638a485c49
Add a testcase for the ring_buffer__consume_n() API. The test produces multiple samples in a ring buffer, using a sys_getpid() fentry prog, and consumes them from user-space in batches, rather than consuming all of them greedily, like ring_buffer__consume() does. Signed-off-by: Andrea Righi <andrea.righi@canonical.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/lkml/CAEf4BzaR4zqUpDmj44KNLdpJ=Tpa97GrvzuzVNO5nM6b7oWd1w@mail.gmail.com Link: https://lore.kernel.org/bpf/20240425140627.112728-1-andrea.righi@canonical.com
47 lines
860 B
C
47 lines
860 B
C
// SPDX-License-Identifier: GPL-2.0
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// Copyright (c) 2024 Andrea Righi <andrea.righi@canonical.com>
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#include <linux/bpf.h>
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#include <sched.h>
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#include <unistd.h>
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#include <bpf/bpf_helpers.h>
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#include "bpf_misc.h"
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char _license[] SEC("license") = "GPL";
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#define TASK_COMM_LEN 16
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struct sample {
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int pid;
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long value;
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char comm[16];
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};
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struct {
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__uint(type, BPF_MAP_TYPE_RINGBUF);
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} ringbuf SEC(".maps");
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int pid = 0;
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long value = 0;
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SEC("fentry/" SYS_PREFIX "sys_getpgid")
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int test_ringbuf_n(void *ctx)
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{
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int cur_pid = bpf_get_current_pid_tgid() >> 32;
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struct sample *sample;
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if (cur_pid != pid)
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return 0;
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sample = bpf_ringbuf_reserve(&ringbuf, sizeof(*sample), 0);
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if (!sample)
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return 0;
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sample->pid = pid;
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sample->value = value;
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bpf_get_current_comm(sample->comm, sizeof(sample->comm));
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bpf_ringbuf_submit(sample, 0);
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return 0;
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}
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