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