Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Alexei Starovoitov says:

====================
pull-request: bpf-next 2024-03-11

We've added 59 non-merge commits during the last 9 day(s) which contain
a total of 88 files changed, 4181 insertions(+), 590 deletions(-).

The main changes are:

1) Enforce VM_IOREMAP flag and range in ioremap_page_range and introduce
   VM_SPARSE kind and vm_area_[un]map_pages to be used in bpf_arena,
   from Alexei.

2) Introduce bpf_arena which is sparse shared memory region between bpf
   program and user space where structures inside the arena can have
   pointers to other areas of the arena, and pointers work seamlessly for
   both user-space programs and bpf programs, from Alexei and Andrii.

3) Introduce may_goto instruction that is a contract between the verifier
   and the program. The verifier allows the program to loop assuming it's
   behaving well, but reserves the right to terminate it, from Alexei.

4) Use IETF format for field definitions in the BPF standard
   document, from Dave.

5) Extend struct_ops libbpf APIs to allow specify version suffixes for
   stuct_ops map types, share the same BPF program between several map
   definitions, and other improvements, from Eduard.

6) Enable struct_ops support for more than one page in trampolines,
   from Kui-Feng.

7) Support kCFI + BPF on riscv64, from Puranjay.

8) Use bpf_prog_pack for arm64 bpf trampoline, from Puranjay.

9) Fix roundup_pow_of_two undefined behavior on 32-bit archs, from Toke.
====================

Link: https://lore.kernel.org/r/20240312003646.8692-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

7 files changed, 372 insertions, 81 deletions

diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h
index 79eaa581be98..cd17f6d0791f 100644
--- a/tools/lib/bpf/bpf_helpers.h
+++ b/tools/lib/bpf/bpf_helpers.h
@@ -13,6 +13,7 @@
 #define __uint(name, val) int (*name)[val]
 #define __type(name, val) typeof(val) *name
 #define __array(name, val) typeof(val) *name[]
+#define __ulong(name, val) enum { ___bpf_concat(__unique_value, __COUNTER__) = val } name
 
 /*
  * Helper macro to place programs, maps, license in
@@ -192,6 +193,7 @@ enum libbpf_tristate {
 #define __arg_nonnull __attribute((btf_decl_tag("arg:nonnull")))
 #define __arg_nullable __attribute((btf_decl_tag("arg:nullable")))
 #define __arg_trusted __attribute((btf_decl_tag("arg:trusted")))
+#define __arg_arena __attribute((btf_decl_tag("arg:arena")))
 
 #ifndef ___bpf_concat
 #define ___bpf_concat(a, b) a ## b
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index a17b4c9c4213..2d0840ef599a 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -4968,7 +4968,7 @@ struct btf *btf__load_vmlinux_btf(void)
 			pr_warn("failed to read kernel BTF from '%s': %d\n", sysfs_btf_path, err);
 			return libbpf_err_ptr(err);
 		}
-		pr_debug("loaded kernel BTF from '%s'\n", path);
+		pr_debug("loaded kernel BTF from '%s'\n", sysfs_btf_path);
 		return btf;
 	}
 
diff --git a/tools/lib/bpf/features.c b/tools/lib/bpf/features.c
index 6b0738ad7063..4e783cc7fc4b 100644
--- a/tools/lib/bpf/features.c
+++ b/tools/lib/bpf/features.c
@@ -147,6 +147,25 @@ static int probe_kern_btf_datasec(int token_fd)
 					     strs, sizeof(strs), token_fd));
 }
 
+static int probe_kern_btf_qmark_datasec(int token_fd)
+{
+	static const char strs[] = "\0x\0?.data";
+	/* static int a; */
+	__u32 types[] = {
+		/* int */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),  /* [1] */
+		/* VAR x */                                     /* [2] */
+		BTF_TYPE_ENC(1, BTF_INFO_ENC(BTF_KIND_VAR, 0, 0), 1),
+		BTF_VAR_STATIC,
+		/* DATASEC ?.data */                            /* [3] */
+		BTF_TYPE_ENC(3, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 1), 4),
+		BTF_VAR_SECINFO_ENC(2, 0, 4),
+	};
+
+	return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
+					     strs, sizeof(strs), token_fd));
+}
+
 static int probe_kern_btf_float(int token_fd)
 {
 	static const char strs[] = "\0float";
@@ -534,6 +553,9 @@ static struct kern_feature_desc {
 	[FEAT_ARG_CTX_TAG] = {
 		"kernel-side __arg_ctx tag", probe_kern_arg_ctx_tag,
 	},
+	[FEAT_BTF_QMARK_DATASEC] = {
+		"BTF DATASEC names starting from '?'", probe_kern_btf_qmark_datasec,
+	},
 };
 
 bool feat_supported(struct kern_feature_cache *cache, enum kern_feature_id feat_id)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 6c2979f1b471..efab29b8935b 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -185,6 +185,7 @@ static const char * const map_type_name[] = {
 	[BPF_MAP_TYPE_BLOOM_FILTER]		= "bloom_filter",
 	[BPF_MAP_TYPE_USER_RINGBUF]             = "user_ringbuf",
 	[BPF_MAP_TYPE_CGRP_STORAGE]		= "cgrp_storage",
+	[BPF_MAP_TYPE_ARENA]			= "arena",
 };
 
