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, PARAMS(proto), PARAMS(args))		\
123	__DEFINE_EVENT(call, call, 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, PARAMS(proto), PARAMS(args)) \
129	__DEFINE_EVENT(call, call, 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 */