linked_maps1.c (1851B)
1// SPDX-License-Identifier: GPL-2.0 2/* Copyright (c) 2021 Facebook */ 3 4#include "vmlinux.h" 5#include <bpf/bpf_helpers.h> 6#include <bpf/bpf_tracing.h> 7 8struct my_key { long x; }; 9struct my_value { long x; }; 10 11struct { 12 __uint(type, BPF_MAP_TYPE_HASH); 13 __type(key, struct my_key); 14 __type(value, struct my_value); 15 __uint(max_entries, 16); 16} map1 SEC(".maps"); 17 18 /* Matches map2 definition in linked_maps2.c. Order of the attributes doesn't 19 * matter. 20 */ 21typedef struct { 22 __uint(max_entries, 8); 23 __type(key, int); 24 __type(value, int); 25 __uint(type, BPF_MAP_TYPE_ARRAY); 26} map2_t; 27 28extern map2_t map2 SEC(".maps"); 29 30/* This should be the winning map definition, but we have no way of verifying, 31 * so we just make sure that it links and works without errors 32 */ 33struct { 34 __uint(type, BPF_MAP_TYPE_ARRAY); 35 __type(key, int); 36 __type(value, int); 37 __uint(max_entries, 16); 38} map_weak __weak SEC(".maps"); 39 40int output_first1; 41int output_second1; 42int output_weak1; 43 44SEC("raw_tp/sys_enter") 45int BPF_PROG(handler_enter1) 46{ 47 /* update values with key = 1 */ 48 int key = 1, val = 1; 49 struct my_key key_struct = { .x = 1 }; 50 struct my_value val_struct = { .x = 1000 }; 51 52 bpf_map_update_elem(&map1, &key_struct, &val_struct, 0); 53 bpf_map_update_elem(&map2, &key, &val, 0); 54 bpf_map_update_elem(&map_weak, &key, &val, 0); 55 56 return 0; 57} 58 59SEC("raw_tp/sys_exit") 60int BPF_PROG(handler_exit1) 61{ 62 /* lookup values with key = 2, set in another file */ 63 int key = 2, *val; 64 struct my_key key_struct = { .x = 2 }; 65 struct my_value *value_struct; 66 67 value_struct = bpf_map_lookup_elem(&map1, &key_struct); 68 if (value_struct) 69 output_first1 = value_struct->x; 70 71 val = bpf_map_lookup_elem(&map2, &key); 72 if (val) 73 output_second1 = *val; 74 75 val = bpf_map_lookup_elem(&map_weak, &key); 76 if (val) 77 output_weak1 = *val; 78 79 return 0; 80} 81 82char LICENSE[] SEC("license") = "GPL";