xref: /linux-6.15/include/linux/dynamic_debug.h (revision c40d04df)
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 struct device;
48 
49 extern __printf(3, 4)
50 int __dynamic_dev_dbg(struct _ddebug *descriptor, const struct device *dev,
51 		      const char *fmt, ...);
52 
53 struct net_device;
54 
55 extern __printf(3, 4)
56 int __dynamic_netdev_dbg(struct _ddebug *descriptor,
57 			 const struct net_device *dev,
58 			 const char *fmt, ...);
59 
60 #define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt)		\
61 	static struct _ddebug __used __aligned(8)		\
62 	__attribute__((section("__verbose"))) name = {		\
63 		.modname = KBUILD_MODNAME,			\
64 		.function = __func__,				\
65 		.filename = __FILE__,				\
66 		.format = (fmt),				\
67 		.lineno = __LINE__,				\
68 		.flags =  _DPRINTK_FLAGS_DEFAULT,		\
69 	}
70 
71 #define dynamic_pr_debug(fmt, ...)				\
72 do {								\
73 	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);		\
74 	if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT))	\
75 		__dynamic_pr_debug(&descriptor, pr_fmt(fmt),	\
76 				   ##__VA_ARGS__);		\
77 } while (0)
78 
79 #define dynamic_dev_dbg(dev, fmt, ...)				\
80 do {								\
81 	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);		\
82 	if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT))	\
83 		__dynamic_dev_dbg(&descriptor, dev, fmt,	\
84 				  ##__VA_ARGS__);		\
85 } while (0)
86 
87 #define dynamic_netdev_dbg(dev, fmt, ...)			\
88 do {								\
89 	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);		\
90 	if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT))	\
91 		__dynamic_netdev_dbg(&descriptor, dev, fmt,	\
92 				     ##__VA_ARGS__);		\
93 } while (0)
94 
95 #else
96 
97 static inline int ddebug_remove_module(const char *mod)
98 {
99 	return 0;
100 }
101 
102 #define dynamic_pr_debug(fmt, ...)					\
103 	do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
104 #define dynamic_dev_dbg(dev, fmt, ...)					\
105 	do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0)
106 #endif
107 
108 #endif
109