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65223741ae
Commit 9df1c28bb7 ("bpf: add writable context for raw tracepoints")
supports writable context for tracepoint, but it misses the support
for bare tracepoint which has no associated trace event.
Bare tracepoint is defined by DECLARE_TRACE(), so adding a corresponding
DECLARE_TRACE_WRITABLE() macro to generate a definition in __bpf_raw_tp_map
section for bare tracepoint in a similar way to DEFINE_TRACE_WRITABLE().
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211004094857.30868-2-hotforest@gmail.com
140 lines
4.7 KiB
C
140 lines
4.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#undef TRACE_SYSTEM_VAR
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#ifdef CONFIG_BPF_EVENTS
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#undef __entry
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#define __entry entry
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#undef __get_dynamic_array
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#define __get_dynamic_array(field) \
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((void *)__entry + (__entry->__data_loc_##field & 0xffff))
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#undef __get_dynamic_array_len
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#define __get_dynamic_array_len(field) \
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((__entry->__data_loc_##field >> 16) & 0xffff)
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#undef __get_str
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#define __get_str(field) ((char *)__get_dynamic_array(field))
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#undef __get_bitmask
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#define __get_bitmask(field) (char *)__get_dynamic_array(field)
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#undef __perf_count
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#define __perf_count(c) (c)
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#undef __perf_task
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#define __perf_task(t) (t)
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/* cast any integer, pointer, or small struct to u64 */
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#define UINTTYPE(size) \
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__typeof__(__builtin_choose_expr(size == 1, (u8)1, \
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__builtin_choose_expr(size == 2, (u16)2, \
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__builtin_choose_expr(size == 4, (u32)3, \
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__builtin_choose_expr(size == 8, (u64)4, \
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(void)5)))))
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#define __CAST_TO_U64(x) ({ \
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typeof(x) __src = (x); \
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UINTTYPE(sizeof(x)) __dst; \
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memcpy(&__dst, &__src, sizeof(__dst)); \
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(u64)__dst; })
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#define __CAST1(a,...) __CAST_TO_U64(a)
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#define __CAST2(a,...) __CAST_TO_U64(a), __CAST1(__VA_ARGS__)
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#define __CAST3(a,...) __CAST_TO_U64(a), __CAST2(__VA_ARGS__)
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#define __CAST4(a,...) __CAST_TO_U64(a), __CAST3(__VA_ARGS__)
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#define __CAST5(a,...) __CAST_TO_U64(a), __CAST4(__VA_ARGS__)
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#define __CAST6(a,...) __CAST_TO_U64(a), __CAST5(__VA_ARGS__)
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#define __CAST7(a,...) __CAST_TO_U64(a), __CAST6(__VA_ARGS__)
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#define __CAST8(a,...) __CAST_TO_U64(a), __CAST7(__VA_ARGS__)
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#define __CAST9(a,...) __CAST_TO_U64(a), __CAST8(__VA_ARGS__)
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#define __CAST10(a,...) __CAST_TO_U64(a), __CAST9(__VA_ARGS__)
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#define __CAST11(a,...) __CAST_TO_U64(a), __CAST10(__VA_ARGS__)
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#define __CAST12(a,...) __CAST_TO_U64(a), __CAST11(__VA_ARGS__)
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/* tracepoints with more than 12 arguments will hit build error */
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#define CAST_TO_U64(...) CONCATENATE(__CAST, COUNT_ARGS(__VA_ARGS__))(__VA_ARGS__)
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#define __BPF_DECLARE_TRACE(call, proto, args) \
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static notrace void \
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__bpf_trace_##call(void *__data, proto) \
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{ \
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struct bpf_prog *prog = __data; \
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CONCATENATE(bpf_trace_run, COUNT_ARGS(args))(prog, CAST_TO_U64(args)); \
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}
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#undef DECLARE_EVENT_CLASS
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#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
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__BPF_DECLARE_TRACE(call, PARAMS(proto), PARAMS(args))
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/*
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* This part is compiled out, it is only here as a build time check
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* to make sure that if the tracepoint handling changes, the
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* bpf probe will fail to compile unless it too is updated.
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*/
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#define __DEFINE_EVENT(template, call, proto, args, size) \
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static inline void bpf_test_probe_##call(void) \
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{ \
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check_trace_callback_type_##call(__bpf_trace_##template); \
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} \
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typedef void (*btf_trace_##call)(void *__data, proto); \
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static union { \
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struct bpf_raw_event_map event; \
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btf_trace_##call handler; \
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} __bpf_trace_tp_map_##call __used \
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__section("__bpf_raw_tp_map") = { \
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.event = { \
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.tp = &__tracepoint_##call, \
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.bpf_func = __bpf_trace_##template, \
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.num_args = COUNT_ARGS(args), \
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.writable_size = size, \
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}, \
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};
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#define FIRST(x, ...) x
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#define __CHECK_WRITABLE_BUF_SIZE(call, proto, args, size) \
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static inline void bpf_test_buffer_##call(void) \
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{ \
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/* BUILD_BUG_ON() is ignored if the code is completely eliminated, but \
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* BUILD_BUG_ON_ZERO() uses a different mechanism that is not \
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* dead-code-eliminated. \
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*/ \
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FIRST(proto); \
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(void)BUILD_BUG_ON_ZERO(size != sizeof(*FIRST(args))); \
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}
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#undef DEFINE_EVENT_WRITABLE
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#define DEFINE_EVENT_WRITABLE(template, call, proto, args, size) \
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__CHECK_WRITABLE_BUF_SIZE(call, PARAMS(proto), PARAMS(args), size) \
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__DEFINE_EVENT(template, call, PARAMS(proto), PARAMS(args), size)
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#undef DEFINE_EVENT
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#define DEFINE_EVENT(template, call, proto, args) \
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__DEFINE_EVENT(template, call, PARAMS(proto), PARAMS(args), 0)
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#undef DEFINE_EVENT_PRINT
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#define DEFINE_EVENT_PRINT(template, name, proto, args, print) \
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DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
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#undef DECLARE_TRACE
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#define DECLARE_TRACE(call, proto, args) \
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__BPF_DECLARE_TRACE(call, PARAMS(proto), PARAMS(args)) \
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__DEFINE_EVENT(call, call, PARAMS(proto), PARAMS(args), 0)
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#undef DECLARE_TRACE_WRITABLE
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#define DECLARE_TRACE_WRITABLE(call, proto, args, size) \
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__CHECK_WRITABLE_BUF_SIZE(call, PARAMS(proto), PARAMS(args), size) \
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__BPF_DECLARE_TRACE(call, PARAMS(proto), PARAMS(args)) \
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__DEFINE_EVENT(call, call, PARAMS(proto), PARAMS(args), size)
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#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
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#undef DECLARE_TRACE_WRITABLE
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#undef DEFINE_EVENT_WRITABLE
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#undef __CHECK_WRITABLE_BUF_SIZE
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#undef __DEFINE_EVENT
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#undef FIRST
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#endif /* CONFIG_BPF_EVENTS */
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