Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2019-04-12

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Improve BPF verifier scalability for large programs through two
   optimizations: i) remove verifier states that are not useful in pruning,
   ii) stop walking parentage chain once first LIVE_READ is seen. Combined
   gives approx 20x speedup. Increase limits for accepting large programs
   under root, and add various stress tests, from Alexei.

2) Implement global data support in BPF. This enables static global variables
   for .data, .rodata and .bss sections to be properly handled which allows
   for more natural program development. This also opens up the possibility
   to optimize program workflow by compiling ELFs only once and later only
   rewriting section data before reload, from Daniel and with test cases and
   libbpf refactoring from Joe.

3) Add config option to generate BTF type info for vmlinux as part of the
   kernel build process. DWARF debug info is converted via pahole to BTF.
   Latter relies on libbpf and makes use of BTF deduplication algorithm which
   results in 100x savings compared to DWARF data. Resulting .BTF section is
   typically about 2MB in size, from Andrii.

4) Add BPF verifier support for stack access with variable offset from
   helpers and add various test cases along with it, from Andrey.

5) Extend bpf_skb_adjust_room() growth BPF helper to mark inner MAC header
   so that L2 encapsulation can be used for tc tunnels, from Alan.

6) Add support for input __sk_buff context in BPF_PROG_TEST_RUN so that
   users can define a subset of allowed __sk_buff fields that get fed into
   the test program, from Stanislav.

7) Add bpf fs multi-dimensional array tests for BTF test suite and fix up
   various UBSAN warnings in bpftool, from Yonghong.

8) Generate a pkg-config file for libbpf, from Luca.

9) Dump program's BTF id in bpftool, from Prashant.

10) libbpf fix to use smaller BPF log buffer size for AF_XDP's XDP
    program, from Magnus.

11) kallsyms related fixes for the case when symbols are not present in
    BPF selftests and samples, from Daniel
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

11 files changed, 651 insertions, 115 deletions

diff --git a/tools/lib/bpf/.gitignore b/tools/lib/bpf/.gitignore
index 4db74758c674..7d9e182a1f51 100644
--- a/tools/lib/bpf/.gitignore
+++ b/tools/lib/bpf/.gitignore
@@ -1,3 +1,4 @@
 libbpf_version.h
+libbpf.pc
 FEATURE-DUMP.libbpf
 test_libbpf
diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
index 8e7c56e9590f..c6c06bc6683c 100644
--- a/tools/lib/bpf/Makefile
+++ b/tools/lib/bpf/Makefile
@@ -3,7 +3,7 @@
 
 BPF_VERSION = 0
 BPF_PATCHLEVEL = 0
-BPF_EXTRAVERSION = 2
+BPF_EXTRAVERSION = 3
 
 MAKEFLAGS += --no-print-directory
 
@@ -90,6 +90,7 @@ LIBBPF_VERSION	= $(BPF_VERSION).$(BPF_PATCHLEVEL).$(BPF_EXTRAVERSION)
 
 LIB_TARGET	= libbpf.a libbpf.so.$(LIBBPF_VERSION)
 LIB_FILE	= libbpf.a libbpf.so*
+PC_FILE		= libbpf.pc
 
 # Set compile option CFLAGS
 ifdef EXTRA_CFLAGS
@@ -134,13 +135,14 @@ VERSION_SCRIPT	:= libbpf.map
 
 LIB_TARGET	:= $(addprefix $(OUTPUT),$(LIB_TARGET))
 LIB_FILE	:= $(addprefix $(OUTPUT),$(LIB_FILE))
+PC_FILE		:= $(addprefix $(OUTPUT),$(PC_FILE))
 
 GLOBAL_SYM_COUNT = $(shell readelf -s --wide $(BPF_IN) | \
 			   awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {s++} END{print s}')
 VERSIONED_SYM_COUNT = $(shell readelf -s --wide $(OUTPUT)libbpf.so | \
 			      grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | sort -u | wc -l)
 
-CMD_TARGETS = $(LIB_TARGET)
+CMD_TARGETS = $(LIB_TARGET) $(PC_FILE)
 
 CXX_TEST_TARGET = $(OUTPUT)test_libbpf
 
@@ -187,6 +189,12 @@ $(OUTPUT)libbpf.a: $(BPF_IN)
 $(OUTPUT)test_libbpf: test_libbpf.cpp $(OUTPUT)libbpf.a
 	$(QUIET_LINK)$(CXX) $(INCLUDES) $^ -lelf -o $@
 
+$(OUTPUT)libbpf.pc:
+	$(QUIET_GEN)sed -e "s|@PREFIX@|$(prefix)|" \
+		-e "s|@LIBDIR@|$(libdir_SQ)|" \
+		-e "s|@VERSION@|$(LIBBPF_VERSION)|" \
+		< libbpf.pc.template > $@
+
 check: check_abi
 
 check_abi: $(OUTPUT)libbpf.so
@@ -224,7 +232,11 @@ install_headers:
 		$(call do_install,btf.h,$(prefix)/include/bpf,644); \
 		$(call do_install,xsk.h,$(prefix)/include/bpf,644);
 
