_end)) |
238 | goto fail; |
239 | if (!debugfs_create_ul("reject-start", mode, dir, &attr->reject_start)) |
240 | goto fail; |
241 | if (!debugfs_create_ul("reject-end", mode, dir, &attr->reject_end)) |
242 | goto fail; |
243 | |
244 | #endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */ |
245 | |
246 | return dir; |
247 | fail: |
248 | debugfs_remove_recursive(dir); |
249 | |
250 | return ERR_PTR(-ENOMEM); |
251 | } |
252 | EXPORT_SYMBOL_GPL(fault_create_debugfs_attr); |
253 | |
254 | #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ |
255 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9