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
14 struct static_call_key;
15
16 struct trace_print_flags {
17 unsigned long mask;
18 const char *name;
19 };
20
21 struct trace_print_flags_u64 {
22 unsigned long long mask;
23 const char *name;
24 };
25
26 struct tracepoint_func {
27 void *func;
28 void *data;
29 int prio;
30 };
31
32 struct tracepoint {
33 const char *name; /* Tracepoint name */
34 struct static_key key;
35 struct static_call_key *static_call_key;
36 void *static_call_tramp;
37 void *iterator;
38 void *probestub;
39 int (*regfunc)(void);
40 void (*unregfunc)(void);
41 struct tracepoint_func __rcu *funcs;
42 };
43
44 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
45 typedef const int tracepoint_ptr_t;
46 #else
47 typedef struct tracepoint * const tracepoint_ptr_t;
48 #endif
49
50 struct bpf_raw_event_map {
51 struct tracepoint *tp;
52 void *bpf_func;
53 u32 num_args;
54 u32 writable_size;
55 } __aligned(32);
56
57 /*
58 * If a tracepoint needs to be called from a header file, it is not
59 * recommended to call it directly, as tracepoints in header files
60 * may cause side-effects and bloat the kernel. Instead, use
61 * tracepoint_enabled() to test if the tracepoint is enabled, then if
62 * it is, call a wrapper function defined in a C file that will then
63 * call the tracepoint.
64 *
65 * For "trace_foo_bar()", you would need to create a wrapper function
66 * in a C file to call trace_foo_bar():
67 * void do_trace_foo_bar(args) { trace_foo_bar(args); }
68 * Then in the header file, declare the tracepoint:
69 * DECLARE_TRACEPOINT(foo_bar);
70 * And call your wrapper:
71 * static inline void some_inlined_function() {
72 * [..]
73 * if (tracepoint_enabled(foo_bar))
74 * do_trace_foo_bar(args);
75 * [..]
76 * }
77 *
78 * Note: tracepoint_enabled(foo_bar) is equivalent to trace_foo_bar_enabled()
79 * but is safe to have in headers, where trace_foo_bar_enabled() is not.
80 */
81 #define DECLARE_TRACEPOINT(tp) \
82 extern struct tracepoint __tracepoint_##tp
83
84 #ifdef CONFIG_TRACEPOINTS
85 # define tracepoint_enabled(tp) \
86 static_key_false(&(__tracepoint_##tp).key)
87 #else
88 # define tracepoint_enabled(tracepoint) false
89 #endif
90
91 #endif
92
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