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 /* exported for module authors to exercise >control */
59 int dynamic_debug_exec_queries(const char *query, const char *modname);
60
61 int ddebug_add_module(struct _ddebug *tab, unsigned int n,
62 const char *modname);
63 extern int ddebug_remove_module(const char *mod_name);
64 extern __printf(2, 3)
65 void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...);
66
67 extern int ddebug_dyndbg_module_param_cb(char *param, char *val,
68 const char *modname);
69
70 struct device;
71
72 extern __printf(3, 4)
73 void __dynamic_dev_dbg(struct _ddebug *descriptor, const struct device *dev,
74 const char *fmt, ...);
75
76 struct net_device;
77
78 extern __printf(3, 4)
79 void __dynamic_netdev_dbg(struct _ddebug *descriptor,
80 const struct net_device *dev,
81 const char *fmt, ...);
82
83 struct ib_device;
84
85 extern __printf(3, 4)
86 void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
87 const struct ib_device *ibdev,
88 const char *fmt, ...);
89
90 #define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt) \
91 static struct _ddebug __aligned(8) \
92 __section("__dyndbg") name = { \
93 .modname = KBUILD_MODNAME, \
94 .function = __func__, \
95 .filename = __FILE__, \
96 .format = (fmt), \
97 .lineno = __LINE__, \
98 .flags = _DPRINTK_FLAGS_DEFAULT, \
99 _DPRINTK_KEY_INIT \
100 }
101
102 #ifdef CONFIG_JUMP_LABEL
103
104 #ifdef DEBUG
105
106 #define _DPRINTK_KEY_INIT .key.dd_key_true = (STATIC_KEY_TRUE_INIT)
107
108 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
109 static_branch_likely(&descriptor.key.dd_key_true)
110 #else
111 #define _DPRINTK_KEY_INIT .key.dd_key_false = (STATIC_KEY_FALSE_INIT)
112
113 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
114 static_branch_unlikely(&descriptor.key.dd_key_false)
115 #endif
116
117 #else /* !CONFIG_JUMP_LABEL */
118
119 #define _DPRINTK_KEY_INIT
120
121 #ifdef DEBUG
122 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
123 likely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
124 #else
125 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
126 unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
127 #endif
128
129 #endif /* CONFIG_JUMP_LABEL */
130
131 #define __dynamic_func_call(id, fmt, func, ...) do { \
132 DEFINE_DYNAMIC_DEBUG_METADATA(id, fmt); \
133 if (DYNAMIC_DEBUG_BRANCH(id)) \
134 func(&id, ##__VA_ARGS__); \
135 } while (0)
136
137 #define __dynamic_func_call_no_desc(id, fmt, func, ...) do { \
138 DEFINE_DYNAMIC_DEBUG_METADATA(id, fmt); \
139 if (DYNAMIC_DEBUG_BRANCH(id)) \
140 func(__VA_ARGS__); \
141 } while (0)
142
143 /*
144 * "Factory macro" for generating a call to func, guarded by a
145 * DYNAMIC_DEBUG_BRANCH. The dynamic debug descriptor will be
146 * initialized using the fmt argument. The function will be called with
147 * the address of the descriptor as first argument, followed by all
148 * the varargs. Note that fmt is repeated in invocations of this
149 * macro.
150 */
151 #define _dynamic_func_call(fmt, func, ...) \
152 __dynamic_func_call(__UNIQUE_ID(ddebug), fmt, func, ##__VA_ARGS__)
153 /*
154 * A variant that does the same, except that the descriptor is not
155 * passed as the first argument to the function; it is only called
156 * with precisely the macro's varargs.
157 */
158 #define _dynamic_func_call_no_desc(fmt, func, ...) \
159 __dynamic_func_call_no_desc(__UNIQUE_ID(ddebug), fmt, func, ##__VA_ARGS__)
160
161 #define dynamic_pr_debug(fmt, ...) \
162 _dynamic_func_call(fmt, __dynamic_pr_debug, \
163 pr_fmt(fmt), ##__VA_ARGS__)
164
165 #define dynamic_dev_dbg(dev, fmt, ...) \
166 _dynamic_func_call(fmt,__dynamic_dev_dbg, \
167 dev, fmt, ##__VA_ARGS__)
168
169 #define dynamic_netdev_dbg(dev, fmt, ...) \
170 _dynamic_func_call(fmt, __dynamic_netdev_dbg, \
171 dev, fmt, ##__VA_ARGS__)
172
173 #define dynamic_ibdev_dbg(dev, fmt, ...) \
174 _dynamic_func_call(fmt, __dynamic_ibdev_dbg, \
175 dev, fmt, ##__VA_ARGS__)
176
177 #define dynamic_hex_dump(prefix_str, prefix_type, rowsize, \
178 groupsize, buf, len, ascii) \
179 _dynamic_func_call_no_desc(__builtin_constant_p(prefix_str) ? prefix_str : "hexdump", \
180 print_hex_dump, \
181 KERN_DEBUG, prefix_str, prefix_type, \
182 rowsize, groupsize, buf, len, ascii)
183
184 #else /* !CONFIG_DYNAMIC_DEBUG_CORE */
185
186 #include <linux/string.h>
187 #include <linux/errno.h>
188 #include <linux/printk.h>
189
ddebug_add_module(struct _ddebug * tab,unsigned int n,const char * modname)190 static inline int ddebug_add_module(struct _ddebug *tab, unsigned int n,
191 const char *modname)
192 {
193 return 0;
194 }
195
ddebug_remove_module(const char * mod)196 static inline int ddebug_remove_module(const char *mod)
197 {
198 return 0;
199 }
200
ddebug_dyndbg_module_param_cb(char * param,char * val,const char * modname)201 static inline int ddebug_dyndbg_module_param_cb(char *param, char *val,
202 const char *modname)
203 {
204 if (strstr(param, "dyndbg")) {
205 /* avoid pr_warn(), which wants pr_fmt() fully defined */
206 printk(KERN_WARNING "dyndbg param is supported only in "
207 "CONFIG_DYNAMIC_DEBUG builds\n");
208 return 0; /* allow and ignore */
209 }
210 return -EINVAL;
211 }
212
213 #define dynamic_pr_debug(fmt, ...) \
214 do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
215 #define dynamic_dev_dbg(dev, fmt, ...) \
216 do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0)
217 #define dynamic_hex_dump(prefix_str, prefix_type, rowsize, \
218 groupsize, buf, len, ascii) \
219 do { if (0) \
220 print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, \
221 rowsize, groupsize, buf, len, ascii); \
222 } while (0)
223
dynamic_debug_exec_queries(const char * query,const char * modname)224 static inline int dynamic_debug_exec_queries(const char *query, const char *modname)
225 {
226 pr_warn("kernel not built with CONFIG_DYNAMIC_DEBUG_CORE\n");
227 return 0;
228 }
229
230 #endif /* !CONFIG_DYNAMIC_DEBUG_CORE */
231
232 #endif
233