1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */ 3 #define BPF_NO_KFUNC_PROTOTYPES 4 #include <vmlinux.h> 5 #include <bpf/bpf_helpers.h> 6 #include <bpf/bpf_tracing.h> 7 #include <bpf/bpf_core_read.h> 8 #include "bpf_experimental.h" 9 10 struct { 11 __uint(type, BPF_MAP_TYPE_ARENA); 12 __uint(map_flags, BPF_F_MMAPABLE); 13 __uint(max_entries, 100); /* number of pages */ 14 } arena SEC(".maps"); 15 16 #include "bpf_arena_htab.h" 17 18 void __arena *htab_for_user; 19 bool skip = false; 20 21 int zero = 0; 22 char __arena arr1[100000]; 23 char arr2[1000]; 24 25 SEC("syscall") 26 int arena_htab_llvm(void *ctx) 27 { 28 #if defined(__BPF_FEATURE_ADDR_SPACE_CAST) || defined(BPF_ARENA_FORCE_ASM) 29 struct htab __arena *htab; 30 char __arena *arr = arr1; 31 __u64 i; 32 33 htab = bpf_alloc(sizeof(*htab)); 34 cast_kern(htab); 35 htab_init(htab); 36 37 cast_kern(arr); 38 39 /* first run. No old elems in the table */ 40 for (i = zero; i < 100000 && can_loop; i++) { 41 htab_update_elem(htab, i, i); 42 arr[i] = i; 43 } 44 45 /* should replace some elems with new ones */ 46 for (i = zero; i < 1000 && can_loop; i++) { 47 htab_update_elem(htab, i, i); 48 /* Access mem to make the verifier use bounded loop logic */ 49 arr2[i] = i; 50 } 51 cast_user(htab); 52 htab_for_user = htab; 53 #else 54 skip = true; 55 #endif 56 return 0; 57 } 58 59 char _license[] SEC("license") = "GPL"; 60