 static const char * const prog_type_name[] = {
@@ -497,6 +498,7 @@ struct bpf_struct_ops {
 #define KSYMS_SEC ".ksyms"
 #define STRUCT_OPS_SEC ".struct_ops"
 #define STRUCT_OPS_LINK_SEC ".struct_ops.link"
+#define ARENA_SEC ".arena.1"
 
 enum libbpf_map_type {
 	LIBBPF_MAP_UNSPEC,
@@ -612,6 +614,7 @@ enum sec_type {
 	SEC_BSS,
 	SEC_DATA,
 	SEC_RODATA,
+	SEC_ST_OPS,
 };
 
 struct elf_sec_desc {
@@ -627,8 +630,7 @@ struct elf_state {
 	Elf *elf;
 	Elf64_Ehdr *ehdr;
 	Elf_Data *symbols;
-	Elf_Data *st_ops_data;
-	Elf_Data *st_ops_link_data;
+	Elf_Data *arena_data;
 	size_t shstrndx; /* section index for section name strings */
 	size_t strtabidx;
 	struct elf_sec_desc *secs;
@@ -637,8 +639,8 @@ struct elf_state {
 	__u32 btf_maps_sec_btf_id;
 	int text_shndx;
 	int symbols_shndx;
-	int st_ops_shndx;
-	int st_ops_link_shndx;
+	bool has_st_ops;
+	int arena_data_shndx;
 };
 
 struct usdt_manager;
@@ -698,6 +700,10 @@ struct bpf_object {
 
 	struct usdt_manager *usdt_man;
 
+	struct bpf_map *arena_map;
+	void *arena_data;
+	size_t arena_data_sz;
+
 	struct kern_feature_cache *feat_cache;
 	char *token_path;
 	int token_fd;
@@ -948,7 +954,7 @@ static int find_btf_by_prefix_kind(const struct btf *btf, const char *prefix,
 				   const char *name, __u32 kind);
 
 static int
-find_struct_ops_kern_types(struct bpf_object *obj, const char *tname,
+find_struct_ops_kern_types(struct bpf_object *obj, const char *tname_raw,
 			   struct module_btf **mod_btf,
 			   const struct btf_type **type, __u32 *type_id,
 			   const struct btf_type **vtype, __u32 *vtype_id,
@@ -958,8 +964,12 @@ find_struct_ops_kern_types(struct bpf_object *obj, const char *tname,
 	const struct btf_member *kern_data_member;
 	struct btf *btf;
 	__s32 kern_vtype_id, kern_type_id;
+	char tname[256];
 	__u32 i;
 
+	snprintf(tname, sizeof(tname), "%.*s",
+		 (int)bpf_core_essential_name_len(tname_raw), tname_raw);
+
 	kern_type_id = find_ksym_btf_id(obj, tname, BTF_KIND_STRUCT,
 					&btf, mod_btf);
 	if (kern_type_id < 0) {
@@ -1027,6 +1037,48 @@ static bool is_valid_st_ops_program(struct bpf_object *obj,
 	return false;
 }
 
+/* For each struct_ops program P, referenced from some struct_ops map M,
+ * enable P.autoload if there are Ms for which M.autocreate is true,
+ * disable P.autoload if for all Ms M.autocreate is false.
+ * Don't change P.autoload for programs that are not referenced from any maps.
+ */
+static int bpf_object_adjust_struct_ops_autoload(struct bpf_object *obj)
+{
+	struct bpf_program *prog, *slot_prog;
+	struct bpf_map *map;
+	int i, j, k, vlen;
+
+	for (i = 0; i < obj->nr_programs; ++i) {
+		int should_load = false;
+		int use_cnt = 0;
+
+		prog = &obj->programs[i];
+		if (prog->type != BPF_PROG_TYPE_STRUCT_OPS)
+			continue;
+
+		for (j = 0; j < obj->nr_maps; ++j) {
+			map = &obj->maps[j];
+			if (!bpf_map__is_struct_ops(map))
+				continue;
+
+			vlen = btf_vlen(map->st_ops->type);
+			for (k = 0; k < vlen; ++k) {
+				slot_prog = map->st_ops->progs[k];
+				if (prog != slot_prog)
+					continue;
+
+				use_cnt++;
+				if (map->autocreate)
+					should_load = true;
+			}
+		}
+		if (use_cnt)
+			prog->autoload = should_load;
+	}
+
+	return 0;
+}
+
 /* Init the map's fields that depend on kern_btf */
 static int bpf_map__init_kern_struct_ops(struct bpf_map *map)
 {
@@ -1142,8 +1194,32 @@ static int bpf_map__init_kern_struct_ops(struct bpf_map *map)
 
