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

Daniel Borkmann says:

====================
bpf-next 2021-10-02

We've added 85 non-merge commits during the last 15 day(s) which contain
a total of 132 files changed, 13779 insertions(+), 6724 deletions(-).

The main changes are:

1) Massive update on test_bpf.ko coverage for JITs as preparatory work for
   an upcoming MIPS eBPF JIT, from Johan Almbladh.

2) Add a batched interface for RX buffer allocation in AF_XDP buffer pool,
   with driver support for i40e and ice from Magnus Karlsson.

3) Add legacy uprobe support to libbpf to complement recently merged legacy
   kprobe support, from Andrii Nakryiko.

4) Add bpf_trace_vprintk() as variadic printk helper, from Dave Marchevsky.

5) Support saving the register state in verifier when spilling <8byte bounded
   scalar to the stack, from Martin Lau.

6) Add libbpf opt-in for stricter BPF program section name handling as part
   of libbpf 1.0 effort, from Andrii Nakryiko.

7) Add a document to help clarifying BPF licensing, from Alexei Starovoitov.

8) Fix skel_internal.h to propagate errno if the loader indicates an internal
   error, from Kumar Kartikeya Dwivedi.

9) Fix build warnings with -Wcast-function-type so that the option can later
   be enabled by default for the kernel, from Kees Cook.

10) Fix libbpf to ignore STT_SECTION symbols in legacy map definitions as it
    otherwise errors out when encountering them, from Toke Høiland-Jørgensen.

11) Teach libbpf to recognize specialized maps (such as for perf RB) and
    internally remove BTF type IDs when creating them, from Hengqi Chen.

12) Various fixes and improvements to BPF selftests.
====================

Link: https://lore.kernel.org/r/20211002001327.15169-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

7 files changed, 631 insertions, 362 deletions

diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h
index b9987c3efa3c..963b1060d944 100644
--- a/tools/lib/bpf/bpf_helpers.h
+++ b/tools/lib/bpf/bpf_helpers.h
@@ -14,14 +14,6 @@
 #define __type(name, val) typeof(val) *name
 #define __array(name, val) typeof(val) *name[]
 
-/* Helper macro to print out debug messages */
-#define bpf_printk(fmt, ...)				\
-({							\
-	char ____fmt[] = fmt;				\
-	bpf_trace_printk(____fmt, sizeof(____fmt),	\
-			 ##__VA_ARGS__);		\
-})
-
 /*
  * Helper macro to place programs, maps, license in
  * different sections in elf_bpf file. Section names
@@ -224,4 +216,47 @@ enum libbpf_tristate {
 		     ___param, sizeof(___param));		\
 })
 
+#ifdef BPF_NO_GLOBAL_DATA
+#define BPF_PRINTK_FMT_MOD
+#else
+#define BPF_PRINTK_FMT_MOD static const
+#endif
+
+#define __bpf_printk(fmt, ...)				\
+({							\
+	BPF_PRINTK_FMT_MOD char ____fmt[] = fmt;	\
+	bpf_trace_printk(____fmt, sizeof(____fmt),	\
+			 ##__VA_ARGS__);		\
+})
+
+/*
+ * __bpf_vprintk wraps the bpf_trace_vprintk helper with variadic arguments
+ * instead of an array of u64.
+ */
+#define __bpf_vprintk(fmt, args...)				\
+({								\
+	static const char ___fmt[] = fmt;			\
+	unsigned long long ___param[___bpf_narg(args)];		\
+								\
+	_Pragma("GCC diagnostic push")				\
+	_Pragma("GCC diagnostic ignored \"-Wint-conversion\"")	\
+	___bpf_fill(___param, args);				\
+	_Pragma("GCC diagnostic pop")				\
+								\
+	bpf_trace_vprintk(___fmt, sizeof(___fmt),		\
+			  ___param, sizeof(___param));		\
+})
+
+/* Use __bpf_printk when bpf_printk call has 3 or fewer fmt args
+ * Otherwise use __bpf_vprintk
+ */
+#define ___bpf_pick_printk(...) \
+	___bpf_nth(_, ##__VA_ARGS__, __bpf_vprintk, __bpf_vprintk, __bpf_vprintk,	\
+		   __bpf_vprintk, __bpf_vprintk, __bpf_vprintk, __bpf_vprintk,		\
+		   __bpf_vprintk, __bpf_vprintk, __bpf_printk /*3*/, __bpf_printk /*2*/,\
+		   __bpf_printk /*1*/, __bpf_printk /*0*/)
+
+/* Helper macro to print out debug messages */
+#define bpf_printk(fmt, args...) ___bpf_pick_printk(args)(fmt, ##args)
+
 #endif
diff --git a/tools/lib/bpf/gen_loader.c b/tools/lib/bpf/gen_loader.c
index 8df718a6b142..80087b13877f 100644
--- a/tools/lib/bpf/gen_loader.c
+++ b/tools/lib/bpf/gen_loader.c
@@ -5,6 +5,7 @@
 #include <string.h>
 #include <errno.h>
 #include <linux/filter.h>
+#include <sys/param.h>
 #include "btf.h"
 #include "bpf.h"
 #include "libbpf.h"
@@ -135,13 +136,17 @@ void bpf_gen__init(struct bpf_gen *gen, int log_level)
 
 static int add_data(struct bpf_gen *gen, const void *data, __u32 size)
 {
+	__u32 size8 = roundup(size, 8);
+	__u64 zero = 0;
 	void *prev;
 
-	if (realloc_data_buf(gen, size))
+	if (realloc_data_buf(gen, size8))
 		return 0;
 	prev = gen->data_cur;
 	memcpy(gen->data_cur, data, size);
 	gen->data_cur += size;
+	memcpy(gen->data_cur, &zero, size8 - size);
+	gen->data_cur += size8 - size;
 	return prev - gen->data_start;
 }
 
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index da65a1666a5e..e23f1b6b9402 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -220,17 +220,40 @@ struct reloc_desc {
 
 struct bpf_sec_def;
 
-typedef struct bpf_link *(*attach_fn_t)(const struct bpf_program *prog);
+typedef int (*init_fn_t)(struct bpf_program *prog, long cookie);
+typedef int (*preload_fn_t)(struct bpf_program *prog, struct bpf_prog_load_params *attr, long cookie);
+typedef struct bpf_link *(*attach_fn_t)(const struct bpf_program *prog, long cookie);
+
+/* stored as sec_def->cookie for all libbpf-supported SEC()s */
+enum sec_def_flags {
+	SEC_NONE = 0,
+	/* expected_attach_type is optional, if kernel doesn't support that */
+	SEC_EXP_ATTACH_OPT = 1,
+	/* legacy, only used by libbpf_get_type_names() and
+	 * libbpf_attach_type_by_name(), not used by libbpf itself at all.
+	 * This used to be associated with cgroup (and few other) BPF programs
+	 * that were attachable through BPF_PROG_ATTACH command. Pretty
+	 * meaningless nowadays, though.
+	 */
+	SEC_ATTACHABLE = 2,
+	SEC_ATTACHABLE_OPT = SEC_ATTACHABLE | SEC_EXP_ATTACH_OPT,
+	/* attachment target is specified through BTF ID in either kernel or
+	 * other BPF program's BTF object */
+	SEC_ATTACH_BTF = 4,
+	/* BPF program type allows sleeping/blocking in kernel */
+	SEC_SLEEPABLE = 8,
+	/* allow non-strict prefix matching */
+	SEC_SLOPPY_PFX = 16,
+};
 
 struct bpf_sec_def {
 	const char *sec;
-	size_t len;
 	enum bpf_prog_type prog_type;
 	enum bpf_attach_type expected_attach_type;
-	bool is_exp_attach_type_optional;
-	bool is_attachable;
-	bool is_attach_btf;
-	bool is_sleepable;
+	long cookie;
+
+	init_fn_t init_fn;
+	preload_fn_t preload_fn;
 	attach_fn_t attach_fn;
 };
 
@@ -1665,7 +1688,7 @@ static int bpf_object__process_kconfig_line(struct bpf_object *obj,
 	void *ext_val;
 	__u64 num;
 
-	if (strncmp(buf, "CONFIG_", 7))
+	if (!str_has_pfx(buf, "CONFIG_"))
 		return 0;
 
 	sep = strchr(buf, '=');
@@ -1845,6 +1868,8 @@ static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict)
 			continue;
 		if (sym.st_shndx != obj->efile.maps_shndx)
 			continue;
+		if (GELF_ST_TYPE(sym.st_info) == STT_SECTION)
+			continue;
 		nr_maps++;
 	}
 	/* Assume equally sized map definitions */
@@ -1869,6 +1894,8 @@ static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict)
 			continue;
 		if (sym.st_shndx != obj->efile.maps_shndx)
 			continue;
+		if (GELF_ST_TYPE(sym.st_info) == STT_SECTION)
+			continue;
 
 		map = bpf_object__add_map(obj);
 		if (IS_ERR(map))
@@ -1881,8 +1908,7 @@ static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict)
 			return -LIBBPF_ERRNO__FORMAT;
 		}
 
