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> 189 190 static inline int ddebug_add_module(struct _ddebug *tab, unsigned int n, 191 const char *modname) 192 { 193 return 0; 194 } 195 196 static inline int ddebug_remove_module(const char *mod) 197 { 198 return 0; 199 } 200 201 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) 223 224 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