diff options
Diffstat (limited to 'include/trace/bpf_probe.h')
| -rw-r--r-- | include/trace/bpf_probe.h | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/include/trace/bpf_probe.h b/include/trace/bpf_probe.h new file mode 100644 index 0000000000..e609cd7da4 --- /dev/null +++ b/include/trace/bpf_probe.h @@ -0,0 +1,126 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#undef TRACE_SYSTEM_VAR + +#ifdef CONFIG_BPF_EVENTS + +#include "stages/stage6_event_callback.h" + +#undef __perf_count +#define __perf_count(c) (c) + +#undef __perf_task +#define __perf_task(t) (t) + +#include <linux/args.h> + +/* cast any integer, pointer, or small struct to u64 */ +#define UINTTYPE(size) \ + __typeof__(__builtin_choose_expr(size == 1, (u8)1, \ + __builtin_choose_expr(size == 2, (u16)2, \ + __builtin_choose_expr(size == 4, (u32)3, \ + __builtin_choose_expr(size == 8, (u64)4, \ + (void)5))))) +#define __CAST_TO_U64(x) ({ \ + typeof(x) __src = (x); \ + UINTTYPE(sizeof(x)) __dst; \ + memcpy(&__dst, &__src, sizeof(__dst)); \ + (u64)__dst; }) + +#define __CAST1(a,...) __CAST_TO_U64(a) +#define __CAST2(a,...) __CAST_TO_U64(a), __CAST1(__VA_ARGS__) +#define __CAST3(a,...) __CAST_TO_U64(a), __CAST2(__VA_ARGS__) +#define __CAST4(a,...) __CAST_TO_U64(a), __CAST3(__VA_ARGS__) +#define __CAST5(a,...) __CAST_TO_U64(a), __CAST4(__VA_ARGS__) +#define __CAST6(a,...) __CAST_TO_U64(a), __CAST5(__VA_ARGS__) +#define __CAST7(a,...) __CAST_TO_U64(a), __CAST6(__VA_ARGS__) +#define __CAST8(a,...) __CAST_TO_U64(a), __CAST7(__VA_ARGS__) +#define __CAST9(a,...) __CAST_TO_U64(a), __CAST8(__VA_ARGS__) +#define __CAST10(a,...) __CAST_TO_U64(a), __CAST9(__VA_ARGS__) +#define __CAST11(a,...) __CAST_TO_U64(a), __CAST10(__VA_ARGS__) +#define __CAST12(a,...) __CAST_TO_U64(a), __CAST11(__VA_ARGS__) +/* tracepoints with more than 12 arguments will hit build error */ +#define CAST_TO_U64(...) CONCATENATE(__CAST, COUNT_ARGS(__VA_ARGS__))(__VA_ARGS__) + +#define __BPF_DECLARE_TRACE(call, proto, args) \ +static notrace void \ +__bpf_trace_##call(void *__data, proto) \ +{ \ + struct bpf_prog *prog = __data; \ + CONCATENATE(bpf_trace_run, COUNT_ARGS(args))(prog, CAST_TO_U64(args)); \ +} + +#undef DECLARE_EVENT_CLASS +#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ + __BPF_DECLARE_TRACE(call, PARAMS(proto), PARAMS(args)) + +/* + * This part is compiled out, it is only here as a build time check + * to make sure that if the tracepoint handling changes, the + * bpf probe will fail to compile unless it too is updated. + */ +#define __DEFINE_EVENT(template, call, proto, args, size) \ +static inline void bpf_test_probe_##call(void) \ +{ \ + check_trace_callback_type_##call(__bpf_trace_##template); \ +} \ +typedef void (*btf_trace_##call)(void *__data, proto); \ +static union { \ + struct bpf_raw_event_map event; \ + btf_trace_##call handler; \ +} __bpf_trace_tp_map_##call __used \ +__section("__bpf_raw_tp_map") = { \ + .event = { \ + .tp = &__tracepoint_##call, \ + .bpf_func = __bpf_trace_##template, \ + .num_args = COUNT_ARGS(args), \ + .writable_size = size, \ + }, \ +}; + +#define FIRST(x, ...) x + +#define __CHECK_WRITABLE_BUF_SIZE(call, proto, args, size) \ +static inline void bpf_test_buffer_##call(void) \ +{ \ + /* BUILD_BUG_ON() is ignored if the code is completely eliminated, but \ + * BUILD_BUG_ON_ZERO() uses a different mechanism that is not \ + * dead-code-eliminated. \ + */ \ + FIRST(proto); \ + (void)BUILD_BUG_ON_ZERO(size != sizeof(*FIRST(args))); \ +} + +#undef DEFINE_EVENT_WRITABLE +#define DEFINE_EVENT_WRITABLE(template, call, proto, args, size) \ + __CHECK_WRITABLE_BUF_SIZE(call, PARAMS(proto), PARAMS(args), size) \ + __DEFINE_EVENT(template, call, PARAMS(proto), PARAMS(args), size) + +#undef DEFINE_EVENT +#define DEFINE_EVENT(template, call, proto, args) \ + __DEFINE_EVENT(template, call, PARAMS(proto), PARAMS(args), 0) + +#undef DEFINE_EVENT_PRINT +#define DEFINE_EVENT_PRINT(template, name, proto, args, print) \ + DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args)) + +#undef DECLARE_TRACE +#define DECLARE_TRACE(call, proto, args) \ + __BPF_DECLARE_TRACE(call, PARAMS(proto), PARAMS(args)) \ + __DEFINE_EVENT(call, call, PARAMS(proto), PARAMS(args), 0) + +#undef DECLARE_TRACE_WRITABLE +#define DECLARE_TRACE_WRITABLE(call, proto, args, size) \ + __CHECK_WRITABLE_BUF_SIZE(call, PARAMS(proto), PARAMS(args), size) \ + __BPF_DECLARE_TRACE(call, PARAMS(proto), PARAMS(args)) \ + __DEFINE_EVENT(call, call, PARAMS(proto), PARAMS(args), size) + +#include TRACE_INCLUDE(TRACE_INCLUDE_FILE) + +#undef DECLARE_TRACE_WRITABLE +#undef DEFINE_EVENT_WRITABLE +#undef __CHECK_WRITABLE_BUF_SIZE +#undef __DEFINE_EVENT +#undef FIRST + +#endif /* CONFIG_BPF_EVENTS */ |