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>

1 files changed, 473 insertions, 94 deletions

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->efile.bss_shndx ||
+	       shndx == obj->efile.rodata_shndx;
+}
+
+static bool bpf_object__shndx_is_maps(const struct bpf_object *obj,
+				      int shndx)
+{
+	return shndx == obj->efile.maps_shndx;
+}
+
+static bool bpf_object__relo_in_known_section(const struct bpf_object *obj,
+					      int shndx)
+{
+	return shndx == obj->efile.text_shndx ||
+	       bpf_object__shndx_is_maps(obj, shndx) ||
+	       bpf_object__shndx_is_data(obj, shndx);
+}
+
+static enum libbpf_map_type
+bpf_object__section_to_libbpf_map_type(const struct bpf_object *obj, int shndx)
+{
+	if (shndx == obj->efile.data_shndx)
+		return LIBBPF_MAP_DATA;
+	else if (shndx == obj->efile.bss_shndx)
+		return LIBBPF_MAP_BSS;
+	else if (shndx == obj->efile.rodata_shndx)
+		return LIBBPF_MAP_RODATA;
+	else
+		return LIBBPF_MAP_UNSPEC;
+}
+
 static int
 bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr,
 			   Elf_Data *data, struct bpf_object *obj)
 {
 	Elf_Data *symbols = obj->efile.symbols;
-	int text_shndx = obj->efile.text_shndx;
-	int maps_shndx = obj->efile.maps_shndx;
 	struct bpf_map *maps = obj->maps;
 	size_t nr_maps = obj->nr_maps;
 	int i, nrels;
@@ -994,7 +1276,10 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr,
 		GElf_Sym sym;
 		GElf_Rel rel;
 		unsigned int insn_idx;
+		unsigned int shdr_idx;
 		struct bpf_insn *insns = prog->insns;
+		enum libbpf_map_type type;
+		const char *name;
 		size_t map_idx;
 
 		if (!gelf_getrel(data, i, &rel)) {
@@ -1009,13 +1294,18 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr,
 				   GELF_R_SYM(rel.r_info));
 			return -LIBBPF_ERRNO__FORMAT;
 		}
-		pr_debug("relo for %lld value %lld name %d\n",
+
+		name = elf_strptr(obj->efile.elf, obj->efile.strtabidx,
+				  sym.st_name) ? : "<?>";
+
+		pr_debug("relo for %lld value %lld name %d (\'%s\')\n",
 			 (long long) (rel.r_info >> 32),
-			 (long long) sym.st_value, sym.st_name);
+			 (long long) sym.st_value, sym.st_name, name);
 
-		if (sym.st_shndx != maps_shndx && sym.st_shndx != text_shndx) {
-			pr_warning("Program '%s' contains non-map related relo data pointing to section %u\n",
-				   prog->section_name, sym.st_shndx);
+		shdr_idx = sym.st_shndx;
+		if (!bpf_object__relo_in_known_section(obj, shdr_idx)) {
+			pr_warning("Program '%s' contains unrecognized relo data pointing to section %u\n",
+				   prog->section_name, shdr_idx);
 			return -LIBBPF_ERRNO__RELOC;
 		}
 
@@ -1040,24 +1330,39 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr,
 			return -LIBBPF_ERRNO__RELOC;
 		}
 
-		/* TODO: 'maps' is sorted. We can use bsearch to make it faster. */
-		for (map_idx = 0; map_idx < nr_maps; map_idx++) {
-			if (maps[map_idx].offset == sym.st_value) {
-				pr_debug("relocation: find map %zd (%s) for insn %u\n",
-					 map_idx, maps[map_idx].name, insn_idx);
-				break;
+		if (bpf_object__shndx_is_maps(obj, shdr_idx) ||
+		    bpf_object__shndx_is_data(obj, shdr_idx)) {
+			type = bpf_object__section_to_libbpf_map_type(obj, shdr_idx);
+			if (type != LIBBPF_MAP_UNSPEC &&
+			    GELF_ST_BIND(sym.st_info) == STB_GLOBAL) {
+				pr_warning("bpf: relocation: not yet supported relo for non-static global \'%s\' variable found in insns[%d].code 0x%x\n",
+					   name, insn_idx, insns[insn_idx].code);
+				return -LIBBPF_ERRNO__RELOC;
 			}
-		}
 
