1 files changed, 1314 insertions, 144 deletions

diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c
index bbb430317260..0381f209920a 100644
--- a/tools/lib/bpf/btf_dump.c
+++ b/tools/lib/bpf/btf_dump.c
@@ -10,16 +10,18 @@
 #include <stddef.h>
 #include <stdlib.h>
 #include <string.h>
+#include <ctype.h>
+#include <endian.h>
 #include <errno.h>
+#include <limits.h>
 #include <linux/err.h>
 #include <linux/btf.h>
+#include <linux/kernel.h>
 #include "btf.h"
 #include "hashmap.h"
 #include "libbpf.h"
 #include "libbpf_internal.h"
-
-/* make sure libbpf doesn't use kernel-only integer typedefs */
-#pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64
+#include "str_error.h"
 
 static const char PREFIXES[] = "\t\t\t\t\t\t\t\t\t\t\t\t\t";
 static const size_t PREFIX_CNT = sizeof(PREFIXES) - 1;
@@ -55,16 +57,41 @@ struct btf_dump_type_aux_state {
 	__u8 referenced: 1;
 };
 
+/* indent string length; one indent string is added for each indent level */
+#define BTF_DATA_INDENT_STR_LEN			32
+
+/*
+ * Common internal data for BTF type data dump operations.
+ */
+struct btf_dump_data {
+	const void *data_end;		/* end of valid data to show */
+	bool compact;
+	bool skip_names;
+	bool emit_zeroes;
+	__u8 indent_lvl;	/* base indent level */
+	char indent_str[BTF_DATA_INDENT_STR_LEN];
+	/* below are used during iteration */
+	int depth;
+	bool is_array_member;
+	bool is_array_terminated;
+	bool is_array_char;
+};
+
 struct btf_dump {
 	const struct btf *btf;
-	const struct btf_ext *btf_ext;
 	btf_dump_printf_fn_t printf_fn;
-	struct btf_dump_opts opts;
+	void *cb_ctx;
+	int ptr_sz;
+	bool strip_mods;
+	bool skip_anon_defs;
+	int last_id;
 
 	/* per-type auxiliary state */
 	struct btf_dump_type_aux_state *type_states;
+	size_t type_states_cap;
 	/* per-type optional cached unique name, must be freed, if present */
 	const char **cached_names;
+	size_t cached_names_cap;
 
 	/* topo-sorted list of dependent type definitions */
 	__u32 *emit_queue;
@@ -86,23 +113,20 @@ struct btf_dump {
 	 * name occurrences
 	 */
 	struct hashmap *ident_names;
+	/*
+	 * data for typed display; allocated if needed.
+	 */
+	struct btf_dump_data *typed_dump;
 };
 
-static size_t str_hash_fn(const void *key, void *ctx)
+static size_t str_hash_fn(long key, void *ctx)
 {
-	const char *s = key;
-	size_t h = 0;
-
-	while (*s) {
-		h = h * 31 + *s;
-		s++;
-	}
-	return h;
+	return str_hash((void *)key);
 }
 
-static bool str_equal_fn(const void *a, const void *b, void *ctx)
+static bool str_equal_fn(long a, long b, void *ctx)
 {
-	return strcmp(a, b) == 0;
+	return strcmp((void *)a, (void *)b) == 0;
 }
 
 static const char *btf_name_of(const struct btf_dump *d, __u32 name_off)
@@ -115,28 +139,35 @@ static void btf_dump_printf(const struct btf_dump *d, const char *fmt, ...)
 	va_list args;
 
 	va_start(args, fmt);
-	d->printf_fn(d->opts.ctx, fmt, args);
+	d->printf_fn(d->cb_ctx, fmt, args);
 	va_end(args);
 }
 
 static int btf_dump_mark_referenced(struct btf_dump *d);
+static int btf_dump_resize(struct btf_dump *d);
 
 struct btf_dump *btf_dump__new(const struct btf *btf,
-			       const struct btf_ext *btf_ext,
-			       const struct btf_dump_opts *opts,
-			       btf_dump_printf_fn_t printf_fn)
+			       btf_dump_printf_fn_t printf_fn,
+			       void *ctx,
+			       const struct btf_dump_opts *opts)
 {
 	struct btf_dump *d;
 	int err;
 
+	if (!OPTS_VALID(opts, btf_dump_opts))
+		return libbpf_err_ptr(-EINVAL);
+
+	if (!printf_fn)
+		return libbpf_err_ptr(-EINVAL);
+
 	d = calloc(1, sizeof(struct btf_dump));
 	if (!d)
-		return ERR_PTR(-ENOMEM);
+		return libbpf_err_ptr(-ENOMEM);
 
 	d->btf = btf;
-	d->btf_ext = btf_ext;
 	d->printf_fn = printf_fn;
-	d->opts.ctx = opts ? opts->ctx : NULL;
+	d->cb_ctx = ctx;
+	d->ptr_sz = btf__pointer_size(btf) ? : sizeof(void *);
 
 	d->type_names = hashmap__new(str_hash_fn, str_equal_fn, NULL);
 	if (IS_ERR(d->type_names)) {
@@ -150,45 +181,71 @@ struct btf_dump *btf_dump__new(const struct btf *btf,
 		d->ident_names = NULL;
 		goto err;
 	}
-	d->type_states = calloc(1 + btf__get_nr_types(d->btf),
-				sizeof(d->type_states[0]));
-	if (!d->type_states) {
-		err = -ENOMEM;
-		goto err;
-	}
-	d->cached_names = calloc(1 + btf__get_nr_types(d->btf),
-				 sizeof(d->cached_names[0]));
-	if (!d->cached_names) {
-		err = -ENOMEM;
-		goto err;
-	}
-
-	/* VOID is special */
-	d->type_states[0].order_state = ORDERED;
-	d->type_states[0].emit_state = EMITTED;
 
-	/* eagerly determine referenced types for anon enums */
-	err = btf_dump_mark_referenced(d);
+	err = btf_dump_resize(d);
 	if (err)
 		goto err;
 
 	return d;
 err:
 	btf_dump__free(d);
-	return ERR_PTR(err);
+	return libbpf_err_ptr(err);
+}
+
+static int btf_dump_resize(struct btf_dump *d)
+{
+	int err, last_id = btf__type_cnt(d->btf) - 1;
+
+	if (last_id <= d->last_id)
+		return 0;
+
+	if (libbpf_ensure_mem((void **)&d->type_states, &d->type_states_cap,
+			      sizeof(*d->type_states), last_id + 1))
+		return -ENOMEM;
+	if (libbpf_ensure_mem((void **)&d->cached_names, &d->cached_names_cap,
+			      sizeof(*d->cached_names), last_id + 1))
+		return -ENOMEM;
+
+	if (d->last_id == 0) {
+		/* VOID is special */
+		d->type_states[0].order_state = ORDERED;
+		d->type_states[0].emit_state = EMITTED;
+	}
+
+	/* eagerly determine referenced types for anon enums */
+	err = btf_dump_mark_referenced(d);
+	if (err)
+		return err;
+
+	d->last_id = last_id;
+	return 0;
+}
+
+static void btf_dump_free_names(struct hashmap *map)
+{
+	size_t bkt;
+	struct hashmap_entry *cur;
+
+	if (!map)
+		return;
+
+	hashmap__for_each_entry(map, cur, bkt)
+		free((void *)cur->pkey);
+
+	hashmap__free(map);
 }
 
 void btf_dump__free(struct btf_dump *d)
 {
-	int i, cnt;
+	int i;
 
-	if (!d)
+	if (IS_ERR_OR_NULL(d))
 		return;
 
 	free(d->type_states);
 	if (d->cached_names) {
 		/* any set cached name is owned by us and should be freed */
-		for (i = 0, cnt = btf__get_nr_types(d->btf); i <= cnt; i++) {
+		for (i = 0; i <= d->last_id; i++) {
 			if (d->cached_names[i])
 				free((void *)d->cached_names[i]);
 		}
@@ -196,8 +253,8 @@ void btf_dump__free(struct btf_dump *d)
 	free(d->cached_names);
 	free(d->emit_queue);
 	free(d->decl_stack);
-	hashmap__free(d->type_names);
-	hashmap__free(d->ident_names);
+	btf_dump_free_names(d->type_names);
+	btf_dump_free_names(d->ident_names);
 
 	free(d);
 }
@@ -225,13 +282,17 @@ int btf_dump__dump_type(struct btf_dump *d, __u32 id)
 {
 	int err, i;
 
-	if (id > btf__get_nr_types(d->btf))
-		return -EINVAL;
+	if (id >= btf__type_cnt(d->btf))
+		return libbpf_err(-EINVAL);
+
+	err = btf_dump_resize(d);
+	if (err)
+		return libbpf_err(err);
 
 	d->emit_queue_cnt = 0;
 	err = btf_dump_order_type(d, id, false);
 	if (err < 0)
-		return err;
+		return libbpf_err(err);
 
 	for (i = 0; i < d->emit_queue_cnt; i++)
 		btf_dump_emit_type(d, d->emit_queue[i], 0 /*top-level*/);
@@ -247,24 +308,26 @@ int btf_dump__dump_type(struct btf_dump *d, __u32 id)
  * definition, in which case they have to be declared inline as part of field
  * type declaration; or as a top-level anonymous enum, typically used for
  * declaring global constants. It's impossible to distinguish between two
- * without knowning whether given enum type was referenced from other type:
+ * without knowing whether given enum type was referenced from other type:
  * top-level anonymous enum won't be referenced by anything, while embedded
  * one will.
  */
 static int btf_dump_mark_referenced(struct btf_dump *d)
 {
-	int i, j, n = btf__get_nr_types(d->btf);
+	int i, j, n = btf__type_cnt(d->btf);
 	const struct btf_type *t;
 	__u16 vlen;
 
-	for (i = 1; i <= n; i++) {
+	for (i = d->last_id + 1; i < n; i++) {
 		t = btf__type_by_id(d->btf, i);
 		vlen = btf_vlen(t);
 
 		switch (btf_kind(t)) {
 		case BTF_KIND_INT:
 		case BTF_KIND_ENUM:
+		case BTF_KIND_ENUM64:
 		case BTF_KIND_FWD:
+		case BTF_KIND_FLOAT:
 			break;
 
 		case BTF_KIND_VOLATILE:
@@ -274,6 +337,8 @@ static int btf_dump_mark_referenced(struct btf_dump *d)
 		case BTF_KIND_TYPEDEF:
 		case BTF_KIND_FUNC:
 		case BTF_KIND_VAR:
+		case BTF_KIND_DECL_TAG:
+		case BTF_KIND_TYPE_TAG:
 			d->type_states[t->type].referenced = 1;
 			break;
 
@@ -312,6 +377,7 @@ static int btf_dump_mark_referenced(struct btf_dump *d)
 	}
 	return 0;
 }
+
 static int btf_dump_add_emit_queue_id(struct btf_dump *d, __u32 id)
 {
 	__u32 *new_queue;
@@ -319,8 +385,7 @@ static int btf_dump_add_emit_queue_id(struct btf_dump *d, __u32 id)
 
 	if (d->emit_queue_cnt >= d->emit_queue_cap) {
 		new_cap = max(16, d->emit_queue_cap * 3 / 2);
-		new_queue = realloc(d->emit_queue,
-				    new_cap * sizeof(new_queue[0]));
+		new_queue = libbpf_reallocarray(d->emit_queue, new_cap, sizeof(new_queue[0]));
 		if (!new_queue)
 			return -ENOMEM;
 		d->emit_queue = new_queue;
@@ -439,6 +504,7 @@ static int btf_dump_order_type(struct btf_dump *d, __u32 id, bool through_ptr)
 
 	switch (btf_kind(t)) {
 	case BTF_KIND_INT:
+	case BTF_KIND_FLOAT:
 		tstate->order_state = ORDERED;
 		return 0;
 
@@ -448,7 +514,7 @@ static int btf_dump_order_type(struct btf_dump *d, __u32 id, bool through_ptr)
 		return err;
 
 	case BTF_KIND_ARRAY:
-		return btf_dump_order_type(d, btf_array(t)->type, through_ptr);
+		return btf_dump_order_type(d, btf_array(t)->type, false);
 
 	case BTF_KIND_STRUCT:
 	case BTF_KIND_UNION: {
@@ -480,6 +546,7 @@ static int btf_dump_order_type(struct btf_dump *d, __u32 id, bool through_ptr)
 		return 1;
 	}
 	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64:
 	case BTF_KIND_FWD:
 		/*
 		 * non-anonymous or non-referenced enums are top-level
@@ -516,6 +583,7 @@ static int btf_dump_order_type(struct btf_dump *d, __u32 id, bool through_ptr)
 	case BTF_KIND_VOLATILE:
 	case BTF_KIND_CONST:
 	case BTF_KIND_RESTRICT:
+	case BTF_KIND_TYPE_TAG:
 		return btf_dump_order_type(d, t->type, through_ptr);
 
 	case BTF_KIND_FUNC_PROTO: {
@@ -540,6 +608,7 @@ static int btf_dump_order_type(struct btf_dump *d, __u32 id, bool through_ptr)
 	case BTF_KIND_FUNC:
 	case BTF_KIND_VAR:
 	case BTF_KIND_DATASEC:
+	case BTF_KIND_DECL_TAG:
 		d->type_states[id].order_state = ORDERED;
 		return 0;
 
@@ -548,6 +617,9 @@ static int btf_dump_order_type(struct btf_dump *d, __u32 id, bool through_ptr)
 	}
 }
 
+static void btf_dump_emit_missing_aliases(struct btf_dump *d, __u32 id,
+					  const struct btf_type *t);
+
 static void btf_dump_emit_struct_fwd(struct btf_dump *d, __u32 id,
 				     const struct btf_type *t);
 static void btf_dump_emit_struct_def(struct btf_dump *d, __u32 id,
@@ -670,9 +742,13 @@ static void btf_dump_emit_type(struct btf_dump *d, __u32 id, __u32 cont_id)
 
 	switch (kind) {
 	case BTF_KIND_INT:
+		/* Emit type alias definitions if necessary */
+		btf_dump_emit_missing_aliases(d, id, t);
+
 		tstate->emit_state = EMITTED;
 		break;
 	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64:
 		if (top_level_def) {
 			btf_dump_emit_enum_def(d, id, t, 0);
 			btf_dump_printf(d, ";\n\n");
@@ -683,6 +759,7 @@ static void btf_dump_emit_type(struct btf_dump *d, __u32 id, __u32 cont_id)
 	case BTF_KIND_VOLATILE:
 	case BTF_KIND_CONST:
 	case BTF_KIND_RESTRICT:
+	case BTF_KIND_TYPE_TAG:
 		btf_dump_emit_type(d, t->type, cont_id);
 		break;
 	case BTF_KIND_ARRAY:
@@ -743,11 +820,11 @@ static void btf_dump_emit_type(struct btf_dump *d, __u32 id, __u32 cont_id)
 		break;
 	case BTF_KIND_FUNC_PROTO: {
 		const struct btf_param *p = btf_params(t);
-		__u16 vlen = btf_vlen(t);
+		__u16 n = btf_vlen(t);
 		int i;
 
 		btf_dump_emit_type(d, t->type, cont_id);
-		for (i = 0; i < vlen; i++, p++)
+		for (i = 0; i < n; i++, p++)
 			btf_dump_emit_type(d, p->type, cont_id);
 
 		break;
@@ -761,14 +838,9 @@ static bool btf_is_struct_packed(const struct btf *btf, __u32 id,
 				 const struct btf_type *t)
 {
 	const struct btf_member *m;
-	int align, i, bit_sz;
+	int max_align = 1, align, i, bit_sz;
 	__u16 vlen;
 
-	align = btf__align_of(btf, id);
-	/* size of a non-packed struct has to be a multiple of its alignment*/
-	if (align && t->size % align)
-		return true;
-
 	m = btf_members(t);
 	vlen = btf_vlen(t);
 	/* all non-bitfield fields have to be naturally aligned */
@@ -777,8 +849,11 @@ static bool btf_is_struct_packed(const struct btf *btf, __u32 id,
 		bit_sz = btf_member_bitfield_size(t, i);
 		if (align && bit_sz == 0 && m->offset % (8 * align) != 0)
 			return true;
+		max_align = max(align, max_align);
 	}
-
+	/* size of a non-packed struct has to be a multiple of its alignment */
+	if (t->size % max_align != 0)
+		return true;
 	/*
 	 * if original struct was marked as packed, but its layout is
 	 * naturally aligned, we'll detect that it's not packed
@@ -786,52 +861,106 @@ static bool btf_is_struct_packed(const struct btf *btf, __u32 id,
 	return false;
 }
 
-static int chip_away_bits(int total, int at_most)
-{
-	return total % at_most ? : at_most;
-}
-
 static void btf_dump_emit_bit_padding(const struct btf_dump *d,
-				      int cur_off, int m_off, int m_bit_sz,
-				      int align, int lvl)
+				      int cur_off, int next_off, int next_align,
+				      bool in_bitfield, int lvl)
 {
-	int off_diff = m_off - cur_off;
-	int ptr_bits = sizeof(void *) * 8;
+	const struct {
+		const char *name;
+		int bits;
+	} pads[] = {
+		{"long", d->ptr_sz * 8}, {"int", 32}, {"short", 16}, {"char", 8}
+	};
+	int new_off = 0, pad_bits = 0, bits, i;
+	const char *pad_type = NULL;
+
+	if (cur_off >= next_off)
+		return; /* no gap */
+
+	/* For filling out padding we want to take advantage of
+	 * natural alignment rules to minimize unnecessary explicit
+	 * padding. First, we find the largest type (among long, int,
+	 * short, or char) that can be used to force naturally aligned
+	 * boundary. Once determined, we'll use such type to fill in
+	 * the remaining padding gap. In some cases we can rely on
+	 * compiler filling some gaps, but sometimes we need to force
+	 * alignment to close natural alignment with markers like
+	 * `long: 0` (this is always the case for bitfields).  Note
+	 * that even if struct itself has, let's say 4-byte alignment
+	 * (i.e., it only uses up to int-aligned types), using `long:
+	 * X;` explicit padding doesn't actually change struct's
+	 * overall alignment requirements, but compiler does take into
+	 * account that type's (long, in this example) natural
+	 * alignment requirements when adding implicit padding. We use
+	 * this fact heavily and don't worry about ruining correct
+	 * struct alignment requirement.
+	 */
+	for (i = 0; i < ARRAY_SIZE(pads); i++) {
+		pad_bits = pads[i].bits;
+		pad_type = pads[i].name;
 
-	if (off_diff <= 0)
-		/* no gap */
-		return;
-	if (m_bit_sz == 0 && off_diff < align * 8)
-		/* natural padding will take care of a gap */
-		return;
+		new_off = roundup(cur_off, pad_bits);
+		if (new_off <= next_off)
+			break;
+	}
 
-	while (off_diff > 0) {
-		const char *pad_type;
-		int pad_bits;
-
-		if (ptr_bits > 32 && off_diff > 32) {
-			pad_type = "long";
-			pad_bits = chip_away_bits(off_diff, ptr_bits);
-		} else if (off_diff > 16) {
-			pad_type = "int";
-			pad_bits = chip_away_bits(off_diff, 32);
-		} else if (off_diff > 8) {
-			pad_type = "short";
-			pad_bits = chip_away_bits(off_diff, 16);
-		} else {
-			pad_type = "char";
-			pad_bits = chip_away_bits(off_diff, 8);
+	if (new_off > cur_off && new_off <= next_off) {
+		/* We need explicit `<type>: 0` aligning mark if next
+		 * field is right on alignment offset and its
+		 * alignment requirement is less strict than <type>'s
+		 * alignment (so compiler won't naturally align to the
+		 * offset we expect), or if subsequent `<type>: X`,
+		 * will actually completely fit in the remaining hole,
+		 * making compiler basically ignore `<type>: X`
+		 * completely.
+		 */
+		if (in_bitfield ||
+		    (new_off == next_off && roundup(cur_off, next_align * 8) != new_off) ||
+		    (new_off != next_off && next_off - new_off <= new_off - cur_off))
+			/* but for bitfields we'll emit explicit bit count */
+			btf_dump_printf(d, "\n%s%s: %d;", pfx(lvl), pad_type,
+					in_bitfield ? new_off - cur_off : 0);
+		cur_off = new_off;
+	}
+
+	/* Now we know we start at naturally aligned offset for a chosen
+	 * padding type (long, int, short, or char), and so the rest is just
+	 * a straightforward filling of remaining padding gap with full
+	 * `<type>: sizeof(<type>);` markers, except for the last one, which
+	 * might need smaller than sizeof(<type>) padding.
+	 */
+	while (cur_off != next_off) {
+		bits = min(next_off - cur_off, pad_bits);
+		if (bits == pad_bits) {
+			btf_dump_printf(d, "\n%s%s: %d;", pfx(lvl), pad_type, pad_bits);
+			cur_off += bits;
+			continue;
+		}
+		/* For the remainder padding that doesn't cover entire
+		 * pad_type bit length, we pick the smallest necessary type.
+		 * This is pure aesthetics, we could have just used `long`,
+		 * but having smallest necessary one communicates better the
+		 * scale of the padding gap.
+		 */
+		for (i = ARRAY_SIZE(pads) - 1; i >= 0; i--) {
+			pad_type = pads[i].name;
+			pad_bits = pads[i].bits;
+			if (pad_bits < bits)
+				continue;
+
+			btf_dump_printf(d, "\n%s%s: %d;", pfx(lvl), pad_type, bits);
+			cur_off += bits;
+			break;
 		}
-		btf_dump_printf(d, "\n%s%s: %d;", pfx(lvl), pad_type, pad_bits);
-		off_diff -= pad_bits;
 	}
 }
 
 static void btf_dump_emit_struct_fwd(struct btf_dump *d, __u32 id,
 				     const struct btf_type *t)
 {
-	btf_dump_printf(d, "%s %s",
+	btf_dump_printf(d, "%s%s%s",
 			btf_is_struct(t) ? "struct" : "union",
+			t->name_off ? " " : "",
 			btf_dump_type_name(d, id));
 }
 
@@ -842,9 +971,11 @@ static void btf_dump_emit_struct_def(struct btf_dump *d,
 {
 	const struct btf_member *m = btf_members(t);
 	bool is_struct = btf_is_struct(t);
-	int align, i, packed, off = 0;
+	bool packed, prev_bitfield = false;
+	int align, i, off = 0;
 	__u16 vlen = btf_vlen(t);
 
+	align = btf__align_of(d->btf, id);
 	packed = is_struct ? btf_is_struct_packed(d->btf, id, t) : 0;
 
 	btf_dump_printf(d, "%s%s%s {",
@@ -854,79 +985,195 @@ static void btf_dump_emit_struct_def(struct btf_dump *d,
 
 	for (i = 0; i < vlen; i++, m++) {
 		const char *fname;
-		int m_off, m_sz;
+		int m_off, m_sz, m_align;
+		bool in_bitfield;
 
 		fname = btf_name_of(d, m->name_off);
 		m_sz = btf_member_bitfield_size(t, i);
 		m_off = btf_member_bit_offset(t, i);
-		align = packed ? 1 : btf__align_of(d->btf, m->type);
+		m_align = packed ? 1 : btf__align_of(d->btf, m->type);
 
-		btf_dump_emit_bit_padding(d, off, m_off, m_sz, align, lvl + 1);
+		in_bitfield = prev_bitfield && m_sz != 0;
+
+		btf_dump_emit_bit_padding(d, off, m_off, m_align, in_bitfield, lvl + 1);
 		btf_dump_printf(d, "\n%s", pfx(lvl + 1));
 		btf_dump_emit_type_decl(d, m->type, fname, lvl + 1);
 
 		if (m_sz) {
 			btf_dump_printf(d, ": %d", m_sz);
 			off = m_off + m_sz;
+			prev_bitfield = true;
 		} else {
-			m_sz = max(0, btf__resolve_size(d->btf, m->type));
+			m_sz = max((__s64)0, btf__resolve_size(d->btf, m->type));
 			off = m_off + m_sz * 8;
+			prev_bitfield = false;
 		}
+
 		btf_dump_printf(d, ";");
 	}
 
 	/* pad at the end, if necessary */
-	if (is_struct) {
-		align = packed ? 1 : btf__align_of(d->btf, id);
-		btf_dump_emit_bit_padding(d, off, t->size * 8, 0, align,
-					  lvl + 1);
-	}
+	if (is_struct)
+		btf_dump_emit_bit_padding(d, off, t->size * 8, align, false, lvl + 1);
 
-	if (vlen)
+	/*
+	 * Keep `struct empty {}` on a single line,
+	 * only print newline when there are regular or padding fields.
+	 */
+	if (vlen || t->size) {
 		btf_dump_printf(d, "\n");
-	btf_dump_printf(d, "%s}", pfx(lvl));
+		btf_dump_printf(d, "%s}", pfx(lvl));
+	} else {
+		btf_dump_printf(d, "}");
+	}
 	if (packed)
 		btf_dump_printf(d, " __attribute__((packed))");
 }
 
+static const char *missing_base_types[][2] = {
+	/*
+	 * GCC emits typedefs to its internal __PolyX_t types when compiling Arm
+	 * SIMD intrinsics. Alias them to standard base types.
+	 */
+	{ "__Poly8_t",		"unsigned char" },
+	{ "__Poly16_t",		"unsigned short" },
+	{ "__Poly64_t",		"unsigned long long" },
+	{ "__Poly128_t",	"unsigned __int128" },
+};
+
+static void btf_dump_emit_missing_aliases(struct btf_dump *d, __u32 id,
+					  const struct btf_type *t)
+{
+	const char *name = btf_dump_type_name(d, id);
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(missing_base_types); i++) {
+		if (strcmp(name, missing_base_types[i][0]) == 0) {
+			btf_dump_printf(d, "typedef %s %s;\n\n",
+					missing_base_types[i][1], name);
+			break;
+		}
+	}
+}
+
 static void btf_dump_emit_enum_fwd(struct btf_dump *d, __u32 id,
 				   const struct btf_type *t)
 {
 	btf_dump_printf(d, "enum %s", btf_dump_type_name(d, id));
 }
 
-static void btf_dump_emit_enum_def(struct btf_dump *d, __u32 id,
-				   const struct btf_type *t,
-				   int lvl)
+static void btf_dump_emit_enum32_val(struct btf_dump *d,
+				     const struct btf_type *t,
+				     int lvl, __u16 vlen)
 {
 	const struct btf_enum *v = btf_enum(t);
-	__u16 vlen = btf_vlen(t);
+	bool is_signed = btf_kflag(t);
+	const char *fmt_str;
 	const char *name;
 	size_t dup_cnt;
 	int i;
 
+	for (i = 0; i < vlen; i++, v++) {
+		name = btf_name_of(d, v->name_off);
+		/* enumerators share namespace with typedef idents */
+		dup_cnt = btf_dump_name_dups(d, d->ident_names, name);
+		if (dup_cnt > 1) {
+			fmt_str = is_signed ? "\n%s%s___%zd = %d," : "\n%s%s___%zd = %u,";
+			btf_dump_printf(d, fmt_str, pfx(lvl + 1), name, dup_cnt, v->val);
+		} else {
+			fmt_str = is_signed ? "\n%s%s = %d," : "\n%s%s = %u,";
+			btf_dump_printf(d, fmt_str, pfx(lvl + 1), name, v->val);
+		}
+	}
+}
+
+static void btf_dump_emit_enum64_val(struct btf_dump *d,
+				     const struct btf_type *t,
+				     int lvl, __u16 vlen)
+{
+	const struct btf_enum64 *v = btf_enum64(t);
+	bool is_signed = btf_kflag(t);
+	const char *fmt_str;
+	const char *name;
+	size_t dup_cnt;
+	__u64 val;
+	int i;
+
+	for (i = 0; i < vlen; i++, v++) {
+		name = btf_name_of(d, v->name_off);
+		dup_cnt = btf_dump_name_dups(d, d->ident_names, name);
+		val = btf_enum64_value(v);
+		if (dup_cnt > 1) {
+			fmt_str = is_signed ? "\n%s%s___%zd = %lldLL,"
+					    : "\n%s%s___%zd = %lluULL,";
+			btf_dump_printf(d, fmt_str,
+					pfx(lvl + 1), name, dup_cnt,
+					(unsigned long long)val);
+		} else {
+			fmt_str = is_signed ? "\n%s%s = %lldLL,"
+					    : "\n%s%s = %lluULL,";
+			btf_dump_printf(d, fmt_str,
+					pfx(lvl + 1), name,
+					(unsigned long long)val);
+		}
+	}
+}
+static void btf_dump_emit_enum_def(struct btf_dump *d, __u32 id,
+				   const struct btf_type *t,
+				   int lvl)
+{
+	__u16 vlen = btf_vlen(t);
+
 	btf_dump_printf(d, "enum%s%s",
 			t->name_off ? " " : "",
 			btf_dump_type_name(d, id));
 
-	if (vlen) {
-		btf_dump_printf(d, " {");
-		for (i = 0; i < vlen; i++, v++) {
-			name = btf_name_of(d, v->name_off);
-			/* enumerators share namespace with typedef idents */
-			dup_cnt = btf_dump_name_dups(d, d->ident_names, name);
-			if (dup_cnt > 1) {
-				btf_dump_printf(d, "\n%s%s___%zu = %u,",
-						pfx(lvl + 1), name, dup_cnt,
-						(__u32)v->val);
-			} else {
-				btf_dump_printf(d, "\n%s%s = %u,",
-						pfx(lvl + 1), name,
-						(__u32)v->val);
+	if (!vlen)
+		return;
+
+	btf_dump_printf(d, " {");
+	if (btf_is_enum(t))
+		btf_dump_emit_enum32_val(d, t, lvl, vlen);
+	else
+		btf_dump_emit_enum64_val(d, t, lvl, vlen);
+	btf_dump_printf(d, "\n%s}", pfx(lvl));
+
+	/* special case enums with special sizes */
+	if (t->size == 1) {
+		/* one-byte enums can be forced with mode(byte) attribute */
+		btf_dump_printf(d, " __attribute__((mode(byte)))");
+	} else if (t->size == 8 && d->ptr_sz == 8) {
+		/* enum can be 8-byte sized if one of the enumerator values
+		 * doesn't fit in 32-bit integer, or by adding mode(word)
+		 * attribute (but probably only on 64-bit architectures); do
+		 * our best here to try to satisfy the contract without adding
+		 * unnecessary attributes
+		 */
+		bool needs_word_mode;
+
+		if (btf_is_enum(t)) {
+			/* enum can't represent 64-bit values, so we need word mode */
+			needs_word_mode = true;
+		} else {
+			/* enum64 needs mode(word) if none of its values has
+			 * non-zero upper 32-bits (which means that all values
+			 * fit in 32-bit integers and won't cause compiler to
+			 * bump enum to be 64-bit naturally
+			 */
+			int i;
+
+			needs_word_mode = true;
+			for (i = 0; i < vlen; i++) {
+				if (btf_enum64(t)[i].val_hi32 != 0) {
+					needs_word_mode = false;
+					break;
+				}
 			}
 		}
-		btf_dump_printf(d, "\n%s}", pfx(lvl));
+		if (needs_word_mode)
+			btf_dump_printf(d, " __attribute__((mode(word)))");
 	}
+
 }
 
 static void btf_dump_emit_fwd_def(struct btf_dump *d, __u32 id,
@@ -967,8 +1214,7 @@ static int btf_dump_push_decl_stack_id(struct btf_dump *d, __u32 id)
 
 	if (d->decl_stack_cnt >= d->decl_stack_cap) {
 		new_cap = max(16, d->decl_stack_cap * 3 / 2);
-		new_stack = realloc(d->decl_stack,
-				    new_cap * sizeof(new_stack[0]));
+		new_stack = libbpf_reallocarray(d->decl_stack, new_cap, sizeof(new_stack[0]));
 		if (!new_stack)
 			return -ENOMEM;
 		d->decl_stack = new_stack;
@@ -1025,14 +1271,20 @@ int btf_dump__emit_type_decl(struct btf_dump *d, __u32 id,
 			     const struct btf_dump_emit_type_decl_opts *opts)
 {
 	const char *fname;
-	int lvl;
+	int lvl, err;
 
 	if (!OPTS_VALID(opts, btf_dump_emit_type_decl_opts))
-		return -EINVAL;
+		return libbpf_err(-EINVAL);
+
+	err = btf_dump_resize(d);
+	if (err)
+		return libbpf_err(err);
 
 	fname = OPTS_GET(opts, field_name, "");
 	lvl = OPTS_GET(opts, indent_level, 0);
+	d->strip_mods = OPTS_GET(opts, strip_mods, false);
 	btf_dump_emit_type_decl(d, id, fname, lvl);
+	d->strip_mods = false;
 	return 0;
 }
 
@@ -1045,6 +1297,10 @@ static void btf_dump_emit_type_decl(struct btf_dump *d, __u32 id,
 
 	stack_start = d->decl_stack_cnt;
 	for (;;) {
+		t = btf__type_by_id(d->btf, id);
+		if (d->strip_mods && btf_is_mod(t))
+			goto skip_mod;
+
 		err = btf_dump_push_decl_stack_id(d, id);
 		if (err < 0) {
 			/*
@@ -1052,22 +1308,22 @@ static void btf_dump_emit_type_decl(struct btf_dump *d, __u32 id,
 			 * chain, restore stack, emit warning, and try to
 			 * proceed nevertheless
 			 */
-			pr_warn("not enough memory for decl stack:%d", err);
+			pr_warn("not enough memory for decl stack: %s\n", errstr(err));
 			d->decl_stack_cnt = stack_start;
 			return;
 		}
-
+skip_mod:
 		/* VOID */
 		if (id == 0)
 			break;
 
-		t = btf__type_by_id(d->btf, id);
 		switch (btf_kind(t)) {
 		case BTF_KIND_PTR:
 		case BTF_KIND_VOLATILE:
 		case BTF_KIND_CONST:
 		case BTF_KIND_RESTRICT:
 		case BTF_KIND_FUNC_PROTO:
+		case BTF_KIND_TYPE_TAG:
 			id = t->type;
 			break;
 		case BTF_KIND_ARRAY:
@@ -1075,10 +1331,12 @@ static void btf_dump_emit_type_decl(struct btf_dump *d, __u32 id,
 			break;
 		case BTF_KIND_INT:
 		case BTF_KIND_ENUM:
+		case BTF_KIND_ENUM64:
 		case BTF_KIND_FWD:
 		case BTF_KIND_STRUCT:
 		case BTF_KIND_UNION:
 		case BTF_KIND_TYPEDEF:
+		case BTF_KIND_FLOAT:
 			goto done;
 		default:
 			pr_warn("unexpected type in decl chain, kind:%u, id:[%u]\n",
@@ -1193,6 +1451,7 @@ static void btf_dump_emit_type_chain(struct btf_dump *d,
 
 		switch (kind) {
 		case BTF_KIND_INT:
+		case BTF_KIND_FLOAT:
 			btf_dump_emit_mods(d, decls);
 			name = btf_name_of(d, t->name_off);
 			btf_dump_printf(d, "%s", name);
@@ -1201,15 +1460,16 @@ static void btf_dump_emit_type_chain(struct btf_dump *d,
 		case BTF_KIND_UNION:
 			btf_dump_emit_mods(d, decls);
 			/* inline anonymous struct/union */
-			if (t->name_off == 0)
+			if (t->name_off == 0 && !d->skip_anon_defs)
 				btf_dump_emit_struct_def(d, id, t, lvl);
 			else
 				btf_dump_emit_struct_fwd(d, id, t);
 			break;
 		case BTF_KIND_ENUM:
+		case BTF_KIND_ENUM64:
 			btf_dump_emit_mods(d, decls);
 			/* inline anonymous enum */
-			if (t->name_off == 0)
+			if (t->name_off == 0 && !d->skip_anon_defs)
 				btf_dump_emit_enum_def(d, id, t, lvl);
 			else
 				btf_dump_emit_enum_fwd(d, id, t);
@@ -1234,6 +1494,14 @@ static void btf_dump_emit_type_chain(struct btf_dump *d,
 		case BTF_KIND_RESTRICT:
 			btf_dump_printf(d, " restrict");
 			break;
+		case BTF_KIND_TYPE_TAG:
+			btf_dump_emit_mods(d, decls);
+			name = btf_name_of(d, t->name_off);
+			if (btf_kflag(t))
+				btf_dump_printf(d, " __attribute__((%s))", name);
+			else
+				btf_dump_printf(d, " __attribute__((btf_type_tag(\"%s\")))", name);
+			break;
 		case BTF_KIND_ARRAY: {
 			const struct btf_array *a = btf_array(t);
 			const struct btf_type *next_t;
@@ -1298,10 +1566,12 @@ static void btf_dump_emit_type_chain(struct btf_dump *d,
 			 * Clang for BPF target generates func_proto with no
 			 * args as a func_proto with a single void arg (e.g.,
 			 * `int (*f)(void)` vs just `int (*f)()`). We are
-			 * going to pretend there are no args for such case.
+			 * going to emit valid empty args (void) syntax for
+			 * such case. Similarly and conveniently, valid
+			 * no args case can be special-cased here as well.
 			 */
-			if (vlen == 1 && p->type == 0) {
-				btf_dump_printf(d, ")");
+			if (vlen == 0 || (vlen == 1 && p->type == 0)) {
+				btf_dump_printf(d, "void)");
 				return;
 			}
 
@@ -1334,15 +1604,59 @@ static void btf_dump_emit_type_chain(struct btf_dump *d,
 	btf_dump_emit_name(d, fname, last_was_ptr);
 }
 
+/* show type name as (type_name) */
+static void btf_dump_emit_type_cast(struct btf_dump *d, __u32 id,
+				    bool top_level)
+{
+	const struct btf_type *t;
+
+	/* for array members, we don't bother emitting type name for each
+	 * member to avoid the redundancy of
+	 * .name = (char[4])[(char)'f',(char)'o',(char)'o',]
+	 */
+	if (d->typed_dump->is_array_member)
+		return;
+
+	/* avoid type name specification for variable/section; it will be done
+	 * for the associated variable value(s).
+	 */
+	t = btf__type_by_id(d->btf, id);
+	if (btf_is_var(t) || btf_is_datasec(t))
+		return;
+
+	if (top_level)
+		btf_dump_printf(d, "(");
+
+	d->skip_anon_defs = true;
+	d->strip_mods = true;
+	btf_dump_emit_type_decl(d, id, "", 0);
+	d->strip_mods = false;
+	d->skip_anon_defs = false;
+
+	if (top_level)
+		btf_dump_printf(d, ")");
+}
+
 /* return number of duplicates (occurrences) of a given name */
 static size_t btf_dump_name_dups(struct btf_dump *d, struct hashmap *name_map,
 				 const char *orig_name)
 {
+	char *old_name, *new_name;
 	size_t dup_cnt = 0;
+	int err;
 
-	hashmap__find(name_map, orig_name, (void **)&dup_cnt);
+	new_name = strdup(orig_name);
+	if (!new_name)
+		return 1;
+
+	(void)hashmap__find(name_map, orig_name, &dup_cnt);
 	dup_cnt++;
-	hashmap__set(name_map, orig_name, (void *)dup_cnt, NULL, NULL);
+
+	err = hashmap__set(name_map, new_name, dup_cnt, &old_name, NULL);
+	if (err)
+		free(new_name);
+
+	free(old_name);
 
 	return dup_cnt;
 }
@@ -1362,6 +1676,11 @@ static const char *btf_dump_resolve_name(struct btf_dump *d, __u32 id,
 	if (s->name_resolved)
 		return *cached_name ? *cached_name : orig_name;
 
+	if (btf_is_fwd(t) || (btf_is_enum(t) && btf_vlen(t) == 0)) {
+		s->name_resolved = 1;
+		return orig_name;
+	}
+
 	dup_cnt = btf_dump_name_dups(d, name_map, orig_name);
 	if (dup_cnt > 1) {
 		const size_t max_len = 256;
@@ -1384,3 +1703,854 @@ static const char *btf_dump_ident_name(struct btf_dump *d, __u32 id)
 {
 	return btf_dump_resolve_name(d, id, d->ident_names);
 }
+
+static int btf_dump_dump_type_data(struct btf_dump *d,
+				   const char *fname,
+				   const struct btf_type *t,
+				   __u32 id,
+				   const void *data,
+				   __u8 bits_offset,
+				   __u8 bit_sz);
+
+static const char *btf_dump_data_newline(struct btf_dump *d)
+{
+	return d->typed_dump->compact || d->typed_dump->depth == 0 ? "" : "\n";
+}
+
+static const char *btf_dump_data_delim(struct btf_dump *d)
+{
+	return d->typed_dump->depth == 0 ? "" : ",";
+}
+
+static void btf_dump_data_pfx(struct btf_dump *d)
+{
+	int i, lvl = d->typed_dump->indent_lvl + d->typed_dump->depth;
+
+	if (d->typed_dump->compact)
+		return;
+
+	for (i = 0; i < lvl; i++)
+		btf_dump_printf(d, "%s", d->typed_dump->indent_str);
+}
+
+/* A macro is used here as btf_type_value[s]() appends format specifiers
+ * to the format specifier passed in; these do the work of appending
+ * delimiters etc while the caller simply has to specify the type values
+ * in the format specifier + value(s).
+ */
+#define btf_dump_type_values(d, fmt, ...)				\
+	btf_dump_printf(d, fmt "%s%s",					\
+			##__VA_ARGS__,					\
+			btf_dump_data_delim(d),				\
+			btf_dump_data_newline(d))
+
+static int btf_dump_unsupported_data(struct btf_dump *d,
+				     const struct btf_type *t,
+				     __u32 id)
+{
+	btf_dump_printf(d, "<unsupported kind:%u>", btf_kind(t));
+	return -ENOTSUP;
+}
+
+static int btf_dump_get_bitfield_value(struct btf_dump *d,
+				       const struct btf_type *t,
+				       const void *data,
+				       __u8 bits_offset,
+				       __u8 bit_sz,
+				       __u64 *value)
+{
+	__u16 left_shift_bits, right_shift_bits;
+	const __u8 *bytes = data;
+	__u8 nr_copy_bits;
+	__u64 num = 0;
+	int i;
+
+	/* Maximum supported bitfield size is 64 bits */
+	if (t->size > 8) {
+		pr_warn("unexpected bitfield size %d\n", t->size);
+		return -EINVAL;
+	}
+
+	/* Bitfield value retrieval is done in two steps; first relevant bytes are
+	 * stored in num, then we left/right shift num to eliminate irrelevant bits.
+	 */
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+	for (i = t->size - 1; i >= 0; i--)
+		num = num * 256 + bytes[i];
+	nr_copy_bits = bit_sz + bits_offset;
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+	for (i = 0; i < t->size; i++)
+		num = num * 256 + bytes[i];
+	nr_copy_bits = t->size * 8 - bits_offset;
+#else
+# error "Unrecognized __BYTE_ORDER__"
+#endif
+	left_shift_bits = 64 - nr_copy_bits;
+	right_shift_bits = 64 - bit_sz;
+
+	*value = (num << left_shift_bits) >> right_shift_bits;
+
+	return 0;
+}
+
+static int btf_dump_bitfield_check_zero(struct btf_dump *d,
+					const struct btf_type *t,
+					const void *data,
+					__u8 bits_offset,
+					__u8 bit_sz)
+{
+	__u64 check_num;
+	int err;
+
+	err = btf_dump_get_bitfield_value(d, t, data, bits_offset, bit_sz, &check_num);
+	if (err)
+		return err;
+	if (check_num == 0)
+		return -ENODATA;
+	return 0;
+}
+
+static int btf_dump_bitfield_data(struct btf_dump *d,
+				  const struct btf_type *t,
+				  const void *data,
+				  __u8 bits_offset,
+				  __u8 bit_sz)
+{
+	__u64 print_num;
+	int err;
+
+	err = btf_dump_get_bitfield_value(d, t, data, bits_offset, bit_sz, &print_num);
+	if (err)
+		return err;
+
+	btf_dump_type_values(d, "0x%llx", (unsigned long long)print_num);
+
+	return 0;
+}
+
+/* ints, floats and ptrs */
+static int btf_dump_base_type_check_zero(struct btf_dump *d,
+					 const struct btf_type *t,
+					 __u32 id,
+					 const void *data)
+{
+	static __u8 bytecmp[16] = {};
+	int nr_bytes;
+
+	/* For pointer types, pointer size is not defined on a per-type basis.
+	 * On dump creation however, we store the pointer size.
+	 */
+	if (btf_kind(t) == BTF_KIND_PTR)
+		nr_bytes = d->ptr_sz;
+	else
+		nr_bytes = t->size;
+
+	if (nr_bytes < 1 || nr_bytes > 16) {
+		pr_warn("unexpected size %d for id [%u]\n", nr_bytes, id);
+		return -EINVAL;
+	}
+
+	if (memcmp(data, bytecmp, nr_bytes) == 0)
+		return -ENODATA;
+	return 0;
+}
+
+static bool ptr_is_aligned(const struct btf *btf, __u32 type_id,
+			   const void *data)
+{
+	int alignment = btf__align_of(btf, type_id);
+
+	if (alignment == 0)
+		return false;
+
+	return ((uintptr_t)data) % alignment == 0;
+}
+
+static int btf_dump_int_data(struct btf_dump *d,
+			     const struct btf_type *t,
+			     __u32 type_id,
+			     const void *data,
+			     __u8 bits_offset)
+{
+	__u8 encoding = btf_int_encoding(t);
+	bool sign = encoding & BTF_INT_SIGNED;
+	char buf[16] __attribute__((aligned(16)));
+	int sz = t->size;
+
+	if (sz == 0 || sz > sizeof(buf)) {
+		pr_warn("unexpected size %d for id [%u]\n", sz, type_id);
+		return -EINVAL;
+	}
+
+	/* handle packed int data - accesses of integers not aligned on
+	 * int boundaries can cause problems on some platforms.
+	 */
+	if (!ptr_is_aligned(d->btf, type_id, data)) {
+		memcpy(buf, data, sz);
+		data = buf;
+	}
+
+	switch (sz) {
+	case 16: {
+		const __u64 *ints = data;
+		__u64 lsi, msi;
+
+		/* avoid use of __int128 as some 32-bit platforms do not
+		 * support it.
+		 */
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+		lsi = ints[0];
+		msi = ints[1];
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+		lsi = ints[1];
+		msi = ints[0];
+#else
+# error "Unrecognized __BYTE_ORDER__"
+#endif
+		if (msi == 0)
+			btf_dump_type_values(d, "0x%llx", (unsigned long long)lsi);
+		else
+			btf_dump_type_values(d, "0x%llx%016llx", (unsigned long long)msi,
+					     (unsigned long long)lsi);
+		break;
+	}
+	case 8:
+		if (sign)
+			btf_dump_type_values(d, "%lld", *(long long *)data);
+		else
+			btf_dump_type_values(d, "%llu", *(unsigned long long *)data);
+		break;
+	case 4:
+		if (sign)
+			btf_dump_type_values(d, "%d", *(__s32 *)data);
+		else
+			btf_dump_type_values(d, "%u", *(__u32 *)data);
+		break;
+	case 2:
+		if (sign)
+			btf_dump_type_values(d, "%d", *(__s16 *)data);
+		else
+			btf_dump_type_values(d, "%u", *(__u16 *)data);
+		break;
+	case 1:
+		if (d->typed_dump->is_array_char) {
+			/* check for null terminator */
+			if (d->typed_dump->is_array_terminated)
+				break;
+			if (*(char *)data == '\0') {
+				btf_dump_type_values(d, "'\\0'");
+				d->typed_dump->is_array_terminated = true;
+				break;
+			}
+			if (isprint(*(char *)data)) {
+				btf_dump_type_values(d, "'%c'", *(char *)data);
+				break;
+			}
+		}
+		if (sign)
+			btf_dump_type_values(d, "%d", *(__s8 *)data);
+		else
+			btf_dump_type_values(d, "%u", *(__u8 *)data);
+		break;
+	default:
+		pr_warn("unexpected sz %d for id [%u]\n", sz, type_id);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+union float_data {
+	long double ld;
+	double d;
+	float f;
+};
+
+static int btf_dump_float_data(struct btf_dump *d,
+			       const struct btf_type *t,
+			       __u32 type_id,
+			       const void *data)
+{
+	const union float_data *flp = data;
+	union float_data fl;
+	int sz = t->size;
+
+	/* handle unaligned data; copy to local union */
+	if (!ptr_is_aligned(d->btf, type_id, data)) {
+		memcpy(&fl, data, sz);
+		flp = &fl;
+	}
+
+	switch (sz) {
+	case 16:
+		btf_dump_type_values(d, "%Lf", flp->ld);
+		break;
+	case 8:
+		btf_dump_type_values(d, "%lf", flp->d);
+		break;
+	case 4:
+		btf_dump_type_values(d, "%f", flp->f);
+		break;
+	default:
+		pr_warn("unexpected size %d for id [%u]\n", sz, type_id);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int btf_dump_var_data(struct btf_dump *d,
+			     const struct btf_type *v,
+			     __u32 id,
+			     const void *data)
+{
+	enum btf_func_linkage linkage = btf_var(v)->linkage;
+	const struct btf_type *t;
+	const char *l;
+	__u32 type_id;
+
+	switch (linkage) {
+	case BTF_FUNC_STATIC:
+		l = "static ";
+		break;
+	case BTF_FUNC_EXTERN:
+		l = "extern ";
+		break;
+	case BTF_FUNC_GLOBAL:
+	default:
+		l = "";
+		break;
+	}
+
+	/* format of output here is [linkage] [type] [varname] = (type)value,
+	 * for example "static int cpu_profile_flip = (int)1"
+	 */
+	btf_dump_printf(d, "%s", l);
+	type_id = v->type;
+	t = btf__type_by_id(d->btf, type_id);
+	btf_dump_emit_type_cast(d, type_id, false);
+	btf_dump_printf(d, " %s = ", btf_name_of(d, v->name_off));
+	return btf_dump_dump_type_data(d, NULL, t, type_id, data, 0, 0);
+}
+
+static int btf_dump_array_data(struct btf_dump *d,
+			       const struct btf_type *t,
+			       __u32 id,
+			       const void *data)
+{
+	const struct btf_array *array = btf_array(t);
+	const struct btf_type *elem_type;
+	__u32 i, elem_type_id;
+	__s64 elem_size;
+	bool is_array_member;
+	bool is_array_terminated;
+
+	elem_type_id = array->type;
+	elem_type = skip_mods_and_typedefs(d->btf, elem_type_id, NULL);
+	elem_size = btf__resolve_size(d->btf, elem_type_id);
+	if (elem_size <= 0) {
+		pr_warn("unexpected elem size %zd for array type [%u]\n",
+			(ssize_t)elem_size, id);
+		return -EINVAL;
+	}
+
+	if (btf_is_int(elem_type)) {
+		/*
+		 * BTF_INT_CHAR encoding never seems to be set for
+		 * char arrays, so if size is 1 and element is
+		 * printable as a char, we'll do that.
+		 */
+		if (elem_size == 1)
+			d->typed_dump->is_array_char = true;
+	}
+
+	/* note that we increment depth before calling btf_dump_print() below;
+	 * this is intentional.  btf_dump_data_newline() will not print a
+	 * newline for depth 0 (since this leaves us with trailing newlines
+	 * at the end of typed display), so depth is incremented first.
+	 * For similar reasons, we decrement depth before showing the closing
+	 * parenthesis.
+	 */
+	d->typed_dump->depth++;
+	btf_dump_printf(d, "[%s", btf_dump_data_newline(d));
+
+	/* may be a multidimensional array, so store current "is array member"
+	 * status so we can restore it correctly later.
+	 */
+	is_array_member = d->typed_dump->is_array_member;
+	d->typed_dump->is_array_member = true;
+	is_array_terminated = d->typed_dump->is_array_terminated;
+	d->typed_dump->is_array_terminated = false;
+	for (i = 0; i < array->nelems; i++, data += elem_size) {
+		if (d->typed_dump->is_array_terminated)
+			break;
+		btf_dump_dump_type_data(d, NULL, elem_type, elem_type_id, data, 0, 0);
+	}
+	d->typed_dump->is_array_member = is_array_member;
+	d->typed_dump->is_array_terminated = is_array_terminated;
+	d->typed_dump->depth--;
+	btf_dump_data_pfx(d);
+	btf_dump_type_values(d, "]");
+
+	return 0;
+}
+
+static int btf_dump_struct_data(struct btf_dump *d,
+				const struct btf_type *t,
+				__u32 id,
+				const void *data)
+{
+	const struct btf_member *m = btf_members(t);
+	__u16 n = btf_vlen(t);
+	int i, err = 0;
+
+	/* note that we increment depth before calling btf_dump_print() below;
+	 * this is intentional.  btf_dump_data_newline() will not print a
+	 * newline for depth 0 (since this leaves us with trailing newlines
+	 * at the end of typed display), so depth is incremented first.
+	 * For similar reasons, we decrement depth before showing the closing
+	 * parenthesis.
+	 */
+	d->typed_dump->depth++;
+	btf_dump_printf(d, "{%s", btf_dump_data_newline(d));
+
+	for (i = 0; i < n; i++, m++) {
+		const struct btf_type *mtype;
+		const char *mname;
+		__u32 moffset;
+		__u8 bit_sz;
+
+		mtype = btf__type_by_id(d->btf, m->type);
+		mname = btf_name_of(d, m->name_off);
+		moffset = btf_member_bit_offset(t, i);
+
+		bit_sz = btf_member_bitfield_size(t, i);
+		err = btf_dump_dump_type_data(d, mname, mtype, m->type, data + moffset / 8,
+					      moffset % 8, bit_sz);
+		if (err < 0)
+			return err;
+	}
+	d->typed_dump->depth--;
+	btf_dump_data_pfx(d);
+	btf_dump_type_values(d, "}");
+	return err;
+}
+
+union ptr_data {
+	unsigned int p;
+	unsigned long long lp;
+};
+
+static int btf_dump_ptr_data(struct btf_dump *d,
+			      const struct btf_type *t,
+			      __u32 id,
+			      const void *data)
+{
+	if (ptr_is_aligned(d->btf, id, data) && d->ptr_sz == sizeof(void *)) {
+		btf_dump_type_values(d, "%p", *(void **)data);
+	} else {
+		union ptr_data pt;
+
+		memcpy(&pt, data, d->ptr_sz);
+		if (d->ptr_sz == 4)
+			btf_dump_type_values(d, "0x%x", pt.p);
+		else
+			btf_dump_type_values(d, "0x%llx", pt.lp);
+	}
+	return 0;
+}
+
+static int btf_dump_get_enum_value(struct btf_dump *d,
+				   const struct btf_type *t,
+				   const void *data,
+				   __u32 id,
+				   __s64 *value)
+{
+	bool is_signed = btf_kflag(t);
+
+	if (!ptr_is_aligned(d->btf, id, data)) {
+		__u64 val;
+		int err;
+
+		err = btf_dump_get_bitfield_value(d, t, data, 0, 0, &val);
+		if (err)
+			return err;
+		*value = (__s64)val;
+		return 0;
+	}
+
+	switch (t->size) {
+	case 8:
+		*value = *(__s64 *)data;
+		return 0;
+	case 4:
+		*value = is_signed ? (__s64)*(__s32 *)data : *(__u32 *)data;
+		return 0;
+	case 2:
+		*value = is_signed ? *(__s16 *)data : *(__u16 *)data;
+		return 0;
+	case 1:
+		*value = is_signed ? *(__s8 *)data : *(__u8 *)data;
+		return 0;
+	default:
+		pr_warn("unexpected size %d for enum, id:[%u]\n", t->size, id);
+		return -EINVAL;
+	}
+}
+
+static int btf_dump_enum_data(struct btf_dump *d,
+			      const struct btf_type *t,
+			      __u32 id,
+			      const void *data)
+{
+	bool is_signed;
+	__s64 value;
+	int i, err;
+
+	err = btf_dump_get_enum_value(d, t, data, id, &value);
+	if (err)
+		return err;
+
+	is_signed = btf_kflag(t);
+	if (btf_is_enum(t)) {
+		const struct btf_enum *e;
+
+		for (i = 0, e = btf_enum(t); i < btf_vlen(t); i++, e++) {
+			if (value != e->val)
+				continue;
+			btf_dump_type_values(d, "%s", btf_name_of(d, e->name_off));
+			return 0;
+		}
+
+		btf_dump_type_values(d, is_signed ? "%d" : "%u", value);
+	} else {
+		const struct btf_enum64 *e;
+
+		for (i = 0, e = btf_enum64(t); i < btf_vlen(t); i++, e++) {
+			if (value != btf_enum64_value(e))
+				continue;
+			btf_dump_type_values(d, "%s", btf_name_of(d, e->name_off));
+			return 0;
+		}
+
+		btf_dump_type_values(d, is_signed ? "%lldLL" : "%lluULL",
+				     (unsigned long long)value);
+	}
+	return 0;
+}
+
+static int btf_dump_datasec_data(struct btf_dump *d,
+				 const struct btf_type *t,
+				 __u32 id,
+				 const void *data)
+{
+	const struct btf_var_secinfo *vsi;
+	const struct btf_type *var;
+	__u32 i;
+	int err;
+
+	btf_dump_type_values(d, "SEC(\"%s\") ", btf_name_of(d, t->name_off));
+
+	for (i = 0, vsi = btf_var_secinfos(t); i < btf_vlen(t); i++, vsi++) {
+		var = btf__type_by_id(d->btf, vsi->type);
+		err = btf_dump_dump_type_data(d, NULL, var, vsi->type, data + vsi->offset, 0, 0);
+		if (err < 0)
+			return err;
+		btf_dump_printf(d, ";");
+	}
+	return 0;
+}
+
+/* return size of type, or if base type overflows, return -E2BIG. */
+static int btf_dump_type_data_check_overflow(struct btf_dump *d,
+					     const struct btf_type *t,
+					     __u32 id,
+					     const void *data,
+					     __u8 bits_offset,
+					     __u8 bit_sz)
+{
+	__s64 size;
+
+	if (bit_sz) {
+		/* bits_offset is at most 7. bit_sz is at most 128. */
+		__u8 nr_bytes = (bits_offset + bit_sz + 7) / 8;
+
+		/* When bit_sz is non zero, it is called from
+		 * btf_dump_struct_data() where it only cares about
+		 * negative error value.
+		 * Return nr_bytes in success case to make it
+		 * consistent as the regular integer case below.
+		 */
+		return data + nr_bytes > d->typed_dump->data_end ? -E2BIG : nr_bytes;
+	}
+
+	size = btf__resolve_size(d->btf, id);
+
+	if (size < 0 || size >= INT_MAX) {
+		pr_warn("unexpected size [%zu] for id [%u]\n",
+			(size_t)size, id);
+		return -EINVAL;
+	}
+
+	/* Only do overflow checking for base types; we do not want to
+	 * avoid showing part of a struct, union or array, even if we
+	 * do not have enough data to show the full object.  By
+	 * restricting overflow checking to base types we can ensure
+	 * that partial display succeeds, while avoiding overflowing
+	 * and using bogus data for display.
+	 */
+	t = skip_mods_and_typedefs(d->btf, id, NULL);
+	if (!t) {
+		pr_warn("unexpected error skipping mods/typedefs for id [%u]\n",
+			id);
+		return -EINVAL;
+	}
+
+	switch (btf_kind(t)) {
+	case BTF_KIND_INT:
+	case BTF_KIND_FLOAT:
+	case BTF_KIND_PTR:
+	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64:
+		if (data + bits_offset / 8 + size > d->typed_dump->data_end)
+			return -E2BIG;
+		break;
+	default:
+		break;
+	}
+	return (int)size;
+}
+
+static int btf_dump_type_data_check_zero(struct btf_dump *d,
+					 const struct btf_type *t,
+					 __u32 id,
+					 const void *data,
+					 __u8 bits_offset,
+					 __u8 bit_sz)
+{
+	__s64 value;
+	int i, err;
+
+	/* toplevel exceptions; we show zero values if
+	 * - we ask for them (emit_zeros)
+	 * - if we are at top-level so we see "struct empty { }"
+	 * - or if we are an array member and the array is non-empty and
+	 *   not a char array; we don't want to be in a situation where we
+	 *   have an integer array 0, 1, 0, 1 and only show non-zero values.
+	 *   If the array contains zeroes only, or is a char array starting
+	 *   with a '\0', the array-level check_zero() will prevent showing it;
+	 *   we are concerned with determining zero value at the array member
+	 *   level here.
+	 */
+	if (d->typed_dump->emit_zeroes || d->typed_dump->depth == 0 ||
+	    (d->typed_dump->is_array_member &&
+	     !d->typed_dump->is_array_char))
+		return 0;
+
+	t = skip_mods_and_typedefs(d->btf, id, NULL);
+
+	switch (btf_kind(t)) {
+	case BTF_KIND_INT:
+		if (bit_sz)
+			return btf_dump_bitfield_check_zero(d, t, data, bits_offset, bit_sz);
+		return btf_dump_base_type_check_zero(d, t, id, data);
+	case BTF_KIND_FLOAT:
+	case BTF_KIND_PTR:
+		return btf_dump_base_type_check_zero(d, t, id, data);
+	case BTF_KIND_ARRAY: {
+		const struct btf_array *array = btf_array(t);
+		const struct btf_type *elem_type;
+		__u32 elem_type_id, elem_size;
+		bool ischar;
+
+		elem_type_id = array->type;
+		elem_size = btf__resolve_size(d->btf, elem_type_id);
+		elem_type = skip_mods_and_typedefs(d->btf, elem_type_id, NULL);
+
+		ischar = btf_is_int(elem_type) && elem_size == 1;
+
+		/* check all elements; if _any_ element is nonzero, all
+		 * of array is displayed.  We make an exception however
+		 * for char arrays where the first element is 0; these
+		 * are considered zeroed also, even if later elements are
+		 * non-zero because the string is terminated.
+		 */
+		for (i = 0; i < array->nelems; i++) {
+			if (i == 0 && ischar && *(char *)data == 0)
+				return -ENODATA;
+			err = btf_dump_type_data_check_zero(d, elem_type,
+							    elem_type_id,
+							    data +
+							    (i * elem_size),
+							    bits_offset, 0);
+			if (err != -ENODATA)
+				return err;
+		}
+		return -ENODATA;
+	}
+	case BTF_KIND_STRUCT:
+	case BTF_KIND_UNION: {
+		const struct btf_member *m = btf_members(t);
+		__u16 n = btf_vlen(t);
+
+		/* if any struct/union member is non-zero, the struct/union
+		 * is considered non-zero and dumped.
+		 */
+		for (i = 0; i < n; i++, m++) {
+			const struct btf_type *mtype;
+			__u32 moffset;
+
+			mtype = btf__type_by_id(d->btf, m->type);
+			moffset = btf_member_bit_offset(t, i);
+
+			/* btf_int_bits() does not store member bitfield size;
+			 * bitfield size needs to be stored here so int display
+			 * of member can retrieve it.
+			 */
+			bit_sz = btf_member_bitfield_size(t, i);
+			err = btf_dump_type_data_check_zero(d, mtype, m->type, data + moffset / 8,
+							    moffset % 8, bit_sz);
+			if (err != ENODATA)
+				return err;
+		}
+		return -ENODATA;
+	}
+	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64:
+		err = btf_dump_get_enum_value(d, t, data, id, &value);
+		if (err)
+			return err;
+		if (value == 0)
+			return -ENODATA;
+		return 0;
+	default:
+		return 0;
+	}
+}
+
+/* returns size of data dumped, or error. */
+static int btf_dump_dump_type_data(struct btf_dump *d,
+				   const char *fname,
+				   const struct btf_type *t,
+				   __u32 id,
+				   const void *data,
+				   __u8 bits_offset,
+				   __u8 bit_sz)
+{
+	int size, err = 0;
+
+	size = btf_dump_type_data_check_overflow(d, t, id, data, bits_offset, bit_sz);
+	if (size < 0)
+		return size;
+	err = btf_dump_type_data_check_zero(d, t, id, data, bits_offset, bit_sz);
+	if (err) {
+		/* zeroed data is expected and not an error, so simply skip
+		 * dumping such data.  Record other errors however.
+		 */
+		if (err == -ENODATA)
+			return size;
+		return err;
+	}
+	btf_dump_data_pfx(d);
+
+	if (!d->typed_dump->skip_names) {
+		if (fname && strlen(fname) > 0)
+			btf_dump_printf(d, ".%s = ", fname);
+		btf_dump_emit_type_cast(d, id, true);
+	}
+
+	t = skip_mods_and_typedefs(d->btf, id, NULL);
+
+	switch (btf_kind(t)) {
+	case BTF_KIND_UNKN:
+	case BTF_KIND_FWD:
+	case BTF_KIND_FUNC:
+	case BTF_KIND_FUNC_PROTO:
+	case BTF_KIND_DECL_TAG:
+		err = btf_dump_unsupported_data(d, t, id);
+		break;
+	case BTF_KIND_INT:
+		if (bit_sz)
+			err = btf_dump_bitfield_data(d, t, data, bits_offset, bit_sz);
+		else
+			err = btf_dump_int_data(d, t, id, data, bits_offset);
+		break;
+	case BTF_KIND_FLOAT:
+		err = btf_dump_float_data(d, t, id, data);
+		break;
+	case BTF_KIND_PTR:
+		err = btf_dump_ptr_data(d, t, id, data);
+		break;
+	case BTF_KIND_ARRAY:
+		err = btf_dump_array_data(d, t, id, data);
+		break;
+	case BTF_KIND_STRUCT:
+	case BTF_KIND_UNION:
+		err = btf_dump_struct_data(d, t, id, data);
+		break;
+	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64:
+		/* handle bitfield and int enum values */
+		if (bit_sz) {
+			__u64 print_num;
+			__s64 enum_val;
+
+			err = btf_dump_get_bitfield_value(d, t, data, bits_offset, bit_sz,
+							  &print_num);
+			if (err)
+				break;
+			enum_val = (__s64)print_num;
+			err = btf_dump_enum_data(d, t, id, &enum_val);
+		} else
+			err = btf_dump_enum_data(d, t, id, data);
+		break;
+	case BTF_KIND_VAR:
+		err = btf_dump_var_data(d, t, id, data);
+		break;
+	case BTF_KIND_DATASEC:
+		err = btf_dump_datasec_data(d, t, id, data);
+		break;
+	default:
+		pr_warn("unexpected kind [%u] for id [%u]\n",
+			BTF_INFO_KIND(t->info), id);
+		return -EINVAL;
+	}
+	if (err < 0)
+		return err;
+	return size;
+}
+
+int btf_dump__dump_type_data(struct btf_dump *d, __u32 id,
+			     const void *data, size_t data_sz,
+			     const struct btf_dump_type_data_opts *opts)
+{
+	struct btf_dump_data typed_dump = {};
+	const struct btf_type *t;
+	int ret;
+
+	if (!OPTS_VALID(opts, btf_dump_type_data_opts))
+		return libbpf_err(-EINVAL);
+
+	t = btf__type_by_id(d->btf, id);
+	if (!t)
+		return libbpf_err(-ENOENT);
+
+	d->typed_dump = &typed_dump;
+	d->typed_dump->data_end = data + data_sz;
+	d->typed_dump->indent_lvl = OPTS_GET(opts, indent_level, 0);
+
+	/* default indent string is a tab */
+	if (!OPTS_GET(opts, indent_str, NULL))
+		d->typed_dump->indent_str[0] = '\t';
+	else
+		libbpf_strlcpy(d->typed_dump->indent_str, opts->indent_str,
+			       sizeof(d->typed_dump->indent_str));
+
+	d->typed_dump->compact = OPTS_GET(opts, compact, false);
+	d->typed_dump->skip_names = OPTS_GET(opts, skip_names, false);
+	d->typed_dump->emit_zeroes = OPTS_GET(opts, emit_zeroes, false);
+
+	ret = btf_dump_dump_type_data(d, NULL, t, id, data, 0, 0);
+
+	d->typed_dump = NULL;
+
+	return libbpf_err(ret);
+}