From 70a9241fbce5398965bf05a595ee892845ae31e9 Mon Sep 17 00:00:00 2001 From: Alan Maguire Date: Thu, 15 Jul 2021 16:15:26 +0100 Subject: [PATCH] selftests/bpf: Add dump type data tests to btf dump tests Test various type data dumping operations by comparing expected format with the dumped string; an snprintf-style printf function is used to record the string dumped. Also verify overflow handling where the data passed does not cover the full size of a type, such as would occur if a tracer has a portion of the 8k "struct task_struct". Signed-off-by: Alan Maguire Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/1626362126-27775-4-git-send-email-alan.maguire@oracle.com --- tools/testing/selftests/bpf/prog_tests/btf_dump.c | 598 ++++++++++++++++++++++ 1 file changed, 598 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/btf_dump.c b/tools/testing/selftests/bpf/prog_tests/btf_dump.c index 1b90e684ff13..0b4ba53b5961 100644 --- a/tools/testing/selftests/bpf/prog_tests/btf_dump.c +++ b/tools/testing/selftests/bpf/prog_tests/btf_dump.c @@ -232,7 +232,576 @@ err_out: btf__free(btf); } +#define STRSIZE 4096 + +static void btf_dump_snprintf(void *ctx, const char *fmt, va_list args) +{ + char *s = ctx, new[STRSIZE]; + + vsnprintf(new, STRSIZE, fmt, args); + if (strlen(s) < STRSIZE) + strncat(s, new, STRSIZE - strlen(s) - 1); +} + +static int btf_dump_data(struct btf *btf, struct btf_dump *d, + char *name, char *prefix, __u64 flags, void *ptr, + size_t ptr_sz, char *str, const char *expected_val) +{ + DECLARE_LIBBPF_OPTS(btf_dump_type_data_opts, opts); + size_t type_sz; + __s32 type_id; + int ret = 0; + + if (flags & BTF_F_COMPACT) + opts.compact = true; + if (flags & BTF_F_NONAME) + opts.skip_names = true; + if (flags & BTF_F_ZERO) + opts.emit_zeroes = true; + if (prefix) { + ASSERT_STRNEQ(name, prefix, strlen(prefix), + "verify prefix match"); + name += strlen(prefix) + 1; + } + type_id = btf__find_by_name(btf, name); + if (!ASSERT_GE(type_id, 0, "find type id")) + return -ENOENT; + type_sz = btf__resolve_size(btf, type_id); + str[0] = '\0'; + ret = btf_dump__dump_type_data(d, type_id, ptr, ptr_sz, &opts); + if (type_sz <= ptr_sz) { + if (!ASSERT_EQ(ret, type_sz, "failed/unexpected type_sz")) + return -EINVAL; + } else { + if (!ASSERT_EQ(ret, -E2BIG, "failed to return -E2BIG")) + return -EINVAL; + } + if (!ASSERT_STREQ(str, expected_val, "ensure expected/actual match")) + return -EFAULT; + return 0; +} + +#define TEST_BTF_DUMP_DATA(_b, _d, _prefix, _str, _type, _flags, \ + _expected, ...) \ + do { \ + char __ptrtype[64] = #_type; \ + char *_ptrtype = (char *)__ptrtype; \ + _type _ptrdata = __VA_ARGS__; \ + void *_ptr = &_ptrdata; \ + \ + (void) btf_dump_data(_b, _d, _ptrtype, _prefix, _flags, \ + _ptr, sizeof(_type), _str, \ + _expected); \ + } while (0) + +/* Use where expected data string matches its stringified declaration */ +#define TEST_BTF_DUMP_DATA_C(_b, _d, _prefix, _str, _type, _flags, \ + ...) \ + TEST_BTF_DUMP_DATA(_b, _d, _prefix, _str, _type, _flags, \ + "(" #_type ")" #__VA_ARGS__, __VA_ARGS__) + +/* overflow test; pass typesize < expected type size, ensure E2BIG returned */ +#define TEST_BTF_DUMP_DATA_OVER(_b, _d, _prefix, _str, _type, _type_sz, \ + _expected, ...) \ + do { \ + char __ptrtype[64] = #_type; \ + char *_ptrtype = (char *)__ptrtype; \ + _type _ptrdata = __VA_ARGS__; \ + void *_ptr = &_ptrdata; \ + \ + (void) btf_dump_data(_b, _d, _ptrtype, _prefix, 0, \ + _ptr, _type_sz, _str, _expected); \ + } while (0) + +#define TEST_BTF_DUMP_VAR(_b, _d, _prefix, _str, _var, _type, _flags, \ + _expected, ...) \ + do { \ + _type _ptrdata = __VA_ARGS__; \ + void *_ptr = &_ptrdata; \ + \ + (void) btf_dump_data(_b, _d, _var, _prefix, _flags, \ + _ptr, sizeof(_type), _str, \ + _expected); \ + } while (0) + +static void test_btf_dump_int_data(struct btf *btf, struct btf_dump *d, + char *str) +{ + /* simple int */ + TEST_BTF_DUMP_DATA_C(btf, d, NULL, str, int, BTF_F_COMPACT, 1234); + TEST_BTF_DUMP_DATA(btf, d, NULL, str, int, BTF_F_COMPACT | BTF_F_NONAME, + "1234", 1234); + TEST_BTF_DUMP_DATA(btf, d, NULL, str, int, 0, "(int)1234", 1234); + + /* zero value should be printed at toplevel */ + TEST_BTF_DUMP_DATA(btf, d, NULL, str, int, BTF_F_COMPACT, "(int)0", 0); + TEST_BTF_DUMP_DATA(btf, d, NULL, str, int, BTF_F_COMPACT | BTF_F_NONAME, + "0", 0); + TEST_BTF_DUMP_DATA(btf, d, NULL, str, int, BTF_F_COMPACT | BTF_F_ZERO, + "(int)0", 0); + TEST_BTF_DUMP_DATA(btf, d, NULL, str, int, + BTF_F_COMPACT | BTF_F_NONAME | BTF_F_ZERO, + "0", 0); + TEST_BTF_DUMP_DATA_C(btf, d, NULL, str, int, BTF_F_COMPACT, -4567); + TEST_BTF_DUMP_DATA(btf, d, NULL, str, int, BTF_F_COMPACT | BTF_F_NONAME, + "-4567", -4567); + TEST_BTF_DUMP_DATA(btf, d, NULL, str, int, 0, "(int)-4567", -4567); + + TEST_BTF_DUMP_DATA_OVER(btf, d, NULL, str, int, sizeof(int)-1, "", 1); +} + +static void test_btf_dump_float_data(struct btf *btf, struct btf_dump *d, + char *str) +{ + float t1 = 1.234567; + float t2 = -1.234567; + float t3 = 0.0; + double t4 = 5.678912; + double t5 = -5.678912; + double t6 = 0.0; + long double t7 = 9.876543; + long double t8 = -9.876543; + long double t9 = 0.0; + + /* since the kernel does not likely have any float types in its BTF, we + * will need to add some of various sizes. + */ + + ASSERT_GT(btf__add_float(btf, "test_float", 4), 0, "add float"); + ASSERT_OK(btf_dump_data(btf, d, "test_float", NULL, 0, &t1, 4, str, + "(test_float)1.234567"), "dump float"); + ASSERT_OK(btf_dump_data(btf, d, "test_float", NULL, 0, &t2, 4, str, + "(test_float)-1.234567"), "dump