fa7f17d066
Add a writable bare tracepoint in bpf_testmod module, and trigger its calling when reading /sys/kernel/bpf_testmod with a specific buffer length. The reading will return the value in writable context if the early return flag is enabled in writable context. 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/20211004094857.30868-4-hotforest@gmail.com
58 lines
1.6 KiB
C
58 lines
1.6 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/* Copyright (c) 2020 Facebook */
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#undef TRACE_SYSTEM
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#define TRACE_SYSTEM bpf_testmod
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#if !defined(_BPF_TESTMOD_EVENTS_H) || defined(TRACE_HEADER_MULTI_READ)
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#define _BPF_TESTMOD_EVENTS_H
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#include <linux/tracepoint.h>
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#include "bpf_testmod.h"
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TRACE_EVENT(bpf_testmod_test_read,
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TP_PROTO(struct task_struct *task, struct bpf_testmod_test_read_ctx *ctx),
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TP_ARGS(task, ctx),
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TP_STRUCT__entry(
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__field(pid_t, pid)
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__array(char, comm, TASK_COMM_LEN)
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__field(loff_t, off)
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__field(size_t, len)
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),
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TP_fast_assign(
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__entry->pid = task->pid;
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memcpy(__entry->comm, task->comm, TASK_COMM_LEN);
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__entry->off = ctx->off;
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__entry->len = ctx->len;
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),
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TP_printk("pid=%d comm=%s off=%llu len=%zu",
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__entry->pid, __entry->comm, __entry->off, __entry->len)
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);
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/* A bare tracepoint with no event associated with it */
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DECLARE_TRACE(bpf_testmod_test_write_bare,
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TP_PROTO(struct task_struct *task, struct bpf_testmod_test_write_ctx *ctx),
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TP_ARGS(task, ctx)
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);
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#undef BPF_TESTMOD_DECLARE_TRACE
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#ifdef DECLARE_TRACE_WRITABLE
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#define BPF_TESTMOD_DECLARE_TRACE(call, proto, args, size) \
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DECLARE_TRACE_WRITABLE(call, PARAMS(proto), PARAMS(args), size)
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#else
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#define BPF_TESTMOD_DECLARE_TRACE(call, proto, args, size) \
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DECLARE_TRACE(call, PARAMS(proto), PARAMS(args))
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#endif
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BPF_TESTMOD_DECLARE_TRACE(bpf_testmod_test_writable_bare,
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TP_PROTO(struct bpf_testmod_test_writable_ctx *ctx),
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TP_ARGS(ctx),
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sizeof(struct bpf_testmod_test_writable_ctx)
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);
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#endif /* _BPF_TESTMOD_EVENTS_H */
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#undef TRACE_INCLUDE_PATH
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#define TRACE_INCLUDE_PATH .
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#define TRACE_INCLUDE_FILE bpf_testmod-events
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#include <trace/define_trace.h>
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