 			if (mod_btf)
 				prog->attach_btf_obj_fd = mod_btf->fd;
-			prog->attach_btf_id = kern_type_id;
-			prog->expected_attach_type = kern_member_idx;
+
+			/* if we haven't yet processed this BPF program, record proper
+			 * attach_btf_id and member_idx
+			 */
+			if (!prog->attach_btf_id) {
+				prog->attach_btf_id = kern_type_id;
+				prog->expected_attach_type = kern_member_idx;
+			}
+
+			/* struct_ops BPF prog can be re-used between multiple
+			 * .struct_ops & .struct_ops.link as long as it's the
+			 * same struct_ops struct definition and the same
+			 * function pointer field
+			 */
+			if (prog->attach_btf_id != kern_type_id) {
+				pr_warn("struct_ops init_kern %s func ptr %s: invalid reuse of prog %s in sec %s with type %u: attach_btf_id %u != kern_type_id %u\n",
+					map->name, mname, prog->name, prog->sec_name, prog->type,
+					prog->attach_btf_id, kern_type_id);
+				return -EINVAL;
+			}
+			if (prog->expected_attach_type != kern_member_idx) {
+				pr_warn("struct_ops init_kern %s func ptr %s: invalid reuse of prog %s in sec %s with type %u: expected_attach_type %u != kern_member_idx %u\n",
+					map->name, mname, prog->name, prog->sec_name, prog->type,
+					prog->expected_attach_type, kern_member_idx);
+				return -EINVAL;
+			}
 
 			st_ops->kern_func_off[i] = kern_data_off + kern_moff;
 
@@ -1184,6 +1260,9 @@ static int bpf_object__init_kern_struct_ops_maps(struct bpf_object *obj)
 		if (!bpf_map__is_struct_ops(map))
 			continue;
 
+		if (!map->autocreate)
+			continue;
+
 		err = bpf_map__init_kern_struct_ops(map);
 		if (err)
 			return err;
@@ -1193,7 +1272,7 @@ static int bpf_object__init_kern_struct_ops_maps(struct bpf_object *obj)
 }
 
 static int init_struct_ops_maps(struct bpf_object *obj, const char *sec_name,
-				int shndx, Elf_Data *data, __u32 map_flags)
+				int shndx, Elf_Data *data)
 {
 	const struct btf_type *type, *datasec;
 	const struct btf_var_secinfo *vsi;
@@ -1251,11 +1330,20 @@ static int init_struct_ops_maps(struct bpf_object *obj, const char *sec_name,
 			return -ENOMEM;
 		map->btf_value_type_id = type_id;
 
+		/* Follow same convention as for programs autoload:
+		 * SEC("?.struct_ops") means map is not created by default.
+		 */
+		if (sec_name[0] == '?') {
+			map->autocreate = false;
+			/* from now on forget there was ? in section name */
+			sec_name++;
+		}
+
 		map->def.type = BPF_MAP_TYPE_STRUCT_OPS;
 		map->def.key_size = sizeof(int);
 		map->def.value_size = type->size;
 		map->def.max_entries = 1;
-		map->def.map_flags = map_flags;
+		map->def.map_flags = strcmp(sec_name, STRUCT_OPS_LINK_SEC) == 0 ? BPF_F_LINK : 0;
 
 		map->st_ops = calloc(1, sizeof(*map->st_ops));
 		if (!map->st_ops)
@@ -1290,15 +1378,25 @@ static int init_struct_ops_maps(struct bpf_object *obj, const char *sec_name,
 
 static int bpf_object_init_struct_ops(struct bpf_object *obj)
 {
-	int err;
+	const char *sec_name;
+	int sec_idx, err;
 
-	err = init_struct_ops_maps(obj, STRUCT_OPS_SEC, obj->efile.st_ops_shndx,
-				   obj->efile.st_ops_data, 0);
-	err = err ?: init_struct_ops_maps(obj, STRUCT_OPS_LINK_SEC,
-					  obj->efile.st_ops_link_shndx,
-					  obj->efile.st_ops_link_data,
-					  BPF_F_LINK);
-	return err;
+	for (sec_idx = 0; sec_idx < obj->efile.sec_cnt; ++sec_idx) {
+		struct elf_sec_desc *desc = &obj->efile.secs[sec_idx];
+
+		if (desc->sec_type != SEC_ST_OPS)
+			continue;
+
+		sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, sec_idx));
+		if (!sec_name)
+			return -LIBBPF_ERRNO__FORMAT;
+
+		err = init_struct_ops_maps(obj, sec_name, sec_idx, desc->data);
+		if (err)
+			return err;
+	}
+
+	return 0;
 }
 
 static struct bpf_object *bpf_object__new(const char *path,
@@ -1336,8 +1434,6 @@ 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.btf_maps_shndx = -1;
-	obj->efile.st_ops_shndx = -1;
-	obj->efile.st_ops_link_shndx = -1;
 	obj->kconfig_map_idx = -1;
 
 	obj->kern_version = get_kernel_version();
@@ -1354,8 +1450,7 @@ static void bpf_object__elf_finish(struct bpf_object *obj)
 	elf_end(obj->efile.elf);
 	obj->efile.elf = NULL;
 	obj->efile.symbols = NULL;
-	obj->efile.st_ops_data = NULL;
-	obj->efile.st_ops_link_data = NULL;
+	obj->efile.arena_data = NULL;
 
 	zfree(&obj->efile.secs);
 	obj->efile.sec_cnt = 0;
@@ -1598,7 +1693,7 @@ static struct bpf_map *bpf_object__add_map(struct bpf_object *obj)
 	return map;
 }
 
