1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */ 3 4 #define BPF_NO_KFUNC_PROTOTYPES 5 #include <vmlinux.h> 6 #include <bpf/bpf_helpers.h> 7 #include <bpf/bpf_tracing.h> 8 #include "bpf_misc.h" 9 #include "bpf_experimental.h" 10 #include "bpf_arena_common.h" 11 12 struct { 13 __uint(type, BPF_MAP_TYPE_ARENA); 14 __uint(map_flags, BPF_F_MMAPABLE); 15 __uint(max_entries, 2); /* arena of two pages close to 32-bit boundary*/ 16 #ifdef __TARGET_ARCH_arm64 17 __ulong(map_extra, (1ull << 32) | (~0u - __PAGE_SIZE * 2 + 1)); /* start of mmap() region */ 18 #else 19 __ulong(map_extra, (1ull << 44) | (~0u - __PAGE_SIZE * 2 + 1)); /* start of mmap() region */ 20 #endif 21 } arena SEC(".maps"); 22 23 SEC("syscall") 24 __success __retval(0) 25 int basic_alloc1(void *ctx) 26 { 27 #if defined(__BPF_FEATURE_ADDR_SPACE_CAST) 28 volatile int __arena *page1, *page2, *no_page, *page3; 29 30 page1 = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0); 31 if (!page1) 32 return 1; 33 *page1 = 1; 34 page2 = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0); 35 if (!page2) 36 return 2; 37 *page2 = 2; 38 no_page = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0); 39 if (no_page) 40 return 3; 41 if (*page1 != 1) 42 return 4; 43 if (*page2 != 2) 44 return 5; 45 bpf_arena_free_pages(&arena, (void __arena *)page2, 1); 46 if (*page1 != 1) 47 return 6; 48 if (*page2 != 0) /* use-after-free should return 0 */ 49 return 7; 50 page3 = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0); 51 if (!page3) 52 return 8; 53 *page3 = 3; 54 if (page2 != page3) 55 return 9; 56 if (*page1 != 1) 57 return 10; 58 #endif 59 return 0; 60 } 61 62 SEC("syscall") 63 __success __retval(0) 64 int basic_alloc2(void *ctx) 65 { 66 #if defined(__BPF_FEATURE_ADDR_SPACE_CAST) 67 volatile char __arena *page1, *page2, *page3, *page4; 68 69 page1 = bpf_arena_alloc_pages(&arena, NULL, 2, NUMA_NO_NODE, 0); 70 if (!page1) 71 return 1; 72 page2 = page1 + __PAGE_SIZE; 73 page3 = page1 + __PAGE_SIZE * 2; 74 page4 = page1 - __PAGE_SIZE; 75 *page1 = 1; 76 *page2 = 2; 77 *page3 = 3; 78 *page4 = 4; 79 if (*page1 != 1) 80 return 1; 81 if (*page2 != 2) 82 return 2; 83 if (*page3 != 0) 84 return 3; 85 if (*page4 != 0) 86 return 4; 87 bpf_arena_free_pages(&arena, (void __arena *)page1, 2); 88 if (*page1 != 0) 89 return 5; 90 if (*page2 != 0) 91 return 6; 92 if (*page3 != 0) 93 return 7; 94 if (*page4 != 0) 95 return 8; 96 #endif 97 return 0; 98 } 99 100 struct bpf_arena___l { 101 struct bpf_map map; 102 } __attribute__((preserve_access_index)); 103 104 SEC("syscall") 105 __success __retval(0) __log_level(2) 106 int basic_alloc3(void *ctx) 107 { 108 struct bpf_arena___l *ar = (struct bpf_arena___l *)&arena; 109 volatile char __arena *pages; 110 111 pages = bpf_arena_alloc_pages(&ar->map, NULL, ar->map.max_entries, NUMA_NO_NODE, 0); 112 if (!pages) 113 return 1; 114 return 0; 115 } 116 117 SEC("iter.s/bpf_map") 118 __success __log_level(2) 119 int iter_maps1(struct bpf_iter__bpf_map *ctx) 120 { 121 struct bpf_map *map = ctx->map; 122 123 if (!map) 124 return 0; 125 bpf_arena_alloc_pages(map, NULL, map->max_entries, 0, 0); 126 return 0; 127 } 128 129 SEC("iter.s/bpf_map") 130 __failure __msg("expected pointer to STRUCT bpf_map") 131 int iter_maps2(struct bpf_iter__bpf_map *ctx) 132 { 133 struct seq_file *seq = ctx->meta->seq; 134 135 bpf_arena_alloc_pages((void *)seq, NULL, 1, 0, 0); 136 return 0; 137 } 138 139 SEC("iter.s/bpf_map") 140 __failure __msg("untrusted_ptr_bpf_map") 141 int iter_maps3(struct bpf_iter__bpf_map *ctx) 142 { 143 struct bpf_map *map = ctx->map; 144 145 if (!map) 146 return 0; 147 bpf_arena_alloc_pages(map->inner_map_meta, NULL, map->max_entries, 0, 0); 148 return 0; 149 } 150 151 char _license[] SEC("license") = "GPL"; 152