xref: /linux/tools/testing/selftests/bpf/progs/verifier_map_ptr.c (revision fd7d598270724cc787982ea48bbe17ad383a8b7f)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Converted from tools/testing/selftests/bpf/verifier/map_ptr.c */
3 
4 #include <linux/bpf.h>
5 #include <bpf/bpf_helpers.h>
6 #include "bpf_misc.h"
7 
8 #define MAX_ENTRIES 11
9 
10 struct test_val {
11 	unsigned int index;
12 	int foo[MAX_ENTRIES];
13 };
14 
15 struct {
16 	__uint(type, BPF_MAP_TYPE_ARRAY);
17 	__uint(max_entries, 1);
18 	__type(key, int);
19 	__type(value, struct test_val);
20 } map_array_48b SEC(".maps");
21 
22 struct other_val {
23 	long long foo;
24 	long long bar;
25 };
26 
27 struct {
28 	__uint(type, BPF_MAP_TYPE_HASH);
29 	__uint(max_entries, 1);
30 	__type(key, long long);
31 	__type(value, struct other_val);
32 } map_hash_16b SEC(".maps");
33 
34 SEC("socket")
35 __description("bpf_map_ptr: read with negative offset rejected")
36 __failure __msg("R1 is bpf_array invalid negative access: off=-8")
37 __failure_unpriv
38 __msg_unpriv("access is allowed only to CAP_PERFMON and CAP_SYS_ADMIN")
39 __naked void read_with_negative_offset_rejected(void)
40 {
41 	asm volatile ("					\
42 	r1 = r10;					\
43 	r1 = %[map_array_48b] ll;			\
44 	r6 = *(u64*)(r1 - 8);				\
45 	r0 = 1;						\
46 	exit;						\
47 "	:
48 	: __imm_addr(map_array_48b)
49 	: __clobber_all);
50 }
51 
52 SEC("socket")
53 __description("bpf_map_ptr: write rejected")
54 __failure __msg("only read from bpf_array is supported")
55 __failure_unpriv
56 __msg_unpriv("access is allowed only to CAP_PERFMON and CAP_SYS_ADMIN")
57 __naked void bpf_map_ptr_write_rejected(void)
58 {
59 	asm volatile ("					\
60 	r0 = 0;						\
61 	*(u64*)(r10 - 8) = r0;				\
62 	r2 = r10;					\
63 	r2 += -8;					\
64 	r1 = %[map_array_48b] ll;			\
65 	*(u64*)(r1 + 0) = r2;				\
66 	r0 = 1;						\
67 	exit;						\
68 "	:
69 	: __imm_addr(map_array_48b)
70 	: __clobber_all);
71 }
72 
73 SEC("socket")
74 __description("bpf_map_ptr: read non-existent field rejected")
75 __failure
76 __msg("cannot access ptr member ops with moff 0 in struct bpf_map with off 1 size 4")
77 __failure_unpriv
78 __msg_unpriv("access is allowed only to CAP_PERFMON and CAP_SYS_ADMIN")
79 __flag(BPF_F_ANY_ALIGNMENT)
80 __naked void read_non_existent_field_rejected(void)
81 {
82 	asm volatile ("					\
83 	r6 = 0;						\
84 	r1 = %[map_array_48b] ll;			\
85 	r6 = *(u32*)(r1 + 1);				\
86 	r0 = 1;						\
87 	exit;						\
88 "	:
89 	: __imm_addr(map_array_48b)
90 	: __clobber_all);
91 }
92 
93 SEC("socket")
94 __description("bpf_map_ptr: read ops field accepted")
95 __success __failure_unpriv
96 __msg_unpriv("access is allowed only to CAP_PERFMON and CAP_SYS_ADMIN")
97 __retval(1)
98 __naked void ptr_read_ops_field_accepted(void)
99 {
100 	asm volatile ("					\
101 	r6 = 0;						\
102 	r1 = %[map_array_48b] ll;			\
103 	r6 = *(u64*)(r1 + 0);				\
104 	r0 = 1;						\
105 	exit;						\
106 "	:
107 	: __imm_addr(map_array_48b)
108 	: __clobber_all);
109 }
110 
111 SEC("socket")
112 __description("bpf_map_ptr: r = 0, map_ptr = map_ptr + r")
113 __success __failure_unpriv
114 __msg_unpriv("R1 has pointer with unsupported alu operation")
115 __retval(0)
116 __naked void map_ptr_map_ptr_r(void)
117 {
118 	asm volatile ("					\
119 	r0 = 0;						\
120 	*(u64*)(r10 - 8) = r0;				\
121 	r2 = r10;					\
122 	r2 += -8;					\
123 	r0 = 0;						\
124 	r1 = %[map_hash_16b] ll;			\
125 	r1 += r0;					\
126 	call %[bpf_map_lookup_elem];			\
127 	r0 = 0;						\
128 	exit;						\
129 "	:
130 	: __imm(bpf_map_lookup_elem),
131 	  __imm_addr(map_hash_16b)
132 	: __clobber_all);
133 }
134 
135 SEC("socket")
136 __description("bpf_map_ptr: r = 0, r = r + map_ptr")
137 __success __failure_unpriv
138 __msg_unpriv("R0 has pointer with unsupported alu operation")
139 __retval(0)
140 __naked void _0_r_r_map_ptr(void)
141 {
142 	asm volatile ("					\
143 	r0 = 0;						\
144 	*(u64*)(r10 - 8) = r0;				\
145 	r2 = r10;					\
146 	r2 += -8;					\
147 	r1 = 0;						\
148 	r0 = %[map_hash_16b] ll;			\
149 	r1 += r0;					\
150 	call %[bpf_map_lookup_elem];			\
151 	r0 = 0;						\
152 	exit;						\
153 "	:
154 	: __imm(bpf_map_lookup_elem),
155 	  __imm_addr(map_hash_16b)
156 	: __clobber_all);
157 }
158 
159 char _license[] SEC("license") = "GPL";
160