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// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */
#include <vmlinux.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include "bpf_misc.h"
#include "bpf_experimental.h"
#include "bpf_arena_common.h"
struct {
__uint(type, BPF_MAP_TYPE_ARENA);
__uint(map_flags, BPF_F_MMAPABLE);
__uint(max_entries, 2); /* arena of two pages close to 32-bit boundary*/
#ifdef __TARGET_ARCH_arm64
__ulong(map_extra, (1ull << 32) | (~0u - __PAGE_SIZE * 2 + 1)); /* start of mmap() region */
#else
__ulong(map_extra, (1ull << 44) | (~0u - __PAGE_SIZE * 2 + 1)); /* start of mmap() region */
#endif
} arena SEC(".maps");
SEC("syscall")
__success __retval(0)
int basic_alloc1(void *ctx)
{
#if defined(__BPF_FEATURE_ADDR_SPACE_CAST)
volatile int __arena *page1, *page2, *no_page, *page3;
page1 = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0);
if (!page1)
return 1;
*page1 = 1;
page2 = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0);
if (!page2)
return 2;
*page2 = 2;
no_page = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0);
if (no_page)
return 3;
if (*page1 != 1)
return 4;
if (*page2 != 2)
return 5;
bpf_arena_free_pages(&arena, (void __arena *)page2, 1);
if (*page1 != 1)
return 6;
if (*page2 != 0) /* use-after-free should return 0 */
return 7;
page3 = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0);
if (!page3)
return 8;
*page3 = 3;
if (page2 != page3)
return 9;
if (*page1 != 1)
return 10;
#endif
return 0;
}
SEC("syscall")
__success __retval(0)
int basic_alloc2(void *ctx)
{
#if defined(__BPF_FEATURE_ADDR_SPACE_CAST)
volatile char __arena *page1, *page2, *page3, *page4;
page1 = bpf_arena_alloc_pages(&arena, NULL, 2, NUMA_NO_NODE, 0);
if (!page1)
return 1;
page2 = page1 + __PAGE_SIZE;
page3 = page1 + __PAGE_SIZE * 2;
page4 = page1 - __PAGE_SIZE;
*page1 = 1;
*page2 = 2;
*page3 = 3;
*page4 = 4;
if (*page1 != 1)
return 1;
if (*page2 != 2)
return 2;
if (*page3 != 0)
return 3;
if (*page4 != 0)
return 4;
bpf_arena_free_pages(&arena, (void __arena *)page1, 2);
if (*page1 != 0)
return 5;
if (*page2 != 0)
return 6;
if (*page3 != 0)
return 7;
if (*page4 != 0)
return 8;
#endif
return 0;
}
struct bpf_arena___l {
struct bpf_map map;
} __attribute__((preserve_access_index));
SEC("syscall")
__success __retval(0) __log_level(2)
int basic_alloc3(void *ctx)
{
struct bpf_arena___l *ar = (struct bpf_arena___l *)&arena;
volatile char __arena *pages;
pages = bpf_arena_alloc_pages(&ar->map, NULL, ar->map.max_entries, NUMA_NO_NODE, 0);
if (!pages)
return 1;
return 0;
}
SEC("iter.s/bpf_map")
__success __log_level(2)
int iter_maps1(struct bpf_iter__bpf_map *ctx)
{
struct bpf_map *map = ctx->map;
if (!map)
return 0;
bpf_arena_alloc_pages(map, NULL, map->max_entries, 0, 0);
return 0;
}
SEC("iter.s/bpf_map")
__failure __msg("expected pointer to STRUCT bpf_map")
int iter_maps2(struct bpf_iter__bpf_map *ctx)
{
struct seq_file *seq = ctx->meta->seq;
bpf_arena_alloc_pages((void *)seq, NULL, 1, 0, 0);
return 0;
}
SEC("iter.s/bpf_map")
__failure __msg("untrusted_ptr_bpf_map")
int iter_maps3(struct bpf_iter__bpf_map *ctx)
{
struct bpf_map *map = ctx->map;
if (!map)
return 0;
bpf_arena_alloc_pages(map->inner_map_meta, NULL, map->max_entries, 0, 0);
return 0;
}
char _license[] SEC("license") = "GPL";
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