xref: /linux-6.15/include/linux/dynamic_debug.h (revision f7be3455)
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:24;
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_PRINT   (1<<0)  /* printk() a message using the format */
25 #define _DPRINTK_FLAGS_INCL_MODNAME	(1<<1)
26 #define _DPRINTK_FLAGS_INCL_FUNCNAME	(1<<2)
27 #define _DPRINTK_FLAGS_INCL_LINENO	(1<<3)
28 #define _DPRINTK_FLAGS_INCL_TID		(1<<4)
29 #define _DPRINTK_FLAGS_DEFAULT 0
30 	unsigned int flags:8;
31 	char enabled;
32 } __attribute__((aligned(8)));
33 
34 
35 int ddebug_add_module(struct _ddebug *tab, unsigned int n,
36 				const char *modname);
37 
38 #if defined(CONFIG_DYNAMIC_DEBUG)
39 extern int ddebug_remove_module(const char *mod_name);
40 extern int __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
41 	__attribute__ ((format (printf, 2, 3)));
42 
43 struct device;
44 
45 extern int __dynamic_dev_dbg(struct _ddebug *descriptor,
46 			     const struct device *dev,
47 			     const char *fmt, ...)
48 	__attribute__ ((format (printf, 3, 4)));
49 
50 struct net_device;
51 
52 extern int __dynamic_netdev_dbg(struct _ddebug *descriptor,
53 			     const struct net_device *dev,
54 			     const char *fmt, ...)
55 	__attribute__ ((format (printf, 3, 4)));
56 
57 #define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt)		\
58 	static struct _ddebug __used __aligned(8)		\
59 	__attribute__((section("__verbose"))) name = {		\
60 		.modname = KBUILD_MODNAME,			\
61 		.function = __func__,				\
62 		.filename = __FILE__,				\
63 		.format = (fmt),				\
64 		.lineno = __LINE__,				\
65 		.flags =  _DPRINTK_FLAGS_DEFAULT,		\
66 		.enabled = false,				\
67 	}
68 
69 #define dynamic_pr_debug(fmt, ...)				\
70 do {								\
71 	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);		\
72 	if (unlikely(descriptor.enabled))			\
73 		__dynamic_pr_debug(&descriptor, pr_fmt(fmt),	\
74 				   ##__VA_ARGS__);		\
75 } while (0)
76 
77 #define dynamic_dev_dbg(dev, fmt, ...)				\
78 do {								\
79 	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);	\
80 	if (unlikely(descriptor.enabled))			\
81 		__dynamic_dev_dbg(&descriptor, dev, fmt,	\
82 				  ##__VA_ARGS__);		\
83 } while (0)
84 
85 #define dynamic_netdev_dbg(dev, fmt, ...)			\
86 do {								\
87 	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);		\
88 	if (unlikely(descriptor.enabled))			\
89 		__dynamic_netdev_dbg(&descriptor, dev, fmt,	\
90 				     ##__VA_ARGS__);		\
91 } while (0)
92 
93 #else
94 
95 static inline int ddebug_remove_module(const char *mod)
96 {
97 	return 0;
98 }
99 
100 #define dynamic_pr_debug(fmt, ...)					\
101 	do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
102 #define dynamic_dev_dbg(dev, fmt, ...)					\
103 	do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0)
104 #endif
105 
106 #endif
107