-install: install_lib
+install_pkgconfig: $(PC_FILE)
+	$(call QUIET_INSTALL, $(PC_FILE)) \
+		$(call do_install,$(PC_FILE),$(libdir_SQ)/pkgconfig,644)
+
+install: install_lib install_pkgconfig
 
 ### Cleaning rules
 
@@ -234,7 +246,7 @@ config-clean:
 
 clean:
 	$(call QUIET_CLEAN, libbpf) $(RM) $(TARGETS) $(CXX_TEST_TARGET) \
-		*.o *~ *.a *.so *.so.$(VERSION) .*.d .*.cmd LIBBPF-CFLAGS
+		*.o *~ *.a *.so *.so.$(VERSION) .*.d .*.cmd *.pc LIBBPF-CFLAGS
 	$(call QUIET_CLEAN, core-gen) $(RM) $(OUTPUT)FEATURE-DUMP.libbpf
 
 
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 9cd015574e83..955191c64b64 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -79,7 +79,6 @@ static inline int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size)
 
 int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr)
 {
-	__u32 name_len = create_attr->name ? strlen(create_attr->name) : 0;
 	union bpf_attr attr;
 
 	memset(&attr, '\0', sizeof(attr));
@@ -89,8 +88,9 @@ int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr)
 	attr.value_size = create_attr->value_size;
 	attr.max_entries = create_attr->max_entries;
 	attr.map_flags = create_attr->map_flags;
-	memcpy(attr.map_name, create_attr->name,
-	       min(name_len, BPF_OBJ_NAME_LEN - 1));
+	if (create_attr->name)
+		memcpy(attr.map_name, create_attr->name,
+		       min(strlen(create_attr->name), BPF_OBJ_NAME_LEN - 1));
 	attr.numa_node = create_attr->numa_node;
 	attr.btf_fd = create_attr->btf_fd;
 	attr.btf_key_type_id = create_attr->btf_key_type_id;
@@ -155,7 +155,6 @@ int bpf_create_map_in_map_node(enum bpf_map_type map_type, const char *name,
 			       int key_size, int inner_map_fd, int max_entries,
 			       __u32 map_flags, int node)
 {
-	__u32 name_len = name ? strlen(name) : 0;
 	union bpf_attr attr;
 
 	memset(&attr, '\0', sizeof(attr));
@@ -166,7 +165,9 @@ int bpf_create_map_in_map_node(enum bpf_map_type map_type, const char *name,
 	attr.inner_map_fd = inner_map_fd;
 	attr.max_entries = max_entries;
 	attr.map_flags = map_flags;
-	memcpy(attr.map_name, name, min(name_len, BPF_OBJ_NAME_LEN - 1));
+	if (name)
+		memcpy(attr.map_name, name,
+		       min(strlen(name), BPF_OBJ_NAME_LEN - 1));
 
 	if (node >= 0) {
 		attr.map_flags |= BPF_F_NUMA_NODE;
@@ -216,18 +217,15 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr,
 	void *finfo = NULL, *linfo = NULL;
 	union bpf_attr attr;
 	__u32 log_level;
-	__u32 name_len;
 	int fd;
 
 	if (!load_attr || !log_buf != !log_buf_sz)
 		return -EINVAL;
 
 	log_level = load_attr->log_level;
-	if (log_level > 2 || (log_level && !log_buf))
+	if (log_level > (4 | 2 | 1) || (log_level && !log_buf))
 		return -EINVAL;
 
-	name_len = load_attr->name ? strlen(load_attr->name) : 0;
-
 	memset(&attr, 0, sizeof(attr));
 	attr.prog_type = load_attr->prog_type;
 	attr.expected_attach_type = load_attr->expected_attach_type;
@@ -253,8 +251,9 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr,
 	attr.line_info_rec_size = load_attr->line_info_rec_size;
 	attr.line_info_cnt = load_attr->line_info_cnt;
 	attr.line_info = ptr_to_u64(load_attr->line_info);
-	memcpy(attr.prog_name, load_attr->name,
-	       min(name_len, BPF_OBJ_NAME_LEN - 1));
+	if (load_attr->name)
+		memcpy(attr.prog_name, load_attr->name,
+		       min(strlen(load_attr->name), BPF_OBJ_NAME_LEN - 1));
 
 	fd = sys_bpf_prog_load(&attr, sizeof(attr));
 	if (fd >= 0)
@@ -429,6 +428,16 @@ int bpf_map_get_next_key(int fd, const void *key, void *next_key)
 	return sys_bpf(BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr));
 }
 
+int bpf_map_freeze(int fd)
+{
+	union bpf_attr attr;
+
+	memset(&attr, 0, sizeof(attr));
+	attr.map_fd = fd;
+
+	return sys_bpf(BPF_MAP_FREEZE, &attr, sizeof(attr));
+}
+
 int bpf_obj_pin(int fd, const char *pathname)
 {
 	union bpf_attr attr;
@@ -545,10 +554,15 @@ int bpf_prog_test_run_xattr(struct bpf_prog_test_run_attr *test_attr)
 	attr.test.data_out = ptr_to_u64(test_attr->data_out);
 	attr.test.data_size_in = test_attr->data_size_in;
 	attr.test.data_size_out = test_attr->data_size_out;
+	attr.test.ctx_in = ptr_to_u64(test_attr->ctx_in);
+	attr.test.ctx_out = ptr_to_u64(test_attr->ctx_out);
+	attr.test.ctx_size_in = test_attr->ctx_size_in;
+	attr.test.ctx_size_out = test_attr->ctx_size_out;
 	attr.test.repeat = test_attr->repeat;
 
