include/trace/bpf_probe.h

   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)  \
  60 static 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)               \
  73 static inline void bpf_test_probe_##call(void)                          \
  74 {                                                                       \
  75         check_trace_callback_type_##call(__bpf_trace_##template);       \
  76 }                                                                       \
  77 static struct bpf_raw_event_map __used                                  \
  78         __attribute__((section("__bpf_raw_tp_map")))                    \
  79 __bpf_trace_tp_map_##call = {                                           \
  80         .tp             = &__tracepoint_##call,                         \
  81         .bpf_func       = (void *)__bpf_trace_##template,               \
  82         .num_args       = COUNT_ARGS(args),                             \
  83         .writable_size  = size,                                         \
  84 };
  85
  86 #define FIRST(x, ...) x
  87
  88 #undef DEFINE_EVENT_WRITABLE
  89 #define DEFINE_EVENT_WRITABLE(template, call, proto, args, size)        \
  90 static inline void bpf_test_buffer_##call(void)                         \
  91 {                                                                       \
  92         /* BUILD_BUG_ON() is ignored if the code is completely eliminated, but \
  93          * BUILD_BUG_ON_ZERO() uses a different mechanism that is not   \
  94          * dead-code-eliminated.                                        \
  95          */                                                             \
  96         FIRST(proto);                                                   \
  97         (void)BUILD_BUG_ON_ZERO(size != sizeof(*FIRST(args)));          \
  98 }                                                                       \
  99 __DEFINE_EVENT(template, call, PARAMS(proto), PARAMS(args), size)
 100
 101 #undef DEFINE_EVENT
 102 #define DEFINE_EVENT(template, call, proto, args)                       \
 103         __DEFINE_EVENT(template, call, PARAMS(proto), PARAMS(args), 0)
 104
 105 #undef DEFINE_EVENT_PRINT
 106 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)  \
 107         DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
 108
 109 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 110
 111 #undef DEFINE_EVENT_WRITABLE
 112 #undef __DEFINE_EVENT
 113 #undef FIRST
 114
 115 #endif /* CONFIG_BPF_EVENTS */