Loading...
Note: File does not exist in v5.4.
1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2020, Oracle and/or its affiliates. */
3
4#include "btf_ptr.h"
5#include <bpf/bpf_helpers.h>
6#include <bpf/bpf_tracing.h>
7#include <bpf/bpf_core_read.h>
8
9#include <errno.h>
10
11long ret = 0;
12int num_subtests = 0;
13int ran_subtests = 0;
14bool skip = false;
15
16#define STRSIZE 2048
17#define EXPECTED_STRSIZE 256
18
19#if defined(bpf_target_s390)
20/* NULL points to a readable struct lowcore on s390, so take the last page */
21#define BADPTR ((void *)0xFFFFFFFFFFFFF000ULL)
22#else
23#define BADPTR 0
24#endif
25
26#ifndef ARRAY_SIZE
27#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
28#endif
29
30struct {
31 __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
32 __uint(max_entries, 1);
33 __type(key, __u32);
34 __type(value, char[STRSIZE]);
35} strdata SEC(".maps");
36
37static int __strncmp(const void *m1, const void *m2, size_t len)
38{
39 const unsigned char *s1 = m1;
40 const unsigned char *s2 = m2;
41 int i, delta = 0;
42
43 for (i = 0; i < len; i++) {
44 delta = s1[i] - s2[i];
45 if (delta || s1[i] == 0 || s2[i] == 0)
46 break;
47 }
48 return delta;
49}
50
51#if __has_builtin(__builtin_btf_type_id)
52#define TEST_BTF(_str, _type, _flags, _expected, ...) \
53 do { \
54 static const char _expectedval[EXPECTED_STRSIZE] = \
55 _expected; \
56 static const char _ptrtype[64] = #_type; \
57 __u64 _hflags = _flags | BTF_F_COMPACT; \
58 static _type _ptrdata = __VA_ARGS__; \
59 static struct btf_ptr _ptr = { }; \
60 int _cmp; \
61 \
62 ++num_subtests; \
63 if (ret < 0) \
64 break; \
65 ++ran_subtests; \
66 _ptr.ptr = &_ptrdata; \
67 _ptr.type_id = bpf_core_type_id_kernel(_type); \
68 if (_ptr.type_id <= 0) { \
69 ret = -EINVAL; \
70 break; \
71 } \
72 ret = bpf_snprintf_btf(_str, STRSIZE, \
73 &_ptr, sizeof(_ptr), _hflags); \
74 if (ret) \
75 break; \
76 _cmp = __strncmp(_str, _expectedval, EXPECTED_STRSIZE); \
77 if (_cmp != 0) { \
78 bpf_printk("(%d) got %s", _cmp, _str); \
79 bpf_printk("(%d) expected %s", _cmp, \
80 _expectedval); \
81 ret = -EBADMSG; \
82 break; \
83 } \
84 } while (0)
85#endif
86
87/* Use where expected data string matches its stringified declaration */
88#define TEST_BTF_C(_str, _type, _flags, ...) \
89 TEST_BTF(_str, _type, _flags, "(" #_type ")" #__VA_ARGS__, \
90 __VA_ARGS__)
91
92/* TRACE_EVENT(netif_receive_skb,
93 * TP_PROTO(struct sk_buff *skb),
94 */
95SEC("tp_btf/netif_receive_skb")
96int BPF_PROG(trace_netif_receive_skb, struct sk_buff *skb)
97{
98 static __u64 flags[] = { 0, BTF_F_COMPACT, BTF_F_ZERO, BTF_F_PTR_RAW,
99 BTF_F_NONAME, BTF_F_COMPACT | BTF_F_ZERO |
100 BTF_F_PTR_RAW | BTF_F_NONAME };
101 static struct btf_ptr p = { };
102 __u32 key = 0;
103 int i, __ret;
104 char *str;
105
106#if __has_builtin(__builtin_btf_type_id)
107 str = bpf_map_lookup_elem(&strdata, &key);
