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

Alexei Starovoitov says:

====================
pull-request: bpf-next 2021-11-01

We've added 181 non-merge commits during the last 28 day(s) which contain
a total of 280 files changed, 11791 insertions(+), 5879 deletions(-).

The main changes are:

1) Fix bpf verifier propagation of 64-bit bounds, from Alexei.

2) Parallelize bpf test_progs, from Yucong and Andrii.

3) Deprecate various libbpf apis including af_xdp, from Andrii, Hengqi, Magnus.

4) Improve bpf selftests on s390, from Ilya.

5) bloomfilter bpf map type, from Joanne.

6) Big improvements to JIT tests especially on Mips, from Johan.

7) Support kernel module function calls from bpf, from Kumar.

8) Support typeless and weak ksym in light skeleton, from Kumar.

9) Disallow unprivileged bpf by default, from Pawan.

10) BTF_KIND_DECL_TAG support, from Yonghong.

11) Various bpftool cleanups, from Quentin.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (181 commits)
  libbpf: Deprecate AF_XDP support
  kbuild: Unify options for BTF generation for vmlinux and modules
  selftests/bpf: Add a testcase for 64-bit bounds propagation issue.
  bpf: Fix propagation of signed bounds from 64-bit min/max into 32-bit.
  bpf: Fix propagation of bounds from 64-bit min/max into 32-bit and var_off.
  selftests/bpf: Fix also no-alu32 strobemeta selftest
  bpf: Add missing map_delete_elem method to bloom filter map
  selftests/bpf: Add bloom map success test for userspace calls
  bpf: Add alignment padding for "map_extra" + consolidate holes
  bpf: Bloom filter map naming fixups
  selftests/bpf: Add test cases for struct_ops prog
  bpf: Add dummy BPF STRUCT_OPS for test purpose
  bpf: Factor out helpers for ctx access checking
  bpf: Factor out a helper to prepare trampoline for struct_ops prog
  selftests, bpf: Fix broken riscv build
  riscv, libbpf: Add RISC-V (RV64) support to bpf_tracing.h
  tools, build: Add RISC-V to HOSTARCH parsing
  riscv, bpf: Increase the maximum number of iterations
  selftests, bpf: Add one test for sockmap with strparser
  selftests, bpf: Fix test_txmsg_ingress_parser error
  ...
====================

Link: https://lore.kernel.org/r/20211102013123.9005-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 799 insertions, 442 deletions

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 8892f2f1bbcc..a1bea1953df6 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -195,8 +195,8 @@ enum kern_feature_id {
 	FEAT_BTF_FLOAT,
 	/* BPF perf link support */
 	FEAT_PERF_LINK,
-	/* BTF_KIND_TAG support */
-	FEAT_BTF_TAG,
+	/* BTF_KIND_DECL_TAG support */
+	FEAT_BTF_DECL_TAG,
 	__FEAT_CNT,
 };
 
@@ -285,7 +285,7 @@ struct bpf_program {
 	size_t sub_insn_off;
 
 	char *name;
-	/* sec_name with / replaced by _; makes recursive pinning
+	/* name with / replaced by _; makes recursive pinning
 	 * in bpf_object__pin_programs easier
 	 */
 	char *pin_name;
@@ -370,15 +370,14 @@ enum libbpf_map_type {
 	LIBBPF_MAP_KCONFIG,
 };
 
-static const char * const libbpf_type_to_btf_name[] = {
-	[LIBBPF_MAP_DATA]	= DATA_SEC,
-	[LIBBPF_MAP_BSS]	= BSS_SEC,
-	[LIBBPF_MAP_RODATA]	= RODATA_SEC,
-	[LIBBPF_MAP_KCONFIG]	= KCONFIG_SEC,
-};
-
 struct bpf_map {
 	char *name;
+	/* real_name is defined for special internal maps (.rodata*,
+	 * .data*, .bss, .kconfig) and preserves their original ELF section
+	 * name. This is important to be be able to find corresponding BTF
+	 * DATASEC information.
+	 */
+	char *real_name;
 	int fd;
 	int sec_idx;
 	size_t sec_offset;
@@ -401,6 +400,7 @@ struct bpf_map {
 	char *pin_path;
 	bool pinned;
 	bool reused;
+	__u64 map_extra;
 };
 
 enum extern_type {
@@ -443,6 +443,11 @@ struct extern_desc {
 
 			/* local btf_id of the ksym extern's type. */
 			__u32 type_id;
+			/* BTF fd index to be patched in for insn->off, this is
+			 * 0 for vmlinux BTF, index in obj->fd_array for module
+			 * BTF
+			 */
+			__s16 btf_fd_idx;
 		} ksym;
 	};
 };
@@ -454,6 +459,41 @@ struct module_btf {
 	char *name;
 	__u32 id;
 	int fd;
+	int fd_array_idx;
+};
+
+enum sec_type {
+	SEC_UNUSED = 0,
+	SEC_RELO,
+	SEC_BSS,
+	SEC_DATA,
+	SEC_RODATA,
+};
+
+struct elf_sec_desc {
+	enum sec_type sec_type;
+	Elf64_Shdr *shdr;
+	Elf_Data *data;
+};
+
+struct elf_state {
+	int fd;
+	const void *obj_buf;
+	size_t obj_buf_sz;
+	Elf *elf;
+	Elf64_Ehdr *ehdr;
+	Elf_Data *symbols;
+	Elf_Data *st_ops_data;
+	size_t shstrndx; /* section index for section name strings */
+	size_t strtabidx;
+	struct elf_sec_desc *secs;
+	int sec_cnt;
+	int maps_shndx;
+	int btf_maps_shndx;
+	__u32 btf_maps_sec_btf_id;
+	int text_shndx;
+	int symbols_shndx;
+	int st_ops_shndx;
 };
 
