Test btf__snprintf with various base/kernel types and ensure display is as expected; tests are identical to those in snprintf_btf test save for the fact these run in userspace rather than BPF program context.
Signed-off-by: Alan Maguire alan.maguire@oracle.com --- .../selftests/bpf/prog_tests/snprintf_btf_user.c | 192 +++++++++++++++++++++ 1 file changed, 192 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/snprintf_btf_user.c
diff --git a/tools/testing/selftests/bpf/prog_tests/snprintf_btf_user.c b/tools/testing/selftests/bpf/prog_tests/snprintf_btf_user.c new file mode 100644 index 0000000..9eb82b2 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/snprintf_btf_user.c @@ -0,0 +1,192 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2021, Oracle and/or its affiliates. */ +#include <test_progs.h> +#include <linux/bpf.h> +#include <bpf/btf.h> + +#include <stdio.h> +#include <string.h> + +#define STRSIZE 2048 +#define EXPECTED_STRSIZE 256 + +#ifndef ARRAY_SIZE +#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) +#endif + +/* skip "enum "/"struct " prefixes */ +#define SKIP_PREFIX(_typestr, _prefix) \ + do { \ + if (strstr(_typestr, _prefix) == _typestr) \ + _typestr += strlen(_prefix) + 1; \ + } while (0) + +#define TEST_BTF(btf, _str, _type, _flags, _expected, ...) \ + do { \ + const char _expectedval[EXPECTED_STRSIZE] = _expected; \ + const char __ptrtype[64] = #_type; \ + char *_ptrtype = (char *)__ptrtype; \ + __u64 _hflags = _flags | BTF_F_COMPACT; \ + static _type _ptrdata = __VA_ARGS__; \ + void *_ptr = &_ptrdata; \ + __s32 _type_id; \ + int _cmp, _ret; \ + \ + SKIP_PREFIX(_ptrtype, "enum"); \ + SKIP_PREFIX(_ptrtype, "struct"); \ + SKIP_PREFIX(_ptrtype, "union"); \ + _ptr = &_ptrdata; \ + _type_id = btf__find_by_name(btf, _ptrtype); \ + if (CHECK(_type_id <= 0, "find type id", \ + "no '%s' in BTF: %d\n", _ptrtype, _type_id)) \ + return; \ + _ret = btf__snprintf(btf, _str, STRSIZE, _type_id, _ptr,\ + _hflags); \ + if (CHECK(_ret < 0, "btf snprintf", "failed: %d\n", \ + _ret)) \ + return; \ + _cmp = strncmp(_str, _expectedval, EXPECTED_STRSIZE); \ + if (CHECK(_cmp, "ensure expected/actual match", \ + "'%s' does not match expected '%s': %d\n", \ + _str, _expectedval, _cmp)) \ + return; \ + } while (0) + +/* Use where expected data string matches its stringified declaration */ +#define TEST_BTF_C(btf, _str, _type, _flags, ...) \ + TEST_BTF(btf, _str, _type, _flags, "(" #_type ")" #__VA_ARGS__, \ + __VA_ARGS__) + +/* Demonstrate that libbpf btf__snprintf succeeds and that various + * data types are formatted correctly. + */ +void test_snprintf_btf_user(void) +{ + struct btf *btf = libbpf_find_kernel_btf(); + int duration = 0; + char str[STRSIZE]; + + if (CHECK(!btf, "get kernel BTF", "no kernel BTF found")) + return; + + /* Verify type display for various types. */ + + /* simple int */ + TEST_BTF_C(btf, str, int, 0, 1234); + TEST_BTF(btf, str, int, BTF_F_NONAME, "1234", 1234); + + /* zero value should be printed at toplevel */ + TEST_BTF(btf, str, int, 0, "(int)0", 0); + TEST_BTF(btf, str, int, BTF_F_NONAME, "0", 0); + TEST_BTF(btf, str, int, BTF_F_ZERO, "(int)0", 0); + TEST_BTF(btf, str, int, BTF_F_NONAME | BTF_F_ZERO, "0", 0); + TEST_BTF_C(btf, str, int, 0, -4567); + TEST_BTF(btf, str, int, BTF_F_NONAME, "-4567", -4567); + + /* simple char */ + TEST_BTF_C(btf, str, char, 0, 100); + TEST_BTF(btf, str, char, BTF_F_NONAME, "100", 100); + /* zero value should be printed at toplevel */ + TEST_BTF(btf, str, char, 0, "(char)0", 0); + TEST_BTF(btf, str, char, BTF_F_NONAME, "0", 