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
36 #define _DPRINTK_FLAGS_INCL_ANY \
37 (_DPRINTK_FLAGS_INCL_MODNAME | _DPRINTK_FLAGS_INCL_FUNCNAME |\
38 _DPRINTK_FLAGS_INCL_LINENO | _DPRINTK_FLAGS_INCL_TID)
39
40 #if defined DEBUG
41 #define _DPRINTK_FLAGS_DEFAULT _DPRINTK_FLAGS_PRINT
42 #else
43 #define _DPRINTK_FLAGS_DEFAULT 0
44 #endif
45 unsigned int flags:8;
46 #ifdef CONFIG_JUMP_LABEL
47 union {
48 struct static_key_true dd_key_true;
49 struct static_key_false dd_key_false;
50 } key;
51 #endif
52 } __attribute__((aligned(8)));
53
54
55
56 #if defined(CONFIG_DYNAMIC_DEBUG_CORE)
57
58 int ddebug_add_module(struct _ddebug *tab, unsigned int n,
59 const char *modname);
60 extern int ddebug_remove_module(const char *mod_name);
61 extern __printf(2, 3)
62 void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...);
63
64 extern int ddebug_dyndbg_module_param_cb(char *param, char *val,
65 const char *modname);
66
67 struct device;
68
69 extern __printf(3, 4)
70 void __dynamic_dev_dbg(struct _ddebug *descriptor, const struct device *dev,
71 const char *fmt, ...);
72
73 struct net_device;
74
75 extern __printf(3, 4)
76 void __dynamic_netdev_dbg(struct _ddebug *descriptor,
77 const struct net_device *dev,
78 const char *fmt, ...);
79
80 struct ib_device;
81
82 extern __printf(3, 4)
83 void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
84 const struct ib_device *ibdev,
85 const char *fmt, ...);
86
87 #define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt) \
88 static struct _ddebug __aligned(8) \
89 __section("__dyndbg") name = { \
90 .modname = KBUILD_MODNAME, \
91 .function = __func__, \
92 .filename = __FILE__, \
93 .format = (fmt), \
94 .lineno = __LINE__, \
95 .flags = _DPRINTK_FLAGS_DEFAULT, \
96 _DPRINTK_KEY_INIT \
97 }
98
99 #ifdef CONFIG_JUMP_LABEL
100
101 #ifdef DEBUG
102
103 #define _DPRINTK_KEY_INIT .key.dd_key_true = (STATIC_KEY_TRUE_INIT)
104
105 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
106 static_branch_likely(&descriptor.key.dd_key_true)
107 #else
108 #define _DPRINTK_KEY_INIT .key.dd_key_false = (STATIC_KEY_FALSE_INIT)
109
110 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
111 static_branch_unlikely(&descriptor.key.dd_key_false)
112 #endif
113
114 #else /* !CONFIG_JUMP_LABEL */
115
116 #define _DPRINTK_KEY_INIT
117
118 #ifdef DEBUG
119 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
120 likely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
121 #else
122 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
123 unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
124 #endif
125
126 #endif /* CONFIG_JUMP_LABEL */
127
128 #define __dynamic_func_call(id, fmt, func, ...) do { \
129 DEFINE_DYNAMIC_DEBUG_METADATA(id, fmt); \
130 if (DYNAMIC_DEBUG_BRANCH(id)) \
131 func(&id, ##__VA_ARGS__); \
132 } while (0)
133
134 #define __dynamic_func_call_no_desc(id, fmt, func, ...) do { \
135 DEFINE_DYNAMIC_DEBUG_METADATA(id, fmt); \
136 if (DYNAMIC_DEBUG_BRANCH(id)) \
137 func(__VA_ARGS__); \
138 } while (0)
139
140 /*
141 * "Factory macro" for generating a call to func, guarded by a
142 * DYNAMIC_DEBUG_BRANCH. The dynamic debug descriptor will be
143 * initialized using the fmt argument. The function will be called with
144 * the address of the descriptor as first argument, followed by all
145 * the varargs. Note that fmt is repeated in invocations of this
146 * macro.
147 */
148 #define _dynamic_func_call(fmt, func, ...) \
149 __dynamic_func_call(__UNIQUE_ID(ddebug), fmt, func, ##__VA_ARGS__)
150 /*
151 * A variant that does the same, except that the descriptor is not
152 * passed as the first argument to the function; it is only called
153 * with precisely the macro's varargs.
154 */
155 #define _dynamic_func_call_no_desc(fmt, func, ...) \
156 __dynamic_func_call_no_desc(__UNIQUE_ID(ddebug), fmt, func, ##__VA_ARGS__)
157
158 #define dynamic_pr_debug(fmt, ...) \
159 _dynamic_func_call(fmt, __dynamic_pr_debug, \
160 pr_fmt(fmt), ##__VA_ARGS__)
161
162 #define dynamic_dev_dbg(dev, fmt, ...) \
163 _dynamic_func_call(fmt,__dynamic_dev_dbg, \
164 dev, fmt, ##__VA_ARGS__)
165
166 #define dynamic_netdev_dbg(dev, fmt, ...) \
167 _dynamic_func_call(fmt, __dynamic_netdev_dbg, \
168 dev, fmt, ##__VA_ARGS__)
169
170 #define dynamic_ibdev_dbg(dev, fmt, ...) \
171 _dynamic_func_call(fmt, __dynamic_ibdev_dbg, \
172 dev, fmt, ##__VA_ARGS__)
173
174 #define dynamic_hex_dump(prefix_str, prefix_type, rowsize, \
175 groupsize, buf, len, ascii) \
176 _dynamic_func_call_no_desc(__builtin_constant_p(prefix_str) ? prefix_str : "hexdump", \
177 print_hex_dump, \
178 KERN_DEBUG, prefix_str, prefix_type, \
179 rowsize, groupsize, buf, len, ascii)
180
181 #else /* !CONFIG_DYNAMIC_DEBUG_CORE */
182
183 #include <linux/string.h>
184 #include <linux/errno.h>
185 #include <linux/printk.h>
186
ddebug_add_module(struct _ddebug * tab,unsigned int n,const char * modname)187 static inline int ddebug_add_module(struct _ddebug *tab, unsigned int n,
188 const char *modname)
189 {
190 return 0;
191 }
192
ddebug_remove_module(const char * mod)193 static inline int ddebug_remove_module(const char *mod)
194 {
195 return 0;
196 }
197
ddebug_dyndbg_module_param_cb(char * param,char * val,const char * modname)198 static inline int ddebug_dyndbg_module_param_cb(char *param, char *val,
199 const char *modname)
200 {
201 if (!strcmp(param, "dyndbg")) {
202 /* avoid pr_warn(), which wants pr_fmt() fully defined */
203 printk(KERN_WARNING "dyndbg param is supported only in "
204 "CONFIG_DYNAMIC_DEBUG builds\n");
205 return 0; /* allow and ignore */
206 }
207 return -EINVAL;
208 }
209
210 #define dynamic_pr_debug(fmt, ...) \
211 do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
212 #define dynamic_dev_dbg(dev, fmt, ...) \
213 do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0)
214 #define dynamic_hex_dump(prefix_str, prefix_type, rowsize, \
215 groupsize, buf, len, ascii) \
216 do { if (0) \
217 print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, \
218 rowsize, groupsize, buf, len, ascii); \
219 } while (0)
220
221 #endif /* !CONFIG_DYNAMIC_DEBUG_CORE */
222
223 #endif
224