1 #ifndef _DYNAMIC_DEBUG_H 2 #define _DYNAMIC_DEBUG_H 3 4 /* dynamic_printk_enabled, and dynamic_printk_enabled2 are bitmasks in which 5 * bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They 6 * use independent hash functions, to reduce the chance of false positives. 7 */ 8 extern long long dynamic_debug_enabled; 9 extern long long dynamic_debug_enabled2; 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 char primary_hash; 26 char secondary_hash; 27 unsigned int lineno:24; 28 /* 29 * The flags field controls the behaviour at the callsite. 30 * The bits here are changed dynamically when the user 31 * writes commands to <debugfs>/dynamic_debug/ddebug 32 */ 33 #define _DPRINTK_FLAGS_PRINT (1<<0) /* printk() a message using the format */ 34 #define _DPRINTK_FLAGS_DEFAULT 0 35 unsigned int flags:8; 36 } __attribute__((aligned(8))); 37 38 39 int ddebug_add_module(struct _ddebug *tab, unsigned int n, 40 const char *modname); 41 42 #if defined(CONFIG_DYNAMIC_DEBUG) 43 extern int ddebug_remove_module(char *mod_name); 44 45 #define __dynamic_dbg_enabled(dd) ({ \ 46 int __ret = 0; \ 47 if (unlikely((dynamic_debug_enabled & (1LL << DEBUG_HASH)) && \ 48 (dynamic_debug_enabled2 & (1LL << DEBUG_HASH2)))) \ 49 if (unlikely(dd.flags)) \ 50 __ret = 1; \ 51 __ret; }) 52 53 #define dynamic_pr_debug(fmt, ...) do { \ 54 static struct _ddebug descriptor \ 55 __used \ 56 __attribute__((section("__verbose"), aligned(8))) = \ 57 { KBUILD_MODNAME, __func__, __FILE__, fmt, DEBUG_HASH, \ 58 DEBUG_HASH2, __LINE__, _DPRINTK_FLAGS_DEFAULT }; \ 59 if (__dynamic_dbg_enabled(descriptor)) \ 60 printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \ 61 } while (0) 62 63 64 #define dynamic_dev_dbg(dev, fmt, ...) do { \ 65 static struct _ddebug descriptor \ 66 __used \ 67 __attribute__((section("__verbose"), aligned(8))) = \ 68 { KBUILD_MODNAME, __func__, __FILE__, fmt, DEBUG_HASH, \ 69 DEBUG_HASH2, __LINE__, _DPRINTK_FLAGS_DEFAULT }; \ 70 if (__dynamic_dbg_enabled(descriptor)) \ 71 dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); \ 72 } while (0) 73 74 #else 75 76 static inline int ddebug_remove_module(char *mod) 77 { 78 return 0; 79 } 80 81 #define dynamic_pr_debug(fmt, ...) \ 82 do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0) 83 #define dynamic_dev_dbg(dev, format, ...) \ 84 do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0) 85 #endif 86 87 #endif 88