-static size_t bpf_map_mmap_sz(unsigned int value_sz, unsigned int max_entries)
+static size_t array_map_mmap_sz(unsigned int value_sz, unsigned int max_entries)
 {
 	const long page_sz = sysconf(_SC_PAGE_SIZE);
 	size_t map_sz;
@@ -1608,6 +1703,20 @@ static size_t bpf_map_mmap_sz(unsigned int value_sz, unsigned int max_entries)
 	return map_sz;
 }
 
+static size_t bpf_map_mmap_sz(const struct bpf_map *map)
+{
+	const long page_sz = sysconf(_SC_PAGE_SIZE);
+
+	switch (map->def.type) {
+	case BPF_MAP_TYPE_ARRAY:
+		return array_map_mmap_sz(map->def.value_size, map->def.max_entries);
+	case BPF_MAP_TYPE_ARENA:
+		return page_sz * map->def.max_entries;
+	default:
+		return 0; /* not supported */
+	}
+}
+
 static int bpf_map_mmap_resize(struct bpf_map *map, size_t old_sz, size_t new_sz)
 {
 	void *mmaped;
@@ -1750,7 +1859,7 @@ bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
 	def->value_size = data_sz;
 	def->max_entries = 1;
 	def->map_flags = type == LIBBPF_MAP_RODATA || type == LIBBPF_MAP_KCONFIG
-			 ? BPF_F_RDONLY_PROG : 0;
+		? BPF_F_RDONLY_PROG : 0;
 
 	/* failures are fine because of maps like .rodata.str1.1 */
 	(void) map_fill_btf_type_info(obj, map);
@@ -1761,7 +1870,7 @@ bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
 	pr_debug("map '%s' (global data): at sec_idx %d, offset %zu, flags %x.\n",
 		 map->name, map->sec_idx, map->sec_offset, def->map_flags);
 
-	mmap_sz = bpf_map_mmap_sz(map->def.value_size, map->def.max_entries);
+	mmap_sz = bpf_map_mmap_sz(map);
 	map->mmaped = mmap(NULL, mmap_sz, PROT_READ | PROT_WRITE,
 			   MAP_SHARED | MAP_ANONYMOUS, -1, 0);
 	if (map->mmaped == MAP_FAILED) {
@@ -2249,6 +2358,46 @@ static bool get_map_field_int(const char *map_name, const struct btf *btf,
 	return true;
 }
 
+static bool get_map_field_long(const char *map_name, const struct btf *btf,
+			       const struct btf_member *m, __u64 *res)
+{
+	const struct btf_type *t = skip_mods_and_typedefs(btf, m->type, NULL);
+	const char *name = btf__name_by_offset(btf, m->name_off);
+
+	if (btf_is_ptr(t)) {
+		__u32 res32;
+		bool ret;
+
+		ret = get_map_field_int(map_name, btf, m, &res32);
+		if (ret)
+			*res = (__u64)res32;
+		return ret;
+	}
+
+	if (!btf_is_enum(t) && !btf_is_enum64(t)) {
+		pr_warn("map '%s': attr '%s': expected ENUM or ENUM64, got %s.\n",
+			map_name, name, btf_kind_str(t));
+		return false;
+	}
+
+	if (btf_vlen(t) != 1) {
+		pr_warn("map '%s': attr '%s': invalid __ulong\n",
+			map_name, name);
+		return false;
+	}
+
+	if (btf_is_enum(t)) {
+		const struct btf_enum *e = btf_enum(t);
+
+		*res = e->val;
+	} else {
+		const struct btf_enum64 *e = btf_enum64(t);
+
+		*res = btf_enum64_value(e);
+	}
+	return true;
+}
+
 static int pathname_concat(char *buf, size_t buf_sz, const char *path, const char *name)
 {
 	int len;
@@ -2482,9 +2631,9 @@ 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;
+			__u64 map_extra;
 
-			if (!get_map_field_int(map_name, btf, m, &map_extra))
+			if (!get_map_field_long(map_name, btf, m, &map_extra))
 				return -EINVAL;
 			map_def->map_extra = map_extra;
 			map_def->parts |= MAP_DEF_MAP_EXTRA;
@@ -2702,6 +2851,32 @@ static int bpf_object__init_user_btf_map(struct bpf_object *obj,
 	return 0;
 }
 
