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 #if defined(CONFIG_DYNAMIC_DEBUG_CORE) 123 124 int ddebug_add_module(struct _ddebug_info *dyndbg, const char *modname); 125 126 extern int ddebug_remove_module(const char *mod_name); 127 extern __printf(2, 3) 128 void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...); 129 130 extern int ddebug_dyndbg_module_param_cb(char *param, char *val, 131 const char *modname); 132 133 struct device; 134 135 extern __printf(3, 4) 136 void __dynamic_dev_dbg(struct _ddebug *descriptor, const struct device *dev, 137 const char *fmt, ...); 138 139 struct net_device; 140 141 extern __printf(3, 4) 142 void __dynamic_netdev_dbg(struct _ddebug *descriptor, 143 const struct net_device *dev, 144 const char *fmt, ...); 145 146 struct ib_device; 147 148 extern __printf(3, 4) 149 void __dynamic_ibdev_dbg(struct _ddebug *descriptor, 150 const struct ib_device *ibdev, 151 const char *fmt, ...); 152 153 #define DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, cls, fmt) \ 154 static struct _ddebug __aligned(8) \ 155 __section("__dyndbg") name = { \ 156 .modname = KBUILD_MODNAME, \ 157 .function = __func__, \ 158 .filename = __FILE__, \ 159 .format = (fmt), \ 160 .lineno = __LINE__, \ 161 .flags = _DPRINTK_FLAGS_DEFAULT, \ 162 .class_id = cls, \ 163 _DPRINTK_KEY_INIT \ 164 }; \ 165 BUILD_BUG_ON_MSG(cls > _DPRINTK_CLASS_DFLT, \ 166 "classid value overflow") 167 168 #define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt) \ 169 DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, _DPRINTK_CLASS_DFLT, fmt) 170 171 #ifdef CONFIG_JUMP_LABEL 172 173 #ifdef DEBUG 174 175 #define _DPRINTK_KEY_INIT .key.dd_key_true = (STATIC_KEY_TRUE_INIT) 176 177 #define DYNAMIC_DEBUG_BRANCH(descriptor) \ 178 static_branch_likely(&descriptor.key.dd_key_true) 179 #else 180 #define _DPRINTK_KEY_INIT .key.dd_key_false = (STATIC_KEY_FALSE_INIT) 181 182 #define DYNAMIC_DEBUG_BRANCH(descriptor) \ 183 static_branch_unlikely(&descriptor.key.dd_key_false) 184 #endif 185 186 #else /* !CONFIG_JUMP_LABEL */ 187 188 #define _DPRINTK_KEY_INIT 189 190 #ifdef DEBUG 191 #define DYNAMIC_DEBUG_BRANCH(descriptor) \ 192 likely(descriptor.flags & _DPRINTK_FLAGS_PRINT) 193 #else 194 #define DYNAMIC_DEBUG_BRANCH(descriptor) \ 195 unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) 196 #endif 197 198 #endif /* CONFIG_JUMP_LABEL */ 199 200 /* 201 * Factory macros: ($prefix)dynamic_func_call($suffix) 202 * 203 * Lower layer (with __ prefix) gets the callsite metadata, and wraps 204 * the func inside a debug-branch/static-key construct. Upper layer 205 * (with _ prefix) does the UNIQUE_ID once, so that lower can ref the 206 * name/label multiple times, and tie the elements together. 207 * Multiple flavors: 208 * (|_cls): adds in _DPRINT_CLASS_DFLT as needed 209 * (|_no_desc): former gets callsite descriptor as 1st arg (for prdbgs) 210 */ 211 #define __dynamic_func_call_cls(id, cls, fmt, func, ...) do { \ 212 DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt); \ 213 if (DYNAMIC_DEBUG_BRANCH(id)) \ 214 func(&id, ##__VA_ARGS__); \ 215 } while (0) 216 #define __dynamic_func_call(id, fmt, func, ...) \ 217 __dynamic_func_call_cls(id, _DPRINTK_CLASS_DFLT, fmt, \ 218 func, ##__VA_ARGS__) 219 220 #define __dynamic_func_call_cls_no_desc(id, cls, fmt, func, ...) do { \ 221 DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt); \ 222 if (DYNAMIC_DEBUG_BRANCH(id)) \ 223 func(__VA_ARGS__); \ 224 } while (0) 225 #define __dynamic_func_call_no_desc(id, fmt, func, ...) \ 226 __dynamic_func_call_cls_no_desc(id, _DPRINTK_CLASS_DFLT, \ 227 fmt, func, ##__VA_ARGS__) 228 229 /* 230 * "Factory macro" for generating a call to func, guarded by a 231 * DYNAMIC_DEBUG_BRANCH. The dynamic debug descriptor will be 232 * initialized using the fmt argument. The function will be called with 233 * the address of the descriptor as first argument, followed by all 234 * the varargs. Note that fmt is repeated in invocations of this 235 * macro. 