0); + TEST_BTF(btf, str, char, BTF_F_ZERO, "(char)0", 0); + TEST_BTF(btf, str, char, BTF_F_NONAME | BTF_F_ZERO, "0", 0); + + /* simple typedef */ + TEST_BTF_C(btf, str, uint64_t, 0, 100); + TEST_BTF(btf, str, u64, BTF_F_NONAME, "1", 1); + /* zero value should be printed at toplevel */ + TEST_BTF(btf, str, u64, 0, "(u64)0", 0); + TEST_BTF(btf, str, u64, BTF_F_NONAME, "0", 0); + TEST_BTF(btf, str, u64, BTF_F_ZERO, "(u64)0", 0); + TEST_BTF(btf, str, u64, BTF_F_NONAME|BTF_F_ZERO, "0", 0); + + /* typedef struct */ + TEST_BTF_C(btf, str, atomic_t, 0, {.counter = (int)1,}); + TEST_BTF(btf, str, atomic_t, BTF_F_NONAME, "{1,}", {.counter = 1,}); + /* typedef with 0 value should be printed at toplevel */ + TEST_BTF(btf, str, atomic_t, 0, "(atomic_t){}", {.counter = 0,}); + TEST_BTF(btf, str, atomic_t, BTF_F_NONAME, "{}", {.counter = 0,}); + TEST_BTF(btf,str, atomic_t, BTF_F_ZERO, "(atomic_t){.counter = (int)0,}", + {.counter = 0,}); + TEST_BTF(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(btf, str, enum bpf_cmd, 0, BPF_MAP_CREATE); + TEST_BTF(btf, str, enum bpf_cmd, 0, "(enum bpf_cmd)BPF_MAP_CREATE", 0); + TEST_BTF(btf, str, enum bpf_cmd, BTF_F_NONAME, "BPF_MAP_CREATE", + BPF_MAP_CREATE); + TEST_BTF(btf, str, enum bpf_cmd, BTF_F_NONAME|BTF_F_ZERO, + "BPF_MAP_CREATE", 0); + + TEST_BTF(btf, str, enum bpf_cmd, BTF_F_ZERO, + "(enum bpf_cmd)BPF_MAP_CREATE", + BPF_MAP_CREATE); + TEST_BTF(btf, str, enum bpf_cmd, BTF_F_NONAME|BTF_F_ZERO, + "BPF_MAP_CREATE", BPF_MAP_CREATE); + TEST_BTF_C(btf, str, enum bpf_cmd, 0, 2000); + TEST_BTF(btf, str, enum bpf_cmd, BTF_F_NONAME, "2000", 2000); + + /* simple struct */ + TEST_BTF_C(btf, str, struct btf_enum, 0, + {.name_off = (__u32)3,.val = (__s32)-1,}); + TEST_BTF(btf, str, struct btf_enum, BTF_F_NONAME, "{3,-1,}", + { .name_off = 3, .val = -1,}); + TEST_BTF(btf, str, struct btf_enum, BTF_F_NONAME, "{-1,}", + { .name_off = 0, .val = -1,}); + TEST_BTF(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(btf, str, struct btf_enum, 0, "(struct btf_enum){}", + { .name_off = 0, .val = 0,}); + TEST_BTF(btf, str, struct btf_enum, BTF_F_NONAME, "{}", + { .name_off = 0, .val = 0,}); + TEST_BTF(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(btf, str, struct list_head, BTF_F_PTR_RAW, + "(struct list_head){.next = (struct list_head *)0x1,}", + { .next = (struct list_head *)1 }); + /* NULL pointer should not be displayed */ + TEST_BTF(btf, str, struct list_head, BTF_F_PTR_RAW, + "(struct list_head){}", + { .next = (struct list_head *)0 }); + + /* struct with char array */ + TEST_BTF(btf, str, struct bpf_prog_info, 0, + "(struct bpf_prog_info){.name = (char[])['f','o','o',],}", + { .name = "foo",}); + TEST_BTF(btf, str, struct bpf_prog_info, BTF_F_NONAME, + "{['f','o','o',],}", + {.name = "foo",}); + /* leading null char means do not display string */ + TEST_BTF(btf, str, struct bpf_prog_info, 0, + "(struct bpf_prog_info){}", + {.name = {'\0', 'f', 'o', 'o'}}); + /* handle non-printable characters */ + TEST_BTF(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(btf, str, struct __sk_buff, 0, + "(struct __sk_buff){.cb = (__u32[])[1,2,3,4,5,],}", + { .cb = {1, 2, 3, 4, 5,},}); + TEST_BTF(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(btf, str, struct __sk_buff, 0, + "(struct __sk_buff){.cb = (__u32[])[1,],}", + { .cb = { 0, 0, 1, 0, 0},}); + + /* struct with bitfields */ + TEST_BTF_C(btf, str, struct bpf_insn, 0, + {.code = (__u8)1,.dst_reg = (__u8)0x2,.src_reg = (__u8)0x3,.off = (__s16)4,.imm = (__s32)5,}); + TEST_BTF(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,}); +}