-		if (GELF_ST_TYPE(sym.st_info) == STT_SECTION
-		    || GELF_ST_BIND(sym.st_info) == STB_LOCAL) {
+		if (GELF_ST_BIND(sym.st_info) == STB_LOCAL) {
 			pr_warn("map '%s' (legacy): static maps are not supported\n", map_name);
 			return -ENOTSUP;
 		}
@@ -2913,7 +2939,7 @@ static Elf_Data *elf_sec_data(const struct bpf_object *obj, Elf_Scn *scn)
 static bool is_sec_name_dwarf(const char *name)
 {
 	/* approximation, but the actual list is too long */
-	return strncmp(name, ".debug_", sizeof(".debug_") - 1) == 0;
+	return str_has_pfx(name, ".debug_");
 }
 
 static bool ignore_elf_section(GElf_Shdr *hdr, const char *name)
@@ -2935,7 +2961,7 @@ static bool ignore_elf_section(GElf_Shdr *hdr, const char *name)
 	if (is_sec_name_dwarf(name))
 		return true;
 
-	if (strncmp(name, ".rel", sizeof(".rel") - 1) == 0) {
+	if (str_has_pfx(name, ".rel")) {
 		name += sizeof(".rel") - 1;
 		/* DWARF section relocations */
 		if (is_sec_name_dwarf(name))
@@ -4643,6 +4669,30 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b
 			create_attr.inner_map_fd = map->inner_map_fd;
 	}
 
+	switch (def->type) {
+	case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
+	case BPF_MAP_TYPE_CGROUP_ARRAY:
+	case BPF_MAP_TYPE_STACK_TRACE:
+	case BPF_MAP_TYPE_ARRAY_OF_MAPS:
+	case BPF_MAP_TYPE_HASH_OF_MAPS:
+	case BPF_MAP_TYPE_DEVMAP:
+	case BPF_MAP_TYPE_DEVMAP_HASH:
+	case BPF_MAP_TYPE_CPUMAP:
+	case BPF_MAP_TYPE_XSKMAP:
+	case BPF_MAP_TYPE_SOCKMAP:
+	case BPF_MAP_TYPE_SOCKHASH:
+	case BPF_MAP_TYPE_QUEUE:
+	case BPF_MAP_TYPE_STACK:
+	case BPF_MAP_TYPE_RINGBUF:
+		create_attr.btf_fd = 0;
+		create_attr.btf_key_type_id = 0;
+		create_attr.btf_value_type_id = 0;
+		map->btf_key_type_id = 0;
+		map->btf_value_type_id = 0;
+	default:
+		break;
+	}
+
 	if (obj->gen_loader) {
 		bpf_gen__map_create(obj->gen_loader, &create_attr, is_inner ? -1 : map - obj->maps);
 		/* Pretend to have valid FD to pass various fd >= 0 checks.
@@ -6094,6 +6144,48 @@ static int bpf_object__sanitize_prog(struct bpf_object *obj, struct bpf_program
 	return 0;
 }
 
+static int libbpf_find_attach_btf_id(struct bpf_program *prog, const char *attach_name,
+				     int *btf_obj_fd, int *btf_type_id);
+
+/* this is called as prog->sec_def->preload_fn for libbpf-supported sec_defs */
+static int libbpf_preload_prog(struct bpf_program *prog,
+			       struct bpf_prog_load_params *attr, long cookie)
+{
+	enum sec_def_flags def = cookie;
+
+	/* old kernels might not support specifying expected_attach_type */
+	if ((def & SEC_EXP_ATTACH_OPT) && !kernel_supports(prog->obj, FEAT_EXP_ATTACH_TYPE))
+		attr->expected_attach_type = 0;
+
+	if (def & SEC_SLEEPABLE)
+		attr->prog_flags |= BPF_F_SLEEPABLE;
+
+	if ((prog->type == BPF_PROG_TYPE_TRACING ||
+	     prog->type == BPF_PROG_TYPE_LSM ||
+	     prog->type == BPF_PROG_TYPE_EXT) && !prog->attach_btf_id) {
+		int btf_obj_fd = 0, btf_type_id = 0, err;
+		const char *attach_name;
+
+		attach_name = strchr(prog->sec_name, '/') + 1;
+		err = libbpf_find_attach_btf_id(prog, attach_name, &btf_obj_fd, &btf_type_id);
+		if (err)
+			return err;
+
+		/* cache resolved BTF FD and BTF type ID in the prog */
+		prog->attach_btf_obj_fd = btf_obj_fd;
+		prog->attach_btf_id = btf_type_id;
+
+		/* but by now libbpf common logic is not utilizing
+		 * prog->atach_btf_obj_fd/prog->attach_btf_id anymore because
+		 * this callback is called after attrs were populated by
+		 * libbpf, so this callback has to update attr explicitly here
+		 */
+		attr->attach_btf_obj_fd = btf_obj_fd;
+		attr->attach_btf_id = btf_type_id;
+	}
+	return 0;
+}
+
 static int
 load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
 	     char *license, __u32 kern_version, int *pfd)
@@ -6102,7 +6194,7 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
 	char *cp, errmsg[STRERR_BUFSIZE];
 	size_t log_buf_size = 0;
 	char *log_buf = NULL;
-	int btf_fd, ret;
+	int btf_fd, ret, err;
 
 	if (prog->type == BPF_PROG_TYPE_UNSPEC) {
 		/*
@@ -6118,22 +6210,15 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
 		return -EINVAL;
 
 	load_attr.prog_type = prog->type;
-	/* old kernels might not support specifying expected_attach_type */
-	if (!kernel_supports(prog->obj, FEAT_EXP_ATTACH_TYPE) && prog->sec_def &&
-	    prog->sec_def->is_exp_attach_type_optional)
-		load_attr.expected_attach_type = 0;
-	else
-		load_attr.expected_attach_type = prog->expected_attach_type;
+	load_attr.expected_attach_type = prog->expected_attach_type;
 	if (kernel_supports(prog->obj, FEAT_PROG_NAME))
 		load_attr.name = prog->name;
 	load_attr.insns = insns;
 	load_attr.insn_cnt = insns_cnt;
 	load_attr.license = license;
 	load_attr.attach_btf_id = prog->attach_btf_id;
-	if (prog->attach_prog_fd)
-		load_attr.attach_prog_fd = prog->attach_prog_fd;
-	else
-		load_attr.attach_btf_obj_fd = prog->attach_btf_obj_fd;
+	load_attr.attach_prog_fd = prog->attach_prog_fd;
+	load_attr.attach_btf_obj_fd = prog->attach_btf_obj_fd;
 	load_attr.attach_btf_id = prog->attach_btf_id;
 	load_attr.kern_version = kern_version;
 	load_attr.prog_ifindex = prog->prog_ifindex;
@@ -6152,6 +6237,16 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
 	load_attr.log_level = prog->log_level;
 	load_attr.prog_flags = prog->prog_flags;
 
+	/* adjust load_attr if sec_def provides custom preload callback */
+	if (prog->sec_def && prog->sec_def->preload_fn) {
+		err = prog->sec_def->preload_fn(prog, &load_attr, prog->sec_def->cookie);
+		if (err < 0) {
+			pr_warn("prog '%s': failed to prepare load attributes: %d\n",
+				prog->name, err);
+			return err;
+		}
+	}
+
 	if (prog->obj->gen_loader) {
 		bpf_gen__prog_load(prog->obj->gen_loader, &load_attr,
 				   prog - prog->obj->programs);
@@ -6267,8 +6362,6 @@ static int bpf_program__record_externs(struct bpf_program *prog)
 	return 0;
 }
 
-static int libbpf_find_attach_btf_id(struct bpf_program *prog, int *btf_obj_fd, int *btf_type_id);
-
 int bpf_program__load(struct bpf_program *prog, char *license, __u32 kern_ver)
 {
 	int err = 0, fd, i;
@@ -6278,19 +6371,6 @@ int bpf_program__load(struct bpf_program *prog, char *license, __u32 kern_ver)
 		return libbpf_err(-EINVAL);
 	}
 