 	ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr));
 	test_attr->data_size_out = attr.test.data_size_out;
+	test_attr->ctx_size_out = attr.test.ctx_size_out;
 	test_attr->retval = attr.test.retval;
 	test_attr->duration = attr.test.duration;
 	return ret;
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 6ffdd79bea89..bc30783d1403 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -92,7 +92,7 @@ struct bpf_load_program_attr {
 #define MAPS_RELAX_COMPAT	0x01
 
 /* Recommend log buffer size */
-#define BPF_LOG_BUF_SIZE (256 * 1024)
+#define BPF_LOG_BUF_SIZE (16 * 1024 * 1024) /* verifier maximum in kernels <= 5.1 */
 LIBBPF_API int
 bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr,
 		       char *log_buf, size_t log_buf_sz);
@@ -117,6 +117,7 @@ LIBBPF_API int bpf_map_lookup_and_delete_elem(int fd, const void *key,
 					      void *value);
 LIBBPF_API int bpf_map_delete_elem(int fd, const void *key);
 LIBBPF_API int bpf_map_get_next_key(int fd, const void *key, void *next_key);
+LIBBPF_API int bpf_map_freeze(int fd);
 LIBBPF_API int bpf_obj_pin(int fd, const char *pathname);
 LIBBPF_API int bpf_obj_get(const char *pathname);
 LIBBPF_API int bpf_prog_attach(int prog_fd, int attachable_fd,
@@ -135,6 +136,11 @@ struct bpf_prog_test_run_attr {
 			      * out: length of data_out */
 	__u32 retval;        /* out: return code of the BPF program */
 	__u32 duration;      /* out: average per repetition in ns */
+	const void *ctx_in; /* optional */
+	__u32 ctx_size_in;
+	void *ctx_out;      /* optional */
+	__u32 ctx_size_out; /* in: max length of ctx_out
+			     * out: length of cxt_out */
 };
 
 LIBBPF_API int bpf_prog_test_run_xattr(struct bpf_prog_test_run_attr *test_attr);
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index cf119c9b6f27..701e7e28ada3 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -24,6 +24,8 @@
 		((k) == BTF_KIND_CONST) || \
 		((k) == BTF_KIND_RESTRICT))
 
+#define IS_VAR(k) ((k) == BTF_KIND_VAR)
+
 static struct btf_type btf_void;
 
 struct btf {
@@ -212,6 +214,10 @@ static int btf_type_size(struct btf_type *t)
 		return base_size + vlen * sizeof(struct btf_member);
 	case BTF_KIND_FUNC_PROTO:
 		return base_size + vlen * sizeof(struct btf_param);
+	case BTF_KIND_VAR:
+		return base_size + sizeof(struct btf_var);
+	case BTF_KIND_DATASEC:
+		return base_size + vlen * sizeof(struct btf_var_secinfo);
 	default:
 		pr_debug("Unsupported BTF_KIND:%u\n", BTF_INFO_KIND(t->info));
 		return -EINVAL;
@@ -283,6 +289,7 @@ __s64 btf__resolve_size(const struct btf *btf, __u32 type_id)
 		case BTF_KIND_STRUCT:
 		case BTF_KIND_UNION:
 		case BTF_KIND_ENUM:
+		case BTF_KIND_DATASEC:
 			size = t->size;
 			goto done;
 		case BTF_KIND_PTR:
@@ -292,6 +299,7 @@ __s64 btf__resolve_size(const struct btf *btf, __u32 type_id)
 		case BTF_KIND_VOLATILE:
 		case BTF_KIND_CONST:
 		case BTF_KIND_RESTRICT:
+		case BTF_KIND_VAR:
 			type_id = t->type;
 			break;
 		case BTF_KIND_ARRAY:
@@ -326,7 +334,8 @@ int btf__resolve_type(const struct btf *btf, __u32 type_id)
 	t = btf__type_by_id(btf, type_id);
 	while (depth < MAX_RESOLVE_DEPTH &&
 	       !btf_type_is_void_or_null(t) &&
-	       IS_MODIFIER(BTF_INFO_KIND(t->info))) {
+	       (IS_MODIFIER(BTF_INFO_KIND(t->info)) ||
+		IS_VAR(BTF_INFO_KIND(t->info)))) {
 		type_id = t->type;
 		t = btf__type_by_id(btf, type_id);
 		depth++;
@@ -408,6 +417,92 @@ done:
 	return btf;
 }
 
