e609cd7da47e8e71af2ed69a5630cf6913aa423d
[linux-modified.git] / bpf_probe.h
1 /* SPDX-License-Identifier: GPL-2.0 */
2
3 #undef TRACE_SYSTEM_VAR
4
5 #ifdef CONFIG_BPF_EVENTS
6
7 #include "stages/stage6_event_callback.h"
8
9 #undef __perf_count
10 #define __perf_count(c) (c)
11
12 #undef __perf_task
13 #define __perf_task(t)  (t)
14
15 #include <linux/args.h>
16
17 /* cast any integer, pointer, or small struct to u64 */
18 #define UINTTYPE(size) \
19         __typeof__(__builtin_choose_expr(size == 1,  (u8)1, \
20                    __builtin_choose_expr(size == 2, (u16)2, \
21                    __builtin_choose_expr(size == 4, (u32)3, \
22                    __builtin_choose_expr(size == 8, (u64)4, \
23                                          (void)5)))))
24 #define __CAST_TO_U64(x) ({ \
25         typeof(x) __src = (x); \
26         UINTTYPE(sizeof(x)) __dst; \
27         memcpy(&__dst, &__src, sizeof(__dst)); \
28         (u64)__dst; })
29
30 #define __CAST1(a,...) __CAST_TO_U64(a)
31 #define __CAST2(a,...) __CAST_TO_U64(a), __CAST1(__VA_ARGS__)
32 #define __CAST3(a,...) __CAST_TO_U64(a), __CAST2(__VA_ARGS__)
33 #define __CAST4(a,...) __CAST_TO_U64(a), __CAST3(__VA_ARGS__)
34 #define __CAST5(a,...) __CAST_TO_U64(a), __CAST4(__VA_ARGS__)
35 #define __CAST6(a,...) __CAST_TO_U64(a), __CAST5(__VA_ARGS__)
36 #define __CAST7(a,...) __CAST_TO_U64(a), __CAST6(__VA_ARGS__)
37 #define __CAST8(a,...) __CAST_TO_U64(a), __CAST7(__VA_ARGS__)
38 #define __CAST9(a,...) __CAST_TO_U64(a), __CAST8(__VA_ARGS__)
39 #define __CAST10(a,...) __CAST_TO_U64(a), __CAST9(__VA_ARGS__)
40 #define __CAST11(a,...) __CAST_TO_U64(a), __CAST10(__VA_ARGS__)
41 #define __CAST12(a,...) __CAST_TO_U64(a), __CAST11(__VA_ARGS__)
42 /* tracepoints with more than 12 arguments will hit build error */
43 #define CAST_TO_U64(...) CONCATENATE(__CAST, COUNT_ARGS(__VA_ARGS__))(__VA_ARGS__)
44
45 #define __BPF_DECLARE_TRACE(call, proto, args)                          \
46 static notrace void                                                     \
47 __bpf_trace_##call(void *__data, proto)                                 \
48 {                                                                       \
49         struct bpf_prog *prog = __data;                                 \
50         CONCATENATE(bpf_trace_run, COUNT_ARGS(args))(prog, CAST_TO_U64(args));  \
51 }
52
53 #undef DECLARE_EVENT_CLASS
54 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)  \
55         __BPF_DECLARE_TRACE(call, PARAMS(proto), PARAMS(args))
56
57 /*
58  * This part is compiled out, it is only here as a build time check
59  * to make sure that if the tracepoint handling changes, the
60  * bpf probe will fail to compile unless it too is updated.
61  */
62 #define __DEFINE_EVENT(template, call, proto, args, size)               \
63 static inline void bpf_test_probe_##call(void)                          \
64 {                                                                       \
65         check_trace_callback_type_##call(__bpf_trace_##template);       \
66 }                                                                       \
67 typedef void (*btf_trace_##call)(void *__data, proto);                  \
68 static union {                                                          \
69         struct bpf_raw_event_map event;                                 \
70         btf_trace_##call handler;                                       \
71 } __bpf_trace_tp_map_##call __used                                      \
72 __section("__bpf_raw_tp_map") = {                                       \
73         .event = {                                                      \
74                 .tp             = &__tracepoint_##call,                 \
75                 .bpf_func       = __bpf_trace_##template,               \
76                 .num_args       = COUNT_ARGS(args),                     \
77                 .writable_size  = size,                                 \
78         },                                                              \
79 };
80
81 #define FIRST(x, ...) x
82
83 #define __CHECK_WRITABLE_BUF_SIZE(call, proto, args, size)              \
84 static inline void bpf_test_buffer_##call(void)                         \
85 {                                                                       \
86         /* BUILD_BUG_ON() is ignored if the code is completely eliminated, but \
87          * BUILD_BUG_ON_ZERO() uses a different mechanism that is not   \
88          * dead-code-eliminated.                                        \
89          */                                                             \
90         FIRST(proto);                                                   \
91         (void)BUILD_BUG_ON_ZERO(size != sizeof(*FIRST(args)));          \
92 }
93
94 #undef DEFINE_EVENT_WRITABLE
95 #define DEFINE_EVENT_WRITABLE(template, call, proto, args, size) \
96         __CHECK_WRITABLE_BUF_SIZE(call, PARAMS(proto), PARAMS(args), size) \
97         __DEFINE_EVENT(template, call, PARAMS(proto), PARAMS(args), size)
98
99 #undef DEFINE_EVENT
100 #define DEFINE_EVENT(template, call, proto, args)                       \
101         __DEFINE_EVENT(template, call, PARAMS(proto), PARAMS(args), 0)
102
103 #undef DEFINE_EVENT_PRINT
104 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)  \
105         DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
106
107 #undef DECLARE_TRACE
108 #define DECLARE_TRACE(call, proto, args)                                \
109         __BPF_DECLARE_TRACE(call, PARAMS(proto), PARAMS(args))          \
110         __DEFINE_EVENT(call, call, PARAMS(proto), PARAMS(args), 0)
111
112 #undef DECLARE_TRACE_WRITABLE
113 #define DECLARE_TRACE_WRITABLE(call, proto, args, size) \
114         __CHECK_WRITABLE_BUF_SIZE(call, PARAMS(proto), PARAMS(args), size) \
115         __BPF_DECLARE_TRACE(call, PARAMS(proto), PARAMS(args)) \
116         __DEFINE_EVENT(call, call, PARAMS(proto), PARAMS(args), size)
117
118 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
119
120 #undef DECLARE_TRACE_WRITABLE
121 #undef DEFINE_EVENT_WRITABLE
122 #undef __CHECK_WRITABLE_BUF_SIZE
123 #undef __DEFINE_EVENT
124 #undef FIRST
125
126 #endif /* CONFIG_BPF_EVENTS */