-	if ((prog->type == BPF_PROG_TYPE_TRACING ||
-	     prog->type == BPF_PROG_TYPE_LSM ||
-	     prog->type == BPF_PROG_TYPE_EXT) && !prog->attach_btf_id) {
-		int btf_obj_fd = 0, btf_type_id = 0;
-
-		err = libbpf_find_attach_btf_id(prog, &btf_obj_fd, &btf_type_id);
-		if (err)
-			return libbpf_err(err);
-
-		prog->attach_btf_obj_fd = btf_obj_fd;
-		prog->attach_btf_id = btf_type_id;
-	}
-
 	if (prog->instances.nr < 0 || !prog->instances.fds) {
 		if (prog->preprocessor) {
 			pr_warn("Internal error: can't load program '%s'\n",
@@ -6400,6 +6480,7 @@ static const struct bpf_sec_def *find_sec_def(const char *sec_name);
 static int bpf_object_init_progs(struct bpf_object *obj, const struct bpf_object_open_opts *opts)
 {
 	struct bpf_program *prog;
+	int err;
 
 	bpf_object__for_each_program(prog, obj) {
 		prog->sec_def = find_sec_def(prog->sec_name);
@@ -6410,8 +6491,6 @@ static int bpf_object_init_progs(struct bpf_object *obj, const struct bpf_object
 			continue;
 		}
 
-		if (prog->sec_def->is_sleepable)
-			prog->prog_flags |= BPF_F_SLEEPABLE;
 		bpf_program__set_type(prog, prog->sec_def->prog_type);
 		bpf_program__set_expected_attach_type(prog, prog->sec_def->expected_attach_type);
 
@@ -6421,6 +6500,18 @@ static int bpf_object_init_progs(struct bpf_object *obj, const struct bpf_object
 		    prog->sec_def->prog_type == BPF_PROG_TYPE_EXT)
 			prog->attach_prog_fd = OPTS_GET(opts, attach_prog_fd, 0);
 #pragma GCC diagnostic pop
+
+		/* sec_def can have custom callback which should be called
+		 * after bpf_program is initialized to adjust its properties
+		 */
+		if (prog->sec_def->init_fn) {
+			err = prog->sec_def->init_fn(prog, prog->sec_def->cookie);
+			if (err < 0) {
+				pr_warn("prog '%s': failed to initialize: %d\n",
+					prog->name, err);
+				return err;
+			}
+		}
 	}
 
 	return 0;
@@ -6847,8 +6938,7 @@ static int bpf_object__resolve_externs(struct bpf_object *obj,
 			if (err)
 				return err;
 			pr_debug("extern (kcfg) %s=0x%x\n", ext->name, kver);
-		} else if (ext->type == EXT_KCFG &&
-			   strncmp(ext->name, "CONFIG_", 7) == 0) {
+		} else if (ext->type == EXT_KCFG && str_has_pfx(ext->name, "CONFIG_")) {
 			need_config = true;
 		} else if (ext->type == EXT_KSYM) {
 			if (ext->ksym.type_id)
@@ -7908,217 +7998,143 @@ void bpf_program__set_expected_attach_type(struct bpf_program *prog,
 	prog->expected_attach_type = type;
 }
 
-#define BPF_PROG_SEC_IMPL(string, ptype, eatype, eatype_optional,	    \
-			  attachable, attach_btf)			    \
-	{								    \
-		.sec = string,						    \
-		.len = sizeof(string) - 1,				    \
-		.prog_type = ptype,					    \
-		.expected_attach_type = eatype,				    \
-		.is_exp_attach_type_optional = eatype_optional,		    \
-		.is_attachable = attachable,				    \
-		.is_attach_btf = attach_btf,				    \
-	}
-
-/* Programs that can NOT be attached. */
-#define BPF_PROG_SEC(string, ptype) BPF_PROG_SEC_IMPL(string, ptype, 0, 0, 0, 0)
-
-/* Programs that can be attached. */
-#define BPF_APROG_SEC(string, ptype, atype) \
-	BPF_PROG_SEC_IMPL(string, ptype, atype, true, 1, 0)
-
-/* Programs that must specify expected attach type at load time. */
-#define BPF_EAPROG_SEC(string, ptype, eatype) \
-	BPF_PROG_SEC_IMPL(string, ptype, eatype, false, 1, 0)
-
-/* Programs that use BTF to identify attach point */
-#define BPF_PROG_BTF(string, ptype, eatype) \
-	BPF_PROG_SEC_IMPL(string, ptype, eatype, false, 0, 1)
-
-/* Programs that can be attached but attach type can't be identified by section
- * name. Kept for backward compatibility.
- */
-#define BPF_APROG_COMPAT(string, ptype) BPF_PROG_SEC(string, ptype)
-
-#define SEC_DEF(sec_pfx, ptype, ...) {					    \
+#define SEC_DEF(sec_pfx, ptype, atype, flags, ...) {			    \
 	.sec = sec_pfx,							    \
-	.len = sizeof(sec_pfx) - 1,					    \
 	.prog_type = BPF_PROG_TYPE_##ptype,				    \
+	.expected_attach_type = atype,					    \
+	.cookie = (long)(flags),					    \
+	.preload_fn = libbpf_preload_prog,				    \
 	__VA_ARGS__							    \
 }
 
-static struct bpf_link *attach_kprobe(const struct bpf_program *prog);
-static struct bpf_link *attach_tp(const struct bpf_program *prog);
-static struct bpf_link *attach_raw_tp(const struct bpf_program *prog);
-static struct bpf_link *attach_trace(const struct bpf_program *prog);
-static struct bpf_link *attach_lsm(const struct bpf_program *prog);
-static struct bpf_link *attach_iter(const struct bpf_program *prog);
+static struct bpf_link *attach_kprobe(const struct bpf_program *prog, long cookie);
+static struct bpf_link *attach_tp(const struct bpf_program *prog, long cookie);
+static struct bpf_link *attach_raw_tp(const struct bpf_program *prog, long cookie);
+static struct bpf_link *attach_trace(const struct bpf_program *prog, long cookie);
+static struct bpf_link *attach_lsm(const struct bpf_program *prog, long cookie);
+static struct bpf_link *attach_iter(const struct bpf_program *prog, long cookie);
 
