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
 12struct {
 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
 23SEC("syscall")
 24__success __retval(0)
 25int 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
 62SEC("syscall")
 63__success __retval(0)
 64int 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
100struct bpf_arena___l {
101        struct bpf_map map;
102} __attribute__((preserve_access_index));
103
104SEC("syscall")
105__success __retval(0) __log_level(2)
106int 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
117SEC("iter.s/bpf_map")
118__success __log_level(2)
119int 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
129SEC("iter.s/bpf_map")
130__failure __msg("expected pointer to STRUCT bpf_map")
131int 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
139SEC("iter.s/bpf_map")
140__failure __msg("untrusted_ptr_bpf_map")
141int 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
151char _license[] SEC("license") = "GPL";