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| 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 KBUILD_MODNAME ":" fmt, \ |
| 61 | + ##__VA_ARGS__); \ |
| 62 | + } while (0) |
| 63 | + |
| 64 | + |
| 65 | +#define dynamic_dev_dbg(dev, fmt, ...) do { \ |
| 66 | + static struct _ddebug descriptor \ |
| 67 | + __used \ |
| 68 | + __attribute__((section("__verbose"), aligned(8))) = \ |
| 69 | + { KBUILD_MODNAME, __func__, __FILE__, fmt, DEBUG_HASH, \ |
| 70 | + DEBUG_HASH2, __LINE__, _DPRINTK_FLAGS_DEFAULT }; \ |
| 71 | + if (__dynamic_dbg_enabled(descriptor)) \ |
| 72 | + dev_printk(KERN_DEBUG, dev, \ |
| 73 | + KBUILD_MODNAME ": " fmt, \ |
| 74 | + ##__VA_ARGS__); \ |
| 75 | + } while (0) |
| 76 | + |
| 77 | +#else |
| 78 | + |
| 79 | +static inline int ddebug_remove_module(char *mod) |
| 80 | +{ |
| 81 | + return 0; |
| 82 | +} |
| 83 | + |
| 84 | +#define dynamic_pr_debug(fmt, ...) do { } while (0) |
| 85 | +#define dynamic_dev_dbg(dev, format, ...) do { } while (0) |
| 86 | +#endif |
| 87 | + |
| 88 | +#endif |
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