-		if (map_idx >= nr_maps) {
-			pr_warning("bpf relocation: map_idx %d large than %d\n",
-				   (int)map_idx, (int)nr_maps - 1);
-			return -LIBBPF_ERRNO__RELOC;
-		}
+			for (map_idx = 0; map_idx < nr_maps; map_idx++) {
+				if (maps[map_idx].libbpf_type != type)
+					continue;
+				if (type != LIBBPF_MAP_UNSPEC ||
+				    (type == LIBBPF_MAP_UNSPEC &&
+				     maps[map_idx].offset == sym.st_value)) {
+					pr_debug("relocation: find map %zd (%s) for insn %u\n",
+						 map_idx, maps[map_idx].name, insn_idx);
+					break;
+				}
+			}
+
+			if (map_idx >= nr_maps) {
+				pr_warning("bpf relocation: map_idx %d large than %d\n",
+					   (int)map_idx, (int)nr_maps - 1);
+				return -LIBBPF_ERRNO__RELOC;
+			}
 
-		prog->reloc_desc[i].type = RELO_LD64;
-		prog->reloc_desc[i].insn_idx = insn_idx;
-		prog->reloc_desc[i].map_idx = map_idx;
+			prog->reloc_desc[i].type = type != LIBBPF_MAP_UNSPEC ?
+						   RELO_DATA : RELO_LD64;
+			prog->reloc_desc[i].insn_idx = insn_idx;
+			prog->reloc_desc[i].map_idx = map_idx;
+		}
 	}
 	return 0;
 }
@@ -1065,18 +1370,27 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr,
 static int bpf_map_find_btf_info(struct bpf_map *map, const struct btf *btf)
 {
 	struct bpf_map_def *def = &map->def;
-	__u32 key_type_id, value_type_id;
+	__u32 key_type_id = 0, value_type_id = 0;
 	int ret;
 
-	ret = btf__get_map_kv_tids(btf, map->name, def->key_size,
-				   def->value_size, &key_type_id,
-				   &value_type_id);
-	if (ret)
+	if (!bpf_map__is_internal(map)) {
+		ret = btf__get_map_kv_tids(btf, map->name, def->key_size,
+					   def->value_size, &key_type_id,
+					   &value_type_id);
+	} else {
+		/*
+		 * LLVM annotates global data differently in BTF, that is,
+		 * only as '.data', '.bss' or '.rodata'.
+		 */
+		ret = btf__find_by_name(btf,
+				libbpf_type_to_btf_name[map->libbpf_type]);
+	}
+	if (ret < 0)
 		return ret;
 
 	map->btf_key_type_id = key_type_id;
-	map->btf_value_type_id = value_type_id;
-
+	map->btf_value_type_id = bpf_map__is_internal(map) ?
+				 ret : value_type_id;
 	return 0;
 }
 
@@ -1188,6 +1502,34 @@ bpf_object__probe_caps(struct bpf_object *obj)
 }
 
 static int
+bpf_object__populate_internal_map(struct bpf_object *obj, struct bpf_map *map)
+{
+	char *cp, errmsg[STRERR_BUFSIZE];
+	int err, zero = 0;
+	__u8 *data;
+
+	/* Nothing to do here since kernel already zero-initializes .bss map. */
+	if (map->libbpf_type == LIBBPF_MAP_BSS)
+		return 0;
+
+	data = map->libbpf_type == LIBBPF_MAP_DATA ?
+	       obj->sections.data : obj->sections.rodata;
+
+	err = bpf_map_update_elem(map->fd, &zero, data, 0);
+	/* Freeze .rodata map as read-only from syscall side. */
+	if (!err && map->libbpf_type == LIBBPF_MAP_RODATA) {
+		err = bpf_map_freeze(map->fd);
+		if (err) {
+			cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
+			pr_warning("Error freezing map(%s) as read-only: %s\n",
+				   map->name, cp);
+			err = 0;
+		}
+	}
+	return err;
+}
+
+static int
 bpf_object__create_maps(struct bpf_object *obj)
 {
 	struct bpf_create_map_attr create_attr = {};
@@ -1244,6 +1586,7 @@ bpf_object__create_maps(struct bpf_object *obj)
 			size_t j;
 
 			err = *pfd;
+err_out:
 			cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
 			pr_warning("failed to create map (name: '%s'): %s\n",
 				   map->name, cp);
@@ -1251,6 +1594,15 @@ bpf_object__create_maps(struct bpf_object *obj)
 				zclose(obj->maps[j].fd);
 			return err;
 		}
+
+		if (bpf_map__is_internal(map)) {
+			err = bpf_object__populate_internal_map(obj, map);
+			if (err < 0) {
+				zclose(*pfd);
+				goto err_out;
+			}
+		}
+
 		pr_debug("create map %s: fd=%d\n", map->name, *pfd);
 	}
 
