LXR linux/include/linux/dynamic

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _DYNAMIC_DEBUG_H
   3#define _DYNAMIC_DEBUG_H
   4
   5#if defined(CONFIG_JUMP_LABEL)
   6#include <linux/jump_label.h>
   7#endif
   8
   9/*
  10 * An instance of this structure is created in a special
  11 * ELF section at every dynamic debug callsite.  At runtime,
  12 * the special section is treated as an array of these.
  13 */
  14struct _ddebug {
  15        /*
  16         * These fields are used to drive the user interface
  17         * for selecting and displaying debug callsites.
  18         */
  19        const char *modname;
  20        const char *function;
  21        const char *filename;
  22        const char *format;
  23        unsigned int lineno:18;
  24        /*
  25         * The flags field controls the behaviour at the callsite.
  26         * The bits here are changed dynamically when the user
  27         * writes commands to <debugfs>/dynamic_debug/control
  28         */
  29#define _DPRINTK_FLAGS_NONE     0
  30#define _DPRINTK_FLAGS_PRINT    (1<<0) /* printk() a message using the format */
  31#define _DPRINTK_FLAGS_INCL_MODNAME     (1<<1)
  32#define _DPRINTK_FLAGS_INCL_FUNCNAME    (1<<2)
  33#define _DPRINTK_FLAGS_INCL_LINENO      (1<<3)
  34#define _DPRINTK_FLAGS_INCL_TID         (1<<4)
  35#if defined DEBUG
  36#define _DPRINTK_FLAGS_DEFAULT _DPRINTK_FLAGS_PRINT
  37#else
  38#define _DPRINTK_FLAGS_DEFAULT 0
  39#endif
  40        unsigned int flags:8;
  41#ifdef CONFIG_JUMP_LABEL
  42        union {
  43                struct static_key_true dd_key_true;
  44                struct static_key_false dd_key_false;
  45        } key;
  46#endif
  47} __attribute__((aligned(8)));
  48
  49
  50
  51#if defined(CONFIG_DYNAMIC_DEBUG)
  52int ddebug_add_module(struct _ddebug *tab, unsigned int n,
  53                                const char *modname);
  54extern int ddebug_remove_module(const char *mod_name);
  55extern __printf(2, 3)
  56void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...);
  57
  58extern int ddebug_dyndbg_module_param_cb(char *param, char *val,
  59                                        const char *modname);
  60
  61struct device;
  62
  63extern __printf(3, 4)
  64void __dynamic_dev_dbg(struct _ddebug *descriptor, const struct device *dev,
  65                       const char *fmt, ...);
  66
  67struct net_device;
  68
  69extern __printf(3, 4)
  70void __dynamic_netdev_dbg(struct _ddebug *descriptor,
  71                          const struct net_device *dev,
  72                          const char *fmt, ...);
  73
  74struct ib_device;
  75
  76extern __printf(3, 4)
  77void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
  78                         const struct ib_device *ibdev,
  79                         const char *fmt, ...);
  80
  81#define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt)                \
  82        static struct _ddebug  __aligned(8)                     \
  83        __attribute__((section("__verbose"))) name = {          \
  84                .modname = KBUILD_MODNAME,                      \
  85                .function = __func__,                           \
  86                .filename = __FILE__,                           \
  87                .format = (fmt),                                \
  88                .lineno = __LINE__,                             \
  89                .flags = _DPRINTK_FLAGS_DEFAULT,                \
  90                _DPRINTK_KEY_INIT                               \
  91        }
  92
  93#ifdef CONFIG_JUMP_LABEL
  94
  95#ifdef DEBUG
  96
  97#define _DPRINTK_KEY_INIT .key.dd_key_true = (STATIC_KEY_TRUE_INIT)
  98
  99#define DYNAMIC_DEBUG_BRANCH(descriptor) \
 100        static_branch_likely(&descriptor.key.dd_key_true)
 101#else
 102#define _DPRINTK_KEY_INIT .key.dd_key_false = (STATIC_KEY_FALSE_INIT)
 103
 104#define DYNAMIC_DEBUG_BRANCH(descriptor) \
 105        static_branch_unlikely(&descriptor.key.dd_key_false)
 106#endif
 107
 108#else /* !HAVE_JUMP_LABEL */
 109
 110#define _DPRINTK_KEY_INIT
 111
 112#ifdef DEBUG
 113#define DYNAMIC_DEBUG_BRANCH(descriptor) \
 114        likely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
 115#else
 116#define DYNAMIC_DEBUG_BRANCH(descriptor) \
 117        unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
 118#endif
 119
 120#endif
 121
 122#define __dynamic_func_call(id, fmt, func, ...) do {    \
 123        DEFINE_DYNAMIC_DEBUG_METADATA(id, fmt);         \
 124        if (DYNAMIC_DEBUG_BRANCH(id))                   \
 125                func(&id, ##__VA_ARGS__);               \
 126} while (0)
 127
 128#define __dynamic_func_call_no_desc(id, fmt, func, ...) do {    \
 129        DEFINE_DYNAMIC_DEBUG_METADATA(id, fmt);                 \
 130        if (DYNAMIC_DEBUG_BRANCH(id))                           \
 131                func(__VA_ARGS__);                              \
 132} while (0)
 133
 134/*
 135 * "Factory macro" for generating a call to func, guarded by a
 136 * DYNAMIC_DEBUG_BRANCH. The dynamic debug decriptor will be
 137 * initialized using the fmt argument. The function will be called with
 138 * the address of the descriptor as first argument, followed by all
 139 * the varargs. Note that fmt is repeated in invocations of this
 140 * macro.