 static const struct bpf_sec_def section_defs[] = {
-	BPF_PROG_SEC("socket",			BPF_PROG_TYPE_SOCKET_FILTER),
-	BPF_EAPROG_SEC("sk_reuseport/migrate",	BPF_PROG_TYPE_SK_REUSEPORT,
-						BPF_SK_REUSEPORT_SELECT_OR_MIGRATE),
-	BPF_EAPROG_SEC("sk_reuseport",		BPF_PROG_TYPE_SK_REUSEPORT,
-						BPF_SK_REUSEPORT_SELECT),
-	SEC_DEF("kprobe/", KPROBE,
-		.attach_fn = attach_kprobe),
-	BPF_PROG_SEC("uprobe/",			BPF_PROG_TYPE_KPROBE),
-	SEC_DEF("kretprobe/", KPROBE,
-		.attach_fn = attach_kprobe),
-	BPF_PROG_SEC("uretprobe/",		BPF_PROG_TYPE_KPROBE),
-	BPF_PROG_SEC("classifier",		BPF_PROG_TYPE_SCHED_CLS),
-	BPF_PROG_SEC("action",			BPF_PROG_TYPE_SCHED_ACT),
-	SEC_DEF("tracepoint/", TRACEPOINT,
-		.attach_fn = attach_tp),
-	SEC_DEF("tp/", TRACEPOINT,
-		.attach_fn = attach_tp),
-	SEC_DEF("raw_tracepoint/", RAW_TRACEPOINT,
-		.attach_fn = attach_raw_tp),
-	SEC_DEF("raw_tp/", RAW_TRACEPOINT,
-		.attach_fn = attach_raw_tp),
-	SEC_DEF("tp_btf/", TRACING,
-		.expected_attach_type = BPF_TRACE_RAW_TP,
-		.is_attach_btf = true,
-		.attach_fn = attach_trace),
-	SEC_DEF("fentry/", TRACING,
-		.expected_attach_type = BPF_TRACE_FENTRY,
-		.is_attach_btf = true,
-		.attach_fn = attach_trace),
-	SEC_DEF("fmod_ret/", TRACING,
-		.expected_attach_type = BPF_MODIFY_RETURN,
-		.is_attach_btf = true,
-		.attach_fn = attach_trace),
-	SEC_DEF("fexit/", TRACING,
-		.expected_attach_type = BPF_TRACE_FEXIT,
-		.is_attach_btf = true,
-		.attach_fn = attach_trace),
-	SEC_DEF("fentry.s/", TRACING,
-		.expected_attach_type = BPF_TRACE_FENTRY,
-		.is_attach_btf = true,
-		.is_sleepable = true,
-		.attach_fn = attach_trace),
-	SEC_DEF("fmod_ret.s/", TRACING,
-		.expected_attach_type = BPF_MODIFY_RETURN,
-		.is_attach_btf = true,
-		.is_sleepable = true,
-		.attach_fn = attach_trace),
-	SEC_DEF("fexit.s/", TRACING,
-		.expected_attach_type = BPF_TRACE_FEXIT,
-		.is_attach_btf = true,
-		.is_sleepable = true,
-		.attach_fn = attach_trace),
-	SEC_DEF("freplace/", EXT,
-		.is_attach_btf = true,
-		.attach_fn = attach_trace),
-	SEC_DEF("lsm/", LSM,
-		.is_attach_btf = true,
-		.expected_attach_type = BPF_LSM_MAC,
-		.attach_fn = attach_lsm),
-	SEC_DEF("lsm.s/", LSM,
-		.is_attach_btf = true,
-		.is_sleepable = true,
-		.expected_attach_type = BPF_LSM_MAC,
-		.attach_fn = attach_lsm),
-	SEC_DEF("iter/", TRACING,
-		.expected_attach_type = BPF_TRACE_ITER,
-		.is_attach_btf = true,
-		.attach_fn = attach_iter),
-	SEC_DEF("syscall", SYSCALL,
-		.is_sleepable = true),
-	BPF_EAPROG_SEC("xdp_devmap/",		BPF_PROG_TYPE_XDP,
-						BPF_XDP_DEVMAP),
-	BPF_EAPROG_SEC("xdp_cpumap/",		BPF_PROG_TYPE_XDP,
-						BPF_XDP_CPUMAP),
-	BPF_APROG_SEC("xdp",			BPF_PROG_TYPE_XDP,
-						BPF_XDP),
-	BPF_PROG_SEC("perf_event",		BPF_PROG_TYPE_PERF_EVENT),
-	BPF_PROG_SEC("lwt_in",			BPF_PROG_TYPE_LWT_IN),
-	BPF_PROG_SEC("lwt_out",			BPF_PROG_TYPE_LWT_OUT),
-	BPF_PROG_SEC("lwt_xmit",		BPF_PROG_TYPE_LWT_XMIT),
-	BPF_PROG_SEC("lwt_seg6local",		BPF_PROG_TYPE_LWT_SEG6LOCAL),
-	BPF_APROG_SEC("cgroup_skb/ingress",	BPF_PROG_TYPE_CGROUP_SKB,
-						BPF_CGROUP_INET_INGRESS),
-	BPF_APROG_SEC("cgroup_skb/egress",	BPF_PROG_TYPE_CGROUP_SKB,
-						BPF_CGROUP_INET_EGRESS),
-	BPF_APROG_COMPAT("cgroup/skb",		BPF_PROG_TYPE_CGROUP_SKB),
-	BPF_EAPROG_SEC("cgroup/sock_create",	BPF_PROG_TYPE_CGROUP_SOCK,
-						BPF_CGROUP_INET_SOCK_CREATE),
-	BPF_EAPROG_SEC("cgroup/sock_release",	BPF_PROG_TYPE_CGROUP_SOCK,
-						BPF_CGROUP_INET_SOCK_RELEASE),
-	BPF_APROG_SEC("cgroup/sock",		BPF_PROG_TYPE_CGROUP_SOCK,
-						BPF_CGROUP_INET_SOCK_CREATE),
-	BPF_EAPROG_SEC("cgroup/post_bind4",	BPF_PROG_TYPE_CGROUP_SOCK,
-						BPF_CGROUP_INET4_POST_BIND),
-	BPF_EAPROG_SEC("cgroup/post_bind6",	BPF_PROG_TYPE_CGROUP_SOCK,
-						BPF_CGROUP_INET6_POST_BIND),
-	BPF_APROG_SEC("cgroup/dev",		BPF_PROG_TYPE_CGROUP_DEVICE,
-						BPF_CGROUP_DEVICE),
-	BPF_APROG_SEC("sockops",		BPF_PROG_TYPE_SOCK_OPS,
-						BPF_CGROUP_SOCK_OPS),
-	BPF_APROG_SEC("sk_skb/stream_parser",	BPF_PROG_TYPE_SK_SKB,
-						BPF_SK_SKB_STREAM_PARSER),
-	BPF_APROG_SEC("sk_skb/stream_verdict",	BPF_PROG_TYPE_SK_SKB,
-						BPF_SK_SKB_STREAM_VERDICT),
-	BPF_APROG_COMPAT("sk_skb",		BPF_PROG_TYPE_SK_SKB),
-	BPF_APROG_SEC("sk_msg",			BPF_PROG_TYPE_SK_MSG,
-						BPF_SK_MSG_VERDICT),
-	BPF_APROG_SEC("lirc_mode2",		BPF_PROG_TYPE_LIRC_MODE2,
-						BPF_LIRC_MODE2),
-	BPF_APROG_SEC("flow_dissector",		BPF_PROG_TYPE_FLOW_DISSECTOR,
-						BPF_FLOW_DISSECTOR),
-	BPF_EAPROG_SEC("cgroup/bind4",		BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
-						BPF_CGROUP_INET4_BIND),
-	BPF_EAPROG_SEC("cgroup/bind6",		BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
-						BPF_CGROUP_INET6_BIND),
-	BPF_EAPROG_SEC("cgroup/connect4",	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
-						BPF_CGROUP_INET4_CONNECT),
-	BPF_EAPROG_SEC("cgroup/connect6",	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
-						BPF_CGROUP_INET6_CONNECT),
-	BPF_EAPROG_SEC("cgroup/sendmsg4",	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
-						BPF_CGROUP_UDP4_SENDMSG),
-	BPF_EAPROG_SEC("cgroup/sendmsg6",	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
-						BPF_CGROUP_UDP6_SENDMSG),
-	BPF_EAPROG_SEC("cgroup/recvmsg4",	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
-						BPF_CGROUP_UDP4_RECVMSG),
-	BPF_EAPROG_SEC("cgroup/recvmsg6",	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
-						BPF_CGROUP_UDP6_RECVMSG),
-	BPF_EAPROG_SEC("cgroup/getpeername4",	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
-						BPF_CGROUP_INET4_GETPEERNAME),
-	BPF_EAPROG_SEC("cgroup/getpeername6",	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
-						BPF_CGROUP_INET6_GETPEERNAME),
-	BPF_EAPROG_SEC("cgroup/getsockname4",	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
-						BPF_CGROUP_INET4_GETSOCKNAME),
-	BPF_EAPROG_SEC("cgroup/getsockname6",	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
-						BPF_CGROUP_INET6_GETSOCKNAME),
-	BPF_EAPROG_SEC("cgroup/sysctl",		BPF_PROG_TYPE_CGROUP_SYSCTL,
-						BPF_CGROUP_SYSCTL),
-	BPF_EAPROG_SEC("cgroup/getsockopt",	BPF_PROG_TYPE_CGROUP_SOCKOPT,
-						BPF_CGROUP_GETSOCKOPT),
-	BPF_EAPROG_SEC("cgroup/setsockopt",	BPF_PROG_TYPE_CGROUP_SOCKOPT,
-						BPF_CGROUP_SETSOCKOPT),
-	BPF_PROG_SEC("struct_ops",		BPF_PROG_TYPE_STRUCT_OPS),
-	BPF_EAPROG_SEC("sk_lookup/",		BPF_PROG_TYPE_SK_LOOKUP,
-						BPF_SK_LOOKUP),
+	SEC_DEF("socket",		SOCKET_FILTER, 0, SEC_NONE | SEC_SLOPPY_PFX),
+	SEC_DEF("sk_reuseport/migrate",	SK_REUSEPORT, BPF_SK_REUSEPORT_SELECT_OR_MIGRATE, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("sk_reuseport",		SK_REUSEPORT, BPF_SK_REUSEPORT_SELECT, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("kprobe/",		KPROBE,	0, SEC_NONE, attach_kprobe),
+	SEC_DEF("uprobe/",		KPROBE,	0, SEC_NONE),
+	SEC_DEF("kretprobe/",		KPROBE, 0, SEC_NONE, attach_kprobe),
+	SEC_DEF("uretprobe/",		KPROBE, 0, SEC_NONE),
+	SEC_DEF("tc",			SCHED_CLS, 0, SEC_NONE),
+	SEC_DEF("classifier",		SCHED_CLS, 0, SEC_NONE | SEC_SLOPPY_PFX),
+	SEC_DEF("action",		SCHED_ACT, 0, SEC_NONE | SEC_SLOPPY_PFX),
+	SEC_DEF("tracepoint/",		TRACEPOINT, 0, SEC_NONE, attach_tp),
+	SEC_DEF("tp/",			TRACEPOINT, 0, SEC_NONE, attach_tp),
+	SEC_DEF("raw_tracepoint/",	RAW_TRACEPOINT, 0, SEC_NONE, attach_raw_tp),
+	SEC_DEF("raw_tp/",		RAW_TRACEPOINT, 0, SEC_NONE, attach_raw_tp),
+	SEC_DEF("tp_btf/",		TRACING, BPF_TRACE_RAW_TP, SEC_ATTACH_BTF, attach_trace),
+	SEC_DEF("fentry/",		TRACING, BPF_TRACE_FENTRY, SEC_ATTACH_BTF, attach_trace),
+	SEC_DEF("fmod_ret/",		TRACING, BPF_MODIFY_RETURN, SEC_ATTACH_BTF, attach_trace),
+	SEC_DEF("fexit/",		TRACING, BPF_TRACE_FEXIT, SEC_ATTACH_BTF, attach_trace),
+	SEC_DEF("fentry.s/",		TRACING, BPF_TRACE_FENTRY, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_trace),
+	SEC_DEF("fmod_ret.s/",		TRACING, BPF_MODIFY_RETURN, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_trace),
+	SEC_DEF("fexit.s/",		TRACING, BPF_TRACE_FEXIT, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_trace),
+	SEC_DEF("freplace/",		EXT, 0, SEC_ATTACH_BTF, attach_trace),
+	SEC_DEF("lsm/",			LSM, BPF_LSM_MAC, SEC_ATTACH_BTF, attach_lsm),
+	SEC_DEF("lsm.s/",		LSM, BPF_LSM_MAC, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_lsm),
+	SEC_DEF("iter/",		TRACING, BPF_TRACE_ITER, SEC_ATTACH_BTF, attach_iter),
+	SEC_DEF("syscall",		SYSCALL, 0, SEC_SLEEPABLE),
+	SEC_DEF("xdp_devmap/",		XDP, BPF_XDP_DEVMAP, SEC_ATTACHABLE),
+	SEC_DEF("xdp_cpumap/",		XDP, BPF_XDP_CPUMAP, SEC_ATTACHABLE),
+	SEC_DEF("xdp",			XDP, BPF_XDP, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
+	SEC_DEF("perf_event",		PERF_EVENT, 0, SEC_NONE | SEC_SLOPPY_PFX),
+	SEC_DEF("lwt_in",		LWT_IN, 0, SEC_NONE | SEC_SLOPPY_PFX),
+	SEC_DEF("lwt_out",		LWT_OUT, 0, SEC_NONE | SEC_SLOPPY_PFX),
+	SEC_DEF("lwt_xmit",		LWT_XMIT, 0, SEC_NONE | SEC_SLOPPY_PFX),
+	SEC_DEF("lwt_seg6local",	LWT_SEG6LOCAL, 0, SEC_NONE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup_skb/ingress",	CGROUP_SKB, BPF_CGROUP_INET_INGRESS, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup_skb/egress",	CGROUP_SKB, BPF_CGROUP_INET_EGRESS, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/skb",		CGROUP_SKB, 0, SEC_NONE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/sock_create",	CGROUP_SOCK, BPF_CGROUP_INET_SOCK_CREATE, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/sock_release",	CGROUP_SOCK, BPF_CGROUP_INET_SOCK_RELEASE, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/sock",		CGROUP_SOCK, BPF_CGROUP_INET_SOCK_CREATE, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/post_bind4",	CGROUP_SOCK, BPF_CGROUP_INET4_POST_BIND, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/post_bind6",	CGROUP_SOCK, BPF_CGROUP_INET6_POST_BIND, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/dev",		CGROUP_DEVICE, BPF_CGROUP_DEVICE, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
+	SEC_DEF("sockops",		SOCK_OPS, BPF_CGROUP_SOCK_OPS, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
+	SEC_DEF("sk_skb/stream_parser",	SK_SKB, BPF_SK_SKB_STREAM_PARSER, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
+	SEC_DEF("sk_skb/stream_verdict",SK_SKB, BPF_SK_SKB_STREAM_VERDICT, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
+	SEC_DEF("sk_skb",		SK_SKB, 0, SEC_NONE | SEC_SLOPPY_PFX),
+	SEC_DEF("sk_msg",		SK_MSG, BPF_SK_MSG_VERDICT, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
+	SEC_DEF("lirc_mode2",		LIRC_MODE2, BPF_LIRC_MODE2, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
+	SEC_DEF("flow_dissector",	FLOW_DISSECTOR, BPF_FLOW_DISSECTOR, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/bind4",		CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_BIND, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/bind6",		CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_BIND, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/connect4",	CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_CONNECT, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/connect6",	CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_CONNECT, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/sendmsg4",	CGROUP_SOCK_ADDR, BPF_CGROUP_UDP4_SENDMSG, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/sendmsg6",	CGROUP_SOCK_ADDR, BPF_CGROUP_UDP6_SENDMSG, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/recvmsg4",	CGROUP_SOCK_ADDR, BPF_CGROUP_UDP4_RECVMSG, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/recvmsg6",	CGROUP_SOCK_ADDR, BPF_CGROUP_UDP6_RECVMSG, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/getpeername4",	CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_GETPEERNAME, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/getpeername6",	CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_GETPEERNAME, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/getsockname4",	CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_GETSOCKNAME, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/getsockname6",	CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_GETSOCKNAME, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/sysctl",	CGROUP_SYSCTL, BPF_CGROUP_SYSCTL, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/getsockopt",	CGROUP_SOCKOPT, BPF_CGROUP_GETSOCKOPT, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/setsockopt",	CGROUP_SOCKOPT, BPF_CGROUP_SETSOCKOPT, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("struct_ops+",		STRUCT_OPS, 0, SEC_NONE),
+	SEC_DEF("sk_lookup",		SK_LOOKUP, BPF_SK_LOOKUP, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
 };
 