+static int init_arena_map_data(struct bpf_object *obj, struct bpf_map *map,
+			       const char *sec_name, int sec_idx,
+			       void *data, size_t data_sz)
+{
+	const long page_sz = sysconf(_SC_PAGE_SIZE);
+	size_t mmap_sz;
+
+	mmap_sz = bpf_map_mmap_sz(obj->arena_map);
+	if (roundup(data_sz, page_sz) > mmap_sz) {
+		pr_warn("elf: sec '%s': declared ARENA map size (%zu) is too small to hold global __arena variables of size %zu\n",
+			sec_name, mmap_sz, data_sz);
+		return -E2BIG;
+	}
+
+	obj->arena_data = malloc(data_sz);
+	if (!obj->arena_data)
+		return -ENOMEM;
+	memcpy(obj->arena_data, data, data_sz);
+	obj->arena_data_sz = data_sz;
+
+	/* make bpf_map__init_value() work for ARENA maps */
+	map->mmaped = obj->arena_data;
+
+	return 0;
+}
+
 static int bpf_object__init_user_btf_maps(struct bpf_object *obj, bool strict,
 					  const char *pin_root_path)
 {
@@ -2751,6 +2926,33 @@ static int bpf_object__init_user_btf_maps(struct bpf_object *obj, bool strict,
 			return err;
 	}
 
+	for (i = 0; i < obj->nr_maps; i++) {
+		struct bpf_map *map = &obj->maps[i];
+
+		if (map->def.type != BPF_MAP_TYPE_ARENA)
+			continue;
+
+		if (obj->arena_map) {
+			pr_warn("map '%s': only single ARENA map is supported (map '%s' is also ARENA)\n",
+				map->name, obj->arena_map->name);
+			return -EINVAL;
+		}
+		obj->arena_map = map;
+
+		if (obj->efile.arena_data) {
+			err = init_arena_map_data(obj, map, ARENA_SEC, obj->efile.arena_data_shndx,
+						  obj->efile.arena_data->d_buf,
+						  obj->efile.arena_data->d_size);
+			if (err)
+				return err;
+		}
+	}
+	if (obj->efile.arena_data && !obj->arena_map) {
+		pr_warn("elf: sec '%s': to use global __arena variables the ARENA map should be explicitly declared in SEC(\".maps\")\n",
+			ARENA_SEC);
+		return -ENOENT;
+	}
+
 	return 0;
 }
 
@@ -2783,6 +2985,11 @@ static bool section_have_execinstr(struct bpf_object *obj, int idx)
 	return sh->sh_flags & SHF_EXECINSTR;
 }
 
+static bool starts_with_qmark(const char *s)
+{
+	return s && s[0] == '?';
+}
+
 static bool btf_needs_sanitization(struct bpf_object *obj)
 {
 	bool has_func_global = kernel_supports(obj, FEAT_BTF_GLOBAL_FUNC);
@@ -2792,9 +2999,10 @@ static bool btf_needs_sanitization(struct bpf_object *obj)
 	bool has_decl_tag = kernel_supports(obj, FEAT_BTF_DECL_TAG);
 	bool has_type_tag = kernel_supports(obj, FEAT_BTF_TYPE_TAG);
 	bool has_enum64 = kernel_supports(obj, FEAT_BTF_ENUM64);
+	bool has_qmark_datasec = kernel_supports(obj, FEAT_BTF_QMARK_DATASEC);
 
 	return !has_func || !has_datasec || !has_func_global || !has_float ||
-	       !has_decl_tag || !has_type_tag || !has_enum64;
+	       !has_decl_tag || !has_type_tag || !has_enum64 || !has_qmark_datasec;
 }
 
 static int bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf)
@@ -2806,6 +3014,7 @@ static int bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf)
 	bool has_decl_tag = kernel_supports(obj, FEAT_BTF_DECL_TAG);
 	bool has_type_tag = kernel_supports(obj, FEAT_BTF_TYPE_TAG);
 	bool has_enum64 = kernel_supports(obj, FEAT_BTF_ENUM64);
+	bool has_qmark_datasec = kernel_supports(obj, FEAT_BTF_QMARK_DATASEC);
 	int enum64_placeholder_id = 0;
 	struct btf_type *t;
 	int i, j, vlen;
@@ -2832,7 +3041,7 @@ static int bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf)
 
 			name = (char *)btf__name_by_offset(btf, t->name_off);
 			while (*name) {
-				if (*name == '.')
+				if (*name == '.' || *name == '?')
 					*name = '_';
 				name++;
 			}
@@ -2847,6 +3056,14 @@ static int bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf)
 				vt = (void *)btf__type_by_id(btf, v->type);
 				m->name_off = vt->name_off;
 			}
+		} else if (!has_qmark_datasec && btf_is_datasec(t) &&
+			   starts_with_qmark(btf__name_by_offset(btf, t->name_off))) {
+			/* replace '?' prefix with '_' for DATASEC names */
+			char *name;
+
+			name = (char *)btf__name_by_offset(btf, t->name_off);
+			if (name[0] == '?')
+				name[0] = '_';
 		} else if (!has_func && btf_is_func_proto(t)) {
 			/* replace FUNC_PROTO with ENUM */
 			vlen = btf_vlen(t);
@@ -2900,14 +3117,13 @@ static int bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf)
 static bool libbpf_needs_btf(const struct bpf_object *obj)
 {
 	return obj->efile.btf_maps_shndx >= 0 ||
-	       obj->efile.st_ops_shndx >= 0 ||
-	       obj->efile.st_ops_link_shndx >= 0 ||
+	       obj->efile.has_st_ops ||
 	       obj->nr_extern > 0;
 }
 
