// SPDX-License-Identifier: GPL-2.0 // Copyright (c) 2024 Andrea Righi <andrea.righi@canonical.com> #include <linux/bpf.h> #include <sched.h> #include <unistd.h> #include <bpf/bpf_helpers.h> #include "bpf_misc.h" char _license[] SEC("license") = "GPL"; #define TASK_COMM_LEN 16 struct sample { int pid; long value; char comm[16]; }; struct { __uint(type, BPF_MAP_TYPE_RINGBUF); } ringbuf SEC(".maps"); int pid = 0; long value = 0; SEC("fentry/" SYS_PREFIX "sys_getpgid") int test_ringbuf_n(void *ctx) { int cur_pid = bpf_get_current_pid_tgid() >> 32; struct sample *sample; if (cur_pid != pid) return 0; sample = bpf_ringbuf_reserve(&ringbuf, sizeof(*sample), 0); if (!sample) return 0; sample->pid = pid; sample->value = value; bpf_get_current_comm(sample->comm, sizeof(sample->comm)); bpf_ringbuf_submit(sample, 0); return 0; }