Commit | Line | Data |
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1427cdf0 LJ |
1 | /* |
2 | * trace binary printk | |
3 | * | |
4 | * Copyright (C) 2008 Lai Jiangshan <laijs@cn.fujitsu.com> | |
5 | * | |
6 | */ | |
7975a2be SR |
7 | #include <linux/seq_file.h> |
8 | #include <linux/debugfs.h> | |
9 | #include <linux/uaccess.h> | |
1427cdf0 LJ |
10 | #include <linux/kernel.h> |
11 | #include <linux/ftrace.h> | |
12 | #include <linux/string.h> | |
7975a2be SR |
13 | #include <linux/module.h> |
14 | #include <linux/marker.h> | |
15 | #include <linux/mutex.h> | |
1427cdf0 LJ |
16 | #include <linux/ctype.h> |
17 | #include <linux/list.h> | |
1427cdf0 | 18 | #include <linux/slab.h> |
1427cdf0 | 19 | #include <linux/fs.h> |
1427cdf0 LJ |
20 | |
21 | #include "trace.h" | |
22 | ||
1ba28e02 LJ |
23 | #ifdef CONFIG_MODULES |
24 | ||
1ba28e02 | 25 | /* |
769b0441 | 26 | * modules trace_printk()'s formats are autosaved in struct trace_bprintk_fmt |
1ba28e02 LJ |
27 | * which are queued on trace_bprintk_fmt_list. |
28 | */ | |
29 | static LIST_HEAD(trace_bprintk_fmt_list); | |
30 | ||
769b0441 FW |
31 | /* serialize accesses to trace_bprintk_fmt_list */ |
32 | static DEFINE_MUTEX(btrace_mutex); | |
33 | ||
1ba28e02 LJ |
34 | struct trace_bprintk_fmt { |
35 | struct list_head list; | |
36 | char fmt[0]; | |
37 | }; | |
38 | ||
1ba28e02 | 39 | static inline struct trace_bprintk_fmt *lookup_format(const char *fmt) |
1427cdf0 | 40 | { |
1ba28e02 LJ |
41 | struct trace_bprintk_fmt *pos; |
42 | list_for_each_entry(pos, &trace_bprintk_fmt_list, list) { | |
43 | if (!strcmp(pos->fmt, fmt)) | |
44 | return pos; | |
45 | } | |
46 | return NULL; | |
1427cdf0 LJ |
47 | } |
48 | ||
1ba28e02 LJ |
49 | static |
50 | void hold_module_trace_bprintk_format(const char **start, const char **end) | |
1427cdf0 | 51 | { |
1ba28e02 | 52 | const char **iter; |
769b0441 FW |
53 | |
54 | mutex_lock(&btrace_mutex); | |
1ba28e02 LJ |
55 | for (iter = start; iter < end; iter++) { |
56 | struct trace_bprintk_fmt *tb_fmt = lookup_format(*iter); | |
57 | if (tb_fmt) { | |
58 | *iter = tb_fmt->fmt; | |
59 | continue; | |
60 | } | |
61 | ||
62 | tb_fmt = kmalloc(offsetof(struct trace_bprintk_fmt, fmt) | |
63 | + strlen(*iter) + 1, GFP_KERNEL); | |
64 | if (tb_fmt) { | |
65 | list_add_tail(&tb_fmt->list, &trace_bprintk_fmt_list); | |
66 | strcpy(tb_fmt->fmt, *iter); | |
67 | *iter = tb_fmt->fmt; | |
68 | } else | |
69 | *iter = NULL; | |
70 | } | |
769b0441 | 71 | mutex_unlock(&btrace_mutex); |
1427cdf0 LJ |
72 | } |
73 | ||
1ba28e02 LJ |
74 | static int module_trace_bprintk_format_notify(struct notifier_block *self, |
75 | unsigned long val, void *data) | |
76 | { | |
77 | struct module *mod = data; | |
78 | if (mod->num_trace_bprintk_fmt) { | |
79 | const char **start = mod->trace_bprintk_fmt_start; | |
80 | const char **end = start + mod->num_trace_bprintk_fmt; | |
81 | ||
82 | if (val == MODULE_STATE_COMING) | |
83 | hold_module_trace_bprintk_format(start, end); | |
84 | } | |
85 | return 0; | |
86 | } | |
87 | ||
88 | #else /* !CONFIG_MODULES */ | |
89 | __init static int | |
90 | module_trace_bprintk_format_notify(struct notifier_block *self, | |
91 | unsigned long val, void *data) | |
92 | { | |
93 | return 0; | |
94 | } | |
95 | #endif /* CONFIG_MODULES */ | |
96 | ||
97 | ||
98 | __initdata_or_module static | |
99 | struct notifier_block module_trace_bprintk_format_nb = { | |
100 | .notifier_call = module_trace_bprintk_format_notify, | |
101 | }; | |
102 | ||
48ead020 | 103 | int __trace_bprintk(unsigned long ip, const char *fmt, ...) |
769b0441 FW |
104 | { |
105 | int ret; | |
106 | va_list ap; | |
1427cdf0 | 107 | |
769b0441 FW |
108 | if (unlikely(!fmt)) |
109 | return 0; | |
1427cdf0 | 110 | |
769b0441 FW |
111 | if (!(trace_flags & TRACE_ITER_PRINTK)) |
112 | return 0; | |
113 | ||
114 | va_start(ap, fmt); | |
40ce74f1 | 115 | ret = trace_vbprintk(ip, fmt, ap); |
769b0441 FW |
116 | va_end(ap); |
117 | return ret; | |
1427cdf0 | 118 | } |
