1 files changed, 525 insertions, 60 deletions

diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c
index 59833125ac0a..946612029dee 100644
--- a/tools/bpf/bpftool/btf.c
+++ b/tools/bpf/bpftool/btf.c
@@ -1,11 +1,15 @@
 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
 /* Copyright (C) 2019 Facebook */
 
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
 #include <errno.h>
 #include <fcntl.h>
 #include <linux/err.h>
 #include <stdbool.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 #include <linux/btf.h>
@@ -20,6 +24,11 @@
 #include "json_writer.h"
 #include "main.h"
 
+#define KFUNC_DECL_TAG		"bpf_kfunc"
+#define FASTCALL_DECL_TAG	"bpf_fastcall"
+
+#define MAX_ROOT_IDS		16
+
 static const char * const btf_kind_str[NR_BTF_KINDS] = {
 	[BTF_KIND_UNKN]		= "UNKNOWN",
 	[BTF_KIND_INT]		= "INT",
@@ -40,11 +49,15 @@ static const char * const btf_kind_str[NR_BTF_KINDS] = {
 	[BTF_KIND_FLOAT]	= "FLOAT",
 	[BTF_KIND_DECL_TAG]	= "DECL_TAG",
 	[BTF_KIND_TYPE_TAG]	= "TYPE_TAG",
+	[BTF_KIND_ENUM64]	= "ENUM64",
 };
 
-struct btf_attach_point {
-	__u32 obj_id;
-	__u32 btf_id;
+struct sort_datum {
+	int index;
+	int type_rank;
+	const char *sort_name;
+	const char *own_name;
+	__u64 disambig_hash;
 };
 
 static const char *btf_int_enc_str(__u8 encoding)
@@ -212,15 +225,18 @@ static int dump_btf_type(const struct btf *btf, __u32 id,
 	case BTF_KIND_ENUM: {
 		const struct btf_enum *v = (const void *)(t + 1);
 		__u16 vlen = BTF_INFO_VLEN(t->info);
+		const char *encoding;
 		int i;
 
+		encoding = btf_kflag(t) ? "SIGNED" : "UNSIGNED";
 		if (json_output) {
+			jsonw_string_field(w, "encoding", encoding);
 			jsonw_uint_field(w, "size", t->size);
 			jsonw_uint_field(w, "vlen", vlen);
 			jsonw_name(w, "values");
 			jsonw_start_array(w);
 		} else {
-			printf(" size=%u vlen=%u", t->size, vlen);
+			printf(" encoding=%s size=%u vlen=%u", encoding, t->size, vlen);
 		}
 		for (i = 0; i < vlen; i++, v++) {
 			const char *name = btf_str(btf, v->name_off);
@@ -228,10 +244,57 @@ static int dump_btf_type(const struct btf *btf, __u32 id,
 			if (json_output) {
 				jsonw_start_object(w);
 				jsonw_string_field(w, "name", name);
-				jsonw_uint_field(w, "val", v->val);
+				if (btf_kflag(t))
+					jsonw_int_field(w, "val", v->val);
+				else
+					jsonw_uint_field(w, "val", v->val);
 				jsonw_end_object(w);
 			} else {
-				printf("\n\t'%s' val=%u", name, v->val);
+				if (btf_kflag(t))
+					printf("\n\t'%s' val=%d", name, v->val);
+				else
+					printf("\n\t'%s' val=%u", name, (__u32)v->val);
+			}
+		}
+		if (json_output)
+			jsonw_end_array(w);
+		break;
+	}
+	case BTF_KIND_ENUM64: {
+		const struct btf_enum64 *v = btf_enum64(t);
+		__u16 vlen = btf_vlen(t);
+		const char *encoding;
+		int i;
+
+		encoding = btf_kflag(t) ? "SIGNED" : "UNSIGNED";
+		if (json_output) {
+			jsonw_string_field(w, "encoding", encoding);
+			jsonw_uint_field(w, "size", t->size);
+			jsonw_uint_field(w, "vlen", vlen);
+			jsonw_name(w, "values");
+			jsonw_start_array(w);
+		} else {
+			printf(" encoding=%s size=%u vlen=%u", encoding, t->size, vlen);
+		}
+		for (i = 0; i < vlen; i++, v++) {
+			const char *name = btf_str(btf, v->name_off);
+			__u64 val = ((__u64)v->val_hi32 << 32) | v->val_lo32;
+
+			if (json_output) {
+				jsonw_start_object(w);
+				jsonw_string_field(w, "name", name);
+				if (btf_kflag(t))
+					jsonw_int_field(w, "val", val);
+				else
+					jsonw_uint_field(w, "val", val);
+				jsonw_end_object(w);
+			} else {
+				if (btf_kflag(t))
+					printf("\n\t'%s' val=%lldLL", name,
+					       (long long)val);
+				else
+					printf("\n\t'%s' val=%lluULL", name,
+					       (unsigned long long)val);
 			}
 		}
 		if (json_output)
@@ -408,22 +471,313 @@ static int dump_btf_raw(const struct btf *btf,
 	return 0;
 }
 