 struct bpf_object {
@@ -471,47 +511,17 @@ struct bpf_object {
 	struct extern_desc *externs;
 	int nr_extern;
 	int kconfig_map_idx;
-	int rodata_map_idx;
 
 	bool loaded;
 	bool has_subcalls;
+	bool has_rodata;
 
 	struct bpf_gen *gen_loader;
 
+	/* Information when doing ELF related work. Only valid if efile.elf is not NULL */
+	struct elf_state efile;
 	/*
-	 * Information when doing elf related work. Only valid if fd
-	 * is valid.
-	 */
-	struct {
-		int fd;
-		const void *obj_buf;
-		size_t obj_buf_sz;
-		Elf *elf;
-		GElf_Ehdr ehdr;
-		Elf_Data *symbols;
-		Elf_Data *data;
-		Elf_Data *rodata;
-		Elf_Data *bss;
-		Elf_Data *st_ops_data;
-		size_t shstrndx; /* section index for section name strings */
-		size_t strtabidx;
-		struct {
-			GElf_Shdr shdr;
-			Elf_Data *data;
-		} *reloc_sects;
-		int nr_reloc_sects;
-		int maps_shndx;
-		int btf_maps_shndx;
-		__u32 btf_maps_sec_btf_id;
-		int text_shndx;
-		int symbols_shndx;
-		int data_shndx;
-		int rodata_shndx;
-		int bss_shndx;
-		int st_ops_shndx;
-	} efile;
-	/*
-	 * All loaded bpf_object is linked in a list, which is
+	 * All loaded bpf_object are linked in a list, which is
 	 * hidden to caller. bpf_objects__<func> handlers deal with
 	 * all objects.
 	 */
@@ -539,17 +549,22 @@ struct bpf_object {
 	void *priv;
 	bpf_object_clear_priv_t clear_priv;
 
+	int *fd_array;
+	size_t fd_array_cap;
+	size_t fd_array_cnt;
+
 	char path[];
 };
-#define obj_elf_valid(o)	((o)->efile.elf)
 
 static const char *elf_sym_str(const struct bpf_object *obj, size_t off);
 static const char *elf_sec_str(const struct bpf_object *obj, size_t off);
 static Elf_Scn *elf_sec_by_idx(const struct bpf_object *obj, size_t idx);
 static Elf_Scn *elf_sec_by_name(const struct bpf_object *obj, const char *name);
-static int elf_sec_hdr(const struct bpf_object *obj, Elf_Scn *scn, GElf_Shdr *hdr);
+static Elf64_Shdr *elf_sec_hdr(const struct bpf_object *obj, Elf_Scn *scn);
 static const char *elf_sec_name(const struct bpf_object *obj, Elf_Scn *scn);
 static Elf_Data *elf_sec_data(const struct bpf_object *obj, Elf_Scn *scn);
+static Elf64_Sym *elf_sym_by_idx(const struct bpf_object *obj, size_t idx);
+static Elf64_Rel *elf_rel_by_idx(Elf_Data *data, size_t idx);
 
 void bpf_program__unload(struct bpf_program *prog)
 {
@@ -604,7 +619,16 @@ static char *__bpf_program__pin_name(struct bpf_program *prog)
 {
 	char *name, *p;
 
-	name = p = strdup(prog->sec_name);
+	if (libbpf_mode & LIBBPF_STRICT_SEC_NAME)
+		name = strdup(prog->name);
+	else
+		name = strdup(prog->sec_name);
+
+	if (!name)
+		return NULL;
+
+	p = name;
+
 	while ((p = strchr(p, '/')))
 		*p = '_';
 
@@ -691,25 +715,25 @@ bpf_object__add_programs(struct bpf_object *obj, Elf_Data *sec_data,
 	size_t sec_sz = sec_data->d_size, sec_off, prog_sz, nr_syms;
 	int nr_progs, err, i;
 	const char *name;
-	GElf_Sym sym;
+	Elf64_Sym *sym;
 
 	progs = obj->programs;
 	nr_progs = obj->nr_programs;
-	nr_syms = symbols->d_size / sizeof(GElf_Sym);
+	nr_syms = symbols->d_size / sizeof(Elf64_Sym);
 	sec_off = 0;
 
 	for (i = 0; i < nr_syms; i++) {
-		if (!gelf_getsym(symbols, i, &sym))
-			continue;
-		if (sym.st_shndx != sec_idx)
+		sym = elf_sym_by_idx(obj, i);
+
+		if (sym->st_shndx != sec_idx)
 			continue;
-		if (GELF_ST_TYPE(sym.st_info) != STT_FUNC)
+		if (ELF64_ST_TYPE(sym->st_info) != STT_FUNC)
 			continue;
 
-		prog_sz = sym.st_size;
-		sec_off = sym.st_value;
+		prog_sz = sym->st_size;
+		sec_off = sym->st_value;
 
