Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
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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_DEFAULT 0
35 unsigned int flags:8;
36 char enabled;
37} __attribute__((aligned(8)));
38
39
40int ddebug_add_module(struct _ddebug *tab, unsigned int n,
41 const char *modname);
42
43#if defined(CONFIG_DYNAMIC_DEBUG)
44extern int ddebug_remove_module(const char *mod_name);
45
46#define dynamic_pr_debug(fmt, ...) do { \
47 __label__ do_printk; \
48 __label__ out; \
49 static struct _ddebug descriptor \
50 __used \
51 __attribute__((section("__verbose"), aligned(8))) = \
52 { KBUILD_MODNAME, __func__, __FILE__, fmt, __LINE__, \
53 _DPRINTK_FLAGS_DEFAULT }; \
54 JUMP_LABEL(&descriptor.enabled, do_printk); \
55 goto out; \
56do_printk: \
57 printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \
58out: ; \
59 } while (0)
60
61
62#define dynamic_dev_dbg(dev, fmt, ...) do { \
63 __label__ do_printk; \
64 __label__ out; \
65 static struct _ddebug descriptor \
66 __used \
67 __attribute__((section("__verbose"), aligned(8))) = \
68 { KBUILD_MODNAME, __func__, __FILE__, fmt, __LINE__, \
69 _DPRINTK_FLAGS_DEFAULT }; \
70 JUMP_LABEL(&descriptor.enabled, do_printk); \
71 goto out; \
72do_printk: \
73 dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); \
74out: ; \
75 } while (0)
76
77#else
78
79static inline int ddebug_remove_module(const char *mod)
80{
81 return 0;
82}
83
84#define dynamic_pr_debug(fmt, ...) \
85 do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
86#define dynamic_dev_dbg(dev, fmt, ...) \
87 do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0)
88#endif
89
90#endif