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 /* exported for module authors to exercise >control */
54 int dynamic_debug_exec_queries(const char *query, const char *modname);
55
56 int ddebug_add_module(struct _ddebug *tab, unsigned int n,
57 const char *modname);
58 extern int ddebug_remove_module(const char *mod_name);
59 extern __printf(2, 3)
60 void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...);
61
62 extern int ddebug_dyndbg_module_param_cb(char *param, char *val,
63 const char *modname);
64
65 struct device;
66
67 extern __printf(3, 4)
68 void __dynamic_dev_dbg(struct _ddebug *descriptor, const struct device *dev,
69 const char *fmt, ...);
70
71 struct net_device;
72
73 extern __printf(3, 4)
74 void __dynamic_netdev_dbg(struct _ddebug *descriptor,
75 const struct net_device *dev,
76 const char *fmt, ...);
77
78 struct ib_device;
79
80 extern __printf(3, 4)
81 void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
82 const struct ib_device *ibdev,
83 const char *fmt, ...);
84
85 #define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt) \
86 static struct _ddebug __aligned(8) \
87 __section("__dyndbg") name = { \
88 .modname = KBUILD_MODNAME, \
89 .function = __func__, \
90 .filename = __FILE__, \
91 .format = (fmt), \
92 .lineno = __LINE__, \
93 .flags = _DPRINTK_FLAGS_DEFAULT, \
94 _DPRINTK_KEY_INIT \
95 }
96
97 #ifdef CONFIG_JUMP_LABEL
98
99 #ifdef DEBUG
100
101 #define _DPRINTK_KEY_INIT .key.dd_key_true = (STATIC_KEY_TRUE_INIT)
102
103 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
104 static_branch_likely(&descriptor.key.dd_key_true)
105 #else
106 #define _DPRINTK_KEY_INIT .key.dd_key_false = (STATIC_KEY_FALSE_INIT)
107
108 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
109 static_branch_unlikely(&descriptor.key.dd_key_false)
110 #endif
111
112 #else /* !CONFIG_JUMP_LABEL */
113
114 #define _DPRINTK_KEY_INIT
115
116 #ifdef DEBUG
117 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
118 likely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
119 #else
120 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
121 unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
122 #endif
123
124 #endif /* CONFIG_JUMP_LABEL */
125
126 #define __dynamic_func_call(id, fmt, func, ...) do { \
127 DEFINE_DYNAMIC_DEBUG_METADATA(id, fmt); \
128 if (DYNAMIC_DEBUG_BRANCH(id)) \
129 func(&id, ##__VA_ARGS__); \
130 } while (0)
131
132 #define __dynamic_func_call_no_desc(id, fmt, func, ...) do { \
133 DEFINE_DYNAMIC_DEBUG_METADATA(id, fmt); \
134 if (DYNAMIC_DEBUG_BRANCH(id)) \
135 func(__VA_ARGS__); \
136 } while (0)
137
138 /*
139 * "Factory macro" for generating a call to func, guarded by a
140 * DYNAMIC_DEBUG_BRANCH. The dynamic debug descriptor will be
141 * initialized using the fmt argument. The function will be called with
142 * the address of the descriptor as first argument, followed by all
143 * the varargs. Note that fmt is repeated in invocations of this
144 * macro.
145 */
146 #define _dynamic_func_call(fmt, func, ...) \
147 __dynamic_func_call(__UNIQUE_ID(ddebug), fmt, func, ##__VA_ARGS__)
148 /*
149 * A variant that does the same, except that the descriptor is not
150 * passed as the first argument to the function; it is only called
151 * with precisely the macro's varargs.
152 */
153 #define _dynamic_func_call_no_desc(fmt, func, ...) \
154 __dynamic_func_call_no_desc(__UNIQUE_ID(ddebug), fmt, func, ##__VA_ARGS__)
155
156 #define dynamic_pr_debug(fmt, ...) \
157 _dynamic_func_call(fmt, __dynamic_pr_debug, \
158 pr_fmt(fmt), ##__VA_ARGS__)
159
160 #define dynamic_dev_dbg(dev, fmt, ...) \
161 _dynamic_func_call(fmt,__dynamic_dev_dbg, \
162 dev, fmt, ##__VA_ARGS__)
163
164 #define dynamic_netdev_dbg(dev, fmt, ...) \
165 _dynamic_func_call(fmt, __dynamic_netdev_dbg, \
166 dev, fmt, ##__VA_ARGS__)
167
168 #define dynamic_ibdev_dbg(dev, fmt, ...) \
169 _dynamic_func_call(fmt, __dynamic_ibdev_dbg, \
170 dev, fmt, ##__VA_ARGS__)
171
172 #define dynamic_hex_dump(prefix_str, prefix_type, rowsize, \
173 groupsize, buf, len, ascii) \
174 _dynamic_func_call_no_desc(__builtin_constant_p(prefix_str) ? prefix_str : "hexdump", \
175 print_hex_dump, \
176 KERN_DEBUG, prefix_str, prefix_type, \
177 rowsize, groupsize, buf, len, ascii)
178
179 #else /* !CONFIG_DYNAMIC_DEBUG_CORE */
180
181 #include <linux/string.h>
182 #include <linux/errno.h>
183 #include <linux/printk.h>
184
ddebug_add_module(struct _ddebug * tab,unsigned int n,const char * modname)185 static inline int ddebug_add_module(struct _ddebug *tab, unsigned int n,
186 const char *modname)
187 {
188 return 0;
189 }
190
ddebug_remove_module(const char * mod)191 static inline int ddebug_remove_module(const char *mod)
192 {
193 return 0;
194 }
195
ddebug_dyndbg_module_param_cb(char * param,char * val,const char * modname)196 static inline int ddebug_dyndbg_module_param_cb(char *param, char *val,
197 const char *modname)
198 {
199 if (strstr(param, "dyndbg")) {
200 /* avoid pr_warn(), which wants pr_fmt() fully defined */
201 printk(KERN_WARNING "dyndbg param is supported only in "
202 "CONFIG_DYNAMIC_DEBUG builds\n");
203 return 0; /* allow and ignore */
204 }
205 return -EINVAL;
206 }
207
208 #define dynamic_pr_debug(fmt, ...) \
209 do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
210 #define dynamic_dev_dbg(dev, fmt, ...) \
211 do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0)
212 #define dynamic_hex_dump(prefix_str, prefix_type, rowsize, \
213 groupsize, buf, len, ascii) \
214 do { if (0) \
215 print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, \
216 rowsize, groupsize, buf, len, ascii); \
217 } while (0)
218
dynamic_debug_exec_queries(const char * query,const char * modname)219 static inline int dynamic_debug_exec_queries(const char *query, const char *modname)
220 {
221 pr_warn("kernel not built with CONFIG_DYNAMIC_DEBUG_CORE\n");
222 return 0;
223 }
224
225 #endif /* !CONFIG_DYNAMIC_DEBUG_CORE */
226
227 #endif
228