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 #define _DPRINTK_FLAGS_INCL_SOURCENAME (1<<5)
41 #define _DPRINTK_FLAGS_INCL_STACK (1<<6)
42
43 #define _DPRINTK_FLAGS_INCL_ANY \
44 (_DPRINTK_FLAGS_INCL_MODNAME | _DPRINTK_FLAGS_INCL_FUNCNAME |\
45 _DPRINTK_FLAGS_INCL_LINENO | _DPRINTK_FLAGS_INCL_TID |\
46 _DPRINTK_FLAGS_INCL_SOURCENAME | _DPRINTK_FLAGS_INCL_STACK)
47
48 #if defined DEBUG
49 #define _DPRINTK_FLAGS_DEFAULT _DPRINTK_FLAGS_PRINT
50 #else
51 #define _DPRINTK_FLAGS_DEFAULT 0
52 #endif
53 unsigned int flags:8;
54 #ifdef CONFIG_JUMP_LABEL
55 union {
56 struct static_key_true dd_key_true;
57 struct static_key_false dd_key_false;
58 } key;
59 #endif
60 } __attribute__((aligned(8)));
61
62 enum class_map_type {
63 DD_CLASS_TYPE_DISJOINT_BITS,
64 /**
65 * DD_CLASS_TYPE_DISJOINT_BITS: classes are independent, one per bit.
66 * expecting hex input. Built for drm.debug, basis for other types.
67 */
68 DD_CLASS_TYPE_LEVEL_NUM,
69 /**
70 * DD_CLASS_TYPE_LEVEL_NUM: input is numeric level, 0-N.
71 * N turns on just bits N-1 .. 0, so N=0 turns all bits off.
72 */
73 DD_CLASS_TYPE_DISJOINT_NAMES,
74 /**
75 * DD_CLASS_TYPE_DISJOINT_NAMES: input is a CSV of [+-]CLASS_NAMES,
76 * classes are independent, like _DISJOINT_BITS.
77 */
78 DD_CLASS_TYPE_LEVEL_NAMES,
79 /**
80 * DD_CLASS_TYPE_LEVEL_NAMES: input is a CSV of [+-]CLASS_NAMES,
81 * intended for names like: INFO,DEBUG,TRACE, with a module prefix
82 * avoid EMERG,ALERT,CRIT,ERR,WARNING: they're not debug
83 */
84 };
85
86 struct ddebug_class_map {
87 struct list_head link;
88 struct module *mod;
89 const char *mod_name; /* needed for builtins */
90 const char **class_names;
91 const int length;
92 const int base; /* index of 1st .class_id, allows split/shared space */
93 enum class_map_type map_type;
94 };
95
96 /**
97 * DECLARE_DYNDBG_CLASSMAP - declare classnames known by a module
98 * @_var: a struct ddebug_class_map, passed to module_param_cb
99 * @_type: enum class_map_type, chooses bits/verbose, numeric/symbolic
100 * @_base: offset of 1st class-name. splits .class_id space
101 * @classes: class-names used to control class'd prdbgs
102 */
103 #define DECLARE_DYNDBG_CLASSMAP(_var, _maptype, _base, ...) \
104 static const char *_var##_classnames[] = { __VA_ARGS__ }; \
105 static struct ddebug_class_map __aligned(8) __used \
106 __section("__dyndbg_classes") _var = { \
107 .mod = THIS_MODULE, \
108 .mod_name = KBUILD_MODNAME, \
109 .base = _base, \
110 .map_type = _maptype, \
111 .length = NUM_TYPE_ARGS(char*, __VA_ARGS__), \
112 .class_names = _var##_classnames, \
113 }
114 #define NUM_TYPE_ARGS(eltype, ...) \
115 (sizeof((eltype[]){__VA_ARGS__}) / sizeof(eltype))
116
117 /* encapsulate linker provided built-in (or module) dyndbg data */
118 struct _ddebug_info {
119 struct _ddebug *descs;
120 struct ddebug_class_map *classes;
121 unsigned int num_descs;
122 unsigned int num_classes;
123 };
124
125 struct ddebug_class_param {
126 union {
127 unsigned long *bits;
128 unsigned int *lvl;
129 };
130 char flags[8];
131 const struct ddebug_class_map *map;
132 };
133
134 /*
135 * pr_debug() and friends are globally enabled or modules have selectively
136 * enabled them.