float"); + ASSERT_OK(btf_dump_data(btf, d, "test_float", NULL, 0, &t3, 4, str, + "(test_float)0.000000"), "dump float"); + + ASSERT_GT(btf__add_float(btf, "test_double", 8), 0, "add_double"); + ASSERT_OK(btf_dump_data(btf, d, "test_double", NULL, 0, &t4, 8, str, + "(test_double)5.678912"), "dump double"); + ASSERT_OK(btf_dump_data(btf, d, "test_double", NULL, 0, &t5, 8, str, + "(test_double)-5.678912"), "dump double"); + ASSERT_OK(btf_dump_data(btf, d, "test_double", NULL, 0, &t6, 8, str, + "(test_double)0.000000"), "dump double"); + + ASSERT_GT(btf__add_float(btf, "test_long_double", 16), 0, "add long double"); + ASSERT_OK(btf_dump_data(btf, d, "test_long_double", NULL, 0, &t7, 16, + str, "(test_long_double)9.876543"), + "dump long_double"); + ASSERT_OK(btf_dump_data(btf, d, "test_long_double", NULL, 0, &t8, 16, + str, "(test_long_double)-9.876543"), + "dump long_double"); + ASSERT_OK(btf_dump_data(btf, d, "test_long_double", NULL, 0, &t9, 16, + str, "(test_long_double)0.000000"), + "dump long_double"); +} + +static void test_btf_dump_char_data(struct btf *btf, struct btf_dump *d, + char *str) +{ + /* simple char */ + TEST_BTF_DUMP_DATA_C(btf, d, NULL, str, char, BTF_F_COMPACT, 100); + TEST_BTF_DUMP_DATA(btf, d, NULL, str, char, BTF_F_COMPACT | BTF_F_NONAME, + "100", 100); + TEST_BTF_DUMP_DATA(btf, d, NULL, str, char, 0, "(char)100", 100); + /* zero value should be printed at toplevel */ + TEST_BTF_DUMP_DATA(btf, d, NULL, str, char, BTF_F_COMPACT, + "(char)0", 0); + TEST_BTF_DUMP_DATA(btf, d, NULL, str, char, BTF_F_COMPACT | BTF_F_NONAME, + "0", 0); + TEST_BTF_DUMP_DATA(btf, d, NULL, str, char, BTF_F_COMPACT | BTF_F_ZERO, + "(char)0", 0); + TEST_BTF_DUMP_DATA(btf, d, NULL, str, char, BTF_F_COMPACT | BTF_F_NONAME | BTF_F_ZERO, + "0", 0); + TEST_BTF_DUMP_DATA(btf, d, NULL, str, char, 0, "(char)0", 0); + + TEST_BTF_DUMP_DATA_OVER(btf, d, NULL, str, char, sizeof(char)-1, "", 100); +} + +static void test_btf_dump_typedef_data(struct btf *btf, struct btf_dump *d, + char *str) +{ + /* simple typedef */ + TEST_BTF_DUMP_DATA_C(btf, d, NULL, str, uint64_t, BTF_F_COMPACT, 100); + TEST_BTF_DUMP_DATA(btf, d, NULL, str, u64, BTF_F_COMPACT | BTF_F_NONAME, + "1", 1); + TEST_BTF_DUMP_DATA(btf, d, NULL, str, u64, 0, "(u64)1", 1); + /* zero value should be printed at toplevel */ + TEST_BTF_DUMP_DATA(btf, d, NULL, str, u64, BTF_F_COMPACT, "(u64)0", 0); + TEST_BTF_DUMP_DATA(btf, d, NULL, str, u64, BTF_F_COMPACT | BTF_F_NONAME, + "0", 0); + TEST_BTF_DUMP_DATA(btf, d, NULL, str, u64, BTF_F_COMPACT | BTF_F_ZERO, + "(u64)0", 0); + TEST_BTF_DUMP_DATA(btf, d, NULL, str, u64, + BTF_F_COMPACT | BTF_F_NONAME | BTF_F_ZERO, + "0", 0); + TEST_BTF_DUMP_DATA(btf, d, NULL, str, u64, 0, "(u64)0", 0); + + /* typedef struct */ + TEST_BTF_DUMP_DATA_C(btf, d, NULL, str, atomic_t, BTF_F_COMPACT, + {.counter = (int)1,}); + TEST_BTF_DUMP_DATA(btf, d, NULL, str, atomic_t, BTF_F_COMPACT | BTF_F_NONAME, + "{1,}", { .counter = 1 }); + TEST_BTF_DUMP_DATA(btf, d, NULL, str, atomic_t, 0, +"(atomic_t){\n" +" .counter = (int)1,\n" +"}", + {.counter = 1,}); + /* typedef with 0 value should be printed at toplevel */ + TEST_BTF_DUMP_DATA(btf, d, NULL, str, atomic_t, BTF_F_COMPACT, "(atomic_t){}", + {.counter = 0,}); + TEST_BTF_DUMP_DATA(btf, d, NULL, str, atomic_t, BTF_F_COMPACT | BTF_F_NONAME, + "{}", {.counter = 0,}); + TEST_BTF_DUMP_DATA(btf, d, NULL, str, atomic_t, 0, +"(atomic_t){\n" +"}", + {.counter = 0,}); + TEST_BTF_DUMP_DATA(btf, d, NULL, str, atomic_t, BTF_F_COMPACT | BTF_F_ZERO, + "(atomic_t){.counter = (int)0,}", + {.counter = 0,}); + TEST_BTF_DUMP_DATA(btf, d, NULL, str, atomic_t, + BTF_F_COMPACT | BTF_F_NONAME | BTF_F_ZERO, + "{0,}", {.counter = 0,}); + TEST_BTF_DUMP_DATA(btf, d, NULL, str, atomic_t, BTF_F_ZERO, +"(atomic_t){\n" +" .counter = (int)0,\n" +"}", + { .counter = 0,}); + + /* overflow should show type but not value since it overflows */ + TEST_BTF_DUMP_DATA_OVER(btf, d, NULL, str, atomic_t, sizeof(atomic_t)-1, + "(atomic_t){\n", { .counter = 1}); +} + +static void test_btf_dump_enum_data(struct btf *btf, struct btf_dump *d, + char *str) +{ + /* enum where enum value does (and does not) exist */ + TEST_BTF_DUMP_DATA_C(btf, d, "enum", str, enum bpf_cmd, BTF_F_COMPACT, + BPF_MAP_CREATE); + TEST_BTF_DUMP_DATA(btf, d, "enum", str, enum bpf_cmd, BTF_F_COMPACT, + "(enum bpf_cmd)BPF_MAP_CREATE", 0); + TEST_BTF_DUMP_DATA(btf, d, "enum", str, enum bpf_cmd, + BTF_F_COMPACT | BTF_F_NONAME, + "BPF_MAP_CREATE", + BPF_MAP_CREATE); + TEST_BTF_DUMP_DATA(btf, d, "enum", str, enum bpf_cmd, 0, + "(enum bpf_cmd)BPF_MAP_CREATE", + BPF_MAP_CREATE); + TEST_BTF_DUMP_DATA(btf, d, "enum", str, enum bpf_cmd, + BTF_F_COMPACT | BTF_F_NONAME | BTF_F_ZERO, + "BPF_MAP_CREATE", 0); + TEST_BTF_DUMP_DATA(btf, d, "enum", str, enum bpf_cmd, + BTF_F_COMPACT | BTF_F_ZERO, + "(enum bpf_cmd)BPF_MAP_CREATE", + BPF_MAP_CREATE); + TEST_BTF_DUMP_DATA(btf, d, "enum", str, enum bpf_cmd, + BTF_F_COMPACT | BTF_F_NONAME | BTF_F_ZERO, + "BPF_MAP_CREATE", BPF_MAP_CREATE); + TEST_BTF_DUMP_DATA_C(btf, d, "enum", str, enum bpf_cmd, BTF_F_COMPACT, 2000); + TEST_BTF_DUMP_DATA(btf, d, "enum", str, enum bpf_cmd, + BTF_F_COMPACT | BTF_F_NONAME, + "2000", 2000); + TEST_BTF_DUMP_DATA(btf, d, "enum", str, enum bpf_cmd, 0, + "(enum bpf_cmd)2000", 2000); + + TEST_BTF_DUMP_DATA_OVER(btf, d, "enum", str, enum bpf_cmd, + sizeof(enum bpf_cmd) - 1, "", BPF_MAP_CREATE); +} + +static void test_btf_dump_struct_data(struct btf *btf, struct btf_dump *d, + char *str) +{ + DECLARE_LIBBPF_OPTS(btf_dump_type_data_opts, opts); + char