-#undef BPF_PROG_SEC_IMPL
-#undef BPF_PROG_SEC
-#undef BPF_APROG_SEC
-#undef BPF_EAPROG_SEC
-#undef BPF_APROG_COMPAT
-#undef SEC_DEF
-
 #define MAX_TYPE_NAME_SIZE 32
 
 static const struct bpf_sec_def *find_sec_def(const char *sec_name)
 {
-	int i, n = ARRAY_SIZE(section_defs);
+	const struct bpf_sec_def *sec_def;
+	enum sec_def_flags sec_flags;
+	int i, n = ARRAY_SIZE(section_defs), len;
+	bool strict = libbpf_mode & LIBBPF_STRICT_SEC_NAME;
 
 	for (i = 0; i < n; i++) {
-		if (strncmp(sec_name,
-			    section_defs[i].sec, section_defs[i].len))
+		sec_def = &section_defs[i];
+		sec_flags = sec_def->cookie;
+		len = strlen(sec_def->sec);
+
+		/* "type/" always has to have proper SEC("type/extras") form */
+		if (sec_def->sec[len - 1] == '/') {
+			if (str_has_pfx(sec_name, sec_def->sec))
+				return sec_def;
+			continue;
+		}
+
+		/* "type+" means it can be either exact SEC("type") or
+		 * well-formed SEC("type/extras") with proper '/' separator
+		 */
+		if (sec_def->sec[len - 1] == '+') {
+			len--;
+			/* not even a prefix */
+			if (strncmp(sec_name, sec_def->sec, len) != 0)
+				continue;
+			/* exact match or has '/' separator */
+			if (sec_name[len] == '\0' || sec_name[len] == '/')
+				return sec_def;
+			continue;
+		}
+
+		/* SEC_SLOPPY_PFX definitions are allowed to be just prefix
+		 * matches, unless strict section name mode
+		 * (LIBBPF_STRICT_SEC_NAME) is enabled, in which case the
+		 * match has to be exact.
+		 */
+		if ((sec_flags & SEC_SLOPPY_PFX) && !strict)  {
+			if (str_has_pfx(sec_name, sec_def->sec))
+				return sec_def;
 			continue;
-		return &section_defs[i];
+		}
+
+		/* Definitions not marked SEC_SLOPPY_PFX (e.g.,
+		 * SEC("syscall")) are exact matches in both modes.
+		 */
+		if (strcmp(sec_name, sec_def->sec) == 0)
+			return sec_def;
 	}
 	return NULL;
 }
@@ -8135,8 +8151,15 @@ static char *libbpf_get_type_names(bool attach_type)
 	buf[0] = '\0';
 	/* Forge string buf with all available names */
 	for (i = 0; i < ARRAY_SIZE(section_defs); i++) {
-		if (attach_type && !section_defs[i].is_attachable)
-			continue;
+		const struct bpf_sec_def *sec_def = &section_defs[i];
+
+		if (attach_type) {
+			if (sec_def->preload_fn != libbpf_preload_prog)
+				continue;
+
+			if (!(sec_def->cookie & SEC_ATTACHABLE))
+				continue;
+		}
 
 		if (strlen(buf) + strlen(section_defs[i].sec) + 2 > len) {
 			free(buf);
@@ -8460,20 +8483,13 @@ static int find_kernel_btf_id(struct bpf_object *obj, const char *attach_name,
 	return -ESRCH;
 }
 
-static int libbpf_find_attach_btf_id(struct bpf_program *prog, int *btf_obj_fd, int *btf_type_id)
+static int libbpf_find_attach_btf_id(struct bpf_program *prog, const char *attach_name,
+				     int *btf_obj_fd, int *btf_type_id)
 {
 	enum bpf_attach_type attach_type = prog->expected_attach_type;
 	__u32 attach_prog_fd = prog->attach_prog_fd;
-	const char *attach_name;
 	int err = 0;
 