-		name = elf_sym_str(obj, sym.st_name);
+		name = elf_sym_str(obj, sym->st_name);
 		if (!name) {
 			pr_warn("sec '%s': failed to get symbol name for offset %zu\n",
 				sec_name, sec_off);
@@ -722,7 +746,7 @@ bpf_object__add_programs(struct bpf_object *obj, Elf_Data *sec_data,
 			return -LIBBPF_ERRNO__FORMAT;
 		}
 
-		if (sec_idx != obj->efile.text_shndx && GELF_ST_BIND(sym.st_info) == STB_LOCAL) {
+		if (sec_idx != obj->efile.text_shndx && ELF64_ST_BIND(sym->st_info) == STB_LOCAL) {
 			pr_warn("sec '%s': program '%s' is static and not supported\n", sec_name, name);
 			return -ENOTSUP;
 		}
@@ -755,9 +779,9 @@ bpf_object__add_programs(struct bpf_object *obj, Elf_Data *sec_data,
 		 * as static to enable more permissive BPF verification mode
 		 * with more outside context available to BPF verifier
 		 */
-		if (GELF_ST_BIND(sym.st_info) != STB_LOCAL
-		    && (GELF_ST_VISIBILITY(sym.st_other) == STV_HIDDEN
-			|| GELF_ST_VISIBILITY(sym.st_other) == STV_INTERNAL))
+		if (ELF64_ST_BIND(sym->st_info) != STB_LOCAL
+		    && (ELF64_ST_VISIBILITY(sym->st_other) == STV_HIDDEN
+			|| ELF64_ST_VISIBILITY(sym->st_other) == STV_INTERNAL))
 			prog->mark_btf_static = true;
 
 		nr_progs++;
@@ -1125,6 +1149,7 @@ static struct bpf_object *bpf_object__new(const char *path,
 					  size_t obj_buf_sz,
 					  const char *obj_name)
 {
+	bool strict = (libbpf_mode & LIBBPF_STRICT_NO_OBJECT_LIST);
 	struct bpf_object *obj;
 	char *end;
 
@@ -1158,24 +1183,21 @@ static struct bpf_object *bpf_object__new(const char *path,
 	obj->efile.obj_buf_sz = obj_buf_sz;
 	obj->efile.maps_shndx = -1;
 	obj->efile.btf_maps_shndx = -1;
-	obj->efile.data_shndx = -1;
-	obj->efile.rodata_shndx = -1;
-	obj->efile.bss_shndx = -1;
 	obj->efile.st_ops_shndx = -1;
 	obj->kconfig_map_idx = -1;
-	obj->rodata_map_idx = -1;
 
 	obj->kern_version = get_kernel_version();
 	obj->loaded = false;
 
 	INIT_LIST_HEAD(&obj->list);
-	list_add(&obj->list, &bpf_objects_list);
+	if (!strict)
+		list_add(&obj->list, &bpf_objects_list);
 	return obj;
 }
 
 static void bpf_object__elf_finish(struct bpf_object *obj)
 {
-	if (!obj_elf_valid(obj))
+	if (!obj->efile.elf)
 		return;
 
 	if (obj->efile.elf) {
@@ -1183,13 +1205,10 @@ 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;
 	obj->efile.st_ops_data = NULL;
 
-	zfree(&obj->efile.reloc_sects);
-	obj->efile.nr_reloc_sects = 0;
+	zfree(&obj->efile.secs);
+	obj->efile.sec_cnt = 0;
 	zclose(obj->efile.fd);
 	obj->efile.obj_buf = NULL;
 	obj->efile.obj_buf_sz = 0;
@@ -1197,10 +1216,11 @@ static void bpf_object__elf_finish(struct bpf_object *obj)
 
 static int bpf_object__elf_init(struct bpf_object *obj)
 {
+	Elf64_Ehdr *ehdr;
 	int err = 0;
-	GElf_Ehdr *ep;
+	Elf *elf;
 
-	if (obj_elf_valid(obj)) {
+	if (obj->efile.elf) {
 		pr_warn("elf: init internal error\n");
 		return -LIBBPF_ERRNO__LIBELF;
 	}
@@ -1210,10 +1230,9 @@ static int bpf_object__elf_init(struct bpf_object *obj)
 		 * obj_buf should have been validated by
 		 * bpf_object__open_buffer().
 		 */
-		obj->efile.elf = elf_memory((char *)obj->efile.obj_buf,
-					    obj->efile.obj_buf_sz);
+		elf = elf_memory((char *)obj->efile.obj_buf, obj->efile.obj_buf_sz);
 	} else {
-		obj->efile.fd = open(obj->path, O_RDONLY);
+		obj->efile.fd = open(obj->path, O_RDONLY | O_CLOEXEC);
 		if (obj->efile.fd < 0) {
 			char errmsg[STRERR_BUFSIZE], *cp;
 
@@ -1223,23 +1242,37 @@ static int bpf_object__elf_init(struct bpf_object *obj)
 			return err;
 		}
 
-		obj->efile.elf = elf_begin(obj->efile.fd, ELF_C_READ_MMAP, NULL);
+		elf = elf_begin(obj->efile.fd, ELF_C_READ_MMAP, NULL);
 	}
 