137 */
138 #if defined(CONFIG_DYNAMIC_DEBUG) || \
139 (defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
140
141 extern __printf(2, 3)
142 void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...);
143
144 struct device;
145
146 extern __printf(3, 4)
147 void __dynamic_dev_dbg(struct _ddebug *descriptor, const struct device *dev,
148 const char *fmt, ...);
149
150 struct net_device;
151
152 extern __printf(3, 4)
153 void __dynamic_netdev_dbg(struct _ddebug *descriptor,
154 const struct net_device *dev,
155 const char *fmt, ...);
156
157 struct ib_device;
158
159 extern __printf(3, 4)
160 void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
161 const struct ib_device *ibdev,
162 const char *fmt, ...);
163
164 #define __dynamic_dump_stack(desc) \
165 { \
166 if (desc.flags & _DPRINTK_FLAGS_INCL_STACK) \
167 dump_stack(); \
168 }
169
170 #define DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, cls, fmt) \
171 static struct _ddebug __aligned(8) \
172 __section("__dyndbg") name = { \
173 .modname = KBUILD_MODNAME, \
174 .function = __func__, \
175 .filename = __FILE__, \
176 .format = (fmt), \
177 .lineno = __LINE__, \
178 .flags = _DPRINTK_FLAGS_DEFAULT, \
179 .class_id = cls, \
180 _DPRINTK_KEY_INIT \
181 }; \
182 BUILD_BUG_ON_MSG(cls > _DPRINTK_CLASS_DFLT, \
183 "classid value overflow")
184
185 #define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt) \
186 DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, _DPRINTK_CLASS_DFLT, fmt)
187
188 #ifdef CONFIG_JUMP_LABEL
189
190 #ifdef DEBUG
191
192 #define _DPRINTK_KEY_INIT .key.dd_key_true = (STATIC_KEY_TRUE_INIT)
193
194 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
195 static_branch_likely(&descriptor.key.dd_key_true)
196 #else
197 #define _DPRINTK_KEY_INIT .key.dd_key_false = (STATIC_KEY_FALSE_INIT)
198
199 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
200 static_branch_unlikely(&descriptor.key.dd_key_false)
201 #endif
202
203 #else /* !CONFIG_JUMP_LABEL */
204
205 #define _DPRINTK_KEY_INIT
206
207 #ifdef DEBUG
208 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
209 likely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
210 #else
211 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
212 unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
213 #endif
214
215 #endif /* CONFIG_JUMP_LABEL */
216
217 /*
218 * Factory macros: ($prefix)dynamic_func_call($suffix)
219 *
220 * Lower layer (with __ prefix) gets the callsite metadata, and wraps
221 * the func inside a debug-branch/static-key construct. Upper layer
222 * (with _ prefix) does the UNIQUE_ID once, so that lower can ref the
223 * name/label multiple times, and tie the elements together.
224 * Multiple flavors:
225 * (|_cls): adds in _DPRINT_CLASS_DFLT as needed
226 * (|_no_desc): former gets callsite descriptor as 1st arg (for prdbgs)
227 */
228 #define __dynamic_func_call_cls(id, cls, fmt, func, ...) do { \
229 DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt); \
230 if (DYNAMIC_DEBUG_BRANCH(id)) { \
231 func(&id, ##__VA_ARGS__); \
232 __dynamic_dump_stack(id); \
233 } \
234 } while (0)
235 #define __dynamic_func_call(id, fmt, func, ...) \
236 __dynamic_func_call_cls(id, _DPRINTK_CLASS_DFLT, fmt, \
237 func, ##__VA_ARGS__)
238
239 #define __dynamic_func_call_cls_no_desc(id, cls, fmt, func, ...) do { \
240 DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt); \
241 if (DYNAMIC_DEBUG_BRANCH(id)) { \
242 func(__VA_ARGS__); \
243 __dynamic_dump_stack(id); \
244 } \
245 } while (0)
246 #define __dynamic_func_call_no_desc(id, fmt, func, ...) \
247 __dynamic_func_call_cls_no_desc(id, _DPRINTK_CLASS_DFLT, \
248 fmt, func, ##__VA_ARGS__)
249
250 /*
251 * "Factory macro" for generating a call to func, guarded by a
252 * DYNAMIC_DEBUG_BRANCH. The dynamic debug descriptor will be
253 * initialized using the fmt argument. The function will be called with
254 * the address of the descriptor as first argument, followed by all
255 * the varargs. Note that fmt is repeated in invocations of this
256 * macro.
257 */
258 #define _dynamic_func_call_cls(cls, fmt, func, ...) \
259 __dynamic_func_call_cls(__UNIQUE_ID(ddebug), cls, fmt, func, ##__VA_ARGS__)
260 #define _dynamic_func_call(fmt, func, ...) \
261 _dynamic_func_call_cls(_DPRINTK_CLASS_DFLT, fmt, func, ##__VA_ARGS__)
262
263 /*
264 * A variant that does the same, except that the descriptor is not
265 * passed as the first argument to the function; it is only called
266 * with precisely the macro's varargs.
