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 #if defined DEBUG 36 #define _DPRINTK_FLAGS_DEFAULT _DPRINTK_FLAGS_PRINT 37 #else 38 #define _DPRINTK_FLAGS_DEFAULT 0 39 #endif 40 unsigned int flags:8; 41 #ifdef CONFIG_JUMP_LABEL 42 union { 43 struct static_key_true dd_key_true; 44 struct static_key_false dd_key_false; 45 } key; 46 #endif 47 } __attribute__((aligned(8))); 48 49 50 51 #if defined(CONFIG_DYNAMIC_DEBUG_CORE) 52 53 /* exported for module authors to exercise >control */ 54 int dynamic_debug_exec_queries(const char *query, const char *modname); 55 56 int ddebug_add_module(struct _ddebug *tab, unsigned int n, 57 const char *modname); 58 extern int ddebug_remove_module(const char *mod_name); 59 extern __printf(2, 3) 60 void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...); 61 62 extern int ddebug_dyndbg_module_param_cb(char *param, char *val, 63 const char *modname); 64 65 struct device; 66 67 extern __printf(3, 4) 68 void __dynamic_dev_dbg(struct _ddebug *descriptor, const struct device *dev, 69 const char *fmt, ...); 70 71 struct net_device; 72 73 extern __printf(3, 4) 74 void __dynamic_netdev_dbg(struct _ddebug *descriptor, 75 const struct net_device *dev, 76 const char *fmt, ...); 77 78 struct ib_device; 79 80 extern __printf(3, 4) 81 void __dynamic_ibdev_dbg(struct _ddebug *descriptor, 82 const struct ib_device *ibdev, 83 const char *fmt, ...); 84 85 #define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt) \ 86 static struct _ddebug __aligned(8) \ 87 __section("__dyndbg") name = { \ 88 .modname = KBUILD_MODNAME, \ 89 .function = __func__, \ 90 .filename = __FILE__, \ 91 .format = (fmt), \ 92 .lineno = __LINE__, \ 93 .flags = _DPRINTK_FLAGS_DEFAULT, \ 94 _DPRINTK_KEY_INIT \ 95 } 96 97 #ifdef CONFIG_JUMP_LABEL 98 99 #ifdef DEBUG 100 101 #define _DPRINTK_KEY_INIT .key.dd_key_true = (STATIC_KEY_TRUE_INIT) 102 103 #define DYNAMIC_DEBUG_BRANCH(descriptor) \ 104 static_branch_likely(&descriptor.key.dd_key_true) 105 #else 106 #define _DPRINTK_KEY_INIT .key.dd_key_false = (STATIC_KEY_FALSE_INIT) 107 108 #define DYNAMIC_DEBUG_BRANCH(descriptor) \ 109 static_branch_unlikely(&descriptor.key.dd_key_false) 110 #endif 111 112 #else /* !CONFIG_JUMP_LABEL */ 113 114 #define _DPRINTK_KEY_INIT 115 116 #ifdef DEBUG 117 #define DYNAMIC_DEBUG_BRANCH(descriptor) \ 118 likely(descriptor.flags & _DPRINTK_FLAGS_PRINT) 119 #else 120 #define DYNAMIC_DEBUG_BRANCH(descriptor) \ 121 unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) 122 #endif 123 124 #endif /* CONFIG_JUMP_LABEL */ 125 126 #define __dynamic_func_call(id, fmt, func, ...) do { \ 127 DEFINE_DYNAMIC_DEBUG_METADATA(id, fmt); \ 128 if (DYNAMIC_DEBUG_BRANCH(id)) \ 129 func(&id, ##__VA_ARGS__); \ 130 } while (0) 131 132 #define __dynamic_func_call_no_desc(id, fmt, func, ...) do { \ 133 DEFINE_DYNAMIC_DEBUG_METADATA(id, fmt); \ 134 if (DYNAMIC_DEBUG_BRANCH(id)) \ 135 func(__VA_ARGS__); \ 136 } while (0) 137 138 /* 139 * "Factory macro" for generating a call to func, guarded by a 140 * DYNAMIC_DEBUG_BRANCH. The dynamic debug descriptor will be 141 * initialized using the fmt argument. The function will be called with 142 * the address of the descriptor as first argument, followed by all 143 * the varargs. Note that fmt is repeated in invocations of this 144 * macro. 