-	if (!obj->efile.elf) {
+	if (!elf) {
 		pr_warn("elf: failed to open %s as ELF file: %s\n", obj->path, elf_errmsg(-1));
 		err = -LIBBPF_ERRNO__LIBELF;
 		goto errout;
 	}
 
-	if (!gelf_getehdr(obj->efile.elf, &obj->efile.ehdr)) {
+	obj->efile.elf = elf;
+
+	if (elf_kind(elf) != ELF_K_ELF) {
+		err = -LIBBPF_ERRNO__FORMAT;
+		pr_warn("elf: '%s' is not a proper ELF object\n", obj->path);
+		goto errout;
+	}
+
+	if (gelf_getclass(elf) != ELFCLASS64) {
+		err = -LIBBPF_ERRNO__FORMAT;
+		pr_warn("elf: '%s' is not a 64-bit ELF object\n", obj->path);
+		goto errout;
+	}
+
+	obj->efile.ehdr = ehdr = elf64_getehdr(elf);
+	if (!obj->efile.ehdr) {
 		pr_warn("elf: failed to get ELF header from %s: %s\n", obj->path, elf_errmsg(-1));
 		err = -LIBBPF_ERRNO__FORMAT;
 		goto errout;
 	}
-	ep = &obj->efile.ehdr;
 
-	if (elf_getshdrstrndx(obj->efile.elf, &obj->efile.shstrndx)) {
+	if (elf_getshdrstrndx(elf, &obj->efile.shstrndx)) {
 		pr_warn("elf: failed to get section names section index for %s: %s\n",
 			obj->path, elf_errmsg(-1));
 		err = -LIBBPF_ERRNO__FORMAT;
@@ -1247,7 +1280,7 @@ static int bpf_object__elf_init(struct bpf_object *obj)
 	}
 
 	/* Elf is corrupted/truncated, avoid calling elf_strptr. */
-	if (!elf_rawdata(elf_getscn(obj->efile.elf, obj->efile.shstrndx), NULL)) {
+	if (!elf_rawdata(elf_getscn(elf, obj->efile.shstrndx), NULL)) {
 		pr_warn("elf: failed to get section names strings from %s: %s\n",
 			obj->path, elf_errmsg(-1));
 		err = -LIBBPF_ERRNO__FORMAT;
@@ -1255,8 +1288,7 @@ static int bpf_object__elf_init(struct bpf_object *obj)
 	}
 
 	/* Old LLVM set e_machine to EM_NONE */
-	if (ep->e_type != ET_REL ||
-	    (ep->e_machine && ep->e_machine != EM_BPF)) {
+	if (ehdr->e_type != ET_REL || (ehdr->e_machine && ehdr->e_machine != EM_BPF)) {
 		pr_warn("elf: %s is not a valid eBPF object file\n", obj->path);
 		err = -LIBBPF_ERRNO__FORMAT;
 		goto errout;
@@ -1270,11 +1302,11 @@ errout:
 
 static int bpf_object__check_endianness(struct bpf_object *obj)
 {
-#if __BYTE_ORDER == __LITTLE_ENDIAN
-	if (obj->efile.ehdr.e_ident[EI_DATA] == ELFDATA2LSB)
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+	if (obj->efile.ehdr->e_ident[EI_DATA] == ELFDATA2LSB)
 		return 0;
-#elif __BYTE_ORDER == __BIG_ENDIAN
-	if (obj->efile.ehdr.e_ident[EI_DATA] == ELFDATA2MSB)
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+	if (obj->efile.ehdr->e_ident[EI_DATA] == ELFDATA2MSB)
 		return 0;
 #else
 # error "Unrecognized __BYTE_ORDER__"
@@ -1314,41 +1346,27 @@ static bool bpf_map_type__is_map_in_map(enum bpf_map_type type)
 	return false;
 }
 
-int bpf_object__section_size(const struct bpf_object *obj, const char *name,
-			     __u32 *size)
+static int find_elf_sec_sz(const struct bpf_object *obj, const char *name, __u32 *size)
 {
 	int ret = -ENOENT;
+	Elf_Data *data;
+	Elf_Scn *scn;
 
 	*size = 0;
-	if (!name) {
+	if (!name)
 		return -EINVAL;
-	} else if (!strcmp(name, DATA_SEC)) {
-		if (obj->efile.data)
-			*size = obj->efile.data->d_size;
-	} else if (!strcmp(name, BSS_SEC)) {
-		if (obj->efile.bss)
-			*size = obj->efile.bss->d_size;
-	} else if (!strcmp(name, RODATA_SEC)) {
-		if (obj->efile.rodata)
-			*size = obj->efile.rodata->d_size;
-	} else if (!strcmp(name, STRUCT_OPS_SEC)) {
-		if (obj->efile.st_ops_data)
-			*size = obj->efile.st_ops_data->d_size;
-	} else {
-		Elf_Scn *scn = elf_sec_by_name(obj, name);
-		Elf_Data *data = elf_sec_data(obj, scn);
 
-		if (data) {
-			ret = 0; /* found it */
-			*size = data->d_size;
-		}
+	scn = elf_sec_by_name(obj, name);
+	data = elf_sec_data(obj, scn);
+	if (data) {
+		ret = 0; /* found it */
+		*size = data->d_size;
 	}
 
 	return *size ? 0 : ret;
 }
 
-int bpf_object__variable_offset(const struct bpf_object *obj, const char *name,
-				__u32 *off)
+static int find_elf_var_offset(const struct bpf_object *obj, const char *name, __u32 *off)
 {
 	Elf_Data *symbols = obj->efile.symbols;
 	const char *sname;
@@ -1357,23 +1375,20 @@ int bpf_object__variable_offset(const struct bpf_object *obj, const char *name,
 	if (!name || !off)
 		return -EINVAL;
 
