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