+struct ptr_array {
+	__u32 cnt;
+	__u32 cap;
+	const void **elems;
+};
+
+static int ptr_array_push(const void *ptr, struct ptr_array *arr)
+{
+	__u32 new_cap;
+	void *tmp;
+
+	if (arr->cnt == arr->cap) {
+		new_cap = (arr->cap ?: 16) * 2;
+		tmp = realloc(arr->elems, sizeof(*arr->elems) * new_cap);
+		if (!tmp)
+			return -ENOMEM;
+		arr->elems = tmp;
+		arr->cap = new_cap;
+	}
+	arr->elems[arr->cnt++] = ptr;
+	return 0;
+}
+
+static void ptr_array_free(struct ptr_array *arr)
+{
+	free(arr->elems);
+}
+
+static int cmp_kfuncs(const void *pa, const void *pb, void *ctx)
+{
+	struct btf *btf = ctx;
+	const struct btf_type *a = *(void **)pa;
+	const struct btf_type *b = *(void **)pb;
+
+	return strcmp(btf__str_by_offset(btf, a->name_off),
+		      btf__str_by_offset(btf, b->name_off));
+}
+
+static int dump_btf_kfuncs(struct btf_dump *d, const struct btf *btf)
+{
+	LIBBPF_OPTS(btf_dump_emit_type_decl_opts, opts);
+	__u32 cnt = btf__type_cnt(btf), i, j;
+	struct ptr_array fastcalls = {};
+	struct ptr_array kfuncs = {};
+	int err = 0;
+
+	printf("\n/* BPF kfuncs */\n");
+	printf("#ifndef BPF_NO_KFUNC_PROTOTYPES\n");
+
+	for (i = 1; i < cnt; i++) {
+		const struct btf_type *t = btf__type_by_id(btf, i);
+		const struct btf_type *ft;
+		const char *name;
+
+		if (!btf_is_decl_tag(t))
+			continue;
+
+		if (btf_decl_tag(t)->component_idx != -1)
+			continue;
+
+		ft = btf__type_by_id(btf, t->type);
+		if (!btf_is_func(ft))
+			continue;
+
+		name = btf__name_by_offset(btf, t->name_off);
+		if (strncmp(name, KFUNC_DECL_TAG, sizeof(KFUNC_DECL_TAG)) == 0) {
+			err = ptr_array_push(ft, &kfuncs);
+			if (err)
+				goto out;
+		}
+
+		if (strncmp(name, FASTCALL_DECL_TAG, sizeof(FASTCALL_DECL_TAG)) == 0) {
+			err = ptr_array_push(ft, &fastcalls);
+			if (err)
+				goto out;
+		}
+	}
+
+	/* Sort kfuncs by name for improved vmlinux.h stability  */
+	qsort_r(kfuncs.elems, kfuncs.cnt, sizeof(*kfuncs.elems), cmp_kfuncs, (void *)btf);
+	for (i = 0; i < kfuncs.cnt; i++) {
+		const struct btf_type *t = kfuncs.elems[i];
+
+		printf("extern ");
+
+		/* Assume small amount of fastcall kfuncs */
+		for (j = 0; j < fastcalls.cnt; j++) {
+			if (fastcalls.elems[j] == t) {
+				printf("__bpf_fastcall ");
+				break;
+			}
+		}
+
+		opts.field_name = btf__name_by_offset(btf, t->name_off);
+		err = btf_dump__emit_type_decl(d, t->type, &opts);
+		if (err)
+			goto out;
+
+		printf(" __weak __ksym;\n");
+	}
+
+	printf("#endif\n\n");
+
+out:
+	ptr_array_free(&fastcalls);
+	ptr_array_free(&kfuncs);
+	return err;
+}
+
 static void __printf(2, 0) btf_dump_printf(void *ctx,
 					   const char *fmt, va_list args)
 {
 	vfprintf(stdout, fmt, args);
 }
 
