Linux kernel mirror (for testing)
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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