1// SPDX-License-Identifier: GPL-2.0
2/* Converted from tools/testing/selftests/bpf/verifier/prevent_map_lookup.c */
3
4#include <linux/bpf.h>
5#include <bpf/bpf_helpers.h>
6#include "bpf_misc.h"
7
8struct {
9 __uint(type, BPF_MAP_TYPE_STACK_TRACE);
10 __uint(max_entries, 1);
11 __type(key, __u32);
12 __type(value, __u64);
13} map_stacktrace SEC(".maps");
14
15struct {
16 __uint(type, BPF_MAP_TYPE_PROG_ARRAY);
17 __uint(max_entries, 8);
18 __uint(key_size, sizeof(int));
19 __array(values, void (void));
20} map_prog2_socket SEC(".maps");
21
22SEC("perf_event")
23__description("prevent map lookup in stack trace")
24__failure __msg("cannot pass map_type 7 into func bpf_map_lookup_elem")
25__naked void map_lookup_in_stack_trace(void)
26{
27 asm volatile (" \
28 r1 = 0; \
29 *(u64*)(r10 - 8) = r1; \
30 r2 = r10; \
31 r2 += -8; \
32 r1 = %[map_stacktrace] ll; \
33 call %[bpf_map_lookup_elem]; \
34 exit; \
35" :
36 : __imm(bpf_map_lookup_elem),
37 __imm_addr(map_stacktrace)
38 : __clobber_all);
39}
40
41SEC("socket")
42__description("prevent map lookup in prog array")
43__failure __msg("cannot pass map_type 3 into func bpf_map_lookup_elem")
44__failure_unpriv
45__naked void map_lookup_in_prog_array(void)
46{
47 asm volatile (" \
48 r1 = 0; \
49 *(u64*)(r10 - 8) = r1; \
50 r2 = r10; \
51 r2 += -8; \
52 r1 = %[map_prog2_socket] ll; \
53 call %[bpf_map_lookup_elem]; \
54 exit; \
55" :
56 : __imm(bpf_map_lookup_elem),
57 __imm_addr(map_prog2_socket)
58 : __clobber_all);
59}
60
61char _license[] SEC("license") = "GPL";
62

source code of linux/tools/testing/selftests/bpf/progs/verifier_prevent_map_lookup.c