+static int btf_type_rank(const struct btf *btf, __u32 index, bool has_name)
+{
+	const struct btf_type *t = btf__type_by_id(btf, index);
+	const int kind = btf_kind(t);
+	const int max_rank = 10;
+
+	if (t->name_off)
+		has_name = true;
+
+	switch (kind) {
+	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64:
+		return has_name ? 1 : 0;
+	case BTF_KIND_INT:
+	case BTF_KIND_FLOAT:
+		return 2;
+	case BTF_KIND_STRUCT:
+	case BTF_KIND_UNION:
+		return has_name ? 3 : max_rank;
+	case BTF_KIND_FUNC_PROTO:
+		return has_name ? 4 : max_rank;
+	case BTF_KIND_ARRAY:
+		if (has_name)
+			return btf_type_rank(btf, btf_array(t)->type, has_name);
+		return max_rank;
+	case BTF_KIND_TYPE_TAG:
+	case BTF_KIND_CONST:
+	case BTF_KIND_PTR:
+	case BTF_KIND_VOLATILE:
+	case BTF_KIND_RESTRICT:
+	case BTF_KIND_TYPEDEF:
+	case BTF_KIND_DECL_TAG:
+		if (has_name)
+			return btf_type_rank(btf, t->type, has_name);
+		return max_rank;
+	default:
+		return max_rank;
+	}
+}
+
+static const char *btf_type_sort_name(const struct btf *btf, __u32 index, bool from_ref)
+{
+	const struct btf_type *t = btf__type_by_id(btf, index);
+
+	switch (btf_kind(t)) {
+	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64: {
+		int name_off = t->name_off;
+
+		if (!from_ref && !name_off && btf_vlen(t))
+			name_off = btf_kind(t) == BTF_KIND_ENUM64 ?
+				btf_enum64(t)->name_off :
+				btf_enum(t)->name_off;
+
+		return btf__name_by_offset(btf, name_off);
+	}
+	case BTF_KIND_ARRAY:
+		return btf_type_sort_name(btf, btf_array(t)->type, true);
+	case BTF_KIND_TYPE_TAG:
+	case BTF_KIND_CONST:
+	case BTF_KIND_PTR:
+	case BTF_KIND_VOLATILE:
+	case BTF_KIND_RESTRICT:
+	case BTF_KIND_TYPEDEF:
+	case BTF_KIND_DECL_TAG:
+		return btf_type_sort_name(btf, t->type, true);
+	default:
+		return btf__name_by_offset(btf, t->name_off);
+	}
+	return NULL;
+}
+
+static __u64 hasher(__u64 hash, __u64 val)
+{
+	return hash * 31 + val;
+}
+
+static __u64 btf_name_hasher(__u64 hash, const struct btf *btf, __u32 name_off)
+{
+	if (!name_off)
+		return hash;
+
+	return hasher(hash, str_hash(btf__name_by_offset(btf, name_off)));
+}
+
+static __u64 btf_type_disambig_hash(const struct btf *btf, __u32 id, bool include_members)
+{
+	const struct btf_type *t = btf__type_by_id(btf, id);
+	int i;
+	size_t hash = 0;
+
+	hash = btf_name_hasher(hash, btf, t->name_off);
+
+	switch (btf_kind(t)) {
+	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64:
+		for (i = 0; i < btf_vlen(t); i++) {
+			__u32 name_off = btf_is_enum(t) ?
+				btf_enum(t)[i].name_off :
+				btf_enum64(t)[i].name_off;
+
+			hash = btf_name_hasher(hash, btf, name_off);
+		}
+		break;
+	case BTF_KIND_STRUCT:
+	case BTF_KIND_UNION:
+		if (!include_members)
+			break;
+		for (i = 0; i < btf_vlen(t); i++) {
+			const struct btf_member *m = btf_members(t) + i;
+
+			hash = btf_name_hasher(hash, btf, m->name_off);
+			/* resolve field type's name and hash it as well */
+			hash = hasher(hash, btf_type_disambig_hash(btf, m->type, false));
+		}
+		break;
+	case BTF_KIND_TYPE_TAG:
+	case BTF_KIND_CONST:
+	case BTF_KIND_PTR:
+	case BTF_KIND_VOLATILE:
+	case BTF_KIND_RESTRICT:
+	case BTF_KIND_TYPEDEF:
+	case BTF_KIND_DECL_TAG:
+		hash = hasher(hash, btf_type_disambig_hash(btf, t->type, include_members));
+		break;
+	case BTF_KIND_ARRAY: {
+		struct btf_array *arr = btf_array(t);
+
+		hash = hasher(hash, arr->nelems);
+		hash = hasher(hash, btf_type_disambig_hash(btf, arr->type, include_members));
+		break;
+	}
+	default:
+		break;
+	}
+	return hash;
+}
+
+static int btf_type_compare(const void *left, const void *right)
+{
+	const struct sort_datum *d1 = (const struct sort_datum *)left;
+	const struct sort_datum *d2 = (const struct sort_datum *)right;
+	int r;
+
+	r = d1->type_rank - d2->type_rank;
+	r = r ?: strcmp(d1->sort_name, d2->sort_name);
+	r = r ?: strcmp(d1->own_name, d2->own_name);
+	if (r)
+		return r;
+
+	if (d1->disambig_hash != d2->disambig_hash)
+		return d1->disambig_hash < d2->disambig_hash ? -1 : 1;
+
+	return d1->index - d2->index;
+}
+
+static struct sort_datum *sort_btf_c(const struct btf *btf)
+{
+	struct sort_datum *datums;
+	int n;
+
+	n = btf__type_cnt(btf);
+	datums = malloc(sizeof(struct sort_datum) * n);
+	if (!datums)
+		return NULL;
+
+	for (int i = 0; i < n; ++i) {
+		struct sort_datum *d = datums + i;
+		const struct btf_type *t = btf__type_by_id(btf, i);
+
+		d->index = i;
+		d->type_rank = btf_type_rank(btf, i, false);
+		d->sort_name = btf_type_sort_name(btf, i, false);
+		d->own_name = btf__name_by_offset(btf, t->name_off);
+		d->disambig_hash = btf_type_disambig_hash(btf, i, true);
+	}
+
+	qsort(datums, n, sizeof(struct sort_datum), btf_type_compare);
+
+	return datums;
+}
+
 static int dump_btf_c(const struct btf *btf,
-		      __u32 *root_type_ids, int root_type_cnt)
+		      __u32 *root_type_ids, int root_type_cnt, bool sort_dump)
 {
+	struct sort_datum *datums = NULL;
 	struct btf_dump *d;
 	int err = 0, i;
 
