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 #if defined DEBUG
  30 #define _DPRINTK_FLAGS_DEFAULT _DPRINTK_FLAGS_PRINT
  31 #else
  32 #define _DPRINTK_FLAGS_DEFAULT 0
  33 #endif
  34         unsigned int flags:8;
  35 } __attribute__((aligned(8)));
  36
  37
  38 int ddebug_add_module(struct _ddebug *tab, unsigned int n,
  39                                 const char *modname);
  40
  41 #if defined(CONFIG_DYNAMIC_DEBUG)
  42 extern int ddebug_remove_module(const char *mod_name);
  43 extern __printf(2, 3)
  44 int __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...);
  45
  46 struct device;
  47
  48 extern __printf(3, 4)
  49 int __dynamic_dev_dbg(struct _ddebug *descriptor, const struct device *dev,
  50                       const char *fmt, ...);
  51
  52 struct net_device;
  53
  54 extern __printf(3, 4)
  55 int __dynamic_netdev_dbg(struct _ddebug *descriptor,
  56                          const struct net_device *dev,
  57                          const char *fmt, ...);
  58
  59 #define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt)                \
  60         static struct _ddebug __used __aligned(8)               \
  61         __attribute__((section("__verbose"))) name = {          \
  62                 .modname = KBUILD_MODNAME,                      \
  63                 .function = __func__,                           \
  64                 .filename = __FILE__,                           \
  65                 .format = (fmt),                                \
  66                 .lineno = __LINE__,                             \
  67                 .flags =  _DPRINTK_FLAGS_DEFAULT,               \
  68         }
  69
  70 #define dynamic_pr_debug(fmt, ...)                              \
  71 do {                                                            \
  72         DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);         \
  73         if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT))  \
  74                 __dynamic_pr_debug(&descriptor, pr_fmt(fmt),    \
  75                                    ##__VA_ARGS__);              \
  76 } while (0)
  77
  78 #define dynamic_dev_dbg(dev, fmt, ...)                          \
  79 do {                                                            \
  80         DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);         \
  81         if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT))  \
  82                 __dynamic_dev_dbg(&descriptor, dev, fmt,        \
  83                                   ##__VA_ARGS__);               \
  84 } while (0)
  85
  86 #define dynamic_netdev_dbg(dev, fmt, ...)                       \
  87 do {                                                            \
  88         DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);         \
  89         if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT))  \
  90                 __dynamic_netdev_dbg(&descriptor, dev, fmt,     \
  91                                      ##__VA_ARGS__);            \
  92 } while (0)
  93
  94 #else
  95
  96 static inline int ddebug_remove_module(const char *mod)
  97 {
  98         return 0;
  99 }
 100
 101 #define dynamic_pr_debug(fmt, ...)                                      \
 102         do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
 103 #define dynamic_dev_dbg(dev, fmt, ...)                                  \
 104         do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0)
 105 #endif
 106
 107 #endif