1// SPDX-License-Identifier: GPL-2.0 2/* 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 arg 54 */ 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't 59 * complain with: 60 * verifier internal error: more than one arg with ref_obj_id R3 61 * 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 using 64 * sample field as value below 65 */ 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