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 | |