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 | 13 | #include <linux/module.h> |
7975a2be | 14 | #include <linux/mutex.h> |
1427cdf0 LJ |
15 | #include <linux/ctype.h> |
16 | #include <linux/list.h> | |
1427cdf0 | 17 | #include <linux/slab.h> |
1427cdf0 | 18 | #include <linux/fs.h> |
1427cdf0 LJ |
19 | |
20 | #include "trace.h" | |
21 | ||
1ba28e02 LJ |
22 | #ifdef CONFIG_MODULES |
23 | ||
1ba28e02 | 24 | /* |
769b0441 | 25 | * modules trace_printk()'s formats are autosaved in struct trace_bprintk_fmt |
1ba28e02 LJ |
26 | * which are queued on trace_bprintk_fmt_list. |
27 | */ | |
28 | static LIST_HEAD(trace_bprintk_fmt_list); | |
29 | ||
769b0441 FW |
30 | /* serialize accesses to trace_bprintk_fmt_list */ |
31 | static DEFINE_MUTEX(btrace_mutex); | |
32 | ||
1ba28e02 LJ |
33 | struct trace_bprintk_fmt { |
34 | struct list_head list; | |
35 | char fmt[0]; | |
36 | }; | |
37 | ||
1ba28e02 | 38 | static inline struct trace_bprintk_fmt *lookup_format(const char *fmt) |
1427cdf0 | 39 | { |
1ba28e02 LJ |
40 | struct trace_bprintk_fmt *pos; |
41 | list_for_each_entry(pos, &trace_bprintk_fmt_list, list) { | |
42 | if (!strcmp(pos->fmt, fmt)) | |
43 | return pos; | |
44 | } | |
45 | return NULL; | |
1427cdf0 LJ |
46 | } |
47 | ||
1ba28e02 LJ |
48 | static |
49 | void hold_module_trace_bprintk_format(const char **start, const char **end) | |
1427cdf0 | 50 | { |
1ba28e02 | 51 | const char **iter; |
769b0441 FW |
52 | |
53 | mutex_lock(&btrace_mutex); | |
1ba28e02 LJ |
54 | for (iter = start; iter < end; iter++) { |
55 | struct trace_bprintk_fmt *tb_fmt = lookup_format(*iter); | |
56 | if (tb_fmt) { | |
57 | *iter = tb_fmt->fmt; | |
58 | continue; | |
59 | } | |
60 | ||
61 | tb_fmt = kmalloc(offsetof(struct trace_bprintk_fmt, fmt) | |
62 | + strlen(*iter) + 1, GFP_KERNEL); | |
63 | if (tb_fmt) { | |
64 | list_add_tail(&tb_fmt->list, &trace_bprintk_fmt_list); | |
65 | strcpy(tb_fmt->fmt, *iter); | |
66 | *iter = tb_fmt->fmt; | |
67 | } else | |
68 | *iter = NULL; | |
69 | } | |
769b0441 | 70 | mutex_unlock(&btrace_mutex); |
1427cdf0 LJ |
71 | } |
72 | ||
1ba28e02 LJ |
73 | static int module_trace_bprintk_format_notify(struct notifier_block *self, |
74 | unsigned long val, void *data) | |
75 | { | |
76 | struct module *mod = data; | |
77 | if (mod->num_trace_bprintk_fmt) { | |
78 | const char **start = mod->trace_bprintk_fmt_start; | |
79 | const char **end = start + mod->num_trace_bprintk_fmt; | |
80 | ||
81 | if (val == MODULE_STATE_COMING) | |
82 | hold_module_trace_bprintk_format(start, end); | |
83 | } | |
84 | return 0; | |
85 | } | |
86 | ||
87 | #else /* !CONFIG_MODULES */ | |
88 | __init static int | |
89 | module_trace_bprintk_format_notify(struct notifier_block *self, | |
90 | unsigned long val, void *data) | |
91 | { | |
92 | return 0; | |
93 | } | |
94 | #endif /* CONFIG_MODULES */ | |
95 | ||
96 | ||
97 | __initdata_or_module static | |
98 | struct notifier_block module_trace_bprintk_format_nb = { | |
99 | .notifier_call = module_trace_bprintk_format_notify, | |
100 | }; | |
101 | ||
48ead020 | 102 | int __trace_bprintk(unsigned long ip, const char *fmt, ...) |
769b0441 FW |
103 | { |
104 | int ret; | |
105 | va_list ap; | |
1427cdf0 | 106 | |
769b0441 FW |
107 | if (unlikely(!fmt)) |
108 | return 0; | |
1427cdf0 | 109 | |
769b0441 FW |
110 | if (!(trace_flags & TRACE_ITER_PRINTK)) |
111 | return 0; | |
112 | ||
113 | va_start(ap, fmt); | |
40ce74f1 | 114 | ret = trace_vbprintk(ip, fmt, ap); |
769b0441 FW |
115 | va_end(ap); |
116 | return ret; | |
1427cdf0 | 117 | } |
48ead020 | 118 | EXPORT_SYMBOL_GPL(__trace_bprintk); |
1427cdf0 | 119 | |
48ead020 | 120 | int __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap) |
769b0441 FW |
121 | { |
122 | if (unlikely(!fmt)) | |
123 | return 0; | |
124 | ||