+static int compare_vsi_off(const void *_a, const void *_b)
+{
+	const struct btf_var_secinfo *a = _a;
+	const struct btf_var_secinfo *b = _b;
+
+	return a->offset - b->offset;
+}
+
+static int btf_fixup_datasec(struct bpf_object *obj, struct btf *btf,
+			     struct btf_type *t)
+{
+	__u32 size = 0, off = 0, i, vars = BTF_INFO_VLEN(t->info);
+	const char *name = btf__name_by_offset(btf, t->name_off);
+	const struct btf_type *t_var;
+	struct btf_var_secinfo *vsi;
+	struct btf_var *var;
+	int ret;
+
+	if (!name) {
+		pr_debug("No name found in string section for DATASEC kind.\n");
+		return -ENOENT;
+	}
+
+	ret = bpf_object__section_size(obj, name, &size);
+	if (ret || !size || (t->size && t->size != size)) {
+		pr_debug("Invalid size for section %s: %u bytes\n", name, size);
+		return -ENOENT;
+	}
+
+	t->size = size;
+
+	for (i = 0, vsi = (struct btf_var_secinfo *)(t + 1);
+	     i < vars; i++, vsi++) {
+		t_var = btf__type_by_id(btf, vsi->type);
+		var = (struct btf_var *)(t_var + 1);
+
+		if (BTF_INFO_KIND(t_var->info) != BTF_KIND_VAR) {
+			pr_debug("Non-VAR type seen in section %s\n", name);
+			return -EINVAL;
+		}
+
+		if (var->linkage == BTF_VAR_STATIC)
+			continue;
+
+		name = btf__name_by_offset(btf, t_var->name_off);
+		if (!name) {
+			pr_debug("No name found in string section for VAR kind\n");
+			return -ENOENT;
+		}
+
+		ret = bpf_object__variable_offset(obj, name, &off);
+		if (ret) {
+			pr_debug("No offset found in symbol table for VAR %s\n", name);
+			return -ENOENT;
+		}
+
+		vsi->offset = off;
+	}
+
+	qsort(t + 1, vars, sizeof(*vsi), compare_vsi_off);
+	return 0;
+}
+
+int btf__finalize_data(struct bpf_object *obj, struct btf *btf)
+{
+	int err = 0;
+	__u32 i;
+
+	for (i = 1; i <= btf->nr_types; i++) {
+		struct btf_type *t = btf->types[i];
+
+		/* Loader needs to fix up some of the things compiler
+		 * couldn't get its hands on while emitting BTF. This
+		 * is section size and global variable offset. We use
+		 * the info from the ELF itself for this purpose.
+		 */
+		if (BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC) {
+			err = btf_fixup_datasec(obj, btf, t);
+			if (err)
+				break;
+		}
+	}
+
+	return err;
+}
+
 int btf__load(struct btf *btf)
 {
 	__u32 log_buf_size = BPF_LOG_BUF_SIZE;
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index 28a1e1e59861..c7b399e81fce 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -21,6 +21,8 @@ struct btf;
 struct btf_ext;
 struct btf_type;
 
+struct bpf_object;
+
 /*
  * The .BTF.ext ELF section layout defined as
  *   struct btf_ext_header
@@ -57,6 +59,7 @@ struct btf_ext_header {
 
 LIBBPF_API void btf__free(struct btf *btf);
 LIBBPF_API struct btf *btf__new(__u8 *data, __u32 size);
+LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf);
 LIBBPF_API int btf__load(struct btf *btf);
 LIBBPF_API __s32 btf__find_by_name(const struct btf *btf,
 				   const char *type_name);
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 11c25d9ea431..67484cf32b2e 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -7,6 +7,7 @@
  * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
  * Copyright (C) 2015 Huawei Inc.
  * Copyright (C) 2017 Nicira, Inc.
+ * Copyright (C) 2019 Isovalent, Inc.
  */
 
 #ifndef _GNU_SOURCE
@@ -52,6 +53,11 @@
 #define BPF_FS_MAGIC		0xcafe4a11
 #endif
 
+/* vsprintf() in __base_pr() uses nonliteral format string. It may break
+ * compilation if user enables corresponding warning. Disable it explicitly.
+ */
+#pragma GCC diagnostic ignored "-Wformat-nonliteral"
+
 #define __printf(a, b)	__attribute__((format(printf, a, b)))
 
 static int __base_pr(enum libbpf_print_level level, const char *format,
@@ -144,6 +150,7 @@ struct bpf_program {
 		enum {
 			RELO_LD64,
 			RELO_CALL,
+			RELO_DATA,
 		} type;
 		int insn_idx;
 		union {
@@ -152,6 +159,7 @@ struct bpf_program {
 		};
 	} *reloc_desc;
 	int nr_reloc;
+	int log_level;
 
 	struct {
 		int nr;
@@ -176,6 +184,19 @@ struct bpf_program {
 	__u32 line_info_cnt;
 };
 