-	for (si = 0; si < symbols->d_size / sizeof(GElf_Sym); si++) {
-		GElf_Sym sym;
+	for (si = 0; si < symbols->d_size / sizeof(Elf64_Sym); si++) {
+		Elf64_Sym *sym = elf_sym_by_idx(obj, si);
 
-		if (!gelf_getsym(symbols, si, &sym))
-			continue;
-		if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL ||
-		    GELF_ST_TYPE(sym.st_info) != STT_OBJECT)
+		if (ELF64_ST_BIND(sym->st_info) != STB_GLOBAL ||
+		    ELF64_ST_TYPE(sym->st_info) != STT_OBJECT)
 			continue;
 
-		sname = elf_sym_str(obj, sym.st_name);
+		sname = elf_sym_str(obj, sym->st_name);
 		if (!sname) {
-			pr_warn("failed to get sym name string for var %s\n",
-				name);
+			pr_warn("failed to get sym name string for var %s\n", name);
 			return -EIO;
 		}
 		if (strcmp(name, sname) == 0) {
-			*off = sym.st_value;
+			*off = sym->st_value;
 			return 0;
 		}
 	}
@@ -1425,17 +1440,55 @@ static size_t bpf_map_mmap_sz(const struct bpf_map *map)
 	return map_sz;
 }
 
-static char *internal_map_name(struct bpf_object *obj,
-			       enum libbpf_map_type type)
+static char *internal_map_name(struct bpf_object *obj, const char *real_name)
 {
 	char map_name[BPF_OBJ_NAME_LEN], *p;
-	const char *sfx = libbpf_type_to_btf_name[type];
-	int sfx_len = max((size_t)7, strlen(sfx));
-	int pfx_len = min((size_t)BPF_OBJ_NAME_LEN - sfx_len - 1,
-			  strlen(obj->name));
+	int pfx_len, sfx_len = max((size_t)7, strlen(real_name));
+
+	/* This is one of the more confusing parts of libbpf for various
+	 * reasons, some of which are historical. The original idea for naming
+	 * internal names was to include as much of BPF object name prefix as
+	 * possible, so that it can be distinguished from similar internal
+	 * maps of a different BPF object.
+	 * As an example, let's say we have bpf_object named 'my_object_name'
+	 * and internal map corresponding to '.rodata' ELF section. The final
+	 * map name advertised to user and to the kernel will be
+	 * 'my_objec.rodata', taking first 8 characters of object name and
+	 * entire 7 characters of '.rodata'.
+	 * Somewhat confusingly, if internal map ELF section name is shorter
+	 * than 7 characters, e.g., '.bss', we still reserve 7 characters
+	 * for the suffix, even though we only have 4 actual characters, and
+	 * resulting map will be called 'my_objec.bss', not even using all 15
+	 * characters allowed by the kernel. Oh well, at least the truncated
+	 * object name is somewhat consistent in this case. But if the map
+	 * name is '.kconfig', we'll still have entirety of '.kconfig' added
+	 * (8 chars) and thus will be left with only first 7 characters of the
+	 * object name ('my_obje'). Happy guessing, user, that the final map
+	 * name will be "my_obje.kconfig".
+	 * Now, with libbpf starting to support arbitrarily named .rodata.*
+	 * and .data.* data sections, it's possible that ELF section name is
+	 * longer than allowed 15 chars, so we now need to be careful to take
+	 * only up to 15 first characters of ELF name, taking no BPF object
+	 * name characters at all. So '.rodata.abracadabra' will result in
+	 * '.rodata.abracad' kernel and user-visible name.
+	 * We need to keep this convoluted logic intact for .data, .bss and
+	 * .rodata maps, but for new custom .data.custom and .rodata.custom
+	 * maps we use their ELF names as is, not prepending bpf_object name
+	 * in front. We still need to truncate them to 15 characters for the
+	 * kernel. Full name can be recovered for such maps by using DATASEC
+	 * BTF type associated with such map's value type, though.
+	 */
+	if (sfx_len >= BPF_OBJ_NAME_LEN)
+		sfx_len = BPF_OBJ_NAME_LEN - 1;
+
+	/* if there are two or more dots in map name, it's a custom dot map */
+	if (strchr(real_name + 1, '.') != NULL)
+		pfx_len = 0;
+	else
+		pfx_len = min((size_t)BPF_OBJ_NAME_LEN - sfx_len - 1, strlen(obj->name));
 
 	snprintf(map_name, sizeof(map_name), "%.*s%.*s", pfx_len, obj->name,
-		 sfx_len, libbpf_type_to_btf_name[type]);
+		 sfx_len, real_name);
 