 static bool kernel_needs_btf(const struct bpf_object *obj)
 {
-	return obj->efile.st_ops_shndx >= 0 || obj->efile.st_ops_link_shndx >= 0;
+	return obj->efile.has_st_ops;
 }
 
 static int bpf_object__init_btf(struct bpf_object *obj,
@@ -3608,12 +3824,17 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
 				sec_desc->sec_type = SEC_RODATA;
 				sec_desc->shdr = sh;
 				sec_desc->data = data;
-			} else if (strcmp(name, STRUCT_OPS_SEC) == 0) {
-				obj->efile.st_ops_data = data;
-				obj->efile.st_ops_shndx = idx;
-			} else if (strcmp(name, STRUCT_OPS_LINK_SEC) == 0) {
-				obj->efile.st_ops_link_data = data;
-				obj->efile.st_ops_link_shndx = idx;
+			} else if (strcmp(name, STRUCT_OPS_SEC) == 0 ||
+				   strcmp(name, STRUCT_OPS_LINK_SEC) == 0 ||
+				   strcmp(name, "?" STRUCT_OPS_SEC) == 0 ||
+				   strcmp(name, "?" STRUCT_OPS_LINK_SEC) == 0) {
+				sec_desc->sec_type = SEC_ST_OPS;
+				sec_desc->shdr = sh;
+				sec_desc->data = data;
+				obj->efile.has_st_ops = true;
+			} else if (strcmp(name, ARENA_SEC) == 0) {
+				obj->efile.arena_data = data;
+				obj->efile.arena_data_shndx = idx;
 			} else {
 				pr_info("elf: skipping unrecognized data section(%d) %s\n",
 					idx, name);
@@ -3629,6 +3850,8 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
 			if (!section_have_execinstr(obj, targ_sec_idx) &&
 			    strcmp(name, ".rel" STRUCT_OPS_SEC) &&
 			    strcmp(name, ".rel" STRUCT_OPS_LINK_SEC) &&
+			    strcmp(name, ".rel?" STRUCT_OPS_SEC) &&
+			    strcmp(name, ".rel?" STRUCT_OPS_LINK_SEC) &&
 			    strcmp(name, ".rel" MAPS_ELF_SEC)) {
 				pr_info("elf: skipping relo section(%d) %s for section(%d) %s\n",
 					idx, name, targ_sec_idx,
@@ -4241,6 +4464,15 @@ static int bpf_program__record_reloc(struct bpf_program *prog,
 	type = bpf_object__section_to_libbpf_map_type(obj, shdr_idx);
 	sym_sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, shdr_idx));
 
+	/* arena data relocation */
+	if (shdr_idx == obj->efile.arena_data_shndx) {
+		reloc_desc->type = RELO_DATA;
+		reloc_desc->insn_idx = insn_idx;
+		reloc_desc->map_idx = obj->arena_map - obj->maps;
+		reloc_desc->sym_off = sym->st_value;
+		return 0;
+	}
+
 	/* generic map reference relocation */
 	if (type == LIBBPF_MAP_UNSPEC) {
 		if (!bpf_object__shndx_is_maps(obj, shdr_idx)) {
@@ -4781,6 +5013,7 @@ bpf_object__populate_internal_map(struct bpf_object *obj, struct bpf_map *map)
 			bpf_gen__map_freeze(obj->gen_loader, map - obj->maps);
 		return 0;
 	}
+
 	err = bpf_map_update_elem(map->fd, &zero, map->mmaped, 0);
 	if (err) {
 		err = -errno;
@@ -4873,6 +5106,7 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b
 	case BPF_MAP_TYPE_SOCKHASH:
 	case BPF_MAP_TYPE_QUEUE:
 	case BPF_MAP_TYPE_STACK:
+	case BPF_MAP_TYPE_ARENA:
 		create_attr.btf_fd = 0;
 		create_attr.btf_key_type_id = 0;
 		create_attr.btf_value_type_id = 0;
@@ -5117,7 +5351,23 @@ retry:
 				if (err < 0)
 					goto err_out;
 			}
-
+			if (map->def.type == BPF_MAP_TYPE_ARENA) {
+				map->mmaped = mmap((void *)map->map_extra, bpf_map_mmap_sz(map),
+						   PROT_READ | PROT_WRITE,
+						   map->map_extra ? MAP_SHARED | MAP_FIXED : MAP_SHARED,
+						   map->fd, 0);
+				if (map->mmaped == MAP_FAILED) {
+					err = -errno;
+					map->mmaped = NULL;
+					pr_warn("map '%s': failed to mmap arena: %d\n",
+						map->name, err);
+					return err;
+				}
+				if (obj->arena_data) {
+					memcpy(map->mmaped, obj->arena_data, obj->arena_data_sz);
+					zfree(&obj->arena_data);
+				}
+			}
 			if (map->init_slots_sz && map->def.type != BPF_MAP_TYPE_PROG_ARRAY) {
 				err = init_map_in_map_slots(obj, map);
 				if (err < 0)
@@ -6926,12 +7176,12 @@ static int bpf_object__collect_relos(struct bpf_object *obj)
 		data = sec_desc->data;
 		idx = shdr->sh_info;
 
