1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2020 Tessares SA <http://www.tessares.net> */ 3 4 #include "vmlinux.h" 5 #include <bpf/bpf_helpers.h> 6 7 __u64 inKey = 0; 8 __u64 inValue = 0; 9 __u32 inPid = 0; 10 11 struct { 12 __uint(type, BPF_MAP_TYPE_PERCPU_HASH); 13 __uint(max_entries, 2); 14 __type(key, __u64); 15 __type(value, __u64); 16 } hashmap1 SEC(".maps"); 17 18 19 SEC("tp/syscalls/sys_enter_getpgid") 20 int sysenter_getpgid(const void *ctx) 21 { 22 /* Just do it for once, when called from our own test prog. This 23 * ensures the map value is only updated for a single CPU. 24 */ 25 int cur_pid = bpf_get_current_pid_tgid() >> 32; 26 27 if (cur_pid == inPid) 28 bpf_map_update_elem(&hashmap1, &inKey, &inValue, BPF_NOEXIST); 29 30 return 0; 31 } 32 33 char _license[] SEC("license") = "GPL"; 34