Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
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 char primary_hash;
26 char secondary_hash;
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/ddebug
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} __attribute__((aligned(8)));
37
38
39int ddebug_add_module(struct _ddebug *tab, unsigned int n,
40 const char *modname);
41
42#if defined(CONFIG_DYNAMIC_DEBUG)
43extern int ddebug_remove_module(char *mod_name);
44
45#define __dynamic_dbg_enabled(dd) ({ \
46 int __ret = 0; \
47 if (unlikely((dynamic_debug_enabled & (1LL << DEBUG_HASH)) && \
48 (dynamic_debug_enabled2 & (1LL << DEBUG_HASH2)))) \
49 if (unlikely(dd.flags)) \
50 __ret = 1; \
51 __ret; })
52
53#define dynamic_pr_debug(fmt, ...) do { \
54 static struct _ddebug descriptor \
55 __used \
56 __attribute__((section("__verbose"), aligned(8))) = \
57 { KBUILD_MODNAME, __func__, __FILE__, fmt, DEBUG_HASH, \
58 DEBUG_HASH2, __LINE__, _DPRINTK_FLAGS_DEFAULT }; \
59 if (__dynamic_dbg_enabled(descriptor)) \
60 printk(KERN_DEBUG KBUILD_MODNAME ":" pr_fmt(fmt), \
61 ##__VA_ARGS__); \
62 } while (0)
63
64
65#define dynamic_dev_dbg(dev, fmt, ...) do { \
66 static struct _ddebug descriptor \
67 __used \
68 __attribute__((section("__verbose"), aligned(8))) = \
69 { KBUILD_MODNAME, __func__, __FILE__, fmt, DEBUG_HASH, \
70 DEBUG_HASH2, __LINE__, _DPRINTK_FLAGS_DEFAULT }; \
71 if (__dynamic_dbg_enabled(descriptor)) \
72 dev_printk(KERN_DEBUG, dev, \
73 KBUILD_MODNAME ": " fmt, \
74 ##__VA_ARGS__); \
75 } while (0)
76
77#else
78
79static inline int ddebug_remove_module(char *mod)
80{
81 return 0;
82}
83
84#define dynamic_pr_debug(fmt, ...) do { } while (0)
85#define dynamic_dev_dbg(dev, format, ...) do { } while (0)
86#endif
87
88#endif