Linux kernel mirror (for testing)
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linux
1#ifndef _DYNAMIC_DEBUG_H
2#define _DYNAMIC_DEBUG_H
3
4#include <linux/jump_label.h>
5
6/* dynamic_printk_enabled, and dynamic_printk_enabled2 are bitmasks in which
7 * bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They
8 * use independent hash functions, to reduce the chance of false positives.
9 */
10extern long long dynamic_debug_enabled;
11extern long long dynamic_debug_enabled2;
12
13/*
14 * An instance of this structure is created in a special
15 * ELF section at every dynamic debug callsite. At runtime,
16 * the special section is treated as an array of these.
17 */
18struct _ddebug {
19 /*
20 * These fields are used to drive the user interface
21 * for selecting and displaying debug callsites.
22 */
23 const char *modname;
24 const char *function;
25 const char *filename;
26 const char *format;
27 unsigned int lineno:24;
28 /*
29 * The flags field controls the behaviour at the callsite.
30 * The bits here are changed dynamically when the user
31 * writes commands to <debugfs>/dynamic_debug/control
32 */
33#define _DPRINTK_FLAGS_PRINT (1<<0) /* printk() a message using the format */
34#define _DPRINTK_FLAGS_INCL_MODNAME (1<<1)
35#define _DPRINTK_FLAGS_INCL_FUNCNAME (1<<2)
36#define _DPRINTK_FLAGS_INCL_LINENO (1<<3)
37#define _DPRINTK_FLAGS_INCL_TID (1<<4)
38#define _DPRINTK_FLAGS_DEFAULT 0
39 unsigned int flags:8;
40 char enabled;
41} __attribute__((aligned(8)));
42
43
44int ddebug_add_module(struct _ddebug *tab, unsigned int n,
45 const char *modname);
46
47#if defined(CONFIG_DYNAMIC_DEBUG)
48extern int ddebug_remove_module(const char *mod_name);
49extern int __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
50 __attribute__ ((format (printf, 2, 3)));
51
52#define dynamic_pr_debug(fmt, ...) do { \
53 static struct _ddebug descriptor \
54 __used \
55 __attribute__((section("__verbose"), aligned(8))) = \
56 { KBUILD_MODNAME, __func__, __FILE__, fmt, __LINE__, \
57 _DPRINTK_FLAGS_DEFAULT }; \
58 if (unlikely(descriptor.enabled)) \
59 __dynamic_pr_debug(&descriptor, pr_fmt(fmt), ##__VA_ARGS__); \
60 } while (0)
61
62
63#define dynamic_dev_dbg(dev, fmt, ...) do { \
64 static struct _ddebug descriptor \
65 __used \
66 __attribute__((section("__verbose"), aligned(8))) = \
67 { KBUILD_MODNAME, __func__, __FILE__, fmt, __LINE__, \
68 _DPRINTK_FLAGS_DEFAULT }; \
69 if (unlikely(descriptor.enabled)) \
70 dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); \
71 } while (0)
72
73#else
74
75static inline int ddebug_remove_module(const char *mod)
76{
77 return 0;
78}
79
80#define dynamic_pr_debug(fmt, ...) \
81 do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
82#define dynamic_dev_dbg(dev, fmt, ...) \
83 do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0)
84#endif
85
86#endif