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// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
#include "bpf_misc.h"
char _license[] SEC("license") = "GPL";
struct sample {
int pid;
int seq;
long value;
char comm[16];
};
struct {
__uint(type, BPF_MAP_TYPE_RINGBUF);
} ringbuf SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_HASH);
__uint(max_entries, 1000);
__type(key, struct sample);
__type(value, int);
} hash_map SEC(".maps");
/* inputs */
int pid = 0;
/* inner state */
long seq = 0;
SEC("fentry/" SYS_PREFIX "sys_getpgid")
int test_ringbuf_mem_map_key(void *ctx)
{
int cur_pid = bpf_get_current_pid_tgid() >> 32;
struct sample *sample, sample_copy;
int *lookup_val;
if (cur_pid != pid)
return 0;
sample = bpf_ringbuf_reserve(&ringbuf, sizeof(*sample), 0);
if (!sample)
return 0;
sample->pid = pid;
bpf_get_current_comm(sample->comm, sizeof(sample->comm));
sample->seq = ++seq;
sample->value = 42;
/* test using 'sample' (PTR_TO_MEM | MEM_ALLOC) as map key arg
*/
lookup_val = (int *)bpf_map_lookup_elem(&hash_map, sample);
/* workaround - memcpy is necessary so that verifier doesn't
* complain with:
* verifier internal error: more than one arg with ref_obj_id R3
* when trying to do bpf_map_update_elem(&hash_map, sample, &sample->seq, BPF_ANY);
*
* Since bpf_map_lookup_elem above uses 'sample' as key, test using
* sample field as value below
*/
__builtin_memcpy(&sample_copy, sample, sizeof(struct sample));
bpf_map_update_elem(&hash_map, &sample_copy, &sample->seq, BPF_ANY);
bpf_ringbuf_submit(sample, 0);
return 0;
}
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