-	if (!prog->sec_def || !prog->sec_def->is_attach_btf) {
-		pr_warn("failed to identify BTF ID based on ELF section name '%s'\n",
-			prog->sec_name);
-		return -ESRCH;
-	}
-	attach_name = prog->sec_name + prog->sec_def->len;
-
 	/* BPF program's BTF ID */
 	if (attach_prog_fd) {
 		err = libbpf_find_prog_btf_id(attach_name, attach_prog_fd);
@@ -8523,7 +8539,9 @@ int libbpf_attach_type_by_name(const char *name,
 		return libbpf_err(-EINVAL);
 	}
 
-	if (!sec_def->is_attachable)
+	if (sec_def->preload_fn != libbpf_preload_prog)
+		return libbpf_err(-EINVAL);
+	if (!(sec_def->cookie & SEC_ATTACHABLE))
 		return libbpf_err(-EINVAL);
 
 	*attach_type = sec_def->expected_attach_type;
@@ -9011,59 +9029,18 @@ int bpf_link__unpin(struct bpf_link *link)
 	return 0;
 }
 
-static int poke_kprobe_events(bool add, const char *name, bool retprobe, uint64_t offset)
-{
-	int fd, ret = 0;
-	pid_t p = getpid();
-	char cmd[260], probename[128], probefunc[128];
-	const char *file = "/sys/kernel/debug/tracing/kprobe_events";
-
-	if (retprobe)
-		snprintf(probename, sizeof(probename), "kretprobes/%s_libbpf_%u", name, p);
-	else
-		snprintf(probename, sizeof(probename), "kprobes/%s_libbpf_%u", name, p);
-
-	if (offset)
-		snprintf(probefunc, sizeof(probefunc), "%s+%zu", name, (size_t)offset);
-
-	if (add) {
-		snprintf(cmd, sizeof(cmd), "%c:%s %s",
-			 retprobe ? 'r' : 'p',
-			 probename,
-			 offset ? probefunc : name);
-	} else {
-		snprintf(cmd, sizeof(cmd), "-:%s", probename);
-	}
-
-	fd = open(file, O_WRONLY | O_APPEND, 0);
-	if (!fd)
-		return -errno;
-	ret = write(fd, cmd, strlen(cmd));
-	if (ret < 0)
-		ret = -errno;
-	close(fd);
-
-	return ret;
-}
-
-static inline int add_kprobe_event_legacy(const char *name, bool retprobe, uint64_t offset)
-{
-	return poke_kprobe_events(true, name, retprobe, offset);
-}
-
-static inline int remove_kprobe_event_legacy(const char *name, bool retprobe)
-{
-	return poke_kprobe_events(false, name, retprobe, 0);
-}
-
 struct bpf_link_perf {
 	struct bpf_link link;
 	int perf_event_fd;
 	/* legacy kprobe support: keep track of probe identifier and type */
 	char *legacy_probe_name;
+	bool legacy_is_kprobe;
 	bool legacy_is_retprobe;
 };
 
+static int remove_kprobe_event_legacy(const char *probe_name, bool retprobe);
+static int remove_uprobe_event_legacy(const char *probe_name, bool retprobe);
+
 static int bpf_link_perf_detach(struct bpf_link *link)
 {
 	struct bpf_link_perf *perf_link = container_of(link, struct bpf_link_perf, link);
@@ -9076,10 +9053,16 @@ static int bpf_link_perf_detach(struct bpf_link *link)
 		close(perf_link->perf_event_fd);
 	close(link->fd);
 
-	/* legacy kprobe needs to be removed after perf event fd closure */
-	if (perf_link->legacy_probe_name)
-		err = remove_kprobe_event_legacy(perf_link->legacy_probe_name,
-						 perf_link->legacy_is_retprobe);
+	/* legacy uprobe/kprobe needs to be removed after perf event fd closure */
+	if (perf_link->legacy_probe_name) {
+		if (perf_link->legacy_is_kprobe) {
+			err = remove_kprobe_event_legacy(perf_link->legacy_probe_name,
+							 perf_link->legacy_is_retprobe);
+		} else {
+			err = remove_uprobe_event_legacy(perf_link->legacy_probe_name,
+							 perf_link->legacy_is_retprobe);
+		}
+	}
 
 	return err;
 }
@@ -9202,18 +9185,6 @@ static int parse_uint_from_file(const char *file, const char *fmt)
 	return ret;
 }
 
-static int determine_kprobe_perf_type_legacy(const char *func_name, bool is_retprobe)
-{
-	char file[192];
-
-	snprintf(file, sizeof(file),
-		 "/sys/kernel/debug/tracing/events/%s/%s_libbpf_%d/id",
-		 is_retprobe ? "kretprobes" : "kprobes",
-		 func_name, getpid());
-
-	return parse_uint_from_file(file, "%d\n");
-}
-
 static int determine_kprobe_perf_type(void)
 {
 	const char *file = "/sys/bus/event_source/devices/kprobe/type";
@@ -9296,21 +9267,79 @@ static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name,
 	return pfd;
 }
 
-static int perf_event_kprobe_open_legacy(bool retprobe, const char *name, uint64_t offset, int pid)
+static int append_to_file(const char *file, const char *fmt, ...)
+{
+	int fd, n, err = 0;
+	va_list ap;
+
+	fd = open(file, O_WRONLY | O_APPEND, 0);
+	if (fd < 0)
+		return -errno;
+
+	va_start(ap, fmt);
+	n = vdprintf(fd, fmt, ap);
+	va_end(ap);
+
+	if (n < 0)
+		err = -errno;
+
+	close(fd);
+	return err;
+}
+
+static void gen_kprobe_legacy_event_name(char *buf, size_t buf_sz,
+					 const char *kfunc_name, size_t offset)
+{
+	snprintf(buf, buf_sz, "libbpf_%u_%s_0x%zx", getpid(), kfunc_name, offset);
+}
+
+static int add_kprobe_event_legacy(const char *probe_name, bool retprobe,
+				   const char *kfunc_name, size_t offset)
+{
+	const char *file = "/sys/kernel/debug/tracing/kprobe_events";
+
+	return append_to_file(file, "%c:%s/%s %s+0x%zx",
+			      retprobe ? 'r' : 'p',
+			      retprobe ? "kretprobes" : "kprobes",
+			      probe_name, kfunc_name, offset);
+}
+
+static int remove_kprobe_event_legacy(const char *probe_name, bool retprobe)
+{
+	const char *file = "/sys/kernel/debug/tracing/kprobe_events";
+
+	return append_to_file(file, "-:%s/%s", retprobe ? "kretprobes" : "kprobes", probe_name);
+}
+
+static int determine_kprobe_perf_type_legacy(const char *probe_name, bool retprobe)
+{
+	char file[256];
+
+	snprintf(file, sizeof(file),
+		 "/sys/kernel/debug/tracing/events/%s/%s/id",
+		 retprobe ? "kretprobes" : "kprobes", probe_name);
+
+	return parse_uint_from_file(file, "%d\n");
+}
+
+static int perf_event_kprobe_open_legacy(const char *probe_name, bool retprobe,
+					 const char *kfunc_name, size_t offset, int pid)
 {
 	struct perf_event_attr attr = {};
 	char errmsg[STRERR_BUFSIZE];
 	int type, pfd, err;
 
-	err = add_kprobe_event_legacy(name, retprobe, offset);
+	err = add_kprobe_event_legacy(probe_name, retprobe, kfunc_name, offset);
 	if (err < 0) {
-		pr_warn("failed to add legacy kprobe event: %s\n",
+		pr_warn("failed to add legacy kprobe event for '%s+0x%zx': %s\n",
+			kfunc_name, offset,
 			libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
 		return err;
 	}
-	type = determine_kprobe_perf_type_legacy(name, retprobe);
+	type = determine_kprobe_perf_type_legacy(probe_name, retprobe);
 	if (type < 0) {
-		pr_warn("failed to determine legacy kprobe event id: %s\n",
+		pr_warn("failed to determine legacy kprobe event id for '%s+0x%zx': %s\n",
+			kfunc_name, offset,
 			libbpf_strerror_r(type, errmsg, sizeof(errmsg)));
 		return type;
 	}
@@ -9340,7 +9369,7 @@ bpf_program__attach_kprobe_opts(const struct bpf_program *prog,
 	char errmsg[STRERR_BUFSIZE];
 	char *legacy_probe = NULL;
 	struct bpf_link *link;
-	unsigned long offset;
+	size_t offset;
 	bool retprobe, legacy;
 	int pfd, err;
 
@@ -9357,36 +9386,48 @@ bpf_program__attach_kprobe_opts(const struct bpf_program *prog,
 					    func_name, offset,
 					    -1 /* pid */, 0 /* ref_ctr_off */);
 	} else {
+		char probe_name[256];
+
+		gen_kprobe_legacy_event_name(probe_name, sizeof(probe_name),
+					     func_name, offset);
+
 		legacy_probe = strdup(func_name);
 		if (!legacy_probe)
 			return libbpf_err_ptr(-ENOMEM);
 