236 */ 237 #define _dynamic_func_call_cls(cls, fmt, func, ...) \ 238 __dynamic_func_call_cls(__UNIQUE_ID(ddebug), cls, fmt, func, ##__VA_ARGS__) 239 #define _dynamic_func_call(fmt, func, ...) \ 240 _dynamic_func_call_cls(_DPRINTK_CLASS_DFLT, fmt, func, ##__VA_ARGS__) 241 242 /* 243 * A variant that does the same, except that the descriptor is not 244 * passed as the first argument to the function; it is only called 245 * with precisely the macro's varargs. 246 */ 247 #define _dynamic_func_call_cls_no_desc(cls, fmt, func, ...) \ 248 __dynamic_func_call_cls_no_desc(__UNIQUE_ID(ddebug), cls, fmt, \ 249 func, ##__VA_ARGS__) 250 #define _dynamic_func_call_no_desc(fmt, func, ...) \ 251 _dynamic_func_call_cls_no_desc(_DPRINTK_CLASS_DFLT, fmt, \ 252 func, ##__VA_ARGS__) 253 254 #define dynamic_pr_debug_cls(cls, fmt, ...) \ 255 _dynamic_func_call_cls(cls, fmt, __dynamic_pr_debug, \ 256 pr_fmt(fmt), ##__VA_ARGS__) 257 258 #define dynamic_pr_debug(fmt, ...) \ 259 _dynamic_func_call(fmt, __dynamic_pr_debug, \ 260 pr_fmt(fmt), ##__VA_ARGS__) 261 262 #define dynamic_dev_dbg(dev, fmt, ...) \ 263 _dynamic_func_call(fmt, __dynamic_dev_dbg, \ 264 dev, fmt, ##__VA_ARGS__) 265 266 #define dynamic_netdev_dbg(dev, fmt, ...) \ 267 _dynamic_func_call(fmt, __dynamic_netdev_dbg, \ 268 dev, fmt, ##__VA_ARGS__) 269 270 #define dynamic_ibdev_dbg(dev, fmt, ...) \ 271 _dynamic_func_call(fmt, __dynamic_ibdev_dbg, \ 272 dev, fmt, ##__VA_ARGS__) 273 274 #define dynamic_hex_dump(prefix_str, prefix_type, rowsize, \ 275 groupsize, buf, len, ascii) \ 276 _dynamic_func_call_no_desc(__builtin_constant_p(prefix_str) ? prefix_str : "hexdump", \ 277 print_hex_dump, \ 278 KERN_DEBUG, prefix_str, prefix_type, \ 279 rowsize, groupsize, buf, len, ascii) 280 281 /* for test only, generally expect drm.debug style macro wrappers */ 282 #define __pr_debug_cls(cls, fmt, ...) do { \ 283 BUILD_BUG_ON_MSG(!__builtin_constant_p(cls), \ 284 "expecting constant class int/enum"); \ 285 dynamic_pr_debug_cls(cls, fmt, ##__VA_ARGS__); \ 286 } while (0) 287 288 #else /* !CONFIG_DYNAMIC_DEBUG_CORE */ 289 290 #include <linux/string.h> 291 #include <linux/errno.h> 292 #include <linux/printk.h> 293 294 static inline int ddebug_add_module(struct _ddebug_info *dinfo, const char *modname) 295 { 296 return 0; 297 } 298 299 static inline int ddebug_remove_module(const char *mod) 300 { 301 return 0; 302 } 303 304 static inline int ddebug_dyndbg_module_param_cb(char *param, char *val, 305 const char *modname) 306 { 307 if (!strcmp(param, "dyndbg")) { 308 /* avoid pr_warn(), which wants pr_fmt() fully defined */ 309 printk(KERN_WARNING "dyndbg param is supported only in " 310 "CONFIG_DYNAMIC_DEBUG builds\n"); 311 return 0; /* allow and ignore */ 312 } 313 return -EINVAL; 314 } 315 316 #define dynamic_pr_debug(fmt, ...) \ 317 do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0) 318 #define dynamic_dev_dbg(dev, fmt, ...) \ 319 do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0) 320 #define dynamic_hex_dump(prefix_str, prefix_type, rowsize, \ 321 groupsize, buf, len, ascii) \ 322 do { if (0) \ 323 print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, \ 324 rowsize, groupsize, buf, len, ascii); \ 325 } while (0) 326 327 #endif /* !CONFIG_DYNAMIC_DEBUG_CORE */ 328 329 #endif 330