root/include/linux/dynamic_debug.h

INCLUDED FROM

DEFINITIONS

1. ddebug_remove_module
2. ddebug_dyndbg_module_param_cb

#ifndef _DYNAMIC_DEBUG_H
#define _DYNAMIC_DEBUG_H

/*
 * An instance of this structure is created in a special
 * ELF section at every dynamic debug callsite.  At runtime,
 * the special section is treated as an array of these.
 */
struct _ddebug {
        /*
         * These fields are used to drive the user interface
         * for selecting and displaying debug callsites.
         */
        const char *modname;
        const char *function;
        const char *filename;
        const char *format;
        unsigned int lineno:18;
        /*
         * The flags field controls the behaviour at the callsite.
         * The bits here are changed dynamically when the user
         * writes commands to <debugfs>/dynamic_debug/control
         */
#define _DPRINTK_FLAGS_NONE     0
#define _DPRINTK_FLAGS_PRINT    (1<<0) /* printk() a message using the format */
#define _DPRINTK_FLAGS_INCL_MODNAME     (1<<1)
#define _DPRINTK_FLAGS_INCL_FUNCNAME    (1<<2)
#define _DPRINTK_FLAGS_INCL_LINENO      (1<<3)
#define _DPRINTK_FLAGS_INCL_TID         (1<<4)
#if defined DEBUG
#define _DPRINTK_FLAGS_DEFAULT _DPRINTK_FLAGS_PRINT
#else
#define _DPRINTK_FLAGS_DEFAULT 0
#endif
        unsigned int flags:8;
} __attribute__((aligned(8)));


int ddebug_add_module(struct _ddebug *tab, unsigned int n,
                                const char *modname);

#if defined(CONFIG_DYNAMIC_DEBUG)
extern int ddebug_remove_module(const char *mod_name);
extern __printf(2, 3)
void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...);

extern int ddebug_dyndbg_module_param_cb(char *param, char *val,
                                        const char *modname);

struct device;

extern __printf(3, 4)
void __dynamic_dev_dbg(struct _ddebug *descriptor, const struct device *dev,
                       const char *fmt, ...);

struct net_device;

extern __printf(3, 4)
void __dynamic_netdev_dbg(struct _ddebug *descriptor,
                          const struct net_device *dev,
                          const char *fmt, ...);

#define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt)                \
        static struct _ddebug  __aligned(8)                     \
        __attribute__((section("__verbose"))) name = {          \
                .modname = KBUILD_MODNAME,                      \
                .function = __func__,                           \
                .filename = __FILE__,                           \
                .format = (fmt),                                \
                .lineno = __LINE__,                             \
                .flags =  _DPRINTK_FLAGS_DEFAULT,               \
        }

#define dynamic_pr_debug(fmt, ...)                              \
do {                                                            \
        DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);         \
        if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT))  \
                __dynamic_pr_debug(&descriptor, pr_fmt(fmt),    \
                                   ##__VA_ARGS__);              \
} while (0)

#define dynamic_dev_dbg(dev, fmt, ...)                          \
do {                                                            \
        DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);         \
        if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT))  \
                __dynamic_dev_dbg(&descriptor, dev, fmt,        \
                                  ##__VA_ARGS__);               \
} while (0)

#define dynamic_netdev_dbg(dev, fmt, ...)                       \
do {                                                            \
        DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);         \
        if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT))  \
                __dynamic_netdev_dbg(&descriptor, dev, fmt,     \
                                     ##__VA_ARGS__);            \
} while (0)

#define dynamic_hex_dump(prefix_str, prefix_type, rowsize,      \
                         groupsize, buf, len, ascii)            \
do {                                                            \
        DEFINE_DYNAMIC_DEBUG_METADATA(descriptor,               \
                __builtin_constant_p(prefix_str) ? prefix_str : "hexdump");\
        if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT))  \
                print_hex_dump(KERN_DEBUG, prefix_str,          \
                               prefix_type, rowsize, groupsize, \
                               buf, len, ascii);                \
} while (0)

#else

#include <linux/string.h>
#include <linux/errno.h>

static inline int ddebug_remove_module(const char *mod)
{
        return 0;
}

static inline int ddebug_dyndbg_module_param_cb(char *param, char *val,
                                                const char *modname)
{
        if (strstr(param, "dyndbg")) {
                /* avoid pr_warn(), which wants pr_fmt() fully defined */
                printk(KERN_WARNING "dyndbg param is supported only in "
                        "CONFIG_DYNAMIC_DEBUG builds\n");
                return 0; /* allow and ignore */
        }
        return -EINVAL;
}

#define dynamic_pr_debug(fmt, ...)                                      \
        do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
#define dynamic_dev_dbg(dev, fmt, ...)                                  \
        do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0)
#endif

#endif