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-rw-r--r--include/trace/bpf_probe.h126
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 */