 	/* sanitise map name to characters allowed by kernel */
 	for (p = map_name; *p && p < map_name + sizeof(map_name); p++)
@@ -1447,7 +1500,7 @@ static char *internal_map_name(struct bpf_object *obj,
 
 static int
 bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
-			      int sec_idx, void *data, size_t data_sz)
+			      const char *real_name, int sec_idx, void *data, size_t data_sz)
 {
 	struct bpf_map_def *def;
 	struct bpf_map *map;
@@ -1460,9 +1513,11 @@ bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
 	map->libbpf_type = type;
 	map->sec_idx = sec_idx;
 	map->sec_offset = 0;
-	map->name = internal_map_name(obj, type);
-	if (!map->name) {
-		pr_warn("failed to alloc map name\n");
+	map->real_name = strdup(real_name);
+	map->name = internal_map_name(obj, real_name);
+	if (!map->real_name || !map->name) {
+		zfree(&map->real_name);
+		zfree(&map->name);
 		return -ENOMEM;
 	}
 
@@ -1485,6 +1540,7 @@ bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
 		map->mmaped = NULL;
 		pr_warn("failed to alloc map '%s' content buffer: %d\n",
 			map->name, err);
+		zfree(&map->real_name);
 		zfree(&map->name);
 		return err;
 	}
@@ -1498,34 +1554,43 @@ bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
 
 static int bpf_object__init_global_data_maps(struct bpf_object *obj)
 {
-	int err;
+	struct elf_sec_desc *sec_desc;
+	const char *sec_name;
+	int err = 0, sec_idx;
 
 	/*
 	 * Populate obj->maps with libbpf internal maps.
 	 */
-	if (obj->efile.data_shndx >= 0) {
-		err = bpf_object__init_internal_map(obj, LIBBPF_MAP_DATA,
-						    obj->efile.data_shndx,
-						    obj->efile.data->d_buf,
-						    obj->efile.data->d_size);
-		if (err)
-			return err;
-	}
-	if (obj->efile.rodata_shndx >= 0) {
-		err = bpf_object__init_internal_map(obj, LIBBPF_MAP_RODATA,
-						    obj->efile.rodata_shndx,
-						    obj->efile.rodata->d_buf,
-						    obj->efile.rodata->d_size);
-		if (err)
-			return err;
-
-		obj->rodata_map_idx = obj->nr_maps - 1;
-	}
-	if (obj->efile.bss_shndx >= 0) {
-		err = bpf_object__init_internal_map(obj, LIBBPF_MAP_BSS,
-						    obj->efile.bss_shndx,
-						    NULL,
-						    obj->efile.bss->d_size);
+	for (sec_idx = 1; sec_idx < obj->efile.sec_cnt; sec_idx++) {
+		sec_desc = &obj->efile.secs[sec_idx];
+
+		switch (sec_desc->sec_type) {
+		case SEC_DATA:
+			sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, sec_idx));
+			err = bpf_object__init_internal_map(obj, LIBBPF_MAP_DATA,
+							    sec_name, sec_idx,
+							    sec_desc->data->d_buf,
+							    sec_desc->data->d_size);
+			break;
+		case SEC_RODATA:
+			obj->has_rodata = true;
+			sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, sec_idx));
+			err = bpf_object__init_internal_map(obj, LIBBPF_MAP_RODATA,
+							    sec_name, sec_idx,
+							    sec_desc->data->d_buf,
+							    sec_desc->data->d_size);
+			break;
+		case SEC_BSS:
+			sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, sec_idx));
+			err = bpf_object__init_internal_map(obj, LIBBPF_MAP_BSS,
+							    sec_name, sec_idx,
+							    NULL,
+							    sec_desc->data->d_size);
+			break;
+		default:
+			/* skip */
+			break;
+		}
 		if (err)
 			return err;
 	}
@@ -1822,7 +1887,7 @@ static int bpf_object__init_kconfig_map(struct bpf_object *obj)
 
 	map_sz = last_ext->kcfg.data_off + last_ext->kcfg.sz;
 	err = bpf_object__init_internal_map(obj, LIBBPF_MAP_KCONFIG,
-					    obj->efile.symbols_shndx,
+					    ".kconfig", obj->efile.symbols_shndx,
 					    NULL, map_sz);
 	if (err)
 		return err;
@@ -1860,15 +1925,13 @@ static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict)
 	 *
 	 * TODO: Detect array of map and report error.
 	 */
-	nr_syms = symbols->d_size / sizeof(GElf_Sym);
+	nr_syms = symbols->d_size / sizeof(Elf64_Sym);
 	for (i = 0; i < nr_syms; i++) {
-		GElf_Sym sym;
+		Elf64_Sym *sym = elf_sym_by_idx(obj, i);
 
-		if (!gelf_getsym(symbols, i, &sym))
+		if (sym->st_shndx != obj->efile.maps_shndx)
 			continue;
-		if (sym.st_shndx != obj->efile.maps_shndx)
-			continue;
-		if (GELF_ST_TYPE(sym.st_info) == STT_SECTION)
+		if (ELF64_ST_TYPE(sym->st_info) == STT_SECTION)
 			continue;
 		nr_maps++;
 	}
@@ -1885,40 +1948,38 @@ static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict)
 
 	/* Fill obj->maps using data in "maps" section.  */
 	for (i = 0; i < nr_syms; i++) {
-		GElf_Sym sym;
+		Elf64_Sym *sym = elf_sym_by_idx(obj, i);
 		const char *map_name;
 		struct bpf_map_def *def;
 		struct bpf_map *map;
 
