23a6576606
Replace hardcoded 4096 with runtime value in the userspace part of the test and set bpf table sizes dynamically according to the value. Do not switch to ASSERT macros, keep CHECK, for consistency with the rest of the test. Can be a separate cleanup patch. Signed-off-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210408061310.95877-6-yauheni.kaliuta@redhat.com
78 lines
1.5 KiB
C
78 lines
1.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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// Copyright (c) 2020 Facebook
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#include <linux/bpf.h>
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#include <bpf/bpf_helpers.h>
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char _license[] SEC("license") = "GPL";
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struct sample {
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int pid;
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int seq;
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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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/* inputs */
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int pid = 0;
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long value = 0;
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long flags = 0;
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/* outputs */
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long total = 0;
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long discarded = 0;
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long dropped = 0;
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long avail_data = 0;
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long ring_size = 0;
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long cons_pos = 0;
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long prod_pos = 0;
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/* inner state */
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long seq = 0;
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SEC("tp/syscalls/sys_enter_getpgid")
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int test_ringbuf(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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int zero = 0;
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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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__sync_fetch_and_add(&dropped, 1);
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return 1;
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}
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sample->pid = pid;
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bpf_get_current_comm(sample->comm, sizeof(sample->comm));
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sample->value = value;
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sample->seq = seq++;
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__sync_fetch_and_add(&total, 1);
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if (sample->seq & 1) {
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/* copy from reserved sample to a new one... */
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bpf_ringbuf_output(&ringbuf, sample, sizeof(*sample), flags);
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/* ...and then discard reserved sample */
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bpf_ringbuf_discard(sample, flags);
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__sync_fetch_and_add(&discarded, 1);
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} else {
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bpf_ringbuf_submit(sample, flags);
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}
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avail_data = bpf_ringbuf_query(&ringbuf, BPF_RB_AVAIL_DATA);
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ring_size = bpf_ringbuf_query(&ringbuf, BPF_RB_RING_SIZE);
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cons_pos = bpf_ringbuf_query(&ringbuf, BPF_RB_CONS_POS);
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prod_pos = bpf_ringbuf_query(&ringbuf, BPF_RB_PROD_POS);
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return 0;
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}
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