1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _DYNAMIC_DEBUG_H
3#define _DYNAMIC_DEBUG_H
4
5#if defined(CC_HAVE_ASM_GOTO) && 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 HAVE_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
50int ddebug_add_module(struct _ddebug *tab, unsigned int n,
51 const char *modname);
52
53#if defined(CONFIG_DYNAMIC_DEBUG)
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
74#define DEFINE_DYNAMIC_DEBUG_METADATA_KEY(name, fmt, key, init) \
75 static struct _ddebug __aligned(8) \
76 __attribute__((section("__verbose"))) name = { \
77 .modname = KBUILD_MODNAME, \
78 .function = __func__, \
79 .filename = __FILE__, \
80 .format = (fmt), \
81 .lineno = __LINE__, \
82 .flags = _DPRINTK_FLAGS_DEFAULT, \
83 dd_key_init(key, init) \
84 }
85
86#ifdef HAVE_JUMP_LABEL
87
88#define dd_key_init(key, init) key = (init)
89
90#ifdef DEBUG
91#define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt) \
92 DEFINE_DYNAMIC_DEBUG_METADATA_KEY(name, fmt, .key.dd_key_true, \
93 (STATIC_KEY_TRUE_INIT))
94
95#define DYNAMIC_DEBUG_BRANCH(descriptor) \
96 static_branch_likely(&descriptor.key.dd_key_true)
97#else
98#define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt) \
99 DEFINE_DYNAMIC_DEBUG_METADATA_KEY(name, fmt, .key.dd_key_false, \
100 (STATIC_KEY_FALSE_INIT))
101
102#define DYNAMIC_DEBUG_BRANCH(descriptor) \
103 static_branch_unlikely(&descriptor.key.dd_key_false)
104#endif
105
106#else
107
108#define dd_key_init(key, init)
109
110#define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt) \
111 DEFINE_DYNAMIC_DEBUG_METADATA_KEY(name, fmt, 0, 0)
112
113#ifdef DEBUG
114#define DYNAMIC_DEBUG_BRANCH(descriptor) \
115 likely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
116#else
117#define DYNAMIC_DEBUG_BRANCH(descriptor) \
118 unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
119#endif
120
121#endif
122
123#define dynamic_pr_debug(fmt, ...) \
124do { \
125 DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); \
126 if (DYNAMIC_DEBUG_BRANCH(descriptor)) \
127 __dynamic_pr_debug(&descriptor, pr_fmt(fmt), \
128 ##__VA_ARGS__); \
129} while (0)
130
131#define dynamic_dev_dbg(dev, fmt, ...) \
132do { \
133 DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); \
134 if (DYNAMIC_DEBUG_BRANCH(descriptor)) \
135 __dynamic_dev_dbg(&descriptor, dev, fmt, \
136 ##__VA_ARGS__); \
137} while (0)
138
139#define dynamic_netdev_dbg(dev, fmt, ...) \
140do { \
141 DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); \
142 if (DYNAMIC_DEBUG_BRANCH(descriptor)) \
143 __dynamic_netdev_dbg(&descriptor, dev, fmt, \
144 ##__VA_ARGS__); \
145} while (0)
146
147#define dynamic_hex_dump(prefix_str, prefix_type, rowsize, \
148 groupsize, buf, len, ascii) \
149do { \
150 DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, \
151 __builtin_constant_p(prefix_str) ? prefix_str : "hexdump");\
152 if (DYNAMIC_DEBUG_BRANCH(descriptor)) \
153 print_hex_dump(KERN_DEBUG, prefix_str, \
154 prefix_type, rowsize, groupsize, \
155 buf, len, ascii); \
156} while (0)
157
158#else
159
160#include <linux/string.h>
161#include <linux/errno.h>
162
163static inline int ddebug_remove_module(const char *mod)
164{
165 return 0;
166}
167
168static inline int ddebug_dyndbg_module_param_cb(char *param, char *val,
169 const char *modname)
170{
171 if (strstr(param, "dyndbg")) {
172 /* avoid pr_warn(), which wants pr_fmt() fully defined */
173 printk(KERN_WARNING "dyndbg param is supported only in "
174 "CONFIG_DYNAMIC_DEBUG builds\n");
175 return 0; /* allow and ignore */
176 }
177 return -EINVAL;
178}
179
180#define dynamic_pr_debug(fmt, ...) \
181 do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
182#define dynamic_dev_dbg(dev, fmt, ...) \
183 do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0)
184#endif
185
186#endif
187