+enum libbpf_map_type {
+	LIBBPF_MAP_UNSPEC,
+	LIBBPF_MAP_DATA,
+	LIBBPF_MAP_BSS,
+	LIBBPF_MAP_RODATA,
+};
+
+static const char * const libbpf_type_to_btf_name[] = {
+	[LIBBPF_MAP_DATA]	= ".data",
+	[LIBBPF_MAP_BSS]	= ".bss",
+	[LIBBPF_MAP_RODATA]	= ".rodata",
+};
+
 struct bpf_map {
 	int fd;
 	char *name;
@@ -187,11 +208,18 @@ struct bpf_map {
 	__u32 btf_value_type_id;
 	void *priv;
 	bpf_map_clear_priv_t clear_priv;
+	enum libbpf_map_type libbpf_type;
+};
+
+struct bpf_secdata {
+	void *rodata;
+	void *data;
 };
 
 static LIST_HEAD(bpf_objects_list);
 
 struct bpf_object {
+	char name[BPF_OBJ_NAME_LEN];
 	char license[64];
 	__u32 kern_version;
 
@@ -199,6 +227,7 @@ struct bpf_object {
 	size_t nr_programs;
 	struct bpf_map *maps;
 	size_t nr_maps;
+	struct bpf_secdata sections;
 
 	bool loaded;
 	bool has_pseudo_calls;
@@ -214,6 +243,9 @@ struct bpf_object {
 		Elf *elf;
 		GElf_Ehdr ehdr;
 		Elf_Data *symbols;
+		Elf_Data *data;
+		Elf_Data *rodata;
+		Elf_Data *bss;
 		size_t strtabidx;
 		struct {
 			GElf_Shdr shdr;
@@ -222,6 +254,9 @@ struct bpf_object {
 		int nr_reloc;
 		int maps_shndx;
 		int text_shndx;
+		int data_shndx;
+		int rodata_shndx;
+		int bss_shndx;
 	} efile;
 	/*
 	 * All loaded bpf_object is linked in a list, which is
@@ -443,6 +478,7 @@ static struct bpf_object *bpf_object__new(const char *path,
 					  size_t obj_buf_sz)
 {
 	struct bpf_object *obj;
+	char *end;
 
 	obj = calloc(1, sizeof(struct bpf_object) + strlen(path) + 1);
 	if (!obj) {
@@ -451,8 +487,14 @@ static struct bpf_object *bpf_object__new(const char *path,
 	}
 
 	strcpy(obj->path, path);
-	obj->efile.fd = -1;
+	/* Using basename() GNU version which doesn't modify arg. */
+	strncpy(obj->name, basename((void *)path),
+		sizeof(obj->name) - 1);
+	end = strchr(obj->name, '.');
+	if (end)
+		*end = 0;
 
+	obj->efile.fd = -1;
 	/*
 	 * Caller of this function should also calls
 	 * bpf_object__elf_finish() after data collection to return
@@ -462,6 +504,9 @@ static struct bpf_object *bpf_object__new(const char *path,
 	obj->efile.obj_buf = obj_buf;
 	obj->efile.obj_buf_sz = obj_buf_sz;
 	obj->efile.maps_shndx = -1;
+	obj->efile.data_shndx = -1;
+	obj->efile.rodata_shndx = -1;
+	obj->efile.bss_shndx = -1;
 
 	obj->loaded = false;
 
@@ -480,6 +525,9 @@ static void bpf_object__elf_finish(struct bpf_object *obj)
 		obj->efile.elf = NULL;
 	}
 	obj->efile.symbols = NULL;
+	obj->efile.data = NULL;
+	obj->efile.rodata = NULL;
+	obj->efile.bss = NULL;
 
 	zfree(&obj->efile.reloc);
 	obj->efile.nr_reloc = 0;
@@ -621,27 +669,182 @@ static bool bpf_map_type__is_map_in_map(enum bpf_map_type type)
 	return false;
 }
 
