Linux kernel mirror (for testing)
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linux
1#ifndef _DYNAMIC_DEBUG_H
2#define _DYNAMIC_DEBUG_H
3
4/* dynamic_printk_enabled, and dynamic_printk_enabled2 are bitmasks in which
5 * bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They
6 * use independent hash functions, to reduce the chance of false positives.
7 */
8extern long long dynamic_debug_enabled;
9extern long long dynamic_debug_enabled2;
10
11/*
12 * An instance of this structure is created in a special
13 * ELF section at every dynamic debug callsite. At runtime,
14 * the special section is treated as an array of these.
15 */
16struct _ddebug {
17 /*
18 * These fields are used to drive the user interface
19 * for selecting and displaying debug callsites.
20 */
21 const char *modname;
22 const char *function;
23 const char *filename;
24 const char *format;
25 unsigned int lineno:24;
26 /*
27 * The flags field controls the behaviour at the callsite.
28 * The bits here are changed dynamically when the user
29 * writes commands to <debugfs>/dynamic_debug/control
30 */
31#define _DPRINTK_FLAGS_PRINT (1<<0) /* printk() a message using the format */
32#define _DPRINTK_FLAGS_INCL_MODNAME (1<<1)
33#define _DPRINTK_FLAGS_INCL_FUNCNAME (1<<2)
34#define _DPRINTK_FLAGS_INCL_LINENO (1<<3)
35#define _DPRINTK_FLAGS_INCL_TID (1<<4)
36#define _DPRINTK_FLAGS_DEFAULT 0
37 unsigned int flags:8;
38 char enabled;
39} __attribute__((aligned(8)));
40
41
42int ddebug_add_module(struct _ddebug *tab, unsigned int n,
43 const char *modname);
44
45#if defined(CONFIG_DYNAMIC_DEBUG)
46extern int ddebug_remove_module(const char *mod_name);
47extern int __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
48 __attribute__ ((format (printf, 2, 3)));
49
50#define dynamic_pr_debug(fmt, ...) do { \
51 static struct _ddebug descriptor \
52 __used \
53 __attribute__((section("__verbose"), aligned(8))) = \
54 { KBUILD_MODNAME, __func__, __FILE__, fmt, __LINE__, \
55 _DPRINTK_FLAGS_DEFAULT }; \
56 if (unlikely(descriptor.enabled)) \
57 __dynamic_pr_debug(&descriptor, pr_fmt(fmt), ##__VA_ARGS__); \
58 } while (0)
59
60
61#define dynamic_dev_dbg(dev, fmt, ...) do { \
62 static struct _ddebug descriptor \
63 __used \
64 __attribute__((section("__verbose"), aligned(8))) = \
65 { KBUILD_MODNAME, __func__, __FILE__, fmt, __LINE__, \
66 _DPRINTK_FLAGS_DEFAULT }; \
67 if (unlikely(descriptor.enabled)) \
68 dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); \
69 } while (0)
70
71#else
72
73static inline int ddebug_remove_module(const char *mod)
74{
75 return 0;
76}
77
78#define dynamic_pr_debug(fmt, ...) \
79 do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
80#define dynamic_dev_dbg(dev, fmt, ...) \
81 do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0)
82#endif
83
84#endif