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 extern __printf(2, 3) 134 void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...); 135 136 extern int ddebug_dyndbg_module_param_cb(char *param, char *val, 137 const char *modname); 138 139 struct device; 140 141 extern __printf(3, 4) 142 void __dynamic_dev_dbg(struct _ddebug *descriptor, const struct device *dev, 143 const char *fmt, ...); 144 145 struct net_device; 146 147 extern __printf(3, 4) 148 void __dynamic_netdev_dbg(struct _ddebug *descriptor, 149 const struct net_device *dev, 150 const char *fmt, ...); 151 152 struct ib_device; 153 154 extern __printf(3, 4) 155 void __dynamic_ibdev_dbg(struct _ddebug *descriptor, 156 const struct ib_device *ibdev, 157 const char *fmt, ...); 158 159 #define DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, cls, fmt) \ 160 static struct _ddebug __aligned(8) \ 161 __section("__dyndbg") name = { \ 162 .modname = KBUILD_MODNAME, \ 163 .function = __func__, \ 164 .filename = __FILE__, \ 165 .format = (fmt), \ 166 .lineno = __LINE__, \ 167 .flags = _DPRINTK_FLAGS_DEFAULT, \ 168 .class_id = cls, \ 169 _DPRINTK_KEY_INIT \ 170 }; \ 171 BUILD_BUG_ON_MSG(cls > _DPRINTK_CLASS_DFLT, \ 172 "classid value overflow") 173 174 #define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt) \ 175 DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, _DPRINTK_CLASS_DFLT, fmt) 176 177 #ifdef CONFIG_JUMP_LABEL 178 179 #ifdef DEBUG 180 181 #define _DPRINTK_KEY_INIT .key.dd_key_true = (STATIC_KEY_TRUE_INIT) 182 183 #define DYNAMIC_DEBUG_BRANCH(descriptor) \ 184 static_branch_likely(&descriptor.key.dd_key_true) 185 #else 186 #define _DPRINTK_KEY_INIT .key.dd_key_false = (STATIC_KEY_FALSE_INIT) 187 188 #define DYNAMIC_DEBUG_BRANCH(descriptor) \ 189 static_branch_unlikely(&descriptor.key.dd_key_false) 190 #endif 191 192 #else /* !CONFIG_JUMP_LABEL */ 193 194 #define _DPRINTK_KEY_INIT 195 196 #ifdef DEBUG 197 #define DYNAMIC_DEBUG_BRANCH(descriptor) \ 198 likely(descriptor.flags & _DPRINTK_FLAGS_PRINT) 199 #else 200 #define DYNAMIC_DEBUG_BRANCH(descriptor) \ 201 unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) 202 #endif 203 204 #endif /* CONFIG_JUMP_LABEL */ 205 206 /* 207 * Factory macros: ($prefix)dynamic_func_call($suffix) 208 * 209 * Lower layer (with __ prefix) gets the callsite metadata, and wraps 210 * the func inside a debug-branch/static-key construct. Upper layer 211 * (with _ prefix) does the UNIQUE_ID once, so that lower can ref the 212 * name/label multiple times, and tie the elements together. 213 * Multiple flavors: 214 * (|_cls): adds in _DPRINT_CLASS_DFLT as needed 215 * (|_no_desc): former gets callsite descriptor as 1st arg (for prdbgs) 216 */ 217 #define __dynamic_func_call_cls(id, cls, fmt, func, ...) do { \ 218 DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt); \ 219 if (DYNAMIC_DEBUG_BRANCH(id)) \ 220 func(&id, ##__VA_ARGS__); \ 221 } while (0) 222 #define __dynamic_func_call(id, fmt, func, ...) \ 223 __dynamic_func_call_cls(id, _DPRINTK_CLASS_DFLT, fmt, \ 224 func, ##__VA_ARGS__) 225 226 #define __dynamic_func_call_cls_no_desc(id, cls, fmt, func, ...) do { \ 227 DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt); \ 228 if (DYNAMIC_DEBUG_BRANCH(id)) \ 229 func(__VA_ARGS__); \ 230 } while (0) 231 #define __dynamic_func_call_no_desc(id, fmt, func, ...) \ 232 __dynamic_func_call_cls_no_desc(id, _DPRINTK_CLASS_DFLT, \ 233 fmt, func, ##__VA_ARGS__) 234 235 /* 236 * "Factory macro" for generating a call to func, guarded by a 237 * DYNAMIC_DEBUG_BRANCH. The dynamic debug descriptor will be 238 * initialized using the fmt argument. The function will be called with 239 * the address of the descriptor as first argument, followed by all 240 * the varargs. Note that fmt is repeated in invocations of this 241 * macro. 242 */ 243 #define _dynamic_func_call_cls(cls, fmt, func, ...) \ 244 __dynamic_func_call_cls(__UNIQUE_ID(ddebug), cls, fmt, func, ##__VA_ARGS__) 245 #define _dynamic_func_call(fmt, func, ...) \ 246 _dynamic_func_call_cls(_DPRINTK_CLASS_DFLT, fmt, func, ##__VA_ARGS__) 247 248 /* 249 * A variant that does the same, except that the descriptor is not 250 * passed as the first argument to the function; it is only called 251 * with precisely the macro's varargs. 252 */ 253 #define _dynamic_func_call_cls_no_desc(cls, fmt, func, ...) \ 254 __dynamic_func_call_cls_no_desc(__UNIQUE_ID(ddebug), cls, fmt, \ 255 func, ##__VA_ARGS__) 256 #define _dynamic_func_call_no_desc(fmt, func, ...) \ 257 _dynamic_func_call_cls_no_desc(_DPRINTK_CLASS_DFLT, fmt, \ 258 func, ##__VA_ARGS__) 259 260 #define dynamic_pr_debug_cls(cls, fmt, ...) \ 261 _dynamic_func_call_cls(cls, fmt, __dynamic_pr_debug, \ 262 pr_fmt(fmt), ##__VA_ARGS__) 263 264 #define dynamic_pr_debug(fmt, ...) \ 265 _dynamic_func_call(fmt, __dynamic_pr_debug, \ 266 pr_fmt(fmt), ##__VA_ARGS__) 267 268 #define dynamic_dev_dbg(dev, fmt, ...) \ 269 _dynamic_func_call(fmt, __dynamic_dev_dbg, \ 270 dev, fmt, ##__VA_ARGS__) 271 272 #define dynamic_netdev_dbg(dev, fmt, ...) \ 273 _dynamic_func_call(fmt, __dynamic_netdev_dbg, \ 274 dev, fmt, ##__VA_ARGS__) 275 276 #define dynamic_ibdev_dbg(dev, fmt, ...) \ 277 _dynamic_func_call(fmt, __dynamic_ibdev_dbg, \ 278 dev, fmt, ##__VA_ARGS__) 279 280 #define dynamic_hex_dump(prefix_str, prefix_type, rowsize, \ 281 groupsize, buf, len, ascii) \ 282 _dynamic_func_call_no_desc(__builtin_constant_p(prefix_str) ? prefix_str : "hexdump", \ 283 print_hex_dump, \ 284 KERN_DEBUG, prefix_str, prefix_type, \ 285 rowsize, groupsize, buf, len, ascii) 286 287 struct kernel_param; 288 int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp); 289 int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp); 290 291 /* for test only, generally expect drm.debug style macro wrappers */ 292 #define __pr_debug_cls(cls, fmt, ...) do { \ 293 BUILD_BUG_ON_MSG(!__builtin_constant_p(cls), \ 294 "expecting constant class int/enum"); \ 295 dynamic_pr_debug_cls(cls, fmt, ##__VA_ARGS__); \ 296 } while (0) 297 298 #else /* !CONFIG_DYNAMIC_DEBUG_CORE */ 299 300 #include <linux/string.h> 301 #include <linux/errno.h> 302 #include <linux/printk.h> 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 struct kernel_param; 328 static inline int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp) 329 { return 0; } 330 static inline int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp) 331 { return 0; } 332 333 #endif /* !CONFIG_DYNAMIC_DEBUG_CORE */ 334 335 extern const struct kernel_param_ops param_ops_dyndbg_classes; 336 337 #endif 338