145 */ 146 #define _dynamic_func_call(fmt, func, ...) \ 147 __dynamic_func_call(__UNIQUE_ID(ddebug), fmt, func, ##__VA_ARGS__) 148 /* 149 * A variant that does the same, except that the descriptor is not 150 * passed as the first argument to the function; it is only called 151 * with precisely the macro's varargs. 152 */ 153 #define _dynamic_func_call_no_desc(fmt, func, ...) \ 154 __dynamic_func_call_no_desc(__UNIQUE_ID(ddebug), fmt, func, ##__VA_ARGS__) 155 156 #define dynamic_pr_debug(fmt, ...) \ 157 _dynamic_func_call(fmt, __dynamic_pr_debug, \ 158 pr_fmt(fmt), ##__VA_ARGS__) 159 160 #define dynamic_dev_dbg(dev, fmt, ...) \ 161 _dynamic_func_call(fmt,__dynamic_dev_dbg, \ 162 dev, fmt, ##__VA_ARGS__) 163 164 #define dynamic_netdev_dbg(dev, fmt, ...) \ 165 _dynamic_func_call(fmt, __dynamic_netdev_dbg, \ 166 dev, fmt, ##__VA_ARGS__) 167 168 #define dynamic_ibdev_dbg(dev, fmt, ...) \ 169 _dynamic_func_call(fmt, __dynamic_ibdev_dbg, \ 170 dev, fmt, ##__VA_ARGS__) 171 172 #define dynamic_hex_dump(prefix_str, prefix_type, rowsize, \ 173 groupsize, buf, len, ascii) \ 174 _dynamic_func_call_no_desc(__builtin_constant_p(prefix_str) ? prefix_str : "hexdump", \ 175 print_hex_dump, \ 176 KERN_DEBUG, prefix_str, prefix_type, \ 177 rowsize, groupsize, buf, len, ascii) 178 179 #else /* !CONFIG_DYNAMIC_DEBUG_CORE */ 180 181 #include <linux/string.h> 182 #include <linux/errno.h> 183 #include <linux/printk.h> 184 185 static inline int ddebug_add_module(struct _ddebug *tab, unsigned int n, 186 const char *modname) 187 { 188 return 0; 189 } 190 191 static inline int ddebug_remove_module(const char *mod) 192 { 193 return 0; 194 } 195 196 static inline int ddebug_dyndbg_module_param_cb(char *param, char *val, 197 const char *modname) 198 { 199 if (strstr(param, "dyndbg")) { 200 /* avoid pr_warn(), which wants pr_fmt() fully defined */ 201 printk(KERN_WARNING "dyndbg param is supported only in " 202 "CONFIG_DYNAMIC_DEBUG builds\n"); 203 return 0; /* allow and ignore */ 204 } 205 return -EINVAL; 206 } 207 208 #define dynamic_pr_debug(fmt, ...) \ 209 do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0) 210 #define dynamic_dev_dbg(dev, fmt, ...) \ 211 do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0) 212 #define dynamic_hex_dump(prefix_str, prefix_type, rowsize, \ 213 groupsize, buf, len, ascii) \ 214 do { if (0) \ 215 print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, \ 216 rowsize, groupsize, buf, len, ascii); \ 217 } while (0) 218 219 static inline int dynamic_debug_exec_queries(const char *query, const char *modname) 220 { 221 pr_warn("kernel not built with CONFIG_DYNAMIC_DEBUG_CORE\n"); 222 return 0; 223 } 224 225 #endif /* !CONFIG_DYNAMIC_DEBUG_CORE */ 226 227 #endif 228