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 #include <linux/build_bug.h>
10
11 /*
12 * An instance of this structure is created in a special
13 * ELF section at every dynamic debug callsite. At runtime,
14 * the special section is treated as an array of these.
15 */
16 struct _ddebug {
17 /*
18 * These fields are used to drive the user interface
19 * for selecting and displaying debug callsites.
20 */
21 const char *modname;
22 const char *function;
23 const char *filename;
24 const char *format;
25 unsigned int lineno:18;
26 #define CLS_BITS 6
27 unsigned int class_id:CLS_BITS;
28 #define _DPRINTK_CLASS_DFLT ((1 << CLS_BITS) - 1)
29 /*
30 * The flags field controls the behaviour at the callsite.
31 * The bits here are changed dynamically when the user
32 * writes commands to <debugfs>/dynamic_debug/control
33 */
34 #define _DPRINTK_FLAGS_NONE 0
35 #define _DPRINTK_FLAGS_PRINT (1<<0) /* printk() a message using the format */
36 #define _DPRINTK_FLAGS_INCL_MODNAME (1<<1)
37 #define _DPRINTK_FLAGS_INCL_FUNCNAME (1<<2)
38 #define _DPRINTK_FLAGS_INCL_LINENO (1<<3)
39 #define _DPRINTK_FLAGS_INCL_TID (1<<4)
40
41 #define _DPRINTK_FLAGS_INCL_ANY \
42 (_DPRINTK_FLAGS_INCL_MODNAME | _DPRINTK_FLAGS_INCL_FUNCNAME |\
43 _DPRINTK_FLAGS_INCL_LINENO | _DPRINTK_FLAGS_INCL_TID)
44
45 #if defined DEBUG
46 #define _DPRINTK_FLAGS_DEFAULT _DPRINTK_FLAGS_PRINT
47 #else
48 #define _DPRINTK_FLAGS_DEFAULT 0
49 #endif
50 unsigned int flags:8;
51 #ifdef CONFIG_JUMP_LABEL
52 union {
53 struct static_key_true dd_key_true;
54 struct static_key_false dd_key_false;
55 } key;
56 #endif
57 } __attribute__((aligned(8)));
58
59 enum class_map_type {
60 DD_CLASS_TYPE_DISJOINT_BITS,
61 /**
62 * DD_CLASS_TYPE_DISJOINT_BITS: classes are independent, one per bit.
63 * expecting hex input. Built for drm.debug, basis for other types.
64 */
65 DD_CLASS_TYPE_LEVEL_NUM,
66 /**
67 * DD_CLASS_TYPE_LEVEL_NUM: input is numeric level, 0-N.
68 * N turns on just bits N-1 .. 0, so N=0 turns all bits off.
69 */
70 DD_CLASS_TYPE_DISJOINT_NAMES,
71 /**
72 * DD_CLASS_TYPE_DISJOINT_NAMES: input is a CSV of [+-]CLASS_NAMES,
73 * classes are independent, like _DISJOINT_BITS.
74 */
75 DD_CLASS_TYPE_LEVEL_NAMES,
76 /**
77 * DD_CLASS_TYPE_LEVEL_NAMES: input is a CSV of [+-]CLASS_NAMES,
78 * intended for names like: INFO,DEBUG,TRACE, with a module prefix
79 * avoid EMERG,ALERT,CRIT,ERR,WARNING: they're not debug
80 */
81 };
82
83 struct ddebug_class_map {
84 struct list_head link;
85 struct module *mod;
86 const char *mod_name; /* needed for builtins */
87 const char **class_names;
88 const int length;
89 const int base; /* index of 1st .class_id, allows split/shared space */
90 enum class_map_type map_type;
91 };
92
93 /**
94 * DECLARE_DYNDBG_CLASSMAP - declare classnames known by a module
95 * @_var: a struct ddebug_class_map, passed to module_param_cb
96 * @_type: enum class_map_type, chooses bits/verbose, numeric/symbolic
97 * @_base: offset of 1st class-name. splits .class_id space
98 * @classes: class-names used to control class'd prdbgs
99 */
100 #define DECLARE_DYNDBG_CLASSMAP(_var, _maptype, _base, ...) \
101 static const char *_var##_classnames[] = { __VA_ARGS__ }; \
102 static struct ddebug_class_map __aligned(8) __used \
103 __section("__dyndbg_classes") _var = { \
104 .mod = THIS_MODULE, \
105 .mod_name = KBUILD_MODNAME, \
106 .base = _base, \
107 .map_type = _maptype, \
108 .length = NUM_TYPE_ARGS(char*, __VA_ARGS__), \
109 .class_names = _var##_classnames, \
110 }
111 #define NUM_TYPE_ARGS(eltype, ...) \
112 (sizeof((eltype[]){__VA_ARGS__}) / sizeof(eltype))
113
114 /* encapsulate linker provided built-in (or module) dyndbg data */
115 struct _ddebug_info {
116 struct _ddebug *descs;
117 struct ddebug_class_map *classes;
118 unsigned int num_descs;
119 unsigned int num_classes;
120 };
121
122 struct ddebug_class_param {
123 union {
124 unsigned long *bits;
125 unsigned int *lvl;
126 };
127 char flags[8];
128 const struct ddebug_class_map *map;
129 };
130
131 #if defined(CONFIG_DYNAMIC_DEBUG_CORE)
132
133 int ddebug_add_module(struct _ddebug_info *dyndbg, const char *modname);
134
135 extern int ddebug_remove_module(const char *mod_name);
136 extern __printf(2, 3)
137 void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...);
138
139 extern int ddebug_dyndbg_module_param_cb(char *param, char *val,
140 const char *modname);
141
142 struct device;
143
144 extern __printf(3, 4)
145 void __dynamic_dev_dbg(struct _ddebug *descriptor, const struct device *dev,
146 const char *fmt, ...);
147
148 struct net_device;
149
150 extern __printf(3, 4)
151 void __dynamic_netdev_dbg(struct _ddebug *descriptor,
152 const struct net_device *dev,
153 const char *fmt, ...);
154
155 struct ib_device;
156
157 extern __printf(3, 4)
158 void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
159 const struct ib_device *ibdev,
160 const char *fmt, ...);
161
162 #define DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, cls, fmt) \
163 static struct _ddebug __aligned(8) \
164 __section("__dyndbg") name = { \
165 .modname = KBUILD_MODNAME, \
166 .function = __func__, \
167 .filename = __FILE__, \
168 .format = (fmt), \
169 .lineno = __LINE__, \
170 .flags = _DPRINTK_FLAGS_DEFAULT, \
171 .class_id = cls, \
172 _DPRINTK_KEY_INIT \
173 }; \
174 BUILD_BUG_ON_MSG(cls > _DPRINTK_CLASS_DFLT, \
175 "classid value overflow")
176
177 #define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt) \
178 DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, _DPRINTK_CLASS_DFLT, fmt)
179
180 #ifdef CONFIG_JUMP_LABEL
181
182 #ifdef DEBUG
183
184 #define _DPRINTK_KEY_INIT .key.dd_key_true = (STATIC_KEY_TRUE_INIT)
185
186 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
187 static_branch_likely(&descriptor.key.dd_key_true)
188 #else
189 #define _DPRINTK_KEY_INIT .key.dd_key_false = (STATIC_KEY_FALSE_INIT)
190
191 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
192 static_branch_unlikely(&descriptor.key.dd_key_false)
193 #endif
194
195 #else /* !CONFIG_JUMP_LABEL */
196
197 #define _DPRINTK_KEY_INIT
198
199 #ifdef DEBUG
200 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
201 likely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
202 #else
203 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
204 unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
205 #endif
206
207 #endif /* CONFIG_JUMP_LABEL */
208
209 /*
210 * Factory macros: ($prefix)dynamic_func_call($suffix)
211 *
212 * Lower layer (with __ prefix) gets the callsite metadata, and wraps
213 * the func inside a debug-branch/static-key construct. Upper layer
214 * (with _ prefix) does the UNIQUE_ID once, so that lower can ref the
215 * name/label multiple times, and tie the elements together.
216 * Multiple flavors:
217 * (|_cls): adds in _DPRINT_CLASS_DFLT as needed
218 * (|_no_desc): former gets callsite descriptor as 1st arg (for prdbgs)
219 */
220 #define __dynamic_func_call_cls(id, cls, fmt, func, ...) do { \
221 DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt); \
222 if (DYNAMIC_DEBUG_BRANCH(id)) \
223 func(&id, ##__VA_ARGS__); \
224 } while (0)
225 #define __dynamic_func_call(id, fmt, func, ...) \
226 __dynamic_func_call_cls(id, _DPRINTK_CLASS_DFLT, fmt, \
227 func, ##__VA_ARGS__)
228
229 #define __dynamic_func_call_cls_no_desc(id, cls, fmt, func, ...) do { \
230 DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt); \
231 if (DYNAMIC_DEBUG_BRANCH(id)) \
232 func(__VA_ARGS__); \
233 } while (0)
234 #define __dynamic_func_call_no_desc(id, fmt, func, ...) \
235 __dynamic_func_call_cls_no_desc(id, _DPRINTK_CLASS_DFLT, \
236 fmt, func, ##__VA_ARGS__)
237
238 /*
239 * "Factory macro" for generating a call to func, guarded by a
240 * DYNAMIC_DEBUG_BRANCH. The dynamic debug descriptor will be
241 * initialized using the fmt argument. The function will be called with
242 * the address of the descriptor as first argument, followed by all
243 * the varargs. Note that fmt is repeated in invocations of this
244 * macro.
