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 __get_rel_dynamic_array
  25 #define __get_rel_dynamic_array(field)  \
  26                 ((void *)(&__entry->__rel_loc_##field) +        \
  27                  sizeof(__entry->__rel_loc_##field) +           \
  28                  (__entry->__rel_loc_##field & 0xffff))
  29
  30 #undef __get_rel_dynamic_array_len
  31 #define __get_rel_dynamic_array_len(field)      \
  32                 ((__entry->__rel_loc_##field >> 16) & 0xffff)
  33
  34 #undef __get_rel_str
  35 #define __get_rel_str(field) ((char *)__get_rel_dynamic_array(field))
  36
  37 #undef __get_rel_bitmask
  38 #define __get_rel_bitmask(field) (char *)__get_rel_dynamic_array(field)
  39
  40 #undef __perf_count
  41 #define __perf_count(c) (c)
  42
  43 #undef __perf_task
  44 #define __perf_task(t)  (t)
  45
  46 /* cast any integer, pointer, or small struct to u64 */
  47 #define UINTTYPE(size) \
  48         __typeof__(__builtin_choose_expr(size == 1,  (u8)1, \
  49                    __builtin_choose_expr(size == 2, (u16)2, \
  50                    __builtin_choose_expr(size == 4, (u32)3, \
  51                    __builtin_choose_expr(size == 8, (u64)4, \
  52                                          (void)5)))))
  53 #define __CAST_TO_U64(x) ({ \
  54         typeof(x) __src = (x); \
  55         UINTTYPE(sizeof(x)) __dst; \
  56         memcpy(&__dst, &__src, sizeof(__dst)); \
  57         (u64)__dst; })
  58
  59 #define __CAST1(a,...) __CAST_TO_U64(a)
  60 #define __CAST2(a,...) __CAST_TO_U64(a), __CAST1(__VA_ARGS__)
  61 #define __CAST3(a,...) __CAST_TO_U64(a), __CAST2(__VA_ARGS__)
  62 #define __CAST4(a,...) __CAST_TO_U64(a), __CAST3(__VA_ARGS__)
  63 #define __CAST5(a,...) __CAST_TO_U64(a), __CAST4(__VA_ARGS__)
  64 #define __CAST6(a,...) __CAST_TO_U64(a), __CAST5(__VA_ARGS__)
  65 #define __CAST7(a,...) __CAST_TO_U64(a), __CAST6(__VA_ARGS__)
  66 #define __CAST8(a,...) __CAST_TO_U64(a), __CAST7(__VA_ARGS__)
  67 #define __CAST9(a,...) __CAST_TO_U64(a), __CAST8(__VA_ARGS__)
  68 #define __CAST10(a,...) __CAST_TO_U64(a), __CAST9(__VA_ARGS__)
  69 #define __CAST11(a,...) __CAST_TO_U64(a), __CAST10(__VA_ARGS__)
  70 #define __CAST12(a,...) __CAST_TO_U64(a), __CAST11(__VA_ARGS__)
  71 /* tracepoints with more than 12 arguments will hit build error */
  72 #define CAST_TO_U64(...) CONCATENATE(__CAST, COUNT_ARGS(__VA_ARGS__))(__VA_ARGS__)
  73
  74 #define __BPF_DECLARE_TRACE(call, proto, args)                          \
  75 static notrace void                                                     \
  76 __bpf_trace_##call(void *__data, proto)                                 \
  77 {                                                                       \
  78         struct bpf_prog *prog = __data;                                 \
  79         CONCATENATE(bpf_trace_run, COUNT_ARGS(args))(prog, CAST_TO_U64(args));  \
  80 }
  81
  82 #undef DECLARE_EVENT_CLASS
  83 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)  \
  84         __BPF_DECLARE_TRACE(call, PARAMS(proto), PARAMS(args))
  85
  86 /*
  87  * This part is compiled out, it is only here as a build time check
  88  * to make sure that if the tracepoint handling changes, the
  89  * bpf probe will fail to compile unless it too is updated.
  90  */
  91 #define __DEFINE_EVENT(template, call, proto, args, size)               \
  92 static inline void bpf_test_probe_##call(void)                          \
  93 {                                                                       \
  94         check_trace_callback_type_##call(__bpf_trace_##template);       \
  95 }                                                                       \
  96 typedef void (*btf_trace_##call)(void *__data, proto);                  \
  97 static union {                                                          \
  98         struct bpf_raw_event_map event;                                 \
  99         btf_trace_##call handler;                                       \
 100 } __bpf_trace_tp_map_##call __used                                      \
 101 __section("__bpf_raw_tp_map") = {                                       \
 102         .event = {                                                      \
 103                 .tp             = &__tracepoint_##call,                 \
 104                 .bpf_func       = __bpf_trace_##template,               \
 105                 .num_args       = COUNT_ARGS(args),                     \
 106                 .writable_size  = size,                                 \
 107         },                                                              \
 108 };
 109
 110 #define FIRST(x, ...) x
 111
 112 #undef DEFINE_EVENT_WRITABLE
 113 #define DEFINE_EVENT_WRITABLE(template, call, proto, args, size)        \
 114 static inline void bpf_test_buffer_##call(void)                         \
 115 {                                                                       \
 116         /* BUILD_BUG_ON() is ignored if the code is completely eliminated, but \
 117          * BUILD_BUG_ON_ZERO() uses a different mechanism that is not   \
 118          * dead-code-eliminated.                                        \
 119          */                                                             \
 120         FIRST(proto);                                                   \
 121         (void)BUILD_BUG_ON_ZERO(size != sizeof(*FIRST(args)));          \
 122 }                                                                       \
 123 __DEFINE_EVENT(template, call, PARAMS(proto), PARAMS(args), size)
 124
 125 #undef DEFINE_EVENT
 126 #define DEFINE_EVENT(template, call, proto, args)                       \
 127         __DEFINE_EVENT(template, call, PARAMS(proto), PARAMS(args), 0)
 128
 129 #undef DEFINE_EVENT_PRINT
 130 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)  \
 131         DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
 132
 133 #undef DECLARE_TRACE
 134 #define DECLARE_TRACE(call, proto, args)                                \
 135         __BPF_DECLARE_TRACE(call, PARAMS(proto), PARAMS(args))          \
 136         __DEFINE_EVENT(call, call, PARAMS(proto), PARAMS(args), 0)
 137
 138 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 139
 140 #undef DEFINE_EVENT_WRITABLE
 141 #undef __DEFINE_EVENT
 142 #undef FIRST
 143
 144 #endif /* CONFIG_BPF_EVENTS */