xref: /openbmc/linux/tools/testing/selftests/bpf/progs/test_map_init.c (revision cdd38c5f1ce4398ec58fec95904b75824daab7b5)
1*d3bec013SDavid Verbeiren // SPDX-License-Identifier: GPL-2.0
2*d3bec013SDavid Verbeiren /* Copyright (c) 2020 Tessares SA <http://www.tessares.net> */
3*d3bec013SDavid Verbeiren 
4*d3bec013SDavid Verbeiren #include "vmlinux.h"
5*d3bec013SDavid Verbeiren #include <bpf/bpf_helpers.h>
6*d3bec013SDavid Verbeiren 
7*d3bec013SDavid Verbeiren __u64 inKey = 0;
8*d3bec013SDavid Verbeiren __u64 inValue = 0;
9*d3bec013SDavid Verbeiren __u32 inPid = 0;
10*d3bec013SDavid Verbeiren 
11*d3bec013SDavid Verbeiren struct {
12*d3bec013SDavid Verbeiren 	__uint(type, BPF_MAP_TYPE_PERCPU_HASH);
13*d3bec013SDavid Verbeiren 	__uint(max_entries, 2);
14*d3bec013SDavid Verbeiren 	__type(key, __u64);
15*d3bec013SDavid Verbeiren 	__type(value, __u64);
16*d3bec013SDavid Verbeiren } hashmap1 SEC(".maps");
17*d3bec013SDavid Verbeiren 
18*d3bec013SDavid Verbeiren 
19*d3bec013SDavid Verbeiren SEC("tp/syscalls/sys_enter_getpgid")
sysenter_getpgid(const void * ctx)20*d3bec013SDavid Verbeiren int sysenter_getpgid(const void *ctx)
21*d3bec013SDavid Verbeiren {
22*d3bec013SDavid Verbeiren 	/* Just do it for once, when called from our own test prog. This
23*d3bec013SDavid Verbeiren 	 * ensures the map value is only updated for a single CPU.
24*d3bec013SDavid Verbeiren 	 */
25*d3bec013SDavid Verbeiren 	int cur_pid = bpf_get_current_pid_tgid() >> 32;
26*d3bec013SDavid Verbeiren 
27*d3bec013SDavid Verbeiren 	if (cur_pid == inPid)
28*d3bec013SDavid Verbeiren 		bpf_map_update_elem(&hashmap1, &inKey, &inValue, BPF_NOEXIST);
29*d3bec013SDavid Verbeiren 
30*d3bec013SDavid Verbeiren 	return 0;
31*d3bec013SDavid Verbeiren }
32*d3bec013SDavid Verbeiren 
33*d3bec013SDavid Verbeiren char _license[] SEC("license") = "GPL";
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