1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _DYNAMIC_DEBUG_H
3 #define _DYNAMIC_DEBUG_H
4
5 #if 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 CONFIG_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
51 #if defined(CONFIG_DYNAMIC_DEBUG_CORE)
52
53 int ddebug_add_module(struct _ddebug *tab, unsigned int n,
54 const char *modname);
55 extern int ddebug_remove_module(const char *mod_name);
56 extern __printf(2, 3)
57 void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...);
58
59 extern int ddebug_dyndbg_module_param_cb(char *param, char *val,
60 const char *modname);
61
62 struct device;
63
64 extern __printf(3, 4)
65 void __dynamic_dev_dbg(struct _ddebug *descriptor, const struct device *dev,
66 const char *fmt, ...);
67
68 struct net_device;
69
70 extern __printf(3, 4)
71 void __dynamic_netdev_dbg(struct _ddebug *descriptor,
72 const struct net_device *dev,
73 const char *fmt, ...);
74
75 struct ib_device;
76
77 extern __printf(3, 4)
78 void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
79 const struct ib_device *ibdev,
80 const char *fmt, ...);
81
82 #define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt) \
83 static struct _ddebug __aligned(8) \
84 __section("__dyndbg") name = { \
85 .modname = KBUILD_MODNAME, \
86 .function = __func__, \
87 .filename = __FILE__, \
88 .format = (fmt), \
89 .lineno = __LINE__, \
90 .flags = _DPRINTK_FLAGS_DEFAULT, \
91 _DPRINTK_KEY_INIT \
92 }
93
94 #ifdef CONFIG_JUMP_LABEL
95
96 #ifdef DEBUG
97
98 #define _DPRINTK_KEY_INIT .key.dd_key_true = (STATIC_KEY_TRUE_INIT)
99
100 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
101 static_branch_likely(&descriptor.key.dd_key_true)
102 #else
103 #define _DPRINTK_KEY_INIT .key.dd_key_false = (STATIC_KEY_FALSE_INIT)
104
105 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
106 static_branch_unlikely(&descriptor.key.dd_key_false)
107 #endif
108
109 #else /* !CONFIG_JUMP_LABEL */
110
111 #define _DPRINTK_KEY_INIT
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 /* CONFIG_JUMP_LABEL */
122
123 #define __dynamic_func_call(id, fmt, func, ...) do { \
124 DEFINE_DYNAMIC_DEBUG_METADATA(id, fmt); \
125 if (DYNAMIC_DEBUG_BRANCH(id)) \
126 func(&id, ##__VA_ARGS__); \
127 } while (0)
128
129 #define __dynamic_func_call_no_desc(id, fmt, func, ...) do { \
130 DEFINE_DYNAMIC_DEBUG_METADATA(id, fmt); \
131 if (DYNAMIC_DEBUG_BRANCH(id)) \
132 func(__VA_ARGS__); \
133 } while (0)
134
135 /*
136 * "Factory macro" for generating a call to func, guarded by a
137 * DYNAMIC_DEBUG_BRANCH. The dynamic debug descriptor will be
138 * initialized using the fmt argument. The function will be called with
139 * the address of the descriptor as first argument, followed by all
140 * the varargs. Note that fmt is repeated in invocations of this
141 * macro.
142 */
143 #define _dynamic_func_call(fmt, func, ...) \
144 __dynamic_func_call(__UNIQUE_ID(ddebug), fmt, func, ##__VA_ARGS__)
145 /*
146 * A variant that does the same, except that the descriptor is not
147 * passed as the first argument to the function; it is only called
148 * with precisely the macro's varargs.
149 */
150 #define _dynamic_func_call_no_desc(fmt, func, ...) \
151 __dynamic_func_call_no_desc(__UNIQUE_ID(ddebug), fmt, func, ##__VA_ARGS__)
152
153 #define dynamic_pr_debug(fmt, ...) \
154 _dynamic_func_call(fmt, __dynamic_pr_debug, \
155 pr_fmt(fmt), ##__VA_ARGS__)
156
157 #define dynamic_dev_dbg(dev, fmt, ...) \
158 _dynamic_func_call(fmt,__dynamic_dev_dbg, \
159 dev, fmt, ##__VA_ARGS__)
160
161 #define dynamic_netdev_dbg(dev, fmt, ...) \
162 _dynamic_func_call(fmt, __dynamic_netdev_dbg, \
163 dev, fmt, ##__VA_ARGS__)
164
165 #define dynamic_ibdev_dbg(dev, fmt, ...) \
166 _dynamic_func_call(fmt, __dynamic_ibdev_dbg, \
167 dev, fmt, ##__VA_ARGS__)
168
169 #define dynamic_hex_dump(prefix_str, prefix_type, rowsize, \
170 groupsize, buf, len, ascii) \
171 _dynamic_func_call_no_desc(__builtin_constant_p(prefix_str) ? prefix_str : "hexdump", \
172 print_hex_dump, \
173 KERN_DEBUG, prefix_str, prefix_type, \
174 rowsize, groupsize, buf, len, ascii)
175
176 #else /* !CONFIG_DYNAMIC_DEBUG_CORE */
177
178 #include <linux/string.h>
179 #include <linux/errno.h>
180 #include <linux/printk.h>
181
ddebug_add_module(struct _ddebug * tab,unsigned int n,const char * modname)182 static inline int ddebug_add_module(struct _ddebug *tab, unsigned int n,
183 const char *modname)
184 {
185 return 0;
186 }
187
ddebug_remove_module(const char * mod)188 static inline int ddebug_remove_module(const char *mod)
189 {
190 return 0;
191 }
192
ddebug_dyndbg_module_param_cb(char * param,char * val,const char * modname)193 static inline int ddebug_dyndbg_module_param_cb(char *param, char *val,
194 const char *modname)
195 {
196 if (!strcmp(param, "dyndbg")) {
197 /* avoid pr_warn(), which wants pr_fmt() fully defined */
198 printk(KERN_WARNING "dyndbg param is supported only in "
199 "CONFIG_DYNAMIC_DEBUG builds\n");
200 return 0; /* allow and ignore */
201 }
202 return -EINVAL;
203 }
204
205 #define dynamic_pr_debug(fmt, ...) \
206 do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
207 #define dynamic_dev_dbg(dev, fmt, ...) \
208 do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0)
209 #define dynamic_hex_dump(prefix_str, prefix_type, rowsize, \
210 groupsize, buf, len, ascii) \
211 do { if (0) \
212 print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, \
213 rowsize, groupsize, buf, len, ascii); \
214 } while (0)
215
216 #endif /* !CONFIG_DYNAMIC_DEBUG_CORE */
217
218 #endif
219