245 */
246 #define _dynamic_func_call_cls(cls, fmt, func, ...) \
247 __dynamic_func_call_cls(__UNIQUE_ID(ddebug), cls, fmt, func, ##__VA_ARGS__)
248 #define _dynamic_func_call(fmt, func, ...) \
249 _dynamic_func_call_cls(_DPRINTK_CLASS_DFLT, fmt, func, ##__VA_ARGS__)
250
251 /*
252 * A variant that does the same, except that the descriptor is not
253 * passed as the first argument to the function; it is only called
254 * with precisely the macro's varargs.
255 */
256 #define _dynamic_func_call_cls_no_desc(cls, fmt, func, ...) \
257 __dynamic_func_call_cls_no_desc(__UNIQUE_ID(ddebug), cls, fmt, \
258 func, ##__VA_ARGS__)
259 #define _dynamic_func_call_no_desc(fmt, func, ...) \
260 _dynamic_func_call_cls_no_desc(_DPRINTK_CLASS_DFLT, fmt, \
261 func, ##__VA_ARGS__)
262
263 #define dynamic_pr_debug_cls(cls, fmt, ...) \
264 _dynamic_func_call_cls(cls, fmt, __dynamic_pr_debug, \
265 pr_fmt(fmt), ##__VA_ARGS__)
266
267 #define dynamic_pr_debug(fmt, ...) \
268 _dynamic_func_call(fmt, __dynamic_pr_debug, \
269 pr_fmt(fmt), ##__VA_ARGS__)
270
271 #define dynamic_dev_dbg(dev, fmt, ...) \
272 _dynamic_func_call(fmt, __dynamic_dev_dbg, \
273 dev, fmt, ##__VA_ARGS__)
274
275 #define dynamic_netdev_dbg(dev, fmt, ...) \
276 _dynamic_func_call(fmt, __dynamic_netdev_dbg, \
277 dev, fmt, ##__VA_ARGS__)
278
279 #define dynamic_ibdev_dbg(dev, fmt, ...) \
280 _dynamic_func_call(fmt, __dynamic_ibdev_dbg, \
281 dev, fmt, ##__VA_ARGS__)
282
283 #define dynamic_hex_dump(prefix_str, prefix_type, rowsize, \
284 groupsize, buf, len, ascii) \
285 _dynamic_func_call_no_desc(__builtin_constant_p(prefix_str) ? prefix_str : "hexdump", \
286 print_hex_dump, \
287 KERN_DEBUG, prefix_str, prefix_type, \
288 rowsize, groupsize, buf, len, ascii)
289
290 struct kernel_param;
291 int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp);
292 int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp);
293
294 /* for test only, generally expect drm.debug style macro wrappers */
295 #define __pr_debug_cls(cls, fmt, ...) do { \
296 BUILD_BUG_ON_MSG(!__builtin_constant_p(cls), \
297 "expecting constant class int/enum"); \
298 dynamic_pr_debug_cls(cls, fmt, ##__VA_ARGS__); \
299 } while (0)
300
301 #else /* !CONFIG_DYNAMIC_DEBUG_CORE */
302
303 #include <linux/string.h>
304 #include <linux/errno.h>
305 #include <linux/printk.h>
306
ddebug_add_module(struct _ddebug_info * dinfo,const char * modname)307 static inline int ddebug_add_module(struct _ddebug_info *dinfo, const char *modname)
308 {
309 return 0;
310 }
311
ddebug_remove_module(const char * mod)312 static inline int ddebug_remove_module(const char *mod)
313 {
314 return 0;
315 }
316
ddebug_dyndbg_module_param_cb(char * param,char * val,const char * modname)317 static inline int ddebug_dyndbg_module_param_cb(char *param, char *val,
318 const char *modname)
319 {
320 if (!strcmp(param, "dyndbg")) {
321 /* avoid pr_warn(), which wants pr_fmt() fully defined */
322 printk(KERN_WARNING "dyndbg param is supported only in "
323 "CONFIG_DYNAMIC_DEBUG builds\n");
324 return 0; /* allow and ignore */
325 }
326 return -EINVAL;
327 }
328
329 #define dynamic_pr_debug(fmt, ...) \
330 do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
331 #define dynamic_dev_dbg(dev, fmt, ...) \
332 do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0)
333 #define dynamic_hex_dump(prefix_str, prefix_type, rowsize, \
334 groupsize, buf, len, ascii) \
335 do { if (0) \
336 print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, \
337 rowsize, groupsize, buf, len, ascii); \
338 } while (0)
339
340 struct kernel_param;
param_set_dyndbg_classes(const char * instr,const struct kernel_param * kp)341 static inline int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
342 { return 0; }
param_get_dyndbg_classes(char * buffer,const struct kernel_param * kp)343 static inline int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp)
344 { return 0; }
345
346 #endif /* !CONFIG_DYNAMIC_DEBUG_CORE */
347
348 extern const struct kernel_param_ops param_ops_dyndbg_classes;
349
350 #endif
351