-		if (shdr->sh_type != SHT_REL) {
+		if (shdr->sh_type != SHT_REL || idx < 0 || idx >= obj->efile.sec_cnt) {
 			pr_warn("internal error at %d\n", __LINE__);
 			return -LIBBPF_ERRNO__INTERNAL;
 		}
 
-		if (idx == obj->efile.st_ops_shndx || idx == obj->efile.st_ops_link_shndx)
+		if (obj->efile.secs[idx].sec_type == SEC_ST_OPS)
 			err = bpf_object__collect_st_ops_relos(obj, shdr, data);
 		else if (idx == obj->efile.btf_maps_shndx)
 			err = bpf_object__collect_map_relos(obj, shdr, data);
@@ -8105,11 +8355,20 @@ static void bpf_map_prepare_vdata(const struct bpf_map *map)
 
 static int bpf_object_prepare_struct_ops(struct bpf_object *obj)
 {
+	struct bpf_map *map;
 	int i;
 
-	for (i = 0; i < obj->nr_maps; i++)
-		if (bpf_map__is_struct_ops(&obj->maps[i]))
-			bpf_map_prepare_vdata(&obj->maps[i]);
+	for (i = 0; i < obj->nr_maps; i++) {
+		map = &obj->maps[i];
+
+		if (!bpf_map__is_struct_ops(map))
+			continue;
+
+		if (!map->autocreate)
+			continue;
+
+		bpf_map_prepare_vdata(map);
+	}
 
 	return 0;
 }
@@ -8135,6 +8394,7 @@ static int bpf_object_load(struct bpf_object *obj, int extra_log_level, const ch
 	err = err ? : bpf_object__resolve_externs(obj, obj->kconfig);
 	err = err ? : bpf_object__sanitize_maps(obj);
 	err = err ? : bpf_object__init_kern_struct_ops_maps(obj);
+	err = err ? : bpf_object_adjust_struct_ops_autoload(obj);
 	err = err ? : bpf_object__relocate(obj, obj->btf_custom_path ? : target_btf_path);
 	err = err ? : bpf_object__sanitize_and_load_btf(obj);
 	err = err ? : bpf_object__create_maps(obj);
@@ -8604,13 +8864,9 @@ static void bpf_map__destroy(struct bpf_map *map)
 	zfree(&map->init_slots);
 	map->init_slots_sz = 0;
 
-	if (map->mmaped) {
-		size_t mmap_sz;
-
-		mmap_sz = bpf_map_mmap_sz(map->def.value_size, map->def.max_entries);
-		munmap(map->mmaped, mmap_sz);
-		map->mmaped = NULL;
-	}
+	if (map->mmaped && map->mmaped != map->obj->arena_data)
+		munmap(map->mmaped, bpf_map_mmap_sz(map));
+	map->mmaped = NULL;
 
 	if (map->st_ops) {
 		zfree(&map->st_ops->data);
@@ -8670,6 +8926,8 @@ void bpf_object__close(struct bpf_object *obj)
 	if (obj->token_fd > 0)
 		close(obj->token_fd);
 
+	zfree(&obj->arena_data);
+
 	free(obj);
 }
 
@@ -9424,27 +9682,6 @@ static int bpf_object__collect_st_ops_relos(struct bpf_object *obj,
 			return -EINVAL;
 		}
 
-		/* if we haven't yet processed this BPF program, record proper
-		 * attach_btf_id and member_idx
-		 */
-		if (!prog->attach_btf_id) {
-			prog->attach_btf_id = st_ops->type_id;
-			prog->expected_attach_type = member_idx;
-		}
-
-		/* struct_ops BPF prog can be re-used between multiple
-		 * .struct_ops & .struct_ops.link as long as it's the
-		 * same struct_ops struct definition and the same
-		 * function pointer field
-		 */
-		if (prog->attach_btf_id != st_ops->type_id ||
-		    prog->expected_attach_type != member_idx) {
-			pr_warn("struct_ops reloc %s: cannot use prog %s in sec %s with type %u attach_btf_id %u expected_attach_type %u for func ptr %s\n",
-				map->name, prog->name, prog->sec_name, prog->type,
-				prog->attach_btf_id, prog->expected_attach_type, name);
-			return -EINVAL;
-		}
-
 		st_ops->progs[member_idx] = prog;
 
 		/* st_ops->data will be exposed to users, being returned by
@@ -9862,11 +10099,14 @@ int bpf_map__set_value_size(struct bpf_map *map, __u32 size)
 		return libbpf_err(-EBUSY);
 
 	if (map->mmaped) {
-		int err;
 		size_t mmap_old_sz, mmap_new_sz;
+		int err;
+
+		if (map->def.type != BPF_MAP_TYPE_ARRAY)
+			return -EOPNOTSUPP;
 