 	d = btf_dump__new(btf, btf_dump_printf, NULL, NULL);
-	err = libbpf_get_error(d);
-	if (err)
-		return err;
+	if (!d)
+		return -errno;
 
 	printf("#ifndef __VMLINUX_H__\n");
 	printf("#define __VMLINUX_H__\n");
@@ -431,6 +785,19 @@ static int dump_btf_c(const struct btf *btf,
 	printf("#ifndef BPF_NO_PRESERVE_ACCESS_INDEX\n");
 	printf("#pragma clang attribute push (__attribute__((preserve_access_index)), apply_to = record)\n");
 	printf("#endif\n\n");
+	printf("#ifndef __ksym\n");
+	printf("#define __ksym __attribute__((section(\".ksyms\")))\n");
+	printf("#endif\n\n");
+	printf("#ifndef __weak\n");
+	printf("#define __weak __attribute__((weak))\n");
+	printf("#endif\n\n");
+	printf("#ifndef __bpf_fastcall\n");
+	printf("#if __has_attribute(bpf_fastcall)\n");
+	printf("#define __bpf_fastcall __attribute__((bpf_fastcall))\n");
+	printf("#else\n");
+	printf("#define __bpf_fastcall\n");
+	printf("#endif\n");
+	printf("#endif\n\n");
 
 	if (root_type_cnt) {
 		for (i = 0; i < root_type_cnt; i++) {
@@ -441,11 +808,19 @@ static int dump_btf_c(const struct btf *btf,
 	} else {
 		int cnt = btf__type_cnt(btf);
 
+		if (sort_dump)
+			datums = sort_btf_c(btf);
 		for (i = 1; i < cnt; i++) {
-			err = btf_dump__dump_type(d, i);
+			int idx = datums ? datums[i].index : i;
+
+			err = btf_dump__dump_type(d, idx);
 			if (err)
 				goto done;
 		}
+
+		err = dump_btf_kfuncs(d, btf);
+		if (err)
+			goto done;
 	}
 
 	printf("#ifndef BPF_NO_PRESERVE_ACCESS_INDEX\n");
@@ -455,20 +830,66 @@ static int dump_btf_c(const struct btf *btf,
 	printf("#endif /* __VMLINUX_H__ */\n");
 
 done:
+	free(datums);
 	btf_dump__free(d);
 	return err;
 }
 
+static const char sysfs_vmlinux[] = "/sys/kernel/btf/vmlinux";
+
+static struct btf *get_vmlinux_btf_from_sysfs(void)
+{
+	struct btf *base;
+
+	base = btf__parse(sysfs_vmlinux, NULL);
+	if (!base)
+		p_err("failed to parse vmlinux BTF at '%s': %d\n",
+		      sysfs_vmlinux, -errno);
+
+	return base;
+}
+
+#define BTF_NAME_BUFF_LEN 64
+
+static bool btf_is_kernel_module(__u32 btf_id)
+{
+	struct bpf_btf_info btf_info = {};
+	char btf_name[BTF_NAME_BUFF_LEN];
+	int btf_fd;
+	__u32 len;
+	int err;
+
+	btf_fd = bpf_btf_get_fd_by_id(btf_id);
+	if (btf_fd < 0) {
+		p_err("can't get BTF object by id (%u): %s", btf_id, strerror(errno));
+		return false;
+	}
+
+	len = sizeof(btf_info);
+	btf_info.name = ptr_to_u64(btf_name);
+	btf_info.name_len = sizeof(btf_name);
+	err = bpf_btf_get_info_by_fd(btf_fd, &btf_info, &len);
+	close(btf_fd);
+	if (err) {
+		p_err("can't get BTF (ID %u) object info: %s", btf_id, strerror(errno));
+		return false;
+	}
+
+	return btf_info.kernel_btf && strncmp(btf_name, "vmlinux", sizeof(btf_name)) != 0;
+}
+
 static int do_dump(int argc, char **argv)
 {
+	bool dump_c = false, sort_dump_c = true;
 	struct btf *btf = NULL, *base = NULL;
-	__u32 root_type_ids[2];
+	__u32 root_type_ids[MAX_ROOT_IDS];
+	bool have_id_filtering;
 	int root_type_cnt = 0;
-	bool dump_c = false;
 	__u32 btf_id = -1;
 	const char *src;
 	int fd = -1;
-	int err;
+	int err = 0;
+	int i;
 
 	if (!REQ_ARGS(2)) {
 		usage();
@@ -484,7 +905,8 @@ static int do_dump(int argc, char **argv)
 			return -1;
 		}
 
-		fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
+		fd = map_parse_fd_and_info(&argc, &argv, &info, &len,
+					   BPF_F_RDONLY);
 		if (fd < 0)
 			return -1;
 
@@ -518,7 +940,7 @@ static int do_dump(int argc, char **argv)
 		if (fd < 0)
 			return -1;
 
-		err = bpf_obj_get_info_by_fd(fd, &info, &len);
+		err = bpf_prog_get_info_by_fd(fd, &info, &len);
 		if (err) {
 			p_err("can't get prog info: %s", strerror(errno));
 			goto done;
@@ -536,25 +958,17 @@ static int do_dump(int argc, char **argv)
 		NEXT_ARG();
 	} else if (is_prefix(src, "file")) {
 		const char sysfs_prefix[] = "/sys/kernel/btf/";
-		const char sysfs_vmlinux[] = "/sys/kernel/btf/vmlinux";
 
 		if (!base_btf &&
 		    strncmp(*argv, sysfs_prefix, sizeof(sysfs_prefix) - 1) == 0 &&
-		    strcmp(*argv, sysfs_vmlinux) != 0) {
-			base = btf__parse(sysfs_vmlinux, NULL);
-			if (libbpf_get_error(base)) {
-				p_err("failed to parse vmlinux BTF at '%s': %ld\n",
-				      sysfs_vmlinux, libbpf_get_error(base));
-				base = NULL;
-			}
-		}
+		    strcmp(*argv, sysfs_vmlinux) != 0)
+			base = get_vmlinux_btf_from_sysfs();
 
 		btf = btf__parse_split(*argv, base ?: base_btf);
-		err = libbpf_get_error(btf);
-		if (err) {
-			btf = NULL;
+		if (!btf) {
+			err = -errno;
 			p_err("failed to load BTF from %s: %s",
-			      *argv, strerror(err));
+			      *argv, strerror(errno));
 			goto done;
 		}
 		NEXT_ARG();
@@ -564,6 +978,8 @@ static int do_dump(int argc, char **argv)
 		goto done;
 	}
 
+	have_id_filtering = !!root_type_cnt;
+
 	while (argc) {
 		if (is_prefix(*argv, "format")) {
 			NEXT_ARG();
@@ -583,6 +999,39 @@ static int do_dump(int argc, char **argv)
 				goto done;
 			}
 			NEXT_ARG();
+		} else if (is_prefix(*argv, "root_id")) {
+			__u32 root_id;
+			char *end;
+
+			if (have_id_filtering) {
+				p_err("cannot use root_id with other type filtering");
+				err = -EINVAL;
+				goto done;
+			} else if (root_type_cnt == MAX_ROOT_IDS) {
+				p_err("only %d root_id are supported", MAX_ROOT_IDS);
+				err = -E2BIG;
+				goto done;
+			}
+
+			NEXT_ARG();
+			root_id = strtoul(*argv, &end, 0);
+			if (*end) {
+				err = -1;
+				p_err("can't parse %s as root ID", *argv);
+				goto done;
+			}
+			for (i = 0; i < root_type_cnt; i++) {
+				if (root_type_ids[i] == root_id) {
+					err = -EINVAL;
+					p_err("duplicate root_id %u supplied", root_id);
+					goto done;
+				}
+			}
+			root_type_ids[root_type_cnt++] = root_id;
+			NEXT_ARG();
+		} else if (is_prefix(*argv, "unsorted")) {
+			sort_dump_c = false;
+			NEXT_ARG();
 		} else {
 			p_err("unrecognized option: '%s'", *argv);
 			err = -EINVAL;
@@ -591,10 +1040,27 @@ static int do_dump(int argc, char **argv)
 	}
 