 141 */
 142#define _dynamic_func_call(fmt, func, ...)                              \
 143        __dynamic_func_call(__UNIQUE_ID(ddebug), fmt, func, ##__VA_ARGS__)
 144/*
 145 * A variant that does the same, except that the descriptor is not
 146 * passed as the first argument to the function; it is only called
 147 * with precisely the macro's varargs.
 148 */
 149#define _dynamic_func_call_no_desc(fmt, func, ...)      \
 150        __dynamic_func_call_no_desc(__UNIQUE_ID(ddebug), fmt, func, ##__VA_ARGS__)
 151
 152#define dynamic_pr_debug(fmt, ...)                              \
 153        _dynamic_func_call(fmt, __dynamic_pr_debug,             \
 154                           pr_fmt(fmt), ##__VA_ARGS__)
 155
 156#define dynamic_dev_dbg(dev, fmt, ...)                          \
 157        _dynamic_func_call(fmt,__dynamic_dev_dbg,               \
 158                           dev, fmt, ##__VA_ARGS__)
 159
 160#define dynamic_netdev_dbg(dev, fmt, ...)                       \
 161        _dynamic_func_call(fmt, __dynamic_netdev_dbg,           \
 162                           dev, fmt, ##__VA_ARGS__)
 163
 164#define dynamic_ibdev_dbg(dev, fmt, ...)                        \
 165        _dynamic_func_call(fmt, __dynamic_ibdev_dbg,            \
 166                           dev, fmt, ##__VA_ARGS__)
 167
 168#define dynamic_hex_dump(prefix_str, prefix_type, rowsize,              \
 169                         groupsize, buf, len, ascii)                    \
 170        _dynamic_func_call_no_desc(__builtin_constant_p(prefix_str) ? prefix_str : "hexdump", \
 171                                   print_hex_dump,                      \
 172                                   KERN_DEBUG, prefix_str, prefix_type, \
 173                                   rowsize, groupsize, buf, len, ascii)
 174
 175#else
 176
 177#include <linux/string.h>
 178#include <linux/errno.h>
 179
 180static inline int ddebug_add_module(struct _ddebug *tab, unsigned int n,
 181                                    const char *modname)
 182{
 183        return 0;
 184}
 185
 186static inline int ddebug_remove_module(const char *mod)
 187{
 188        return 0;
 189}
 190
 191static inline int ddebug_dyndbg_module_param_cb(char *param, char *val,
 192                                                const char *modname)
 193{
 194        if (strstr(param, "dyndbg")) {
 195                /* avoid pr_warn(), which wants pr_fmt() fully defined */
 196                printk(KERN_WARNING "dyndbg param is supported only in "
 197                        "CONFIG_DYNAMIC_DEBUG builds\n");
 198                return 0; /* allow and ignore */
 199        }
 200        return -EINVAL;
 201}
 202
 203#define dynamic_pr_debug(fmt, ...)                                      \
 204        do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
 205#define dynamic_dev_dbg(dev, fmt, ...)                                  \
 206        do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0)
 207#define dynamic_hex_dump(prefix_str, prefix_type, rowsize,              \
 208                         groupsize, buf, len, ascii)                    \
 209        do { if (0)                                                     \
 210                print_hex_dump(KERN_DEBUG, prefix_str, prefix_type,     \
 211                                rowsize, groupsize, buf, len, ascii);   \
 212        } while (0)
 213#endif
 214
 215#endif
 216