1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _DYNAMIC_DEBUG_H
3 #define _DYNAMIC_DEBUG_H
4
5 #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
6 #include <linux/jump_label.h>
7 #endif
8
9 /*
10 * An instance of this structure is created in a special
11 * ELF section at every dynamic debug callsite. At runtime,
12 * the special section is treated as an array of these.
13 */
14 struct _ddebug {
15 /*
16 * These fields are used to drive the user interface
17 * for selecting and displaying debug callsites.
18 */
19 const char *modname;
20 const char *function;
21 const char *filename;
22 const char *format;
23 unsigned int lineno:18;
24 /*
25 * The flags field controls the behaviour at the callsite.
26 * The bits here are changed dynamically when the user
27 * writes commands to <debugfs>/dynamic_debug/control
28 */
29 #define _DPRINTK_FLAGS_NONE 0
30 #define _DPRINTK_FLAGS_PRINT (1<<0) /* printk() a message using the format */
31 #define _DPRINTK_FLAGS_INCL_MODNAME (1<<1)
32 #define _DPRINTK_FLAGS_INCL_FUNCNAME (1<<2)
33 #define _DPRINTK_FLAGS_INCL_LINENO (1<<3)
34 #define _DPRINTK_FLAGS_INCL_TID (1<<4)
35 #if defined DEBUG
36 #define _DPRINTK_FLAGS_DEFAULT _DPRINTK_FLAGS_PRINT
37 #else
38 #define _DPRINTK_FLAGS_DEFAULT 0
39 #endif
40 unsigned int flags:8;
41 #ifdef HAVE_JUMP_LABEL
42 union {
43 struct static_key_true dd_key_true;
44 struct static_key_false dd_key_false;
45 } key;
46 #endif
47 } __attribute__((aligned(8)));
48
49
50 int ddebug_add_module(struct _ddebug *tab, unsigned int n,
51 const char *modname);
52
53 #if defined(CONFIG_DYNAMIC_DEBUG)
54 extern int ddebug_remove_module(const char *mod_name);
55 extern __printf(2, 3)
56 void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...);
57
58 extern int ddebug_dyndbg_module_param_cb(char *param, char *val,
59 const char *modname);
60
61 struct device;
62
63 extern __printf(3, 4)
64 void __dynamic_dev_dbg(struct _ddebug *descriptor, const struct device *dev,
65 const char *fmt, ...);
66
67 struct net_device;
68
69 extern __printf(3, 4)
70 void __dynamic_netdev_dbg(struct _ddebug *descriptor,
71 const struct net_device *dev,
72 const char *fmt, ...);
73
74 #define DEFINE_DYNAMIC_DEBUG_METADATA_KEY(name, fmt, key, init) \
75 static struct _ddebug __aligned(8) \
76 __attribute__((section("__verbose"))) name = { \
77 .modname = KBUILD_MODNAME, \
78 .function = __func__, \
79 .filename = __FILE__, \
80 .format = (fmt), \
81 .lineno = __LINE__, \
82 .flags = _DPRINTK_FLAGS_DEFAULT, \
83 dd_key_init(key, init) \
84 }
85
86 #ifdef HAVE_JUMP_LABEL
87
88 #define dd_key_init(key, init) key = (init)
89
90 #ifdef DEBUG
91 #define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt) \
92 DEFINE_DYNAMIC_DEBUG_METADATA_KEY(name, fmt, .key.dd_key_true, \
93 (STATIC_KEY_TRUE_INIT))
94
95 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
96 static_branch_likely(&descriptor.key.dd_key_true)
97 #else
98 #define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt) \
99 DEFINE_DYNAMIC_DEBUG_METADATA_KEY(name, fmt, .key.dd_key_false, \
100 (STATIC_KEY_FALSE_INIT))
101
102 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
103 static_branch_unlikely(&descriptor.key.dd_key_false)
104 #endif
105
106 #else
107
108 #define dd_key_init(key, init)
109
110 #define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt) \
111 DEFINE_DYNAMIC_DEBUG_METADATA_KEY(name, fmt, 0, 0)
112
113 #ifdef DEBUG
114 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
115 likely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
116 #else
117 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
118 unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
119 #endif
120
121 #endif
122
123 #define dynamic_pr_debug(fmt, ...) \
124 do { \
125 DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); \
126 if (DYNAMIC_DEBUG_BRANCH(descriptor)) \
127 __dynamic_pr_debug(&descriptor, pr_fmt(fmt), \
128 ##__VA_ARGS__); \
129 } while (0)
130
131 #define dynamic_dev_dbg(dev, fmt, ...) \
132 do { \
133 DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); \
134 if (DYNAMIC_DEBUG_BRANCH(descriptor)) \
135 __dynamic_dev_dbg(&descriptor, dev, fmt, \
136 ##__VA_ARGS__); \
137 } while (0)
138
139 #define dynamic_netdev_dbg(dev, fmt, ...) \
140 do { \
141 DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); \
142 if (DYNAMIC_DEBUG_BRANCH(descriptor)) \
143 __dynamic_netdev_dbg(&descriptor, dev, fmt, \
144 ##__VA_ARGS__); \
145 } while (0)
146
147 #define dynamic_hex_dump(prefix_str, prefix_type, rowsize, \
148 groupsize, buf, len, ascii) \
149 do { \
150 DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, \
151 __builtin_constant_p(prefix_str) ? prefix_str : "hexdump");\
152 if (DYNAMIC_DEBUG_BRANCH(descriptor)) \
153 print_hex_dump(KERN_DEBUG, prefix_str, \
154 prefix_type, rowsize, groupsize, \
155 buf, len, ascii); \
156 } while (0)
157
158 #else
159
160 #include <linux/string.h>
161 #include <linux/errno.h>
162
ddebug_remove_module(const char * mod)163 static inline int ddebug_remove_module(const char *mod)
164 {
165 return 0;
166 }
167
ddebug_dyndbg_module_param_cb(char * param,char * val,const char * modname)168 static inline int ddebug_dyndbg_module_param_cb(char *param, char *val,
169 const char *modname)
170 {
171 if (strstr(param, "dyndbg")) {
172 /* avoid pr_warn(), which wants pr_fmt() fully defined */
173 printk(KERN_WARNING "dyndbg param is supported only in "
174 "CONFIG_DYNAMIC_DEBUG builds\n");
175 return 0; /* allow and ignore */
176 }
177 return -EINVAL;
178 }
179
180 #define dynamic_pr_debug(fmt, ...) \
181 do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
182 #define dynamic_dev_dbg(dev, fmt, ...) \
183 do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0)
184 #endif
185
186 #endif
187