@@ -1405,21 +1757,29 @@ bpf_program__relocate(struct bpf_program *prog, struct bpf_object *obj)
 		return 0;
 
 	for (i = 0; i < prog->nr_reloc; i++) {
-		if (prog->reloc_desc[i].type == RELO_LD64) {
+		if (prog->reloc_desc[i].type == RELO_LD64 ||
+		    prog->reloc_desc[i].type == RELO_DATA) {
+			bool relo_data = prog->reloc_desc[i].type == RELO_DATA;
 			struct bpf_insn *insns = prog->insns;
 			int insn_idx, map_idx;
 
 			insn_idx = prog->reloc_desc[i].insn_idx;
 			map_idx = prog->reloc_desc[i].map_idx;
 
-			if (insn_idx >= (int)prog->insns_cnt) {
+			if (insn_idx + 1 >= (int)prog->insns_cnt) {
 				pr_warning("relocation out of range: '%s'\n",
 					   prog->section_name);
 				return -LIBBPF_ERRNO__RELOC;
 			}
-			insns[insn_idx].src_reg = BPF_PSEUDO_MAP_FD;
+
+			if (!relo_data) {
+				insns[insn_idx].src_reg = BPF_PSEUDO_MAP_FD;
+			} else {
+				insns[insn_idx].src_reg = BPF_PSEUDO_MAP_VALUE;
+				insns[insn_idx + 1].imm = insns[insn_idx].imm;
+			}
 			insns[insn_idx].imm = obj->maps[map_idx].fd;
-		} else {
+		} else if (prog->reloc_desc[i].type == RELO_CALL) {
 			err = bpf_program__reloc_text(prog, obj,
 						      &prog->reloc_desc[i]);
 			if (err)
@@ -1494,6 +1854,7 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
 {
 	struct bpf_load_program_attr load_attr;
 	char *cp, errmsg[STRERR_BUFSIZE];
+	int log_buf_size = BPF_LOG_BUF_SIZE;
 	char *log_buf;
 	int ret;
 
@@ -1514,21 +1875,30 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
 	load_attr.line_info = prog->line_info;
 	load_attr.line_info_rec_size = prog->line_info_rec_size;
 	load_attr.line_info_cnt = prog->line_info_cnt;
+	load_attr.log_level = prog->log_level;
 	if (!load_attr.insns || !load_attr.insns_cnt)
 		return -EINVAL;
 
-	log_buf = malloc(BPF_LOG_BUF_SIZE);
+retry_load:
+	log_buf = malloc(log_buf_size);
 	if (!log_buf)
 		pr_warning("Alloc log buffer for bpf loader error, continue without log\n");
 
-	ret = bpf_load_program_xattr(&load_attr, log_buf, BPF_LOG_BUF_SIZE);
+	ret = bpf_load_program_xattr(&load_attr, log_buf, log_buf_size);
 
 	if (ret >= 0) {
+		if (load_attr.log_level)
+			pr_debug("verifier log:\n%s", log_buf);
 		*pfd = ret;
 		ret = 0;
 		goto out;
 	}
 
+	if (errno == ENOSPC) {
+		log_buf_size <<= 1;
+		free(log_buf);
+		goto retry_load;
+	}
 	ret = -LIBBPF_ERRNO__LOAD;
 	cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
 	pr_warning("load bpf program failed: %s\n", cp);
@@ -2303,6 +2673,9 @@ void bpf_object__close(struct bpf_object *obj)
 		obj->maps[i].priv = NULL;
 		obj->maps[i].clear_priv = NULL;
 	}
+
+	zfree(&obj->sections.rodata);
+	zfree(&obj->sections.data);
 	zfree(&obj->maps);
 	obj->nr_maps = 0;
 
@@ -2780,6 +3153,11 @@ bool bpf_map__is_offload_neutral(struct bpf_map *map)
 	return map->def.type == BPF_MAP_TYPE_PERF_EVENT_ARRAY;
 }
 
+bool bpf_map__is_internal(struct bpf_map *map)
+{
+	return map->libbpf_type != LIBBPF_MAP_UNSPEC;
+}
+
 void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex)
 {
 	map->map_ifindex = ifindex;
@@ -2938,6 +3316,7 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
 		bpf_program__set_expected_attach_type(prog,
 						      expected_attach_type);
 
+		prog->log_level = attr->log_level;
 		if (!first_prog)
 			first_prog = prog;
 	}