125 | if (!(trace_flags & TRACE_ITER_PRINTK)) | |
126 | return 0; | |
127 | ||
40ce74f1 | 128 | return trace_vbprintk(ip, fmt, ap); |
48ead020 FW |
129 | } |
130 | EXPORT_SYMBOL_GPL(__ftrace_vbprintk); | |
131 | ||
132 | int __trace_printk(unsigned long ip, const char *fmt, ...) | |
133 | { | |
134 | int ret; | |
135 | va_list ap; | |
136 | ||
137 | if (!(trace_flags & TRACE_ITER_PRINTK)) | |
138 | return 0; | |
139 | ||
140 | va_start(ap, fmt); | |
40ce74f1 | 141 | ret = trace_vprintk(ip, fmt, ap); |
48ead020 FW |
142 | va_end(ap); |
143 | return ret; | |
144 | } | |
145 | EXPORT_SYMBOL_GPL(__trace_printk); | |
146 | ||
147 | int __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap) | |
148 | { | |
149 | if (!(trace_flags & TRACE_ITER_PRINTK)) | |
150 | return 0; | |
151 | ||
40ce74f1 | 152 | return trace_vprintk(ip, fmt, ap); |
1427cdf0 | 153 | } |
769b0441 | 154 | EXPORT_SYMBOL_GPL(__ftrace_vprintk); |
1427cdf0 | 155 | |
7975a2be | 156 | static void * |
c8961ec6 | 157 | t_start(struct seq_file *m, loff_t *pos) |
7975a2be | 158 | { |
c8961ec6 | 159 | const char **fmt = __start___trace_bprintk_fmt + *pos; |
7975a2be SR |
160 | |
161 | if ((unsigned long)fmt >= (unsigned long)__stop___trace_bprintk_fmt) | |
162 | return NULL; | |
7975a2be SR |
163 | return fmt; |
164 | } | |
165 | ||
c8961ec6 | 166 | static void *t_next(struct seq_file *m, void * v, loff_t *pos) |
7975a2be | 167 | { |
c8961ec6 LZ |
168 | (*pos)++; |
169 | return t_start(m, pos); | |
7975a2be SR |
170 | } |
171 | ||
172 | static int t_show(struct seq_file *m, void *v) | |
173 | { | |
174 | const char **fmt = v; | |
175 | const char *str = *fmt; | |
176 | int i; | |
177 | ||
4c739ff0 | 178 | seq_printf(m, "0x%lx : \"", *(unsigned long *)fmt); |
7975a2be SR |
179 | |
180 | /* | |
181 | * Tabs and new lines need to be converted. | |
182 | */ | |
183 | for (i = 0; str[i]; i++) { | |
184 | switch (str[i]) { | |
185 | case '\n': | |
186 | seq_puts(m, "\\n"); | |
187 | break; | |
188 | case '\t': | |
189 | seq_puts(m, "\\t"); | |
190 | break; | |
191 | case '\\': | |
192 | seq_puts(m, "\\"); | |
193 | break; | |
194 | case '"': | |
195 | seq_puts(m, "\\\""); | |
196 | break; | |
197 | default: | |
198 | seq_putc(m, str[i]); | |
199 | } | |
200 | } | |
201 | seq_puts(m, "\"\n"); | |
202 | ||
203 | return 0; | |
204 | } | |
205 | ||
206 | static void t_stop(struct seq_file *m, void *p) | |
207 | { | |
208 | } | |
209 | ||
210 | static const struct seq_operations show_format_seq_ops = { | |
211 | .start = t_start, | |
212 | .next = t_next, | |
213 | .show = t_show, | |
214 | .stop = t_stop, | |
215 | }; | |
216 | ||
217 | static int | |
218 | ftrace_formats_open(struct inode *inode, struct file *file) | |
219 | { | |
c8961ec6 | 220 | return seq_open(file, &show_format_seq_ops); |
7975a2be SR |
221 | } |
222 | ||
223 | static const struct file_operations ftrace_formats_fops = { | |
224 | .open = ftrace_formats_open, | |
225 | .read = seq_read, | |
226 | .llseek = seq_lseek, | |
227 | .release = seq_release, | |
228 | }; | |
229 | ||
230 | static __init int init_trace_printk_function_export(void) | |
231 | { | |
232 | struct dentry *d_tracer; | |
7975a2be SR |
233 | |
234 | d_tracer = tracing_init_dentry(); | |
235 | if (!d_tracer) | |
236 | return 0; | |
237 | ||
5452af66 | 238 | trace_create_file("printk_formats", 0444, d_tracer, |
7975a2be | 239 | NULL, &ftrace_formats_fops); |
7975a2be SR |
240 | |
241 | return 0; | |
242 | } | |
243 | ||
244 | fs_initcall(init_trace_printk_function_export); | |
245 | ||
769b0441 | 246 | static __init int init_trace_printk(void) |
1427cdf0 | 247 | { |
769b0441 | 248 | return register_module_notifier(&module_trace_bprintk_format_nb); |
1427cdf0 LJ |
249 | } |
250 | ||
769b0441 | 251 | early_initcall(init_trace_printk); |