zero_data[512] = { }; + char type_data[512]; + void *fops = type_data; + void *skb = type_data; + size_t type_sz; + __s32 type_id; + char *cmpstr; + int ret; + + memset(type_data, 255, sizeof(type_data)); + + /* simple struct */ + TEST_BTF_DUMP_DATA_C(btf, d, "struct", str, struct btf_enum, BTF_F_COMPACT, + {.name_off = (__u32)3,.val = (__s32)-1,}); + TEST_BTF_DUMP_DATA(btf, d, "struct", str, struct btf_enum, + BTF_F_COMPACT | BTF_F_NONAME, + "{3,-1,}", + { .name_off = 3, .val = -1,}); + TEST_BTF_DUMP_DATA(btf, d, "struct", str, struct btf_enum, 0, +"(struct btf_enum){\n" +" .name_off = (__u32)3,\n" +" .val = (__s32)-1,\n" +"}", + { .name_off = 3, .val = -1,}); + TEST_BTF_DUMP_DATA(btf, d, "struct", str, struct btf_enum, + BTF_F_COMPACT | BTF_F_NONAME, + "{-1,}", + { .name_off = 0, .val = -1,}); + TEST_BTF_DUMP_DATA(btf, d, "struct", str, struct btf_enum, + BTF_F_COMPACT | BTF_F_NONAME | BTF_F_ZERO, + "{0,-1,}", + { .name_off = 0, .val = -1,}); + /* empty struct should be printed */ + TEST_BTF_DUMP_DATA(btf, d, "struct", str, struct btf_enum, BTF_F_COMPACT, + "(struct btf_enum){}", + { .name_off = 0, .val = 0,}); + TEST_BTF_DUMP_DATA(btf, d, "struct", str, struct btf_enum, + BTF_F_COMPACT | BTF_F_NONAME, + "{}", + { .name_off = 0, .val = 0,}); + TEST_BTF_DUMP_DATA(btf, d, "struct", str, struct btf_enum, 0, +"(struct btf_enum){\n" +"}", + { .name_off = 0, .val = 0,}); + TEST_BTF_DUMP_DATA(btf, d, "struct", str, struct btf_enum, + BTF_F_COMPACT | BTF_F_ZERO, + "(struct btf_enum){.name_off = (__u32)0,.val = (__s32)0,}", + { .name_off = 0, .val = 0,}); + TEST_BTF_DUMP_DATA(btf, d, "struct", str, struct btf_enum, + BTF_F_ZERO, +"(struct btf_enum){\n" +" .name_off = (__u32)0,\n" +" .val = (__s32)0,\n" +"}", + { .name_off = 0, .val = 0,}); + + /* struct with pointers */ + TEST_BTF_DUMP_DATA(btf, d, "struct", str, struct list_head, BTF_F_COMPACT, + "(struct list_head){.next = (struct list_head *)0x1,}", + { .next = (struct list_head *)1 }); + TEST_BTF_DUMP_DATA(btf, d, "struct", str, struct list_head, 0, +"(struct list_head){\n" +" .next = (struct list_head *)0x1,\n" +"}", + { .next = (struct list_head *)1 }); + /* NULL pointer should not be displayed */ + TEST_BTF_DUMP_DATA(btf, d, "struct", str, struct list_head, BTF_F_COMPACT, + "(struct list_head){}", + { .next = (struct list_head *)0 }); + TEST_BTF_DUMP_DATA(btf, d, "struct", str, struct list_head, 0, +"(struct list_head){\n" +"}", + { .next = (struct list_head *)0 }); + + /* struct with function pointers */ + type_id = btf__find_by_name(btf, "file_operations"); + if (ASSERT_GT(type_id, 0, "find type id")) { + type_sz = btf__resolve_size(btf, type_id); + str[0] = '\0'; + + ret = btf_dump__dump_type_data(d, type_id, fops, type_sz, &opts); + ASSERT_EQ(ret, type_sz, + "unexpected