+static int bpf_object_search_section_size(const struct bpf_object *obj,
+					  const char *name, size_t *d_size)
+{
+	const GElf_Ehdr *ep = &obj->efile.ehdr;
+	Elf *elf = obj->efile.elf;
+	Elf_Scn *scn = NULL;
+	int idx = 0;
+
+	while ((scn = elf_nextscn(elf, scn)) != NULL) {
+		const char *sec_name;
+		Elf_Data *data;
+		GElf_Shdr sh;
+
+		idx++;
+		if (gelf_getshdr(scn, &sh) != &sh) {
+			pr_warning("failed to get section(%d) header from %s\n",
+				   idx, obj->path);
+			return -EIO;
+		}
+
+		sec_name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name);
+		if (!sec_name) {
+			pr_warning("failed to get section(%d) name from %s\n",
+				   idx, obj->path);
+			return -EIO;
+		}
+
+		if (strcmp(name, sec_name))
+			continue;
+
+		data = elf_getdata(scn, 0);
+		if (!data) {
+			pr_warning("failed to get section(%d) data from %s(%s)\n",
+				   idx, name, obj->path);
+			return -EIO;
+		}
+
+		*d_size = data->d_size;
+		return 0;
+	}
+
+	return -ENOENT;
+}
+
+int bpf_object__section_size(const struct bpf_object *obj, const char *name,
+			     __u32 *size)
+{
+	int ret = -ENOENT;
+	size_t d_size;
+
+	*size = 0;
+	if (!name) {
+		return -EINVAL;
+	} else if (!strcmp(name, ".data")) {
+		if (obj->efile.data)
+			*size = obj->efile.data->d_size;
+	} else if (!strcmp(name, ".bss")) {
+		if (obj->efile.bss)
+			*size = obj->efile.bss->d_size;
+	} else if (!strcmp(name, ".rodata")) {
+		if (obj->efile.rodata)
+			*size = obj->efile.rodata->d_size;
+	} else {
+		ret = bpf_object_search_section_size(obj, name, &d_size);
+		if (!ret)
+			*size = d_size;
+	}
+
+	return *size ? 0 : ret;
+}
+
+int bpf_object__variable_offset(const struct bpf_object *obj, const char *name,
+				__u32 *off)
+{
+	Elf_Data *symbols = obj->efile.symbols;
+	const char *sname;
+	size_t si;
+
+	if (!name || !off)
+		return -EINVAL;
+
+	for (si = 0; si < symbols->d_size / sizeof(GElf_Sym); si++) {
+		GElf_Sym sym;
+
+		if (!gelf_getsym(symbols, si, &sym))
+			continue;
+		if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL ||
+		    GELF_ST_TYPE(sym.st_info) != STT_OBJECT)
+			continue;
+
+		sname = elf_strptr(obj->efile.elf, obj->efile.strtabidx,
+				   sym.st_name);
+		if (!sname) {
+			pr_warning("failed to get sym name string for var %s\n",
+				   name);
+			return -EIO;
+		}
+		if (strcmp(name, sname) == 0) {
+			*off = sym.st_value;
+			return 0;
+		}
+	}
+
+	return -ENOENT;
+}
+
+static bool bpf_object__has_maps(const struct bpf_object *obj)
+{
+	return obj->efile.maps_shndx >= 0 ||
+	       obj->efile.data_shndx >= 0 ||
+	       obj->efile.rodata_shndx >= 0 ||
+	       obj->efile.bss_shndx >= 0;
+}
+
+static int
+bpf_object__init_internal_map(struct bpf_object *obj, struct bpf_map *map,
+			      enum libbpf_map_type type, Elf_Data *data,
+			      void **data_buff)
+{
+	struct bpf_map_def *def = &map->def;
+	char map_name[BPF_OBJ_NAME_LEN];
+
+	map->libbpf_type = type;
+	map->offset = ~(typeof(map->offset))0;
+	snprintf(map_name, sizeof(map_name), "%.8s%.7s", obj->name,
+		 libbpf_type_to_btf_name[type]);
+	map->name = strdup(map_name);
+	if (!map->name) {
+		pr_warning("failed to alloc map name\n");
+		return -ENOMEM;
+	}
+
+	def->type = BPF_MAP_TYPE_ARRAY;
+	def->key_size = sizeof(int);
+	def->value_size = data->d_size;
+	def->max_entries = 1;
+	def->map_flags = type == LIBBPF_MAP_RODATA ?
+			 BPF_F_RDONLY_PROG : 0;
+	if (data_buff) {
+		*data_buff = malloc(data->d_size);
+		if (!*data_buff) {
+			zfree(&map->name);
+			pr_warning("failed to alloc map content buffer\n");
+			return -ENOMEM;
+		}
+		memcpy(*data_buff, data->d_buf, data->d_size);
+	}
+
+	pr_debug("map %ld is \"%s\"\n", map - obj->maps, map->name);
+	return 0;
+}
+
 static int
 bpf_object__init_maps(struct bpf_object *obj, int flags)
 {
+	int i, map_idx, map_def_sz = 0, nr_syms, nr_maps = 0, nr_maps_glob = 0;
 	bool strict = !(flags & MAPS_RELAX_COMPAT);
-	int i, map_idx, map_def_sz, nr_maps = 0;
-	Elf_Scn *scn;
-	Elf_Data *data = NULL;
 	Elf_Data *symbols = obj->efile.symbols;
+	Elf_Data *data = NULL;
+	int ret = 0;
 
-	if (obj->efile.maps_shndx < 0)
-		return -EINVAL;
 	if (!symbols)
 		return -EINVAL;
+	nr_syms = symbols->d_size / sizeof(GElf_Sym);
 
-	scn = elf_getscn(obj->efile.elf, obj->efile.maps_shndx);
-	if (scn)
-		data = elf_getdata(scn, NULL);
-	if (!scn || !data) {
-		pr_warning("failed to get Elf_Data from map section %d\n",
-			   obj->efile.maps_shndx);
-		return -EINVAL;
+	if (obj->efile.maps_shndx >= 0) {
+		Elf_Scn *scn = elf_getscn(obj->efile.elf,
+					  obj->efile.maps_shndx);
+
+		if (scn)
+			data = elf_getdata(scn, NULL);
+		if (!scn || !data) {
+			pr_warning("failed to get Elf_Data from map section %d\n",
+				   obj->efile.maps_shndx);
+			return -EINVAL;
+		}
 	}
 
