71 lines
1.6 KiB
C
71 lines
1.6 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
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#include <linux/bpf.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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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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struct {
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__uint(type, BPF_MAP_TYPE_HASH);
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__uint(max_entries, 1000);
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__type(key, struct sample);
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__type(value, int);
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} hash_map SEC(".maps");
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/* inputs */
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int pid = 0;
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/* inner state */
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long seq = 0;
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SEC("fentry/" SYS_PREFIX "sys_getpgid")
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int test_ringbuf_mem_map_key(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, sample_copy;
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int *lookup_val;
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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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bpf_get_current_comm(sample->comm, sizeof(sample->comm));
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sample->seq = ++seq;
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sample->value = 42;
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/* test using 'sample' (PTR_TO_MEM | MEM_ALLOC) as map key arg
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*/
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lookup_val = (int *)bpf_map_lookup_elem(&hash_map, sample);
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/* workaround - memcpy is necessary so that verifier doesn't
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* complain with:
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* verifier internal error: more than one arg with ref_obj_id R3
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* when trying to do bpf_map_update_elem(&hash_map, sample, &sample->seq, BPF_ANY);
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*
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* Since bpf_map_lookup_elem above uses 'sample' as key, test using
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* sample field as value below
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*/
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__builtin_memcpy(&sample_copy, sample, sizeof(struct sample));
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bpf_map_update_elem(&hash_map, &sample_copy, &sample->seq, BPF_ANY);
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bpf_ringbuf_submit(sample, 0);
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return 0;
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}
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