summaryrefslogtreecommitdiffstats
path: root/tools/testing/selftests/bpf/progs/verifier_arena_large.c
blob: f94f30cf1bb80f64552318e074fe23cb04e679a0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */

#define BPF_NO_KFUNC_PROTOTYPES
#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"

#define ARENA_SIZE (1ull << 32)

struct {
	__uint(type, BPF_MAP_TYPE_ARENA);
	__uint(map_flags, BPF_F_MMAPABLE);
	__uint(max_entries, ARENA_SIZE / PAGE_SIZE);
} arena SEC(".maps");

SEC("syscall")
__success __retval(0)
int big_alloc1(void *ctx)
{
#if defined(__BPF_FEATURE_ADDR_SPACE_CAST)
	volatile char __arena *page1, *page2, *no_page, *page3;
	void __arena *base;

	page1 = base = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0);
	if (!page1)
		return 1;
	*page1 = 1;
	page2 = bpf_arena_alloc_pages(&arena, base + ARENA_SIZE - PAGE_SIZE * 2,
				      1, NUMA_NO_NODE, 0);
	if (!page2)
		return 2;
	*page2 = 2;
	no_page = bpf_arena_alloc_pages(&arena, base + ARENA_SIZE - PAGE_SIZE,
					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 *)page1, 1);
	if (*page2 != 2)
		return 6;
	if (*page1 != 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 (page1 != page3)
		return 9;
	if (*page2 != 2)
		return 10;
	if (*(page1 + PAGE_SIZE) != 0)
		return 11;
	if (*(page1 - PAGE_SIZE) != 0)
		return 12;
	if (*(page2 + PAGE_SIZE) != 0)
		return 13;
	if (*(page2 - PAGE_SIZE) != 0)
		return 14;
#endif
	return 0;
}

#if defined(__BPF_FEATURE_ADDR_SPACE_CAST)
#define PAGE_CNT 100
__u8 __arena * __arena page[PAGE_CNT]; /* occupies the first page */
__u8 __arena *base;

/*
 * Check that arena's range_tree algorithm allocates pages sequentially
 * on the first pass and then fills in all gaps on the second pass.
 */
__noinline int alloc_pages(int page_cnt, int pages_atonce, bool first_pass,
		int max_idx, int step)
{
	__u8 __arena *pg;
	int i, pg_idx;

	for (i = 0; i < page_cnt; i++) {
		pg = bpf_arena_alloc_pages(&arena, NULL, pages_atonce,
					   NUMA_NO_NODE, 0);
		if (!pg)
			return step;
		pg_idx = (unsigned long) (pg - base) / PAGE_SIZE;
		if (first_pass) {
			/* Pages must be allocated sequentially */
			if (pg_idx != i)
				return step + 100;
		} else {
			/* Allocator must fill into gaps */
			if (pg_idx >= max_idx || (pg_idx & 1))
				return step + 200;
		}
		*pg = pg_idx;
		page[pg_idx] = pg;
		cond_break;
	}
	return 0;
}

SEC("syscall")
__success __retval(0)
int big_alloc2(void *ctx)
{
	__u8 __arena *pg;
	int i, err;

	base = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0);
	if (!base)
		return 1;
	bpf_arena_free_pages(&arena, (void __arena *)base, 1);

	err = alloc_pages(PAGE_CNT, 1, true, PAGE_CNT, 2);
	if (err)
		return err;

	/* Clear all even pages */
	for (i = 0; i < PAGE_CNT; i += 2) {
		pg = page[i];
		if (*pg != i)
			return 3;
		bpf_arena_free_pages(&arena, (void __arena *)pg, 1);
		page[i] = NULL;
		cond_break;
	}

	/* Allocate into freed gaps */
	err = alloc_pages(PAGE_CNT / 2, 1, false, PAGE_CNT, 4);
	if (err)
		return err;

	/* Free pairs of pages */
	for (i = 0; i < PAGE_CNT; i += 4) {
		pg = page[i];
		if (*pg != i)
			return 5;
		bpf_arena_free_pages(&arena, (void __arena *)pg, 2);
		page[i] = NULL;
		page[i + 1] = NULL;
		cond_break;
	}

	/* Allocate 2 pages at a time into freed gaps */
	err = alloc_pages(PAGE_CNT / 4, 2, false, PAGE_CNT, 6);
	if (err)
		return err;

	/* Check pages without freeing */
	for (i = 0; i < PAGE_CNT; i += 2) {
		pg = page[i];
		if (*pg != i)
			return 7;
		cond_break;
	}

	pg = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0);

	if (!pg)
		return 8;
	/*
	 * The first PAGE_CNT pages are occupied. The new page
	 * must be above.
	 */
	if ((pg - base) / PAGE_SIZE < PAGE_CNT)
		return 9;
	return 0;
}
#endif
char _license[] SEC("license") = "GPL";