108 if (!str)
109 return 0;
110
111 /* Ensure we can write skb string representation */
112 p.type_id = bpf_core_type_id_kernel(struct sk_buff);
113 p.ptr = skb;
114 for (i = 0; i < ARRAY_SIZE(flags); i++) {
115 ++num_subtests;
116 ret = bpf_snprintf_btf(str, STRSIZE, &p, sizeof(p), 0);
117 if (ret < 0)
118 bpf_printk("returned %d when writing skb", ret);
119 ++ran_subtests;
120 }
121
122 /* Check invalid ptr value */
123 p.ptr = BADPTR;
124 __ret = bpf_snprintf_btf(str, STRSIZE, &p, sizeof(p), 0);
125 if (__ret >= 0) {
126 bpf_printk("printing %llx should generate error, got (%d)",
127 (unsigned long long)BADPTR, __ret);
128 ret = -ERANGE;
129 }
130
131 /* Verify type display for various types. */
132
133 /* simple int */
134 TEST_BTF_C(str, int, 0, 1234);
135 TEST_BTF(str, int, BTF_F_NONAME, "1234", 1234);
136 /* zero value should be printed at toplevel */
137 TEST_BTF(str, int, 0, "(int)0", 0);
138 TEST_BTF(str, int, BTF_F_NONAME, "0", 0);
139 TEST_BTF(str, int, BTF_F_ZERO, "(int)0", 0);
140 TEST_BTF(str, int, BTF_F_NONAME | BTF_F_ZERO, "0", 0);
141 TEST_BTF_C(str, int, 0, -4567);
142 TEST_BTF(str, int, BTF_F_NONAME, "-4567", -4567);
143
144 /* simple char */
145 TEST_BTF_C(str, char, 0, 100);
146 TEST_BTF(str, char, BTF_F_NONAME, "100", 100);
147 /* zero value should be printed at toplevel */
148 TEST_BTF(str, char, 0, "(char)0", 0);
149 TEST_BTF(str, char, BTF_F_NONAME, "0", 0);
150 TEST_BTF(str, char, BTF_F_ZERO, "(char)0", 0);
151 TEST_BTF(str, char, BTF_F_NONAME | BTF_F_ZERO, "0", 0);
152
153 /* simple typedef */
154 TEST_BTF_C(str, uint64_t, 0, 100);
155 TEST_BTF(str, u64, BTF_F_NONAME, "1", 1);
156 /* zero value should be printed at toplevel */
157 TEST_BTF(str, u64, 0, "(u64)0", 0);
158 TEST_BTF(str, u64, BTF_F_NONAME, "0", 0);
159 TEST_BTF(str, u64, BTF_F_ZERO, "(u64)0", 0);
160 TEST_BTF(str, u64, BTF_F_NONAME|BTF_F_ZERO, "0", 0);
161
162 /* typedef struct */
163 TEST_BTF_C(str, atomic_t, 0, {.counter = (int)1,});
164 TEST_BTF(str, atomic_t, BTF_F_NONAME, "{1,}", {.counter = 1,});
165 /* typedef with 0 value should be printed at toplevel */
166 TEST_BTF(str, atomic_t, 0, "(atomic_t){}", {.counter = 0,});
167 TEST_BTF(str, atomic_t, BTF_F_NONAME, "{}", {.counter = 0,});
168 TEST_BTF(str, atomic_t, BTF_F_ZERO, "(atomic_t){.counter = (int)0,}",
169 {.counter = 0,});
170 TEST_BTF(str, atomic_t, BTF_F_NONAME|BTF_F_ZERO,
171 "{0,}", {.counter = 0,});
172
173 /* enum where enum value does (and does not) exist */
174 TEST_BTF_C(str, enum bpf_cmd, 0, BPF_MAP_CREATE);
175 TEST_BTF(str, enum bpf_cmd, 0, "(enum bpf_cmd)BPF_MAP_CREATE", 0);
176 TEST_BTF(str, enum bpf_cmd, BTF_F_NONAME, "BPF_MAP_CREATE",
177 BPF_MAP_CREATE);
178 TEST_BTF(str, enum bpf_cmd, BTF_F_NONAME|BTF_F_ZERO,
179 "BPF_MAP_CREATE", 0);
180
181 TEST_BTF(str, enum bpf_cmd, BTF_F_ZERO, "(enum bpf_cmd)BPF_MAP_CREATE",
