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_cpumask
  25 #define __get_cpumask(field) (char *)__get_dynamic_array(field)
  26
  27 #undef __get_sockaddr
  28 #define __get_sockaddr(field) ((struct sockaddr *)__get_dynamic_array(field))
  29
  30 #undef __get_rel_dynamic_array
  31 #define __get_rel_dynamic_array(field)  \
  32                 ((void *)(&__entry->__rel_loc_##field) +        \
  33                  sizeof(__entry->__rel_loc_##field) +           \
  34                  (__entry->__rel_loc_##field & 0xffff))
  35
  36 #undef __get_rel_dynamic_array_len
  37 #define __get_rel_dynamic_array_len(field)      \
  38                 ((__entry->__rel_loc_##field >> 16) & 0xffff)
  39
  40 #undef __get_rel_str
  41 #define __get_rel_str(field) ((char *)__get_rel_dynamic_array(field))
  42
  43 #undef __get_rel_bitmask
  44 #define __get_rel_bitmask(field) (char *)__get_rel_dynamic_array(field)
  45
  46 #undef __get_rel_cpumask
  47 #define __get_rel_cpumask(field) (char *)__get_rel_dynamic_array(field)
  48
  49 #undef __get_rel_sockaddr
  50 #define __get_rel_sockaddr(field) ((struct sockaddr *)__get_rel_dynamic_array(field))
  51
  52 #undef __perf_count
  53 #define __perf_count(c) (c)
  54
  55 #undef __perf_task
  56 #define __perf_task(t)  (t)
  57
  58 /* cast any integer, pointer, or small struct to u64 */
  59 #define UINTTYPE(size) \
  60         __typeof__(__builtin_choose_expr(size == 1,  (u8)1, \
  61                    __builtin_choose_expr(size == 2, (u16)2, \
  62                    __builtin_choose_expr(size == 4, (u32)3, \
  63                    __builtin_choose_expr(size == 8, (u64)4, \
  64                                          (void)5)))))
  65 #define __CAST_TO_U64(x) ({ \
  66         typeof(x) __src = (x); \
  67         UINTTYPE(sizeof(x)) __dst; \
  68         memcpy(&__dst, &__src, sizeof(__dst)); \
  69         (u64)__dst; })
  70
  71 #define __CAST1(a,...) __CAST_TO_U64(a)
  72 #define __CAST2(a,...) __CAST_TO_U64(a), __CAST1(__VA_ARGS__)
  73 #define __CAST3(a,...) __CAST_TO_U64(a), __CAST2(__VA_ARGS__)
  74 #define __CAST4(a,...) __CAST_TO_U64(a), __CAST3(__VA_ARGS__)
  75 #define __CAST5(a,...) __CAST_TO_U64(a), __CAST4(__VA_ARGS__)
  76 #define __CAST6(a,...) __CAST_TO_U64(a), __CAST5(__VA_ARGS__)
  77 #define __CAST7(a,...) __CAST_TO_U64(a), __CAST6(__VA_ARGS__)
  78 #define __CAST8(a,...) __CAST_TO_U64(a), __CAST7(__VA_ARGS__)
  79 #define __CAST9(a,...) __CAST_TO_U64(a), __CAST8(__VA_ARGS__)
  80 #define __CAST10(a,...) __CAST_TO_U64(a), __CAST9(__VA_ARGS__)
  81 #define __CAST11(a,...) __CAST_TO_U64(a), __CAST10(__VA_ARGS__)
  82 #define __CAST12(a,...) __CAST_TO_U64(a), __CAST11(__VA_ARGS__)
  83 /* tracepoints with more than 12 arguments will hit build error */
  84 #define CAST_TO_U64(...) CONCATENATE(__CAST, COUNT_ARGS(__VA_ARGS__))(__VA_ARGS__)
  85
  86 #define __BPF_DECLARE_TRACE(call, proto, args)                          \
  87 static notrace void                                                     \
  88 __bpf_trace_##call(void *__data, proto)                                 \
  89 {                                                                       \
  90         struct bpf_prog *prog = __data;                                 \
  91         CONCATENATE(bpf_trace_run, COUNT_ARGS(args))(prog, CAST_TO_U64(args));  \
  92 }
  93
  94 #undef DECLARE_EVENT_CLASS
  95 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)  \
  96         __BPF_DECLARE_TRACE(call, PARAMS(proto), PARAMS(args))
  97
  98 /*
  99  * This part is compiled out, it is only here as a build time check
 100  * to make sure that if the tracepoint handling changes, the
 101  * bpf probe will fail to compile unless it too is updated.
 102  */
 103 #define __DEFINE_EVENT(template, call, proto, args, size)               \
 104 static inline void bpf_test_probe_##call(void)                          \
 105 {                                                                       \
 106         check_trace_callback_type_##call(__bpf_trace_##template);       \
 107 }                                                                       \
 108 typedef void (*btf_trace_##call)(void *__data, proto);                  \
 109 static union {                                                          \
 110         struct bpf_raw_event_map event;                                 \
 111         btf_trace_##call handler;                                       \
 112 } __bpf_trace_tp_map_##call __used                                      \
 113 __section("__bpf_raw_tp_map") = {                                       \
 114         .event = {                                                      \
 115                 .tp             = &__tracepoint_##call,                 \
 116                 .bpf_func       = __bpf_trace_##template,               \
 117                 .num_args       = COUNT_ARGS(args),                     \
 118                 .writable_size  = size,                                 \
 119         },                                                              \
 120 };
 121
 122 #define FIRST(x, ...) x
 123
 124 #define __CHECK_WRITABLE_BUF_SIZE(call, proto, args, size)              \
 125 static inline void bpf_test_buffer_##call(void)                         \
 126 {                                                                       \
 127         /* BUILD_BUG_ON() is ignored if the code is completely eliminated, but \
 128          * BUILD_BUG_ON_ZERO() uses a different mechanism that is not   \
 129          * dead-code-eliminated.                                        \
 130          */                                                             \
 131         FIRST(proto);                                                   \
 132         (void)BUILD_BUG_ON_ZERO(size != sizeof(*FIRST(args)));          \
 133 }
 134
 135 #undef DEFINE_EVENT_WRITABLE
 136 #define DEFINE_EVENT_WRITABLE(template, call, proto, args, size) \
 137         __CHECK_WRITABLE_BUF_SIZE(call, PARAMS(proto), PARAMS(args), size) \
 138         __DEFINE_EVENT(template, call, PARAMS(proto), PARAMS(args), size)
 139
 140 #undef DEFINE_EVENT
 141 #define DEFINE_EVENT(template, call, proto, args)                       \
 142         __DEFINE_EVENT(template, call, PARAMS(proto), PARAMS(args), 0)
 143
 144 #undef DEFINE_EVENT_PRINT
 145 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)  \
 146         DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
 147
 148 #undef DECLARE_TRACE
 149 #define DECLARE_TRACE(call, proto, args)                                \
 150         __BPF_DECLARE_TRACE(call, PARAMS(proto), PARAMS(args))          \
 151         __DEFINE_EVENT(call, call, PARAMS(proto), PARAMS(args), 0)
 152
 153 #undef DECLARE_TRACE_WRITABLE
 154 #define DECLARE_TRACE_WRITABLE(call, proto, args, size) \
 155         __CHECK_WRITABLE_BUF_SIZE(call, PARAMS(proto), PARAMS(args), size) \
 156         __BPF_DECLARE_TRACE(call, PARAMS(proto), PARAMS(args)) \
 157         __DEFINE_EVENT(call, call, PARAMS(proto), PARAMS(args), size)
 158
 159 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 160
 161 #undef DECLARE_TRACE_WRITABLE
 162 #undef DEFINE_EVENT_WRITABLE
 163 #undef __CHECK_WRITABLE_BUF_SIZE
 164 #undef __DEFINE_EVENT
 165 #undef FIRST
 166
 167 #endif /* CONFIG_BPF_EVENTS */