-		if (!gelf_getsym(symbols, i, &sym))
-			continue;
-		if (sym.st_shndx != obj->efile.maps_shndx)
+		if (sym->st_shndx != obj->efile.maps_shndx)
 			continue;
-		if (GELF_ST_TYPE(sym.st_info) == STT_SECTION)
+		if (ELF64_ST_TYPE(sym->st_info) == STT_SECTION)
 			continue;
 
 		map = bpf_object__add_map(obj);
 		if (IS_ERR(map))
 			return PTR_ERR(map);
 
-		map_name = elf_sym_str(obj, sym.st_name);
+		map_name = elf_sym_str(obj, sym->st_name);
 		if (!map_name) {
 			pr_warn("failed to get map #%d name sym string for obj %s\n",
 				i, obj->path);
 			return -LIBBPF_ERRNO__FORMAT;
 		}
 
-		if (GELF_ST_BIND(sym.st_info) == STB_LOCAL) {
+		if (ELF64_ST_BIND(sym->st_info) == STB_LOCAL) {
 			pr_warn("map '%s' (legacy): static maps are not supported\n", map_name);
 			return -ENOTSUP;
 		}
 
 		map->libbpf_type = LIBBPF_MAP_UNSPEC;
-		map->sec_idx = sym.st_shndx;
-		map->sec_offset = sym.st_value;
+		map->sec_idx = sym->st_shndx;
+		map->sec_offset = sym->st_value;
 		pr_debug("map '%s' (legacy): at sec_idx %d, offset %zu.\n",
 			 map_name, map->sec_idx, map->sec_offset);
-		if (sym.st_value + map_def_sz > data->d_size) {
+		if (sym->st_value + map_def_sz > data->d_size) {
 			pr_warn("corrupted maps section in %s: last map \"%s\" too small\n",
 				obj->path, map_name);
 			return -EINVAL;
@@ -1926,11 +1987,11 @@ static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict)
 
 		map->name = strdup(map_name);
 		if (!map->name) {
-			pr_warn("failed to alloc map name\n");
+			pr_warn("map '%s': failed to alloc map name\n", map_name);
 			return -ENOMEM;
 		}
 		pr_debug("map %d is \"%s\"\n", i, map->name);
-		def = (struct bpf_map_def *)(data->d_buf + sym.st_value);
+		def = (struct bpf_map_def *)(data->d_buf + sym->st_value);
 		/*
 		 * If the definition of the map in the object file fits in
 		 * bpf_map_def, copy it.  Any extra fields in our version
@@ -2014,7 +2075,7 @@ static const char *__btf_kind_str(__u16 kind)
 	case BTF_KIND_VAR: return "var";
 	case BTF_KIND_DATASEC: return "datasec";
 	case BTF_KIND_FLOAT: return "float";
-	case BTF_KIND_TAG: return "tag";
+	case BTF_KIND_DECL_TAG: return "decl_tag";
 	default: return "unknown";
 	}
 }
@@ -2264,6 +2325,13 @@ int parse_btf_map_def(const char *map_name, struct btf *btf,
 			}
 			map_def->pinning = val;
 			map_def->parts |= MAP_DEF_PINNING;
+		} else if (strcmp(name, "map_extra") == 0) {
+			__u32 map_extra;
+
+			if (!get_map_field_int(map_name, btf, m, &map_extra))
+				return -EINVAL;
+			map_def->map_extra = map_extra;
+			map_def->parts |= MAP_DEF_MAP_EXTRA;
 		} else {
 			if (strict) {
 				pr_warn("map '%s': unknown field '%s'.\n", map_name, name);
@@ -2288,6 +2356,7 @@ static void fill_map_from_def(struct bpf_map *map, const struct btf_map_def *def
 	map->def.value_size = def->value_size;
 	map->def.max_entries = def->max_entries;
 	map->def.map_flags = def->map_flags;
+	map->map_extra = def->map_extra;
 
 	map->numa_node = def->numa_node;
 	map->btf_key_type_id = def->key_type_id;
@@ -2311,7 +2380,10 @@ static void fill_map_from_def(struct bpf_map *map, const struct btf_map_def *def
 	if (def->parts & MAP_DEF_MAX_ENTRIES)
 		pr_debug("map '%s': found max_entries = %u.\n", map->name, def->max_entries);
 	if (def->parts & MAP_DEF_MAP_FLAGS)
-		pr_debug("map '%s': found map_flags = %u.\n", map->name, def->map_flags);
+		pr_debug("map '%s': found map_flags = 0x%x.\n", map->name, def->map_flags);
+	if (def->parts & MAP_DEF_MAP_EXTRA)
+		pr_debug("map '%s': found map_extra = 0x%llx.\n", map->name,
+			 (unsigned long long)def->map_extra);
 	if (def->parts & MAP_DEF_PINNING)
 		pr_debug("map '%s': found pinning = %u.\n", map->name, def->pinning);
 	if (def->parts & MAP_DEF_NUMA_NODE)
@@ -2448,8 +2520,8 @@ static int bpf_object__init_user_btf_maps(struct bpf_object *obj, bool strict,
 		return -EINVAL;
 	}
 
-	nr_types = btf__get_nr_types(obj->btf);
-	for (i = 1; i <= nr_types; i++) {
+	nr_types = btf__type_cnt(obj->btf);
+	for (i = 1; i < nr_types; i++) {
 		t = btf__type_by_id(obj->btf, i);
 		if (!btf_is_datasec(t))
 			continue;
@@ -2500,12 +2572,13 @@ static int bpf_object__init_maps(struct bpf_object *obj,
 
 static bool section_have_execinstr(struct bpf_object *obj, int idx)
 {
-	GElf_Shdr sh;
+	Elf64_Shdr *sh;
 