 	if (!btf) {
+		if (!base_btf && btf_is_kernel_module(btf_id)) {
+			p_info("Warning: valid base BTF was not specified with -B option, falling back to standard base BTF (%s)",
+			       sysfs_vmlinux);
+			base_btf = get_vmlinux_btf_from_sysfs();
+		}
+
 		btf = btf__load_from_kernel_by_id_split(btf_id, base_btf);
-		err = libbpf_get_error(btf);
-		if (err) {
-			p_err("get btf by id (%u): %s", btf_id, strerror(err));
+		if (!btf) {
+			err = -errno;
+			p_err("get btf by id (%u): %s", btf_id, strerror(errno));
+			goto done;
+		}
+	}
+
+	/* Invalid root IDs causes half emitted boilerplate and then unclean
+	 * exit. It's an ugly user experience, so handle common error here.
+	 */
+	for (i = 0; i < root_type_cnt; i++) {
+		if (root_type_ids[i] >= btf__type_cnt(btf)) {
+			err = -EINVAL;
+			p_err("invalid root ID: %u", root_type_ids[i]);
 			goto done;
 		}
 	}
@@ -605,7 +1071,7 @@ static int do_dump(int argc, char **argv)
 			err = -ENOTSUP;
 			goto done;
 		}
-		err = dump_btf_c(btf, root_type_ids, root_type_cnt);
+		err = dump_btf_c(btf, root_type_ids, root_type_cnt, sort_dump_c);
 	} else {
 		err = dump_btf_raw(btf, root_type_ids, root_type_cnt);
 	}
@@ -653,10 +1119,13 @@ build_btf_type_table(struct hashmap *tab, enum bpf_obj_type type,
 		[BPF_OBJ_PROG]		= "prog",
 		[BPF_OBJ_MAP]		= "map",
 	};
+	LIBBPF_OPTS(bpf_get_fd_by_id_opts, opts_ro);
 	__u32 btf_id, id = 0;
 	int err;
 	int fd;
 
+	opts_ro.open_flags = BPF_F_RDONLY;
+
 	while (true) {
 		switch (type) {
 		case BPF_OBJ_PROG:
@@ -667,7 +1136,7 @@ build_btf_type_table(struct hashmap *tab, enum bpf_obj_type type,
 			break;
 		default:
 			err = -1;
-			p_err("unexpected object type: %d", type);
+			p_err("unexpected object type: %u", type);
 			goto err_free;
 		}
 		if (err) {
@@ -686,11 +1155,11 @@ build_btf_type_table(struct hashmap *tab, enum bpf_obj_type type,
 			fd = bpf_prog_get_fd_by_id(id);
 			break;
 		case BPF_OBJ_MAP:
-			fd = bpf_map_get_fd_by_id(id);
+			fd = bpf_map_get_fd_by_id_opts(id, &opts_ro);
 			break;
 		default:
 			err = -1;
-			p_err("unexpected object type: %d", type);
+			p_err("unexpected object type: %u", type);
 			goto err_free;
 		}
 		if (fd < 0) {
@@ -703,7 +1172,10 @@ build_btf_type_table(struct hashmap *tab, enum bpf_obj_type type,
 		}
 
 		memset(info, 0, *len);
-		err = bpf_obj_get_info_by_fd(fd, info, len);
+		if (type == BPF_OBJ_PROG)
+			err = bpf_prog_get_info_by_fd(fd, info, len);
+		else
+			err = bpf_map_get_info_by_fd(fd, info, len);
 		close(fd);
 		if (err) {
 			p_err("can't get %s info: %s", names[type],
@@ -720,17 +1192,16 @@ build_btf_type_table(struct hashmap *tab, enum bpf_obj_type type,
 			break;
 		default:
 			err = -1;
-			p_err("unexpected object type: %d", type);
+			p_err("unexpected object type: %u", type);
 			goto err_free;
 		}
 		if (!btf_id)
 			continue;
 
-		err = hashmap__append(tab, u32_as_hash_field(btf_id),
-				      u32_as_hash_field(id));
+		err = hashmap__append(tab, btf_id, id);
 		if (err) {
 			p_err("failed to append entry to hashmap for BTF ID %u, object ID %u: %s",
-			      btf_id, id, strerror(errno));
+			      btf_id, id, strerror(-err));
 			goto err_free;
 		}
 	}
@@ -786,17 +1257,13 @@ show_btf_plain(struct bpf_btf_info *info, int fd,
 	printf("size %uB", info->btf_size);
 
 	n = 0;
-	hashmap__for_each_key_entry(btf_prog_table, entry,
-				    u32_as_hash_field(info->id)) {
-		printf("%s%u", n++ == 0 ? "  prog_ids " : ",",
-		       hash_field_as_u32(entry->value));
+	hashmap__for_each_key_entry(btf_prog_table, entry, info->id) {
+		printf("%s%lu", n++ == 0 ? "  prog_ids " : ",", (unsigned long)entry->value);
 	}
 