-		mmap_old_sz = bpf_map_mmap_sz(map->def.value_size, map->def.max_entries);
-		mmap_new_sz = bpf_map_mmap_sz(size, map->def.max_entries);
+		mmap_old_sz = bpf_map_mmap_sz(map);
+		mmap_new_sz = array_map_mmap_sz(size, map->def.max_entries);
 		err = bpf_map_mmap_resize(map, mmap_old_sz, mmap_new_sz);
 		if (err) {
 			pr_warn("map '%s': failed to resize memory-mapped region: %d\n",
@@ -9899,18 +10139,26 @@ __u32 bpf_map__btf_value_type_id(const struct bpf_map *map)
 int bpf_map__set_initial_value(struct bpf_map *map,
 			       const void *data, size_t size)
 {
+	size_t actual_sz;
+
 	if (map->obj->loaded || map->reused)
 		return libbpf_err(-EBUSY);
 
-	if (!map->mmaped || map->libbpf_type == LIBBPF_MAP_KCONFIG ||
-	    size != map->def.value_size)
+	if (!map->mmaped || map->libbpf_type == LIBBPF_MAP_KCONFIG)
+		return libbpf_err(-EINVAL);
+
+	if (map->def.type == BPF_MAP_TYPE_ARENA)
+		actual_sz = map->obj->arena_data_sz;
+	else
+		actual_sz = map->def.value_size;
+	if (size != actual_sz)
 		return libbpf_err(-EINVAL);
 
 	memcpy(map->mmaped, data, size);
 	return 0;
 }
 
-void *bpf_map__initial_value(struct bpf_map *map, size_t *psize)
+void *bpf_map__initial_value(const struct bpf_map *map, size_t *psize)
 {
 	if (bpf_map__is_struct_ops(map)) {
 		if (psize)
@@ -9920,7 +10168,12 @@ void *bpf_map__initial_value(struct bpf_map *map, size_t *psize)
 
 	if (!map->mmaped)
 		return NULL;
-	*psize = map->def.value_size;
+
+	if (map->def.type == BPF_MAP_TYPE_ARENA)
+		*psize = map->obj->arena_data_sz;
+	else
+		*psize = map->def.value_size;
+
 	return map->mmaped;
 }
 
@@ -13397,7 +13650,7 @@ int bpf_object__load_skeleton(struct bpf_object_skeleton *s)
 
 	for (i = 0; i < s->map_cnt; i++) {
 		struct bpf_map *map = *s->maps[i].map;
-		size_t mmap_sz = bpf_map_mmap_sz(map->def.value_size, map->def.max_entries);
+		size_t mmap_sz = bpf_map_mmap_sz(map);
 		int prot, map_fd = map->fd;
 		void **mmaped = s->maps[i].mmaped;
 
@@ -13409,6 +13662,11 @@ int bpf_object__load_skeleton(struct bpf_object_skeleton *s)
 			continue;
 		}
 
+		if (map->def.type == BPF_MAP_TYPE_ARENA) {
+			*mmaped = map->mmaped;
+			continue;
+		}
+
 		if (map->def.map_flags & BPF_F_RDONLY_PROG)
 			prot = PROT_READ;
 		else
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 5723cbbfcc41..7b510761f545 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -1014,7 +1014,7 @@ LIBBPF_API int bpf_map__set_map_extra(struct bpf_map *map, __u64 map_extra);
 
 LIBBPF_API int bpf_map__set_initial_value(struct bpf_map *map,
 					  const void *data, size_t size);
-LIBBPF_API void *bpf_map__initial_value(struct bpf_map *map, size_t *psize);
+LIBBPF_API void *bpf_map__initial_value(const struct bpf_map *map, size_t *psize);
 
 /**
  * @brief **bpf_map__is_internal()** tells the caller whether or not the
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index ad936ac5e639..864b36177424 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h
@@ -374,6 +374,8 @@ enum kern_feature_id {
 	FEAT_UPROBE_MULTI_LINK,
 	/* Kernel supports arg:ctx tag (__arg_ctx) for global subprogs natively */
 	FEAT_ARG_CTX_TAG,
+	/* Kernel supports '?' at the front of datasec names */
+	FEAT_BTF_QMARK_DATASEC,
 	__FEAT_CNT,
 };
 
diff --git a/tools/lib/bpf/libbpf_probes.c b/tools/lib/bpf/libbpf_probes.c
index ee9b1dbea9eb..302188122439 100644
--- a/tools/lib/bpf/libbpf_probes.c
+++ b/tools/lib/bpf/libbpf_probes.c
@@ -338,6 +338,13 @@ static int probe_map_create(enum bpf_map_type map_type)
 		key_size = 0;
 		max_entries = 1;
 		break;
+	case BPF_MAP_TYPE_ARENA:
+		key_size	= 0;
+		value_size	= 0;
+		max_entries	= 1; /* one page */
+		opts.map_extra	= 0; /* can mmap() at any address */
+		opts.map_flags	= BPF_F_MMAPABLE;
+		break;
 	case BPF_MAP_TYPE_HASH:
 	case BPF_MAP_TYPE_ARRAY:
 	case BPF_MAP_TYPE_PROG_ARRAY: