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