1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef TRACEPOINT_DEFS_H
3#define TRACEPOINT_DEFS_H 1
4
5/*
6 * File can be included directly by headers who only want to access
7 * tracepoint->key to guard out of line trace calls, or the definition of
8 * trace_print_flags{_u64}. Otherwise linux/tracepoint.h should be used.
9 */
10
11#include <linux/atomic.h>
12#include <linux/static_key.h>
13
14struct static_call_key;
15
16struct trace_print_flags {
17 unsigned long mask;
18 const char *name;
19};
20
21struct trace_print_flags_u64 {
22 unsigned long long mask;
23 const char *name;
24};
25
26struct tracepoint_func {
27 void *func;
28 void *data;
29 int prio;
30};
31
32struct tracepoint_ext {
33 int (*regfunc)(void);
34 void (*unregfunc)(void);
35 /* Flags. */
36 unsigned int faultable:1;
37};
38
39struct tracepoint {
40 const char *name; /* Tracepoint name */
41 struct static_key_false key;
42 struct static_call_key *static_call_key;
43 void *static_call_tramp;
44 void *iterator;
45 void *probestub;
46 struct tracepoint_func __rcu *funcs;
47 struct tracepoint_ext *ext;
48};
49
50#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
51typedef const int tracepoint_ptr_t;
52#else
53typedef struct tracepoint * const tracepoint_ptr_t;
54#endif
55
56struct bpf_raw_event_map {
57 struct tracepoint *tp;
58 void *bpf_func;
59 u32 num_args;
60 u32 writable_size;
61} __aligned(32);
62
63/*
64 * If a tracepoint needs to be called from a header file, it is not
65 * recommended to call it directly, as tracepoints in header files
66 * may cause side-effects and bloat the kernel. Instead, use
67 * tracepoint_enabled() to test if the tracepoint is enabled, then if
68 * it is, call a wrapper function defined in a C file that will then
69 * call the tracepoint.
70 *
71 * For "trace_foo_bar()", you would need to create a wrapper function
72 * in a C file to call trace_foo_bar():
73 * void do_trace_foo_bar(args) { trace_foo_bar(args); }
74 * Then in the header file, declare the tracepoint:
75 * DECLARE_TRACEPOINT(foo_bar);
76 * And call your wrapper:
77 * static inline void some_inlined_function() {
78 * [..]
79 * if (tracepoint_enabled(foo_bar))
80 * do_trace_foo_bar(args);
81 * [..]
82 * }
83 *
84 * Note: tracepoint_enabled(foo_bar) is equivalent to trace_foo_bar_enabled()
85 * but is safe to have in headers, where trace_foo_bar_enabled() is not.
86 */
87#define DECLARE_TRACEPOINT(tp) \
88 extern struct tracepoint __tracepoint_##tp
89
90#ifdef CONFIG_TRACEPOINTS
91# define tracepoint_enabled(tp) \
92 static_branch_unlikely(&(__tracepoint_##tp).key)
93#else
94# define tracepoint_enabled(tracepoint) false
95#endif
96
97#endif
98

source code of linux/include/linux/tracepoint-defs.h