 	/*
@@ -651,7 +854,13 @@ bpf_object__init_maps(struct bpf_object *obj, int flags)
 	 *
 	 * TODO: Detect array of map and report error.
 	 */
-	for (i = 0; i < symbols->d_size / sizeof(GElf_Sym); i++) {
+	if (obj->efile.data_shndx >= 0)
+		nr_maps_glob++;
+	if (obj->efile.rodata_shndx >= 0)
+		nr_maps_glob++;
+	if (obj->efile.bss_shndx >= 0)
+		nr_maps_glob++;
+	for (i = 0; data && i < nr_syms; i++) {
 		GElf_Sym sym;
 
 		if (!gelf_getsym(symbols, i, &sym))
@@ -664,19 +873,21 @@ bpf_object__init_maps(struct bpf_object *obj, int flags)
 	/* Alloc obj->maps and fill nr_maps. */
 	pr_debug("maps in %s: %d maps in %zd bytes\n", obj->path,
 		 nr_maps, data->d_size);
-
-	if (!nr_maps)
+	if (!nr_maps && !nr_maps_glob)
 		return 0;
 
 	/* Assume equally sized map definitions */
-	map_def_sz = data->d_size / nr_maps;
-	if (!data->d_size || (data->d_size % nr_maps) != 0) {
-		pr_warning("unable to determine map definition size "
-			   "section %s, %d maps in %zd bytes\n",
-			   obj->path, nr_maps, data->d_size);
-		return -EINVAL;
+	if (data) {
+		map_def_sz = data->d_size / nr_maps;
+		if (!data->d_size || (data->d_size % nr_maps) != 0) {
+			pr_warning("unable to determine map definition size "
+				   "section %s, %d maps in %zd bytes\n",
+				   obj->path, nr_maps, data->d_size);
+			return -EINVAL;
+		}
 	}
 
+	nr_maps += nr_maps_glob;
 	obj->maps = calloc(nr_maps, sizeof(obj->maps[0]));
 	if (!obj->maps) {
 		pr_warning("alloc maps for object failed\n");
@@ -697,7 +908,7 @@ bpf_object__init_maps(struct bpf_object *obj, int flags)
 	/*
 	 * Fill obj->maps using data in "maps" section.
 	 */
-	for (i = 0, map_idx = 0; i < symbols->d_size / sizeof(GElf_Sym); i++) {
+	for (i = 0, map_idx = 0; data && i < nr_syms; i++) {
 		GElf_Sym sym;
 		const char *map_name;
 		struct bpf_map_def *def;
@@ -710,6 +921,8 @@ bpf_object__init_maps(struct bpf_object *obj, int flags)
 		map_name = elf_strptr(obj->efile.elf,
 				      obj->efile.strtabidx,
 				      sym.st_name);
+
+		obj->maps[map_idx].libbpf_type = LIBBPF_MAP_UNSPEC;
 		obj->maps[map_idx].offset = sym.st_value;
 		if (sym.st_value + map_def_sz > data->d_size) {
 			pr_warning("corrupted maps section in %s: last map \"%s\" too small\n",
@@ -758,8 +971,27 @@ bpf_object__init_maps(struct bpf_object *obj, int flags)
 		map_idx++;
 	}
 
-	qsort(obj->maps, obj->nr_maps, sizeof(obj->maps[0]), compare_bpf_map);
-	return 0;
+	/*
+	 * Populate rest of obj->maps with libbpf internal maps.
+	 */
+	if (obj->efile.data_shndx >= 0)
+		ret = bpf_object__init_internal_map(obj, &obj->maps[map_idx++],
+						    LIBBPF_MAP_DATA,
+						    obj->efile.data,
+						    &obj->sections.data);
+	if (!ret && obj->efile.rodata_shndx >= 0)
+		ret = bpf_object__init_internal_map(obj, &obj->maps[map_idx++],
+						    LIBBPF_MAP_RODATA,
+						    obj->efile.rodata,
+						    &obj->sections.rodata);
+	if (!ret && obj->efile.bss_shndx >= 0)
+		ret = bpf_object__init_internal_map(obj, &obj->maps[map_idx++],
+						    LIBBPF_MAP_BSS,
+						    obj->efile.bss, NULL);
+	if (!ret)
+		qsort(obj->maps, obj->nr_maps, sizeof(obj->maps[0]),
+		      compare_bpf_map);
+	return ret;
 }
 
 static bool section_have_execinstr(struct bpf_object *obj, int idx)
@@ -785,6 +1017,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
 	Elf *elf = obj->efile.elf;
 	GElf_Ehdr *ep = &obj->efile.ehdr;
 	Elf_Data *btf_ext_data = NULL;
+	Elf_Data *btf_data = NULL;
 	Elf_Scn *scn = NULL;
 	int idx = 0, err = 0;
 
@@ -828,32 +1061,18 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
 			 (int)sh.sh_link, (unsigned long)sh.sh_flags,
 			 (int)sh.sh_type);
 
