include/linux/dynamic_debug.h

   1 #ifndef _DYNAMIC_DEBUG_H
   2 #define _DYNAMIC_DEBUG_H
   3
   4 /*
   5  * An instance of this structure is created in a special
   6  * ELF section at every dynamic debug callsite.  At runtime,
   7  * the special section is treated as an array of these.
   8  */
   9 struct _ddebug {
  10         /*
  11          * These fields are used to drive the user interface
  12          * for selecting and displaying debug callsites.
  13          */
  14         const char *modname;
  15         const char *function;
  16         const char *filename;
  17         const char *format;
  18         unsigned int lineno:24;
  19         /*
  20          * The flags field controls the behaviour at the callsite.
  21          * The bits here are changed dynamically when the user
  22          * writes commands to <debugfs>/dynamic_debug/control
  23          */
  24 #define _DPRINTK_FLAGS_PRINT   (1<<0)  /* printk() a message using the format */
  25 #define _DPRINTK_FLAGS_INCL_MODNAME     (1<<1)
  26 #define _DPRINTK_FLAGS_INCL_FUNCNAME    (1<<2)
  27 #define _DPRINTK_FLAGS_INCL_LINENO      (1<<3)
  28 #define _DPRINTK_FLAGS_INCL_TID         (1<<4)
  29 #define _DPRINTK_FLAGS_DEFAULT 0
  30         unsigned int flags:8;
  31         char enabled;
  32 } __attribute__((aligned(8)));
  33
  34
  35 int ddebug_add_module(struct _ddebug *tab, unsigned int n,
  36                                 const char *modname);
  37
  38 #if defined(CONFIG_DYNAMIC_DEBUG)
  39 extern int ddebug_remove_module(const char *mod_name);
  40 extern int __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
  41         __attribute__ ((format (printf, 2, 3)));
  42
  43 struct device;
  44
  45 extern int __dynamic_dev_dbg(struct _ddebug *descriptor,
  46                              const struct device *dev,
  47                              const char *fmt, ...)
  48         __attribute__ ((format (printf, 3, 4)));
  49
  50 struct net_device;
  51
  52 extern int __dynamic_netdev_dbg(struct _ddebug *descriptor,
  53                              const struct net_device *dev,
  54                              const char *fmt, ...)
  55         __attribute__ ((format (printf, 3, 4)));
  56
  57 #define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt)                \
  58         static struct _ddebug __used __aligned(8)               \
  59         __attribute__((section("__verbose"))) name = {          \
  60                 .modname = KBUILD_MODNAME,                      \
  61                 .function = __func__,                           \
  62                 .filename = __FILE__,                           \
  63                 .format = (fmt),                                \
  64                 .lineno = __LINE__,                             \
  65                 .flags =  _DPRINTK_FLAGS_DEFAULT,               \
  66                 .enabled = false,                               \
  67         }
  68
  69 #define dynamic_pr_debug(fmt, ...)                              \
  70 do {                                                            \
  71         DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);         \
  72         if (unlikely(descriptor.enabled))                       \
  73                 __dynamic_pr_debug(&descriptor, pr_fmt(fmt),    \
  74                                    ##__VA_ARGS__);              \
  75 } while (0)
  76
  77 #define dynamic_dev_dbg(dev, fmt, ...)                          \
  78 do {                                                            \
  79         DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); \
  80         if (unlikely(descriptor.enabled))                       \
  81                 __dynamic_dev_dbg(&descriptor, dev, fmt,        \
  82                                   ##__VA_ARGS__);               \
  83 } while (0)
  84
  85 #define dynamic_netdev_dbg(dev, fmt, ...)                       \
  86 do {                                                            \
  87         DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);         \
  88         if (unlikely(descriptor.enabled))                       \
  89                 __dynamic_netdev_dbg(&descriptor, dev, fmt,     \
  90                                      ##__VA_ARGS__);            \
  91 } while (0)
  92
  93 #else
  94
  95 static inline int ddebug_remove_module(const char *mod)
  96 {
  97         return 0;
  98 }
  99
 100 #define dynamic_pr_debug(fmt, ...)                                      \
 101         do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
 102 #define dynamic_dev_dbg(dev, fmt, ...)                                  \
 103         do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0)
 104 #endif
 105
 106 #endif