return value dumping file_operations"); + cmpstr = +"(struct file_operations){\n" +" .owner = (struct module *)0xffffffffffffffff,\n" +" .llseek = (loff_t (*)(struct file *, loff_t, int))0xffffffffffffffff,"; + + ASSERT_STRNEQ(str, cmpstr, strlen(cmpstr), "file_operations"); + } + + /* struct with char array */ + TEST_BTF_DUMP_DATA(btf, d, "struct", str, struct bpf_prog_info, BTF_F_COMPACT, + "(struct bpf_prog_info){.name = (char[16])['f','o','o',],}", + { .name = "foo",}); + TEST_BTF_DUMP_DATA(btf, d, "struct", str, struct bpf_prog_info, + BTF_F_COMPACT | BTF_F_NONAME, + "{['f','o','o',],}", + {.name = "foo",}); + TEST_BTF_DUMP_DATA(btf, d, "struct", str, struct bpf_prog_info, 0, +"(struct bpf_prog_info){\n" +" .name = (char[16])[\n" +" 'f',\n" +" 'o',\n" +" 'o',\n" +" ],\n" +"}", + {.name = "foo",}); + /* leading null char means do not display string */ + TEST_BTF_DUMP_DATA(btf, d, "struct", str, struct bpf_prog_info, BTF_F_COMPACT, + "(struct bpf_prog_info){}", + {.name = {'\0', 'f', 'o', 'o'}}); + /* handle non-printable characters */ + TEST_BTF_DUMP_DATA(btf, d, "struct", str, struct bpf_prog_info, BTF_F_COMPACT, + "(struct bpf_prog_info){.name = (char[16])[1,2,3,],}", + { .name = {1, 2, 3, 0}}); + + /* struct with non-char array */ + TEST_BTF_DUMP_DATA(btf, d, "struct", str, struct __sk_buff, BTF_F_COMPACT, + "(struct __sk_buff){.cb = (__u32[5])[1,2,3,4,5,],}", + { .cb = {1, 2, 3, 4, 5,},}); + TEST_BTF_DUMP_DATA(btf, d, "struct", str, struct __sk_buff, + BTF_F_COMPACT | BTF_F_NONAME, + "{[1,2,3,4,5,],}", + { .cb = { 1, 2, 3, 4, 5},}); + TEST_BTF_DUMP_DATA(btf, d, "struct", str, struct __sk_buff, 0, +"(struct __sk_buff){\n" +" .cb = (__u32[5])[\n" +" 1,\n" +" 2,\n" +" 3,\n" +" 4,\n" +" 5,\n" +" ],\n" +"}", + { .cb = { 1, 2, 3, 4, 5},}); + /* For non-char, arrays, show non-zero values only */ + TEST_BTF_DUMP_DATA(btf, d, "struct", str, struct __sk_buff, BTF_F_COMPACT, + "(struct __sk_buff){.cb = (__u32[5])[0,0,1,0,0,],}", + { .cb = { 0, 0, 1, 0, 0},}); + TEST_BTF_DUMP_DATA(btf, d, "struct", str, struct __sk_buff, 0, +"(struct __sk_buff){\n" +" .cb = (__u32[5])[\n" +" 0,\n" +" 0,\n" +" 1,\n" +" 0,\n" +" 0,\n" +" ],\n" +"}", + { .cb = { 0, 0, 1, 0, 0},}); + + /* struct with bitfields */ + TEST_BTF_DUMP_DATA_C(btf, d, "struct", str, struct bpf_insn, BTF_F_COMPACT, + {.code = (__u8)1,.dst_reg = (__u8)0x2,.src_reg = (__u8)0x3,.off = (__s16)4,.imm = (__s32)5,}); + TEST_BTF_DUMP_DATA(btf, d, "struct", str, struct bpf_insn, + BTF_F_COMPACT | BTF_F_NONAME, + "{1,0x2,0x3,4,5,}", + { .code = 1, .dst_reg = 0x2, .src_reg = 0x3, .off = 4, + .imm = 5,}); + TEST_BTF_DUMP_DATA(btf, d, "struct", str, struct bpf_insn, 0, +"(struct bpf_insn){\n" +" .code = (__u8)1,\n" +" .dst_reg = (__u8)0x2,\n" +" .src_reg = (__u8)0x3,\n" +" .off = (__s16)4,\n" +" .imm = (__s32)5,\n" +"}", + {.code = 1, .dst_reg = 2, .src_reg = 3, .off = 4, .imm = 5}); + + /* zeroed bitfields should not be displayed */ + TEST_BTF_DUMP_DATA(btf, d, "struct", str, struct bpf_insn, BTF_F_COMPACT, + "(struct bpf_insn){.dst_reg = (__u8)0x1,}", + { .code = 0, .dst_reg = 1}); + + /* struct with enum bitfield */ + type_id = btf__find_by_name(btf, "fs_context"); + if (ASSERT_GT(type_id, 0, "find fs_context")) { + type_sz = btf__resolve_size(btf, type_id); + str[0] = '\0'; + + opts.emit_zeroes = true; + ret = btf_dump__dump_type_data(d, type_id, zero_data, type_sz, &opts); + ASSERT_EQ(ret, type_sz, + "unexpected return value dumping fs_context"); + + ASSERT_NEQ(strstr(str, "FS_CONTEXT_FOR_MOUNT"), NULL, + "bitfield value not present"); + } + + /* struct with nested anon union */ + TEST_BTF_DUMP_DATA(btf, d, "struct", str, struct bpf_sock_ops, BTF_F_COMPACT, + "(struct bpf_sock_ops){.op = (__u32)1,(union){.args = (__u32[4])[1,2,3,4,],.reply = (__u32)1,.replylong = (__u32[4])[1,2,3,4,],},}", + { .op = 1, .args = { 1, 2, 3, 4}}); + + /* union with nested struct */ + TEST_BTF_DUMP_DATA(btf, d, "union", str, union bpf_iter_link_info, BTF_F_COMPACT, + "(union bpf_iter_link_info){.map = (struct){.map_fd = (__u32)1,},}", + { .map = { .map_fd = 1 }}); + + /* struct skb with nested structs/unions; because type output is so + * complex, we don't do a string comparison, just verify we return + * the type size as the amount of data displayed. + */ + type_id = btf__find_by_name(btf, "sk_buff"); + if (ASSERT_GT(type_id, 0, "find struct sk_buff")) { + type_sz = btf__resolve_size(btf, type_id); + str[0] = '\0'; + + ret = btf_dump__dump_type_data(d, type_id, skb, type_sz, &opts); + ASSERT_EQ(ret, type_sz, + "unexpected return value dumping sk_buff"); + } + + /* overflow bpf_sock_ops struct with final element nonzero/zero. + * Regardless of the value of the final field, we don't have all the + * data we need to display it, so we should trigger an overflow. + * In other words oveflow checking should trump "is field zero?" + * checks because if we've overflowed, it shouldn't matter what the + * field is - we can't trust its value so shouldn't display it. + */ + TEST_BTF_DUMP_DATA_OVER(btf, d, "struct", str, struct bpf_sock_ops, + sizeof(struct bpf_sock_ops) - 1, + "(struct bpf_sock_ops){\n\t.op = (__u32)1,\n", + { .op = 1, .skb_tcp_flags = 2}); + TEST_BTF_DUMP_DATA_OVER(btf, d, "struct", str, struct bpf_sock_ops, + sizeof(struct bpf_sock_ops) - 1, + "(struct bpf_sock_ops){\n\t.op = (__u32)1,\n", + { .op = 1, .skb_tcp_flags = 0}); +} + +static void test_btf_dump_var_data(struct btf *btf, struct btf_dump *d, + char *str) +{ + TEST_BTF_DUMP_VAR(btf, d, NULL, str, "cpu_number", int, BTF_F_COMPACT, + "int cpu_number = (int)100", 100); + TEST_BTF_DUMP_VAR(btf, d, NULL, str, "cpu_profile_flip", int, BTF_F_COMPACT, + "static int cpu_profile_flip = (int)2", 2); +} + +static void test_btf_datasec(struct btf *btf, struct btf_dump *d, char *str, + const char *name, const char *expected_val, + void *data, size_t data_sz) +{ + DECLARE_LIBBPF_OPTS(btf_dump_type_data_opts, opts); + int ret = 0, cmp; + size_t secsize; + __s32 type_id; + + opts.compact = true; + + type_id = btf__find_by_name(btf, name); + if (!ASSERT_GT(type_id, 0, "find type id")) + return; + + secsize = btf__resolve_size(btf, type_id); + ASSERT_EQ(secsize, 0, "verify section size"); + + str[0] = '\0'; + ret = btf_dump__dump_type_data(d, type_id, data, data_sz, &opts); + ASSERT_EQ(ret, 0, "unexpected return value"); + + cmp = strcmp(str, expected_val); + ASSERT_EQ(cmp, 0, "ensure expected/actual match"); +} + +static void test_btf_dump_datasec_data(char *str) +{ + struct btf *btf = btf__parse("xdping_kern.o", NULL); + struct btf_dump_opts opts = { .ctx = str }; + char license[4] = "GPL"; + struct btf_dump *d; + + if (!ASSERT_OK_PTR(btf, "xdping_kern.o BTF not found")) + return; + + d = btf_dump__new(btf, NULL, &opts, btf_dump_snprintf); + if (!ASSERT_OK_PTR(d, "could not create BTF dump")) + return; + + test_btf_datasec(btf, d, str, "license", + "SEC(\"license\") char[4] _license = (char[4])['G','P','L',];", + license, sizeof(license)); +} + void test_btf_dump() { + char str[STRSIZE]; + struct btf_dump_opts opts = { .ctx = str }; + struct btf_dump *d; + struct btf *btf; int i; for (i = 0; i < ARRAY_SIZE(btf_dump_test_cases); i++) { @@ -245,4 +814,33 @@ void test_btf_dump() { } if (test__start_subtest("btf_dump: incremental")) test_btf_dump_incremental(); + + btf = libbpf_find_kernel_btf(); + if (!ASSERT_OK_PTR(btf, "no kernel BTF found")) + return; + + d = btf_dump__new(btf, NULL, &opts, btf_dump_snprintf); + if (!ASSERT_OK_PTR(d, "could not create BTF dump")) + return; + + /* Verify type display for various types. */ + if (test__start_subtest("btf_dump: int_data")) + test_btf_dump_int_data(btf, d, str); + if (test__start_subtest("btf_dump: float_data")) + test_btf_dump_float_data(btf, d, str); + if (test__start_subtest("btf_dump: char_data")) + test_btf_dump_char_data(btf, d, str); + if (test__start_subtest("btf_dump: typedef_data")) + test_btf_dump_typedef_data(btf, d, str); + if (test__start_subtest("btf_dump: enum_data")) + test_btf_dump_enum_data(btf, d, str); + if (test__start_subtest("btf_dump: struct_data")) + test_btf_dump_struct_data(btf, d, str); + if (test__start_subtest("btf_dump: var_data")) + test_btf_dump_var_data(btf, d, str); + btf_dump__free(d); + btf__free(btf); + + if (test__start_subtest("btf_dump: datasec_data")) + test_btf_dump_datasec_data(str); } -- 2.11.0