72 lines · c
1// SPDX-License-Identifier: GPL-2.02/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */3 4#include <linux/bpf.h>5#include <bpf/bpf_helpers.h>6#include "bpf_misc.h"7 8char _license[] SEC("license") = "GPL";9 10struct sample {11 int pid;12 int seq;13 long value;14 char comm[16];15};16 17struct {18 __uint(type, BPF_MAP_TYPE_RINGBUF);19} ringbuf SEC(".maps");20 21struct {22 __uint(type, BPF_MAP_TYPE_HASH);23 __uint(max_entries, 1000);24 __type(key, struct sample);25 __type(value, int);26} hash_map SEC(".maps");27 28/* inputs */29int pid = 0;30 31/* inner state */32long seq = 0;33 34SEC("fentry/" SYS_PREFIX "sys_getpgid")35int test_ringbuf_mem_map_key(void *ctx)36{37 int cur_pid = bpf_get_current_pid_tgid() >> 32;38 struct sample *sample, sample_copy;39 int *lookup_val;40 41 if (cur_pid != pid)42 return 0;43 44 sample = bpf_ringbuf_reserve(&ringbuf, sizeof(*sample), 0);45 if (!sample)46 return 0;47 48 sample->pid = pid;49 bpf_get_current_comm(sample->comm, sizeof(sample->comm));50 sample->seq = ++seq;51 sample->value = 42;52 53 /* test using 'sample' (PTR_TO_MEM | MEM_ALLOC) as map key arg54 */55 lookup_val = (int *)bpf_map_lookup_elem(&hash_map, sample);56 __sink(lookup_val);57 58 /* workaround - memcpy is necessary so that verifier doesn't59 * complain with:60 * verifier internal error: more than one arg with ref_obj_id R361 * when trying to do bpf_map_update_elem(&hash_map, sample, &sample->seq, BPF_ANY);62 *63 * Since bpf_map_lookup_elem above uses 'sample' as key, test using64 * sample field as value below65 */66 __builtin_memcpy(&sample_copy, sample, sizeof(struct sample));67 bpf_map_update_elem(&hash_map, &sample_copy, &sample->seq, BPF_ANY);68 69 bpf_ringbuf_submit(sample, 0);70 return 0;71}72