48ead020 | 119 | EXPORT_SYMBOL_GPL(__trace_bprintk); |
1427cdf0 | 120 | |
48ead020 | 121 | int __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap) |
769b0441 FW |
122 | { |
123 | if (unlikely(!fmt)) | |
124 | return 0; | |
125 | ||
126 | if (!(trace_flags & TRACE_ITER_PRINTK)) | |
127 | return 0; | |
128 | ||
40ce74f1 | 129 | return trace_vbprintk(ip, fmt, ap); |
48ead020 FW |
130 | } |
131 | EXPORT_SYMBOL_GPL(__ftrace_vbprintk); | |
132 | ||
133 | int __trace_printk(unsigned long ip, const char *fmt, ...) | |
134 | { | |
135 | int ret; | |
136 | va_list ap; | |
137 | ||
138 | if (!(trace_flags & TRACE_ITER_PRINTK)) | |
139 | return 0; | |
140 | ||
141 | va_start(ap, fmt); | |
40ce74f1 | 142 | ret = trace_vprintk(ip, fmt, ap); |
48ead020 FW |
143 | va_end(ap); |
144 | return ret; | |
145 | } | |
146 | EXPORT_SYMBOL_GPL(__trace_printk); | |
147 | ||
148 | int __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap) | |
149 | { | |
150 | if (!(trace_flags & TRACE_ITER_PRINTK)) | |
151 | return 0; | |
152 | ||
40ce74f1 | 153 | return trace_vprintk(ip, fmt, ap); |
1427cdf0 | 154 | } |
769b0441 | 155 | EXPORT_SYMBOL_GPL(__ftrace_vprintk); |
1427cdf0 | 156 | |
7975a2be | 157 | static void * |
c8961ec6 | 158 | t_start(struct seq_file *m, loff_t *pos) |
7975a2be | 159 | { |
c8961ec6 | 160 | const char **fmt = __start___trace_bprintk_fmt + *pos; |
7975a2be SR |
161 | |
162 | if ((unsigned long)fmt >= (unsigned long)__stop___trace_bprintk_fmt) | |
163 | return NULL; | |
7975a2be SR |
164 | return fmt; |
165 | } | |
166 | ||
c8961ec6 | 167 | static void *t_next(struct seq_file *m, void * v, loff_t *pos) |
7975a2be | 168 | { |
c8961ec6 LZ |
169 | (*pos)++; |
170 | return t_start(m, pos); | |
7975a2be SR |
171 | } |
172 | ||
173 | static int t_show(struct seq_file *m, void *v) | |
174 | { | |
175 | const char **fmt = v; | |
176 | const char *str = *fmt; | |
177 | int i; | |
178 | ||
179 | seq_printf(m, "0x%lx : \"", (unsigned long)fmt); | |
180 | ||
181 | /* | |
182 | * Tabs and new lines need to be converted. | |
183 | */ | |
184 | for (i = 0; str[i]; i++) { | |
185 | switch (str[i]) { | |
186 | case '\n': | |
187 | seq_puts(m, "\\n"); | |
188 | break; | |
189 | case '\t': | |
190 | seq_puts(m, "\\t"); | |
191 | break; | |
192 | case '\\': | |
193 | seq_puts(m, "\\"); | |
194 | break; | |
195 | case '"': | |
196 | seq_puts(m, "\\\""); | |
197 | break; | |
198 | default: | |
199 | seq_putc(m, str[i]); | |
200 | } | |
201 | } | |
202 | seq_puts(m, "\"\n"); | |
203 | ||
204 | return 0; | |
205 | } | |
206 | ||
207 | static void t_stop(struct seq_file *m, void *p) | |
208 | { | |
209 | } | |
210 | ||
211 | static const struct seq_operations show_format_seq_ops = { | |
212 | .start = t_start, | |
213 | .next = t_next, | |
214 | .show = t_show, | |
215 | .stop = t_stop, | |
216 | }; | |
217 | ||
218 | static int | |
219 | ftrace_formats_open(struct inode *inode, struct file *file) | |
220 | { | |
c8961ec6 | 221 | return seq_open(file, &show_format_seq_ops); |
7975a2be SR |
222 | } |
223 | ||
224 | static const struct file_operations ftrace_formats_fops = { | |
225 | .open = ftrace_formats_open, | |
226 | .read = seq_read, | |
227 | .llseek = seq_lseek, | |
228 | .release = seq_release, | |
229 | }; | |
230 | ||
231 | static __init int init_trace_printk_function_export(void) | |
232 | { | |
233 | struct dentry *d_tracer; | |
7975a2be SR |
234 | |
235 | d_tracer = tracing_init_dentry(); | |
236 | if (!d_tracer) | |
237 | return 0; | |
238 | ||
5452af66 | 239 | trace_create_file("printk_formats", 0444, d_tracer, |
7975a2be | 240 | NULL, &ftrace_formats_fops); |
7975a2be SR |
241 | |
242 | return 0; | |
243 | } | |
244 | ||
245 | fs_initcall(init_trace_printk_function_export); | |
246 | ||
769b0441 | 247 | static __init int init_trace_printk(void) |
1427cdf0 | 248 | { |
769b0441 | 249 | return register_module_notifier(&module_trace_bprintk_format_nb); |
1427cdf0 LJ |
250 | } |
251 | ||
769b0441 | 252 | early_initcall(init_trace_printk); |