Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

1 files changed, 905 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/btf_dump.c b/tools/testing/selftests/bpf/prog_tests/btf_dump.c
new file mode 100644
index 000000000..e9ea38aa8
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/btf_dump.c
@@ -0,0 +1,905 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <test_progs.h>
+#include <bpf/btf.h>
+
+static int duration = 0;
+
+void btf_dump_printf(void *ctx, const char *fmt, va_list args)
+{
+	vfprintf(ctx, fmt, args);
+}
+
+static struct btf_dump_test_case {
+	const char *name;
+	const char *file;
+	bool known_ptr_sz;
+} btf_dump_test_cases[] = {
+	{"btf_dump: syntax", "btf_dump_test_case_syntax", true},
+	{"btf_dump: ordering", "btf_dump_test_case_ordering", false},
+	{"btf_dump: padding", "btf_dump_test_case_padding", true},
+	{"btf_dump: packing", "btf_dump_test_case_packing", true},
+	{"btf_dump: bitfields", "btf_dump_test_case_bitfields", true},
+	{"btf_dump: multidim", "btf_dump_test_case_multidim", false},
+	{"btf_dump: namespacing", "btf_dump_test_case_namespacing", false},
+};
+
+static int btf_dump_all_types(const struct btf *btf, void *ctx)
+{
+	size_t type_cnt = btf__type_cnt(btf);
+	struct btf_dump *d;
+	int err = 0, id;
+
+	d = btf_dump__new(btf, btf_dump_printf, ctx, NULL);
+	err = libbpf_get_error(d);
+	if (err)
+		return err;
+
+	for (id = 1; id < type_cnt; id++) {
+		err = btf_dump__dump_type(d, id);
+		if (err)
+			goto done;
+	}
+
+done:
+	btf_dump__free(d);
+	return err;
+}
+
+static int test_btf_dump_case(int n, struct btf_dump_test_case *t)
+{
+	char test_file[256], out_file[256], diff_cmd[1024];
+	struct btf *btf = NULL;
+	int err = 0, fd = -1;
+	FILE *f = NULL;
+
+	snprintf(test_file, sizeof(test_file), "%s.bpf.o", t->file);
+
+	btf = btf__parse_elf(test_file, NULL);
+	if (!ASSERT_OK_PTR(btf, "btf_parse_elf")) {
+		err = -PTR_ERR(btf);
+		btf = NULL;
+		goto done;
+	}
+
+	/* tests with t->known_ptr_sz have no "long" or "unsigned long" type,
+	 * so it's impossible to determine correct pointer size; but if they
+	 * do, it should be 8 regardless of host architecture, becaues BPF
+	 * target is always 64-bit
+	 */
+	if (!t->known_ptr_sz) {
+		btf__set_pointer_size(btf, 8);
+	} else {
+		CHECK(btf__pointer_size(btf) != 8, "ptr_sz", "exp %d, got %zu\n",
+		      8, btf__pointer_size(btf));
+	}
+
+	snprintf(out_file, sizeof(out_file), "/tmp/%s.output.XXXXXX", t->file);
+	fd = mkstemp(out_file);
+	if (!ASSERT_GE(fd, 0, "create_tmp")) {
+		err = fd;
+		goto done;
+	}
+	f = fdopen(fd, "w");
+	if (CHECK(f == NULL, "open_tmp",  "failed to open file: %s(%d)\n",
+		  strerror(errno), errno)) {
+		close(fd);
+		goto done;
+	}
+
+	err = btf_dump_all_types(btf, f);
+	fclose(f);
+	close(fd);
+	if (CHECK(err, "btf_dump", "failure during C dumping: %d\n", err)) {
+		goto done;
+	}
+
+	snprintf(test_file, sizeof(test_file), "progs/%s.c", t->file);
+	if (access(test_file, R_OK) == -1)
+		/*
+		 * When the test is run with O=, kselftest copies TEST_FILES
+		 * without preserving the directory structure.
+		 */
+		snprintf(test_file, sizeof(test_file), "%s.c", t->file);
+	/*
+	 * Diff test output and expected test output, contained between
+	 * START-EXPECTED-OUTPUT and END-EXPECTED-OUTPUT lines in test case.
+	 * For expected output lines, everything before '*' is stripped out.
+	 * Also lines containing comment start and comment end markers are
+	 * ignored. 
+	 */
+	snprintf(diff_cmd, sizeof(diff_cmd),
+		 "awk '/START-EXPECTED-OUTPUT/{out=1;next} "
+		 "/END-EXPECTED-OUTPUT/{out=0} "
+		 "/\\/\\*|\\*\\//{next} " /* ignore comment start/end lines */
+		 "out {sub(/^[ \\t]*\\*/, \"\"); print}' '%s' | diff -u - '%s'",
+		 test_file, out_file);
+	err = system(diff_cmd);
+	if (CHECK(err, "diff",
+		  "differing test output, output=%s, err=%d, diff cmd:\n%s\n",
+		  out_file, err, diff_cmd))
+		goto done;
+
+	remove(out_file);
+
+done:
+	btf__free(btf);
+	return err;
+}
+
+static char *dump_buf;
+static size_t dump_buf_sz;
+static FILE *dump_buf_file;
+
+static void test_btf_dump_incremental(void)
+{
+	struct btf *btf = NULL;
+	struct btf_dump *d = NULL;
+	int id, err, i;
+
+	dump_buf_file = open_memstream(&dump_buf, &dump_buf_sz);
+	if (!ASSERT_OK_PTR(dump_buf_file, "dump_memstream"))
+		return;
+	btf = btf__new_empty();
+	if (!ASSERT_OK_PTR(btf, "new_empty"))
+		goto err_out;
+	d = btf_dump__new(btf, btf_dump_printf, dump_buf_file, NULL);
+	if (!ASSERT_OK(libbpf_get_error(d), "btf_dump__new"))
+		goto err_out;
+
+	/* First, generate BTF corresponding to the following C code:
+	 *
+	 * enum x;
+	 *
+	 * enum x { X = 1 };
+	 *
+	 * enum { Y = 1 };
+	 *
+	 * struct s;
+	 *
+	 * struct s { int x; };
+	 *
+	 */
+	id = btf__add_enum(btf, "x", 4);
+	ASSERT_EQ(id, 1, "enum_declaration_id");
+	id = btf__add_enum(btf, "x", 4);
+	ASSERT_EQ(id, 2, "named_enum_id");
+	err = btf__add_enum_value(btf, "X", 1);
+	ASSERT_OK(err, "named_enum_val_ok");
+
+	id = btf__add_enum(btf, NULL, 4);
+	ASSERT_EQ(id, 3, "anon_enum_id");
+	err = btf__add_enum_value(btf, "Y", 1);
+	ASSERT_OK(err, "anon_enum_val_ok");
+
+	id = btf__add_int(btf, "int", 4, BTF_INT_SIGNED);
+	ASSERT_EQ(id, 4, "int_id");
+
+	id = btf__add_fwd(btf, "s", BTF_FWD_STRUCT);
+	ASSERT_EQ(id, 5, "fwd_id");
+
+	id = btf__add_struct(btf, "s", 4);
+	ASSERT_EQ(id, 6, "struct_id");
+	err = btf__add_field(btf, "x", 4, 0, 0);
+	ASSERT_OK(err, "field_ok");
+
+	for (i = 1; i < btf__type_cnt(btf); i++) {
+		err = btf_dump__dump_type(d, i);
+		ASSERT_OK(err, "dump_type_ok");
+	}
+
+	fflush(dump_buf_file);
+	dump_buf[dump_buf_sz] = 0; /* some libc implementations don't do this */
+
+	ASSERT_STREQ(dump_buf,
+"enum x;\n"
+"\n"
+"enum x {\n"
+"	X = 1,\n"
+"};\n"
+"\n"
+"enum {\n"
+"	Y = 1,\n"
+"};\n"
+"\n"
+"struct s;\n"
+"\n"
+"struct s {\n"
+"	int x;\n"
+"};\n\n", "c_dump1");
+
+	/* Now, after dumping original BTF, append another struct that embeds
+	 * anonymous enum. It also has a name conflict with the first struct:
+	 *
+	 * struct s___2 {
+	 *     enum { VAL___2 = 1 } x;
+	 *     struct s s;
+	 * };
+	 *
+	 * This will test that btf_dump'er maintains internal state properly.
+	 * Note that VAL___2 enum value. It's because we've already emitted
+	 * that enum as a global anonymous enum, so btf_dump will ensure that
+	 * enum values don't conflict;
+	 *
+	 */
+	fseek(dump_buf_file, 0, SEEK_SET);
+
+	id = btf__add_struct(btf, "s", 4);
+	ASSERT_EQ(id, 7, "struct_id");
+	err = btf__add_field(btf, "x", 2, 0, 0);
+	ASSERT_OK(err, "field_ok");
+	err = btf__add_field(btf, "y", 3, 32, 0);
+	ASSERT_OK(err, "field_ok");
+	err = btf__add_field(btf, "s", 6, 64, 0);
+	ASSERT_OK(err, "field_ok");
+
+	for (i = 1; i < btf__type_cnt(btf); i++) {
+		err = btf_dump__dump_type(d, i);
+		ASSERT_OK(err, "dump_type_ok");
+	}
+
+	fflush(dump_buf_file);
+	dump_buf[dump_buf_sz] = 0; /* some libc implementations don't do this */
+	ASSERT_STREQ(dump_buf,
+"struct s___2 {\n"
+"	enum x x;\n"
+"	enum {\n"
+"		Y___2 = 1,\n"
+"	} y;\n"
+"	struct s s;\n"
+"};\n\n" , "c_dump1");
+
+err_out:
+	fclose(dump_buf_file);
+	free(dump_buf);
+	btf_dump__free(d);
+	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)
+{
+#ifdef __SIZEOF_INT128__
+	unsigned __int128 i = 0xffffffffffffffff;
+
+	/* this dance is required because we cannot directly initialize
+	 * a 128-bit value to anything larger than a 64-bit value.
+	 */
+	i = (i << 64) | (i - 1);
+#endif
+	/* 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);
+
+#ifdef __SIZEOF_INT128__
+	/* gcc encode unsigned __int128 type with name "__int128 unsigned" in dwarf,
+	 * and clang encode it with name "unsigned __int128" in dwarf.
+	 * Do an availability test for either variant before doing actual test.
+	 */
+	if (btf__find_by_name(btf, "unsigned __int128") > 0) {
+		TEST_BTF_DUMP_DATA(btf, d, NULL, str, unsigned __int128, BTF_F_COMPACT,
+				   "(unsigned __int128)0xffffffffffffffff",
+				   0xffffffffffffffff);
+		ASSERT_OK(btf_dump_data(btf, d, "unsigned __int128", NULL, 0, &i, 16, str,
+					"(unsigned __int128)0xfffffffffffffffffffffffffffffffe"),
+			  "dump unsigned __int128");
+	} else if (btf__find_by_name(btf, "__int128 unsigned") > 0) {
+		TEST_BTF_DUMP_DATA(btf, d, NULL, str, __int128 unsigned, BTF_F_COMPACT,
+				   "(__int128 unsigned)0xffffffffffffffff",
+				   0xffffffffffffffff);
+		ASSERT_OK(btf_dump_data(btf, d, "__int128 unsigned", NULL, 0, &i, 16, str,
+					"(__int128 unsigned)0xfffffffffffffffffffffffffffffffe"),
+			  "dump unsigned __int128");
+	} else {
+		ASSERT_TRUE(false, "unsigned_int128_not_found");
+	}
+#endif
+}
+
+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,},.cgroup = (struct){.order = (enum bpf_cgroup_iter_order)BPF_CGROUP_ITER_SELF_ONLY,.cgroup_fd = (__u32)1,},.task = (struct){.tid = (__u32)1,.pid = (__u32)1,},}",
+			   { .cgroup = { .order = 1, .cgroup_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 overflow 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_hwtstamp = 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_hwtstamp = 0});
+}
+
+static void test_btf_dump_var_data(struct btf *btf, struct btf_dump *d,
+				   char *str)
+{
+#if 0
+	TEST_BTF_DUMP_VAR(btf, d, NULL, str, "cpu_number", int, BTF_F_COMPACT,
+			  "int cpu_number = (int)100", 100);
+#endif
+	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;
+	char license[4] = "GPL";
+	struct btf_dump *d;
+
+	btf = btf__parse("xdping_kern.bpf.o", NULL);
+	if (!ASSERT_OK_PTR(btf, "xdping_kern.bpf.o BTF not found"))
+		return;
+
+	d = btf_dump__new(btf, btf_dump_snprintf, str, NULL);
+	if (!ASSERT_OK_PTR(d, "could not create BTF dump"))
+		goto out;
+
+	test_btf_datasec(btf, d, str, "license",
+			 "SEC(\"license\") char[4] _license = (char[4])['G','P','L',];",
+			 license, sizeof(license));
+out:
+	btf_dump__free(d);
+	btf__free(btf);
+}
+
+void test_btf_dump() {
+	char str[STRSIZE];
+	struct btf_dump *d;
+	struct btf *btf;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(btf_dump_test_cases); i++) {
+		struct btf_dump_test_case *t = &btf_dump_test_cases[i];
+
+		if (!test__start_subtest(t->name))
+			continue;
+
+		test_btf_dump_case(i, &btf_dump_test_cases[i]);
+	}
+	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, btf_dump_snprintf, str, NULL);
+	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);
+}