267 */
268 #define _dynamic_func_call_cls_no_desc(cls, fmt, func, ...) \
269 __dynamic_func_call_cls_no_desc(__UNIQUE_ID(ddebug), cls, fmt, \
270 func, ##__VA_ARGS__)
271 #define _dynamic_func_call_no_desc(fmt, func, ...) \
272 _dynamic_func_call_cls_no_desc(_DPRINTK_CLASS_DFLT, fmt, \
273 func, ##__VA_ARGS__)
274
275 #define dynamic_pr_debug_cls(cls, fmt, ...) \
276 _dynamic_func_call_cls(cls, fmt, __dynamic_pr_debug, \
277 pr_fmt(fmt), ##__VA_ARGS__)
278
279 #define dynamic_pr_debug(fmt, ...) \
280 _dynamic_func_call(fmt, __dynamic_pr_debug, \
281 pr_fmt(fmt), ##__VA_ARGS__)
282
283 #define dynamic_dev_dbg(dev, fmt, ...) \
284 _dynamic_func_call(fmt, __dynamic_dev_dbg, \
285 dev, fmt, ##__VA_ARGS__)
286
287 #define dynamic_netdev_dbg(dev, fmt, ...) \
288 _dynamic_func_call(fmt, __dynamic_netdev_dbg, \
289 dev, fmt, ##__VA_ARGS__)
290
291 #define dynamic_ibdev_dbg(dev, fmt, ...) \
292 _dynamic_func_call(fmt, __dynamic_ibdev_dbg, \
293 dev, fmt, ##__VA_ARGS__)
294
295 #define dynamic_hex_dump(prefix_str, prefix_type, rowsize, \
296 groupsize, buf, len, ascii) \
297 _dynamic_func_call_no_desc(__builtin_constant_p(prefix_str) ? prefix_str : "hexdump", \
298 print_hex_dump, \
299 KERN_DEBUG, prefix_str, prefix_type, \
300 rowsize, groupsize, buf, len, ascii)
301
302 /* for test only, generally expect drm.debug style macro wrappers */
303 #define __pr_debug_cls(cls, fmt, ...) do { \
304 BUILD_BUG_ON_MSG(!__builtin_constant_p(cls), \
305 "expecting constant class int/enum"); \
306 dynamic_pr_debug_cls(cls, fmt, ##__VA_ARGS__); \
307 } while (0)
308
309 #else /* !(CONFIG_DYNAMIC_DEBUG || (CONFIG_DYNAMIC_DEBUG_CORE && DYNAMIC_DEBUG_MODULE)) */
310
311 #include <linux/string.h>
312 #include <linux/errno.h>
313 #include <linux/printk.h>
314
315 #define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt)
316 #define DYNAMIC_DEBUG_BRANCH(descriptor) false
317
318 #define dynamic_pr_debug(fmt, ...) \
319 no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
320 #define dynamic_dev_dbg(dev, fmt, ...) \
321 dev_no_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__)
322 #define dynamic_hex_dump(prefix_str, prefix_type, rowsize, \
323 groupsize, buf, len, ascii) \
324 do { if (0) \
325 print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, \
326 rowsize, groupsize, buf, len, ascii); \
327 } while (0)
328
329 #endif /* CONFIG_DYNAMIC_DEBUG || (CONFIG_DYNAMIC_DEBUG_CORE && DYNAMIC_DEBUG_MODULE) */
330
331
332 #ifdef CONFIG_DYNAMIC_DEBUG_CORE
333
334 extern int ddebug_dyndbg_module_param_cb(char *param, char *val,
335 const char *modname);
336 struct kernel_param;
337 int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp);
338 int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp);
339
340 #else
341
ddebug_dyndbg_module_param_cb(char * param,char * val,const char * modname)342 static inline int ddebug_dyndbg_module_param_cb(char *param, char *val,
343 const char *modname)
344 {
345 if (!strcmp(param, "dyndbg")) {
346 /* avoid pr_warn(), which wants pr_fmt() fully defined */
347 printk(KERN_WARNING "dyndbg param is supported only in "
348 "CONFIG_DYNAMIC_DEBUG builds\n");
349 return 0; /* allow and ignore */
350 }
351 return -EINVAL;
352 }
353
354 struct kernel_param;
param_set_dyndbg_classes(const char * instr,const struct kernel_param * kp)355 static inline int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
356 { return 0; }
param_get_dyndbg_classes(char * buffer,const struct kernel_param * kp)357 static inline int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp)
358 { return 0; }
359
360 #endif
361
362
363 extern const struct kernel_param_ops param_ops_dyndbg_classes;
364
365 #endif /* _DYNAMIC_DEBUG_H */
366