LXR linux/include/trace/bpf

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