-		pfd = perf_event_kprobe_open_legacy(retprobe, func_name,
+		pfd = perf_event_kprobe_open_legacy(legacy_probe, retprobe, func_name,
 						    offset, -1 /* pid */);
 	}
 	if (pfd < 0) {
-		pr_warn("prog '%s': failed to create %s '%s' perf event: %s\n",
-			prog->name, retprobe ? "kretprobe" : "kprobe", func_name,
-			libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
-		return libbpf_err_ptr(pfd);
+		err = -errno;
+		pr_warn("prog '%s': failed to create %s '%s+0x%zx' perf event: %s\n",
+			prog->name, retprobe ? "kretprobe" : "kprobe",
+			func_name, offset,
+			libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
+		goto err_out;
 	}
 	link = bpf_program__attach_perf_event_opts(prog, pfd, &pe_opts);
 	err = libbpf_get_error(link);
 	if (err) {
 		close(pfd);
-		pr_warn("prog '%s': failed to attach to %s '%s': %s\n",
-			prog->name, retprobe ? "kretprobe" : "kprobe", func_name,
+		pr_warn("prog '%s': failed to attach to %s '%s+0x%zx': %s\n",
+			prog->name, retprobe ? "kretprobe" : "kprobe",
+			func_name, offset,
 			libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
-		return libbpf_err_ptr(err);
+		goto err_out;
 	}
 	if (legacy) {
 		struct bpf_link_perf *perf_link = container_of(link, struct bpf_link_perf, link);
 
 		perf_link->legacy_probe_name = legacy_probe;
+		perf_link->legacy_is_kprobe = true;
 		perf_link->legacy_is_retprobe = retprobe;
 	}
 
 	return link;
+err_out:
+	free(legacy_probe);
+	return libbpf_err_ptr(err);
 }
 
 struct bpf_link *bpf_program__attach_kprobe(const struct bpf_program *prog,
@@ -9400,7 +9441,7 @@ struct bpf_link *bpf_program__attach_kprobe(const struct bpf_program *prog,
 	return bpf_program__attach_kprobe_opts(prog, func_name, &opts);
 }
 
-static struct bpf_link *attach_kprobe(const struct bpf_program *prog)
+static struct bpf_link *attach_kprobe(const struct bpf_program *prog, long cookie)
 {
 	DECLARE_LIBBPF_OPTS(bpf_kprobe_opts, opts);
 	unsigned long offset = 0;
@@ -9409,8 +9450,11 @@ static struct bpf_link *attach_kprobe(const struct bpf_program *prog)
 	char *func;
 	int n, err;
 
-	func_name = prog->sec_name + prog->sec_def->len;
-	opts.retprobe = strcmp(prog->sec_def->sec, "kretprobe/") == 0;
+	opts.retprobe = str_has_pfx(prog->sec_name, "kretprobe/");
+	if (opts.retprobe)
+		func_name = prog->sec_name + sizeof("kretprobe/") - 1;
+	else
+		func_name = prog->sec_name + sizeof("kprobe/") - 1;
 
 	n = sscanf(func_name, "%m[a-zA-Z0-9_.]+%li", &func, &offset);
 	if (n < 1) {
@@ -9431,17 +9475,96 @@ static struct bpf_link *attach_kprobe(const struct bpf_program *prog)
 	return link;
 }
 
+static void gen_uprobe_legacy_event_name(char *buf, size_t buf_sz,
+					 const char *binary_path, uint64_t offset)
+{
+	int i;
+
+	snprintf(buf, buf_sz, "libbpf_%u_%s_0x%zx", getpid(), binary_path, (size_t)offset);
+
+	/* sanitize binary_path in the probe name */
+	for (i = 0; buf[i]; i++) {
+		if (!isalnum(buf[i]))
+			buf[i] = '_';
+	}
+}
+
+static inline int add_uprobe_event_legacy(const char *probe_name, bool retprobe,
+					  const char *binary_path, size_t offset)
+{
+	const char *file = "/sys/kernel/debug/tracing/uprobe_events";
+
+	return append_to_file(file, "%c:%s/%s %s:0x%zx",
+			      retprobe ? 'r' : 'p',
+			      retprobe ? "uretprobes" : "uprobes",
+			      probe_name, binary_path, offset);
+}
+
+static inline int remove_uprobe_event_legacy(const char *probe_name, bool retprobe)
+{
+	const char *file = "/sys/kernel/debug/tracing/uprobe_events";
+
+	return append_to_file(file, "-:%s/%s", retprobe ? "uretprobes" : "uprobes", probe_name);
+}
+
+static int determine_uprobe_perf_type_legacy(const char *probe_name, bool retprobe)
+{
+	char file[512];
+
+	snprintf(file, sizeof(file),
+		 "/sys/kernel/debug/tracing/events/%s/%s/id",
+		 retprobe ? "uretprobes" : "uprobes", probe_name);
+
+	return parse_uint_from_file(file, "%d\n");
+}
+
+static int perf_event_uprobe_open_legacy(const char *probe_name, bool retprobe,
+					 const char *binary_path, size_t offset, int pid)
+{
+	struct perf_event_attr attr;
+	int type, pfd, err;
+
+	err = add_uprobe_event_legacy(probe_name, retprobe, binary_path, offset);
+	if (err < 0) {
+		pr_warn("failed to add legacy uprobe event for %s:0x%zx: %d\n",
+			binary_path, (size_t)offset, err);
+		return err;
+	}
+	type = determine_uprobe_perf_type_legacy(probe_name, retprobe);
+	if (type < 0) {
+		pr_warn("failed to determine legacy uprobe event id for %s:0x%zx: %d\n",
+			binary_path, offset, err);
+		return type;
+	}
+
+	memset(&attr, 0, sizeof(attr));
+	attr.size = sizeof(attr);
+	attr.config = type;
+	attr.type = PERF_TYPE_TRACEPOINT;
+
+	pfd = syscall(__NR_perf_event_open, &attr,
+		      pid < 0 ? -1 : pid, /* pid */
+		      pid == -1 ? 0 : -1, /* cpu */
+		      -1 /* group_fd */,  PERF_FLAG_FD_CLOEXEC);
+	if (pfd < 0) {
+		err = -errno;
+		pr_warn("legacy uprobe perf_event_open() failed: %d\n", err);
+		return err;
+	}
+	return pfd;
+}
+
 LIBBPF_API struct bpf_link *
 bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid,
 				const char *binary_path, size_t func_offset,
 				const struct bpf_uprobe_opts *opts)
 {
 	DECLARE_LIBBPF_OPTS(bpf_perf_event_opts, pe_opts);
-	char errmsg[STRERR_BUFSIZE];
+	char errmsg[STRERR_BUFSIZE], *legacy_probe = NULL;
 	struct bpf_link *link;
 	size_t ref_ctr_off;
 	int pfd, err;
-	bool retprobe;
+	bool retprobe, legacy;
 
 	if (!OPTS_VALID(opts, bpf_uprobe_opts))
 		return libbpf_err_ptr(-EINVAL);
@@ -9450,15 +9573,35 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid,
 	ref_ctr_off = OPTS_GET(opts, ref_ctr_offset, 0);
 	pe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0);
 
-	pfd = perf_event_open_probe(true /* uprobe */, retprobe, binary_path,
-				    func_offset, pid, ref_ctr_off);
+	legacy = determine_uprobe_perf_type() < 0;
+	if (!legacy) {
+		pfd = perf_event_open_probe(true /* uprobe */, retprobe, binary_path,
+					    func_offset, pid, ref_ctr_off);
+	} else {
+		char probe_name[512];
+
+		if (ref_ctr_off)
+			return libbpf_err_ptr(-EINVAL);
+
+		gen_uprobe_legacy_event_name(probe_name, sizeof(probe_name),
+					     binary_path, func_offset);
+
+		legacy_probe = strdup(probe_name);
+		if (!legacy_probe)
+			return libbpf_err_ptr(-ENOMEM);
+
+		pfd = perf_event_uprobe_open_legacy(legacy_probe, retprobe,
+						    binary_path, func_offset, pid);
+	}
 	if (pfd < 0) {
+		err = -errno;
 		pr_warn("prog '%s': failed to create %s '%s:0x%zx' perf event: %s\n",
 			prog->name, retprobe ? "uretprobe" : "uprobe",
 			binary_path, func_offset,
-			libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
-		return libbpf_err_ptr(pfd);
+			libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
+		goto err_out;
 	}
+
 	link = bpf_program__attach_perf_event_opts(prog, pfd, &pe_opts);
 	err = libbpf_get_error(link);
 	if (err) {
@@ -9467,9 +9610,20 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid,
 			prog->name, retprobe ? "uretprobe" : "uprobe",
 			binary_path, func_offset,
 			libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
-		return libbpf_err_ptr(err);
+		goto err_out;
+	}
+	if (legacy) {
+		struct bpf_link_perf *perf_link = container_of(link, struct bpf_link_perf, link);
+
+		perf_link->legacy_probe_name = legacy_probe;
+		perf_link->legacy_is_kprobe = false;
+		perf_link->legacy_is_retprobe = retprobe;
 	}
 	return link;
+err_out:
+	free(legacy_probe);
+	return libbpf_err_ptr(err);
+
 }
 
 struct bpf_link *bpf_program__attach_uprobe(const struct bpf_program *prog,
@@ -9573,7 +9727,7 @@ struct bpf_link *bpf_program__attach_tracepoint(const struct bpf_program *prog,
 	return bpf_program__attach_tracepoint_opts(prog, tp_category, tp_name, NULL);
 }
 
