]> www.infradead.org Git - users/jedix/linux-maple.git/commitdiff
selftests/bpf: Add dump type data tests to btf dump tests
authorAlan Maguire <alan.maguire@oracle.com>
Thu, 15 Jul 2021 15:15:26 +0000 (16:15 +0100)
committerAndrii Nakryiko <andrii@kernel.org>
Fri, 16 Jul 2021 20:50:36 +0000 (13:50 -0700)
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 <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
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

index 1b90e684ff133b92bac7754b284456649f312073..0b4ba53b596120658aa1ab6e8de79ff905aea61a 100644 (file)
@@ -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);
 }