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