aboutsummaryrefslogtreecommitdiffstats
path: root/include/linux/dynamic_debug.h
blob: 6c809440f31978228acb3f29762ccb6901fd8341 (plain) (blame)
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
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _DYNAMIC_DEBUG_H
#define _DYNAMIC_DEBUG_H

#if defined(CONFIG_JUMP_LABEL)
#include <linux/jump_label.h>
#endif

/*
 * An instance of this structure is created in a special
 * ELF section at every dynamic debug callsite.  At runtime,
 * the special section is treated as an array of these.
 */
struct _ddebug {
	/*
	 * These fields are used to drive the user interface
	 * for selecting and displaying debug callsites.
	 */
	const char *modname;
	const char *function;
	const char *filename;
	const char *format;
	unsigned int lineno:18;
	/*
	 * The flags field controls the behaviour at the callsite.
	 * The bits here are changed dynamically when the user
	 * writes commands to <debugfs>/dynamic_debug/control
	 */
#define _DPRINTK_FLAGS_NONE	0
#define _DPRINTK_FLAGS_PRINT	(1<<0) /* printk() a message using the format */
#define _DPRINTK_FLAGS_INCL_MODNAME	(1<<1)
#define _DPRINTK_FLAGS_INCL_FUNCNAME	(1<<2)
#define _DPRINTK_FLAGS_INCL_LINENO	(1<<3)
#define _DPRINTK_FLAGS_INCL_TID		(1<<4)
#if defined DEBUG
#define _DPRINTK_FLAGS_DEFAULT _DPRINTK_FLAGS_PRINT
#else
#define _DPRINTK_FLAGS_DEFAULT 0
#endif
	unsigned int flags:8;
#ifdef CONFIG_JUMP_LABEL
	union {
		struct static_key_true dd_key_true;
		struct static_key_false dd_key_false;
	} key;
#endif
} __attribute__((aligned(8)));



#if defined(CONFIG_DYNAMIC_DEBUG)
int ddebug_add_module(struct _ddebug *tab, unsigned int n,
				const char *modname);
extern int ddebug_remove_module(const char *mod_name);
extern __printf(2, 3)
void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...);

extern int ddebug_dyndbg_module_param_cb(char *param, char *val,
					const char *modname);

struct device;

extern __printf(3, 4)
void __dynamic_dev_dbg(struct _ddebug *descriptor, const struct device *dev,
		       const char *fmt, ...);

struct net_device;

extern __printf(3, 4)
void __dynamic_netdev_dbg(struct _ddebug *descriptor,
			  const struct net_device *dev,
			  const char *fmt, ...);

struct ib_device;

extern __printf(3, 4)
void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
			 const struct ib_device *ibdev,
			 const char *fmt, ...);

#define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt)		\
	static struct _ddebug  __aligned(8)			\
	__attribute__((section("__verbose"))) name = {		\
		.modname = KBUILD_MODNAME,			\
		.function = __func__,				\
		.filename = __FILE__,				\
		.format = (fmt),				\
		.lineno = __LINE__,				\
		.flags = _DPRINTK_FLAGS_DEFAULT,		\
		_DPRINTK_KEY_INIT				\
	}

#ifdef CONFIG_JUMP_LABEL

#ifdef DEBUG

#define _DPRINTK_KEY_INIT .key.dd_key_true = (STATIC_KEY_TRUE_INIT)

#define DYNAMIC_DEBUG_BRANCH(descriptor) \
	static_branch_likely(&descriptor.key.dd_key_true)
#else
#define _DPRINTK_KEY_INIT .key.dd_key_false = (STATIC_KEY_FALSE_INIT)

#define DYNAMIC_DEBUG_BRANCH(descriptor) \
	static_branch_unlikely(&descriptor.key.dd_key_false)
#endif

#else /* !HAVE_JUMP_LABEL */

#define _DPRINTK_KEY_INIT

#ifdef DEBUG
#define DYNAMIC_DEBUG_BRANCH(descriptor) \
	likely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
#else
#define DYNAMIC_DEBUG_BRANCH(descriptor) \
	unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
#endif

#endif

#define __dynamic_func_call(id, fmt, func, ...) do {	\
	DEFINE_DYNAMIC_DEBUG_METADATA(id, fmt);		\
	if (DYNAMIC_DEBUG_BRANCH(id))			\
		func(&id, ##__VA_ARGS__);		\
} while (0)

#define __dynamic_func_call_no_desc(id, fmt, func, ...) do {	\
	DEFINE_DYNAMIC_DEBUG_METADATA(id, fmt);			\
	if (DYNAMIC_DEBUG_BRANCH(id))				\
		func(__VA_ARGS__);				\
} while (0)

/*
 * "Factory macro" for generating a call to func, guarded by a
 * DYNAMIC_DEBUG_BRANCH. The dynamic debug decriptor will be
 * initialized using the fmt argument. The function will be called with
 * the address of the descriptor as first argument, followed by all
 * the varargs. Note that fmt is repeated in invocations of this
 * macro.
 */
#define _dynamic_func_call(fmt, func, ...)				\
	__dynamic_func_call(__UNIQUE_ID(ddebug), fmt, func, ##__VA_ARGS__)
/*
 * A variant that does the same, except that the descriptor is not
 * passed as the first argument to the function; it is only called
 * with precisely the macro's varargs.
 */
#define _dynamic_func_call_no_desc(fmt, func, ...)	\
	__dynamic_func_call_no_desc(__UNIQUE_ID(ddebug), fmt, func, ##__VA_ARGS__)

#define dynamic_pr_debug(fmt, ...)				\
	_dynamic_func_call(fmt,	__dynamic_pr_debug,		\
			   pr_fmt(fmt), ##__VA_ARGS__)

#define dynamic_dev_dbg(dev, fmt, ...)				\
	_dynamic_func_call(fmt,__dynamic_dev_dbg, 		\
			   dev, fmt, ##__VA_ARGS__)

#define dynamic_netdev_dbg(dev, fmt, ...)			\
	_dynamic_func_call(fmt, __dynamic_netdev_dbg,		\
			   dev, fmt, ##__VA_ARGS__)

#define dynamic_ibdev_dbg(dev, fmt, ...)			\
	_dynamic_func_call(fmt, __dynamic_ibdev_dbg,		\
			   dev, fmt, ##__VA_ARGS__)

#define dynamic_hex_dump(prefix_str, prefix_type, rowsize,		\
			 groupsize, buf, len, ascii)			\
	_dynamic_func_call_no_desc(__builtin_constant_p(prefix_str) ? prefix_str : "hexdump", \
				   print_hex_dump,			\
				   KERN_DEBUG, prefix_str, prefix_type,	\
				   rowsize, groupsize, buf, len, ascii)

#else

#include <linux/string.h>
#include <linux/errno.h>

static inline int ddebug_add_module(struct _ddebug *tab, unsigned int n,
				    const char *modname)
{
	return 0;
}

static inline int ddebug_remove_module(const char *mod)
{
	return 0;
}

static inline int ddebug_dyndbg_module_param_cb(char *param, char *val,
						const char *modname)
{
	if (strstr(param, "dyndbg")) {
		/* avoid pr_warn(), which wants pr_fmt() fully defined */
		printk(KERN_WARNING "dyndbg param is supported only in "
			"CONFIG_DYNAMIC_DEBUG builds\n");
		return 0; /* allow and ignore */
	}
	return -EINVAL;
}

#define dynamic_pr_debug(fmt, ...)					\
	do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
#define dynamic_dev_dbg(dev, fmt, ...)					\
	do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0)
#endif

#endif