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#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)                          \
  46static notrace void                                                     \
  47__bpf_trace_##call(void *__data, proto)                                 \
  48{                                                                       \
  49        CONCATENATE(bpf_trace_run, COUNT_ARGS(args))(__data, CAST_TO_U64(args));        \
  50}
  51
  52#undef DECLARE_EVENT_CLASS
  53#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)  \
  54        __BPF_DECLARE_TRACE(call, PARAMS(proto), PARAMS(args))
  55
  56#define __BPF_DECLARE_TRACE_SYSCALL(call, proto, args)                  \
  57static notrace void                                                     \
  58__bpf_trace_##call(void *__data, proto)                                 \
  59{                                                                       \
  60        might_fault();                                                  \
  61        preempt_disable_notrace();                                      \
  62        CONCATENATE(bpf_trace_run, COUNT_ARGS(args))(__data, CAST_TO_U64(args));        \
  63        preempt_enable_notrace();                                       \
  64}
  65
  66#undef DECLARE_EVENT_SYSCALL_CLASS
  67#define DECLARE_EVENT_SYSCALL_CLASS(call, proto, args, tstruct, assign, print)  \
  68        __BPF_DECLARE_TRACE_SYSCALL(call, PARAMS(proto), PARAMS(args))
  69
  70/*
  71 * This part is compiled out, it is only here as a build time check
  72 * to make sure that if the tracepoint handling changes, the
  73 * bpf probe will fail to compile unless it too is updated.
  74 */
  75#define __DEFINE_EVENT(template, call, proto, args, size)               \
  76static inline void bpf_test_probe_##call(void)                          \
  77{                                                                       \
  78        check_trace_callback_type_##call(__bpf_trace_##template);       \
  79}                                                                       \
  80typedef void (*btf_trace_##call)(void *__data, proto);                  \
  81static union {                                                          \
  82        struct bpf_raw_event_map event;                                 \
  83        btf_trace_##call handler;                                       \
  84} __bpf_trace_tp_map_##call __used                                      \
  85__section("__bpf_raw_tp_map") = {                                       \
  86        .event = {                                                      \
  87                .tp             = &__tracepoint_##call,                 \
  88                .bpf_func       = __bpf_trace_##template,               \
  89                .num_args       = COUNT_ARGS(args),                     \
  90                .writable_size  = size,                                 \
  91        },                                                              \
  92};
  93
  94#define FIRST(x, ...) x
  95
  96#define __CHECK_WRITABLE_BUF_SIZE(call, proto, args, size)              \
  97static inline void bpf_test_buffer_##call(void)                         \
  98{                                                                       \
  99        /* BUILD_BUG_ON() is ignored if the code is completely eliminated, but \
 100         * BUILD_BUG_ON_ZERO() uses a different mechanism that is not   \
 101         * dead-code-eliminated.                                        \
 102         */                                                             \
 103        FIRST(proto);                                                   \
 104        (void)BUILD_BUG_ON_ZERO(size != sizeof(*FIRST(args)));          \
 105}
 106
 107#undef DEFINE_EVENT_WRITABLE
 108#define DEFINE_EVENT_WRITABLE(template, call, proto, args, size) \
 109        __CHECK_WRITABLE_BUF_SIZE(call, PARAMS(proto), PARAMS(args), size) \
 110        __DEFINE_EVENT(template, call, PARAMS(proto), PARAMS(args), size)
 111
 112#undef DEFINE_EVENT
 113#define DEFINE_EVENT(template, call, proto, args)                       \
 114        __DEFINE_EVENT(template, call, PARAMS(proto), PARAMS(args), 0)
 115
 116#undef DEFINE_EVENT_PRINT
 117#define DEFINE_EVENT_PRINT(template, name, proto, args, print)  \
 118        DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
 119
 120#undef DECLARE_TRACE
 121#define DECLARE_TRACE(call, proto, args)                                \
 122        __BPF_DECLARE_TRACE(call##_tp, PARAMS(proto), PARAMS(args))             \
 123        __DEFINE_EVENT(call##_tp, call##_tp, PARAMS(proto), PARAMS(args), 0)
 124
 125#undef DECLARE_TRACE_WRITABLE
 126#define DECLARE_TRACE_WRITABLE(call, proto, args, size) \
 127        __CHECK_WRITABLE_BUF_SIZE(call, PARAMS(proto), PARAMS(args), size) \
 128        __BPF_DECLARE_TRACE(call##_tp, PARAMS(proto), PARAMS(args)) \
 129        __DEFINE_EVENT(call##_tp, call##_tp, PARAMS(proto), PARAMS(args), size)
 130
 131#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 132
 133#undef DECLARE_TRACE_WRITABLE
 134#undef DEFINE_EVENT_WRITABLE
 135#undef __CHECK_WRITABLE_BUF_SIZE
 136#undef __DEFINE_EVENT
 137#undef FIRST
 138
 139#endif /* CONFIG_BPF_EVENTS */
 140