 	n = 0;
-	hashmap__for_each_key_entry(btf_map_table, entry,
-				    u32_as_hash_field(info->id)) {
-		printf("%s%u", n++ == 0 ? "  map_ids " : ",",
-		       hash_field_as_u32(entry->value));
+	hashmap__for_each_key_entry(btf_map_table, entry, info->id) {
+		printf("%s%lu", n++ == 0 ? "  map_ids " : ",", (unsigned long)entry->value);
 	}
 
 	emit_obj_refs_plain(refs_table, info->id, "\n\tpids ");
@@ -818,17 +1285,15 @@ show_btf_json(struct bpf_btf_info *info, int fd,
 
 	jsonw_name(json_wtr, "prog_ids");
 	jsonw_start_array(json_wtr);	/* prog_ids */
-	hashmap__for_each_key_entry(btf_prog_table, entry,
-				    u32_as_hash_field(info->id)) {
-		jsonw_uint(json_wtr, hash_field_as_u32(entry->value));
+	hashmap__for_each_key_entry(btf_prog_table, entry, info->id) {
+		jsonw_uint(json_wtr, entry->value);
 	}
 	jsonw_end_array(json_wtr);	/* prog_ids */
 
 	jsonw_name(json_wtr, "map_ids");
 	jsonw_start_array(json_wtr);	/* map_ids */
-	hashmap__for_each_key_entry(btf_map_table, entry,
-				    u32_as_hash_field(info->id)) {
-		jsonw_uint(json_wtr, hash_field_as_u32(entry->value));
+	hashmap__for_each_key_entry(btf_map_table, entry, info->id) {
+		jsonw_uint(json_wtr, entry->value);
 	}
 	jsonw_end_array(json_wtr);	/* map_ids */
 
@@ -852,7 +1317,7 @@ show_btf(int fd, struct hashmap *btf_prog_table,
 	int err;
 
 	memset(&info, 0, sizeof(info));
-	err = bpf_obj_get_info_by_fd(fd, &info, &len);
+	err = bpf_btf_get_info_by_fd(fd, &info, &len);
 	if (err) {
 		p_err("can't get BTF object info: %s", strerror(errno));
 		return -1;
@@ -864,7 +1329,7 @@ show_btf(int fd, struct hashmap *btf_prog_table,
 		info.name = ptr_to_u64(name);
 		len = sizeof(info);
 
-		err = bpf_obj_get_info_by_fd(fd, &info, &len);
+		err = bpf_btf_get_info_by_fd(fd, &info, &len);
 		if (err) {
 			p_err("can't get BTF object info: %s", strerror(errno));
 			return -1;
@@ -902,7 +1367,7 @@ static int do_show(int argc, char **argv)
 				      equal_fn_for_key_as_id, NULL);
 	btf_map_table = hashmap__new(hash_fn_for_key_as_id,
 				     equal_fn_for_key_as_id, NULL);
-	if (!btf_prog_table || !btf_map_table) {
+	if (IS_ERR(btf_prog_table) || IS_ERR(btf_map_table)) {
 		hashmap__free(btf_prog_table);
 		hashmap__free(btf_map_table);
 		if (fd >= 0)
@@ -977,11 +1442,11 @@ static int do_help(int argc, char **argv)
 
 	fprintf(stderr,
 		"Usage: %1$s %2$s { show | list } [id BTF_ID]\n"
-		"       %1$s %2$s dump BTF_SRC [format FORMAT]\n"
+		"       %1$s %2$s dump BTF_SRC [format FORMAT] [root_id ROOT_ID]\n"
 		"       %1$s %2$s help\n"
 		"\n"
 		"       BTF_SRC := { id BTF_ID | prog PROG | map MAP [{key | value | kv | all}] | file FILE }\n"
-		"       FORMAT  := { raw | c }\n"
+		"       FORMAT  := { raw | c [unsorted] }\n"
 		"       " HELP_SPEC_MAP "\n"
 		"       " HELP_SPEC_PROGRAM "\n"
 		"       " HELP_SPEC_OPTIONS " |\n"