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:18;
  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_NONE     0
  25 #define _DPRINTK_FLAGS_PRINT    (1<<0) /* printk() a message using the format */
  26 #define _DPRINTK_FLAGS_INCL_MODNAME     (1<<1)
  27 #define _DPRINTK_FLAGS_INCL_FUNCNAME    (1<<2)
  28 #define _DPRINTK_FLAGS_INCL_LINENO      (1<<3)
  29 #define _DPRINTK_FLAGS_INCL_TID         (1<<4)
  30 #if defined DEBUG
  31 #define _DPRINTK_FLAGS_DEFAULT _DPRINTK_FLAGS_PRINT
  32 #else
  33 #define _DPRINTK_FLAGS_DEFAULT 0
  34 #endif
  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(const char *mod_name);
  44 extern __printf(2, 3)
  45 int __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...);
  46
  47 extern int ddebug_dyndbg_module_param_cb(char *param, char *val,
  48                                         const char *modname);
  49
  50 struct device;
  51
  52 extern __printf(3, 4)
  53 int __dynamic_dev_dbg(struct _ddebug *descriptor, const struct device *dev,
  54                       const char *fmt, ...);
  55
  56 struct net_device;
  57
  58 extern __printf(3, 4)
  59 int __dynamic_netdev_dbg(struct _ddebug *descriptor,
  60                          const struct net_device *dev,
  61                          const char *fmt, ...);
  62
  63 #define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt)                \
  64         static struct _ddebug __used __aligned(8)               \
  65         __attribute__((section("__verbose"))) name = {          \
  66                 .modname = KBUILD_MODNAME,                      \
  67                 .function = __func__,                           \
  68                 .filename = __FILE__,                           \
  69                 .format = (fmt),                                \
  70                 .lineno = __LINE__,                             \
  71                 .flags =  _DPRINTK_FLAGS_DEFAULT,               \
  72         }
  73
  74 #define dynamic_pr_debug(fmt, ...)                              \
  75 do {                                                            \
  76         DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);         \
  77         if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT))  \
  78                 __dynamic_pr_debug(&descriptor, pr_fmt(fmt),    \
  79                                    ##__VA_ARGS__);              \
  80 } while (0)
  81
  82 #define dynamic_dev_dbg(dev, fmt, ...)                          \
  83 do {                                                            \
  84         DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);         \
  85         if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT))  \
  86                 __dynamic_dev_dbg(&descriptor, dev, fmt,        \
  87                                   ##__VA_ARGS__);               \
  88 } while (0)
  89
  90 #define dynamic_netdev_dbg(dev, fmt, ...)                       \
  91 do {                                                            \
  92         DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);         \
  93         if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT))  \
  94                 __dynamic_netdev_dbg(&descriptor, dev, fmt,     \
  95                                      ##__VA_ARGS__);            \
  96 } while (0)
  97
  98 #else
  99
 100 #include <linux/string.h>
 101 #include <linux/errno.h>
 102
 103 static inline int ddebug_remove_module(const char *mod)
 104 {
 105         return 0;
 106 }
 107
 108 static inline int ddebug_dyndbg_module_param_cb(char *param, char *val,
 109                                                 const char *modname)
 110 {
 111         if (strstr(param, "dyndbg")) {
 112                 /* avoid pr_warn(), which wants pr_fmt() fully defined */
 113                 printk(KERN_WARNING "dyndbg param is supported only in "
 114                         "CONFIG_DYNAMIC_DEBUG builds\n");
 115                 return 0; /* allow and ignore */
 116         }
 117         return -EINVAL;
 118 }
 119
 120 #define dynamic_pr_debug(fmt, ...)                                      \
 121         do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
 122 #define dynamic_dev_dbg(dev, fmt, ...)                                  \
 123         do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0)
 124 #endif
 125
 126 #endif