-		if (strcmp(name, "license") == 0)
+		if (strcmp(name, "license") == 0) {
 			err = bpf_object__init_license(obj,
 						       data->d_buf,
 						       data->d_size);
-		else if (strcmp(name, "version") == 0)
+		} else if (strcmp(name, "version") == 0) {
 			err = bpf_object__init_kversion(obj,
 							data->d_buf,
 							data->d_size);
-		else if (strcmp(name, "maps") == 0)
+		} else if (strcmp(name, "maps") == 0) {
 			obj->efile.maps_shndx = idx;
-		else if (strcmp(name, BTF_ELF_SEC) == 0) {
-			obj->btf = btf__new(data->d_buf, data->d_size);
-			if (IS_ERR(obj->btf)) {
-				pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n",
-					   BTF_ELF_SEC, PTR_ERR(obj->btf));
-				obj->btf = NULL;
-				continue;
-			}
-			err = btf__load(obj->btf);
-			if (err) {
-				pr_warning("Error loading %s into kernel: %d. Ignored and continue.\n",
-					   BTF_ELF_SEC, err);
-				btf__free(obj->btf);
-				obj->btf = NULL;
-				err = 0;
-			}
+		} else if (strcmp(name, BTF_ELF_SEC) == 0) {
+			btf_data = data;
 		} else if (strcmp(name, BTF_EXT_ELF_SEC) == 0) {
 			btf_ext_data = data;
 		} else if (sh.sh_type == SHT_SYMTAB) {
@@ -865,20 +1084,28 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
 				obj->efile.symbols = data;
 				obj->efile.strtabidx = sh.sh_link;
 			}
-		} else if ((sh.sh_type == SHT_PROGBITS) &&
-			   (sh.sh_flags & SHF_EXECINSTR) &&
-			   (data->d_size > 0)) {
-			if (strcmp(name, ".text") == 0)
-				obj->efile.text_shndx = idx;
-			err = bpf_object__add_program(obj, data->d_buf,
-						      data->d_size, name, idx);
-			if (err) {
-				char errmsg[STRERR_BUFSIZE];
-				char *cp = libbpf_strerror_r(-err, errmsg,
-							     sizeof(errmsg));
-
-				pr_warning("failed to alloc program %s (%s): %s",
-					   name, obj->path, cp);
+		} else if (sh.sh_type == SHT_PROGBITS && data->d_size > 0) {
+			if (sh.sh_flags & SHF_EXECINSTR) {
+				if (strcmp(name, ".text") == 0)
+					obj->efile.text_shndx = idx;
+				err = bpf_object__add_program(obj, data->d_buf,
+							      data->d_size, name, idx);
+				if (err) {
+					char errmsg[STRERR_BUFSIZE];
+					char *cp = libbpf_strerror_r(-err, errmsg,
+								     sizeof(errmsg));
+
+					pr_warning("failed to alloc program %s (%s): %s",
+						   name, obj->path, cp);
+				}
+			} else if (strcmp(name, ".data") == 0) {
+				obj->efile.data = data;
+				obj->efile.data_shndx = idx;
+			} else if (strcmp(name, ".rodata") == 0) {
+				obj->efile.rodata = data;
+				obj->efile.rodata_shndx = idx;
+			} else {
+				pr_debug("skip section(%d) %s\n", idx, name);
 			}
 		} else if (sh.sh_type == SHT_REL) {
 			void *reloc = obj->efile.reloc;
@@ -906,6 +1133,9 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
 				obj->efile.reloc[n].shdr = sh;
 				obj->efile.reloc[n].data = data;
 			}
+		} else if (sh.sh_type == SHT_NOBITS && strcmp(name, ".bss") == 0) {
+			obj->efile.bss = data;
+			obj->efile.bss_shndx = idx;
 		} else {
 			pr_debug("skip section(%d) %s\n", idx, name);
 		}
@@ -917,6 +1147,25 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
 		pr_warning("Corrupted ELF file: index of strtab invalid\n");
 		return LIBBPF_ERRNO__FORMAT;
 	}
+	if (btf_data) {
+		obj->btf = btf__new(btf_data->d_buf, btf_data->d_size);
+		if (IS_ERR(obj->btf)) {
+			pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n",
+				   BTF_ELF_SEC, PTR_ERR(obj->btf));
+			obj->btf = NULL;
+		} else {
+			err = btf__finalize_data(obj, obj->btf);
+			if (!err)
+				err = btf__load(obj->btf);
+			if (err) {
+				pr_warning("Error finalizing and loading %s into kernel: %d. Ignored and continue.\n",
+					   BTF_ELF_SEC, err);
+				btf__free(obj->btf);
+				obj->btf = NULL;
+				err = 0;
+			}
+		}
+	}
 	if (btf_ext_data) {
 		if (!obj->btf) {
 			pr_debug("Ignore ELF section %s because its depending ELF section %s is not found.\n",
@@ -932,7 +1181,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
 			}
 		}
 	}
-	if (obj->efile.maps_shndx >= 0) {
+	if (bpf_object__has_maps(obj)) {
 		err = bpf_object__init_maps(obj, flags);
 		if (err)
 			goto out;
@@ -968,13 +1217,46 @@ bpf_object__find_program_by_title(struct bpf_object *obj, const char *title)
 	return NULL;
 }
 
+static bool bpf_object__shndx_is_data(const struct bpf_object *obj,
+				      int shndx)
+{
+	return shndx == obj->efile.data_shndx ||
+	       shndx == obj->efi