182 BPF_MAP_CREATE);
183 TEST_BTF(str, enum bpf_cmd, BTF_F_NONAME|BTF_F_ZERO,
184 "BPF_MAP_CREATE", BPF_MAP_CREATE);
185 TEST_BTF_C(str, enum bpf_cmd, 0, 2000);
186 TEST_BTF(str, enum bpf_cmd, BTF_F_NONAME, "2000", 2000);
187
188 /* simple struct */
189 TEST_BTF_C(str, struct btf_enum, 0,
190 {.name_off = (__u32)3,.val = (__s32)-1,});
191 TEST_BTF(str, struct btf_enum, BTF_F_NONAME, "{3,-1,}",
192 { .name_off = 3, .val = -1,});
193 TEST_BTF(str, struct btf_enum, BTF_F_NONAME, "{-1,}",
194 { .name_off = 0, .val = -1,});
195 TEST_BTF(str, struct btf_enum, BTF_F_NONAME|BTF_F_ZERO, "{0,-1,}",
196 { .name_off = 0, .val = -1,});
197 /* empty struct should be printed */
198 TEST_BTF(str, struct btf_enum, 0, "(struct btf_enum){}",
199 { .name_off = 0, .val = 0,});
200 TEST_BTF(str, struct btf_enum, BTF_F_NONAME, "{}",
201 { .name_off = 0, .val = 0,});
202 TEST_BTF(str, struct btf_enum, BTF_F_ZERO,
203 "(struct btf_enum){.name_off = (__u32)0,.val = (__s32)0,}",
204 { .name_off = 0, .val = 0,});
205
206 /* struct with pointers */
207 TEST_BTF(str, struct list_head, BTF_F_PTR_RAW,
208 "(struct list_head){.next = (struct list_head *)0x0000000000000001,}",
209 { .next = (struct list_head *)1 });
210 /* NULL pointer should not be displayed */
211 TEST_BTF(str, struct list_head, BTF_F_PTR_RAW,
212 "(struct list_head){}",
213 { .next = (struct list_head *)0 });
214
215 /* struct with char array */
216 TEST_BTF(str, struct bpf_prog_info, 0,
217 "(struct bpf_prog_info){.name = (char[])['f','o','o',],}",
218 { .name = "foo",});
219 TEST_BTF(str, struct bpf_prog_info, BTF_F_NONAME,
220 "{['f','o','o',],}",
221 {.name = "foo",});
222 /* leading null char means do not display string */
223 TEST_BTF(str, struct bpf_prog_info, 0,
224 "(struct bpf_prog_info){}",
225 {.name = {'\0', 'f', 'o', 'o'}});
226 /* handle non-printable characters */
227 TEST_BTF(str, struct bpf_prog_info, 0,
228 "(struct bpf_prog_info){.name = (char[])[1,2,3,],}",
229 { .name = {1, 2, 3, 0}});
230
231 /* struct with non-char array */
232 TEST_BTF(str, struct __sk_buff, 0,
233 "(struct __sk_buff){.cb = (__u32[])[1,2,3,4,5,],}",
234 { .cb = {1, 2, 3, 4, 5,},});
235 TEST_BTF(str, struct __sk_buff, BTF_F_NONAME,
236 "{[1,2,3,4,5,],}",
237 { .cb = { 1, 2, 3, 4, 5},});
238 /* For non-char, arrays, show non-zero values only */
239 TEST_BTF(str, struct __sk_buff, 0,
240 "(struct __sk_buff){.cb = (__u32[])[1,],}",
241 { .cb = { 0, 0, 1, 0, 0},});
242
243 /* struct with bitfields */
244 TEST_BTF_C(str, struct bpf_insn, 0,
245 {.code = (__u8)1,.dst_reg = (__u8)0x2,.src_reg = (__u8)0x3,.off = (__s16)4,.imm = (__s32)5,});
246 TEST_BTF(str, struct bpf_insn, BTF_F_NONAME, "{1,0x2,0x3,4,5,}",
247 {.code = 1, .dst_reg = 0x2, .src_reg = 0x3, .off = 4,
248 .imm = 5,});
249#else
250 skip = true;
251#endif
252
253 return 0;
254}
255
256char _license[] SEC("license") = "GPL";