1// SPDX-License-Identifier: GPL-2.0
2/* Converted from tools/testing/selftests/bpf/verifier/map_ret_val.c */
3
4#include <linux/bpf.h>
5#include <bpf/bpf_helpers.h>
6#include "../../../include/linux/filter.h"
7#include "bpf_misc.h"
8
9struct {
10 __uint(type, BPF_MAP_TYPE_HASH);
11 __uint(max_entries, 1);
12 __type(key, long long);
13 __type(value, long long);
14} map_hash_8b SEC(".maps");
15
16SEC("socket")
17__description("invalid map_fd for function call")
18__failure __msg("fd 0 is not pointing to valid bpf_map")
19__failure_unpriv
20__naked void map_fd_for_function_call(void)
21{
22 asm volatile (" \
23 r2 = 0; \
24 *(u64*)(r10 - 8) = r2; \
25 r2 = r10; \
26 r2 += -8; \
27 .8byte %[ld_map_fd]; \
28 .8byte 0; \
29 call %[bpf_map_delete_elem]; \
30 exit; \
31" :
32 : __imm(bpf_map_delete_elem),
33 __imm_insn(ld_map_fd, BPF_RAW_INSN(BPF_LD | BPF_DW | BPF_IMM, BPF_REG_1, BPF_PSEUDO_MAP_FD, 0, 0))
34 : __clobber_all);
35}
36
37SEC("socket")
38__description("don't check return value before access")
39__failure __msg("R0 invalid mem access 'map_value_or_null'")
40__failure_unpriv
41__naked void check_return_value_before_access(void)
42{
43 asm volatile (" \
44 r1 = 0; \
45 *(u64*)(r10 - 8) = r1; \
46 r2 = r10; \
47 r2 += -8; \
48 r1 = %[map_hash_8b] ll; \
49 call %[bpf_map_lookup_elem]; \
50 r1 = 0; \
51 *(u64*)(r0 + 0) = r1; \
52 exit; \
53" :
54 : __imm(bpf_map_lookup_elem),
55 __imm_addr(map_hash_8b)
56 : __clobber_all);
57}
58
59SEC("socket")
60__description("access memory with incorrect alignment")
61__failure __msg("misaligned value access")
62__failure_unpriv
63__flag(BPF_F_STRICT_ALIGNMENT)
64__naked void access_memory_with_incorrect_alignment_1(void)
65{
66 asm volatile (" \
67 r1 = 0; \
68 *(u64*)(r10 - 8) = r1; \
69 r2 = r10; \
70 r2 += -8; \
71 r1 = %[map_hash_8b] ll; \
72 call %[bpf_map_lookup_elem]; \
73 if r0 == 0 goto l0_%=; \
74 r1 = 0; \
75 *(u64*)(r0 + 4) = r1; \
76l0_%=: exit; \
77" :
78 : __imm(bpf_map_lookup_elem),
79 __imm_addr(map_hash_8b)
80 : __clobber_all);
81}
82
83SEC("socket")
84__description("sometimes access memory with incorrect alignment")
85__failure __msg("R0 invalid mem access")
86__msg_unpriv("R0 leaks addr")
87__flag(BPF_F_STRICT_ALIGNMENT)
88__naked void access_memory_with_incorrect_alignment_2(void)
89{
90 asm volatile (" \
91 r1 = 0; \
92 *(u64*)(r10 - 8) = r1; \
93 r2 = r10; \
94 r2 += -8; \
95 r1 = %[map_hash_8b] ll; \
96 call %[bpf_map_lookup_elem]; \
97 if r0 == 0 goto l0_%=; \
98 r1 = 0; \
99 *(u64*)(r0 + 0) = r1; \
100 exit; \
101l0_%=: r1 = 1; \
102 *(u64*)(r0 + 0) = r1; \
103 exit; \
104" :
105 : __imm(bpf_map_lookup_elem),
106 __imm_addr(map_hash_8b)
107 : __clobber_all);
108}
109
110char _license[] SEC("license") = "GPL";
111

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