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