-	if (elf_sec_hdr(obj, elf_sec_by_idx(obj, idx), &sh))
+	sh = elf_sec_hdr(obj, elf_sec_by_idx(obj, idx));
+	if (!sh)
 		return false;
 
-	return sh.sh_flags & SHF_EXECINSTR;
+	return sh->sh_flags & SHF_EXECINSTR;
 }
 
 static bool btf_needs_sanitization(struct bpf_object *obj)
@@ -2514,9 +2587,9 @@ static bool btf_needs_sanitization(struct bpf_object *obj)
 	bool has_datasec = kernel_supports(obj, FEAT_BTF_DATASEC);
 	bool has_float = kernel_supports(obj, FEAT_BTF_FLOAT);
 	bool has_func = kernel_supports(obj, FEAT_BTF_FUNC);
-	bool has_tag = kernel_supports(obj, FEAT_BTF_TAG);
+	bool has_decl_tag = kernel_supports(obj, FEAT_BTF_DECL_TAG);
 
-	return !has_func || !has_datasec || !has_func_global || !has_float || !has_tag;
+	return !has_func || !has_datasec || !has_func_global || !has_float || !has_decl_tag;
 }
 
 static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf)
@@ -2525,15 +2598,15 @@ static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf)
 	bool has_datasec = kernel_supports(obj, FEAT_BTF_DATASEC);
 	bool has_float = kernel_supports(obj, FEAT_BTF_FLOAT);
 	bool has_func = kernel_supports(obj, FEAT_BTF_FUNC);
-	bool has_tag = kernel_supports(obj, FEAT_BTF_TAG);
+	bool has_decl_tag = kernel_supports(obj, FEAT_BTF_DECL_TAG);
 	struct btf_type *t;
 	int i, j, vlen;
 
-	for (i = 1; i <= btf__get_nr_types(btf); i++) {
+	for (i = 1; i < btf__type_cnt(btf); i++) {
 		t = (struct btf_type *)btf__type_by_id(btf, i);
 
-		if ((!has_datasec && btf_is_var(t)) || (!has_tag && btf_is_tag(t))) {
-			/* replace VAR/TAG with INT */
+		if ((!has_datasec && btf_is_var(t)) || (!has_decl_tag && btf_is_decl_tag(t))) {
+			/* replace VAR/DECL_TAG with INT */
 			t->info = BTF_INFO_ENC(BTF_KIND_INT, 0, 0);
 			/*
 			 * using size = 1 is the safest choice, 4 will be too
@@ -2640,6 +2713,104 @@ out:
 	return 0;
 }
 
+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_vlen(t);
+	const char *name = btf__name_by_offset(btf, t->name_off);
+	const struct btf_type *t_var;
+	struct btf_var_secinfo *vsi;
+	const struct btf_var *var;
+	int ret;
+
+	if (!name) {
+		pr_debug("No name found in string section for DATASEC kind.\n");
+		return -ENOENT;
+	}
+
+	/* .extern datasec size and var offsets were set correctly during
+	 * extern collection step, so just skip straight to sorting variables
+	 */
+	if (t->size)
+		goto sort_vars;
+
+	ret = find_elf_sec_sz(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 = btf_var_secinfos(t); i < vars; i++, vsi++) {
+		t_var = btf__type_by_id(btf, vsi->type);
+		var = btf_var(t_var);
+
+		if (!btf_is_var(t_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 = find_elf_var_offset(obj, name, &off);
+		if (ret) {
+			pr_debug("No offset found in symbol table for VAR %s\n",
+				 name);
+			return -ENOENT;
+		}
+
+		vsi->offset = off;
+	}
+
+sort_vars:
+	qsort(btf_var_secinfos(t), vars, sizeof(*vsi), compare_vsi_off);
+	return 0;
+}
+
+static int btf_finalize_data(struct bpf_object *obj, struct btf *btf)
+{
+	int err = 0;
+	__u32 i, n = btf__type_cnt(btf);
+
+	for (i = 1; i < n; i++) {
+		struct btf_type *t = btf_type_by_id(btf, 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_is_datasec(t)) {
+			err = btf_fixup_datasec(obj, btf, t);
+			if (err)
+				break;
+		}
+	}
+
+	return libbpf_err(err);
+}
+
+int btf__finalize_data(struct bpf_object *obj, struct btf *btf)
+{
+	return btf_finalize_data(obj, btf);
+}
+
 static int bpf_object__finalize_btf(struct bpf_object *obj)
 {
 	int err;
@@ -2647,7 +2818,7 @@ static int bpf_object__finalize_btf(struct bpf_object *obj)
 	if (!obj->btf)
 		return 0;
 
-	err = btf__finalize_data(obj, obj->btf);
+	err = btf_finalize_data(obj, obj->btf);
 	if (err) {
 		pr_warn("Error finalizing %s: %d.\n", BTF_ELF_SEC, err);
 		return err;
@@ -2757,8 +2928,8 @@ static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj)
 		if (!prog->mark_btf_static || !prog_is_subprog(obj, prog))
 			con