-static struct bpf_link *attach_tp(const struct bpf_program *prog)
+static struct bpf_link *attach_tp(const struct bpf_program *prog, long cookie)
 {
 	char *sec_name, *tp_cat, *tp_name;
 	struct bpf_link *link;
@@ -9582,8 +9736,11 @@ static struct bpf_link *attach_tp(const struct bpf_program *prog)
 	if (!sec_name)
 		return libbpf_err_ptr(-ENOMEM);
 
-	/* extract "tp/<category>/<name>" */
-	tp_cat = sec_name + prog->sec_def->len;
+	/* extract "tp/<category>/<name>" or "tracepoint/<category>/<name>" */
+	if (str_has_pfx(prog->sec_name, "tp/"))
+		tp_cat = sec_name + sizeof("tp/") - 1;
+	else
+		tp_cat = sec_name + sizeof("tracepoint/") - 1;
 	tp_name = strchr(tp_cat, '/');
 	if (!tp_name) {
 		free(sec_name);
@@ -9627,9 +9784,14 @@ struct bpf_link *bpf_program__attach_raw_tracepoint(const struct bpf_program *pr
 	return link;
 }
 
-static struct bpf_link *attach_raw_tp(const struct bpf_program *prog)
+static struct bpf_link *attach_raw_tp(const struct bpf_program *prog, long cookie)
 {
-	const char *tp_name = prog->sec_name + prog->sec_def->len;
+	const char *tp_name;
+
+	if (str_has_pfx(prog->sec_name, "raw_tp/"))
+		tp_name = prog->sec_name + sizeof("raw_tp/") - 1;
+	else
+		tp_name = prog->sec_name + sizeof("raw_tracepoint/") - 1;
 
 	return bpf_program__attach_raw_tracepoint(prog, tp_name);
 }
@@ -9674,12 +9836,12 @@ struct bpf_link *bpf_program__attach_lsm(const struct bpf_program *prog)
 	return bpf_program__attach_btf_id(prog);
 }
 
-static struct bpf_link *attach_trace(const struct bpf_program *prog)
+static struct bpf_link *attach_trace(const struct bpf_program *prog, long cookie)
 {
 	return bpf_program__attach_trace(prog);
 }
 
-static struct bpf_link *attach_lsm(const struct bpf_program *prog)
+static struct bpf_link *attach_lsm(const struct bpf_program *prog, long cookie)
 {
 	return bpf_program__attach_lsm(prog);
 }
@@ -9810,7 +9972,7 @@ bpf_program__attach_iter(const struct bpf_program *prog,
 	return link;
 }
 
-static struct bpf_link *attach_iter(const struct bpf_program *prog)
+static struct bpf_link *attach_iter(const struct bpf_program *prog, long cookie)
 {
 	return bpf_program__attach_iter(prog, NULL);
 }
@@ -9820,7 +9982,7 @@ struct bpf_link *bpf_program__attach(const struct bpf_program *prog)
 	if (!prog->sec_def || !prog->sec_def->attach_fn)
 		return libbpf_err_ptr(-ESRCH);
 
-	return prog->sec_def->attach_fn(prog);
+	return prog->sec_def->attach_fn(prog, prog->sec_def->cookie);
 }
 
 static int bpf_link__detach_struct_ops(struct bpf_link *link)
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index c90e3d79e72c..e35490c54eb3 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -269,7 +269,7 @@ struct bpf_kprobe_opts {
 	/* custom user-provided value fetchable through bpf_get_attach_cookie() */
 	__u64 bpf_cookie;
 	/* function's offset to install kprobe to */
-	unsigned long offset;
+	size_t offset;
 	/* kprobe is return probe */
 	bool retprobe;
 	size_t :0;
@@ -481,9 +481,13 @@ struct bpf_map_def {
 	unsigned int map_flags;
 };
 
-/*
- * The 'struct bpf_map' in include/linux/bpf.h is internal to the kernel,
- * so no need to worry about a name clash.
+/**
+ * @brief **bpf_object__find_map_by_name()** returns BPF map of
+ * the given name, if it exists within the passed BPF object
+ * @param obj BPF object
+ * @param name name of the BPF map
+ * @return BPF map instance, if such map exists within the BPF object;
+ * or NULL otherwise.
  */
 LIBBPF_API struct bpf_map *
 bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name);
@@ -509,7 +513,12 @@ bpf_map__next(const struct bpf_map *map, const struct bpf_object *obj);
 LIBBPF_API struct bpf_map *
 bpf_map__prev(const struct bpf_map *map, const struct bpf_object *obj);
 
-/* get/set map FD */
+/**
+ * @brief **bpf_map__fd()** gets the file descriptor of the passed
+ * BPF map
+ * @param map the BPF map instance
+ * @return the file descriptor; or -EINVAL in case of an error
+ */
 LIBBPF_API int bpf_map__fd(const struct bpf_map *map);
 LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd);
 /* get map definition */
@@ -550,6 +559,14 @@ LIBBPF_API int bpf_map__set_initial_value(struct bpf_map *map,
 					  const void *data, size_t size);
 LIBBPF_API const void *bpf_map__initial_value(struct bpf_map *map, size_t *psize);
 LIBBPF_API bool bpf_map__is_offload_neutral(const struct bpf_map *map);
+
+/**
+ * @brief **bpf_map__is_internal()** tells the caller whether or not the
+ * passed map is a special map created by libbpf automatically for things like
+ * global variables, __ksym externs, Kconfig values, etc
+ * @param map the bpf_map
+ * @return true, if the map is an internal map; false, otherwise
+ */
 LIBBPF_API bool bpf_map__is_internal(const struct bpf_map *map);
 LIBBPF_API int bpf_map__set_pin_path(struct bpf_map *map, const char *path);
 LIBBPF_API const char *bpf_map__get_pin_path(const struct bpf_map *map);
@@ -561,6 +578,38 @@ LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path);
 LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd);
 LIBBPF_API struct bpf_map *bpf_map__inner_map(struct bpf_map *map);
 
+/**
+ * @brief **libbpf_get_error()** extracts the error code from the passed
+ * pointer
+ * @param ptr pointer returned from libbpf API function
+ * @return error code; or 0 if no error occured
+ *
+ * Many libbpf API functions which return pointers have logic to encode error
+ * codes as pointers, and do not return NULL. Meaning **libbpf_get_error()**
+ * should be used on the return value from these functions immediately after
+ * calling the API function, with no intervening calls that could clobber the
+ * `errno` variable. Consult the individual functions documentation to verify
+ * if this logic applies should be used.
+ *
+ * For these API functions, if `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)`
+ * is enabled, NULL is returned on error instead.
+ *
+ * If ptr is NULL, then errno should be already set by the failing
+ * API, because libbpf never returns NULL on success and it now always
+ * sets errno on error.
+ *
+ * Example usage:
+ *
+ *   struct perf_buffer *pb;
+ *
+ *   pb = perf_buffer__new(bpf_map__fd(obj->maps.events), PERF_BUFFER_PAGES, &opts);
+ *   err = libbpf_get_error(pb);
+ *   if (err) {
+ *	  pb = NULL;
+ *	  fprintf(stderr, "failed to open perf buffer: %d\n", err);
+ *	  goto cleanup;
+ *   }
+ */
 LIBBPF_API long libbpf_get_error(const void *ptr);
 
 struct bpf_prog_load_attr {
@@ -825,9 +874,10 @@ bpf_program__bpil_addr_to_offs(struct bpf_prog_info_linear *info_linear);
 LIBBPF_API void
 bpf_program__bpil_offs_to_addr(struct bpf_prog_info_linear *info_linear);
 
-/*
- * A helper function to get the number of possible CPUs before looking up
- * per-CPU maps. Negative errno is returned on failure.
+/**
+ * @brief **libbpf_num_possible_cpus()** is a helper function to get the
+ * number of possible CPUs that the host kernel supports and expects.
+ * @return number of possible CPUs; or error code on failure
  *
  * Example usage:
  *
@@ -837,7 +887,6 @@ bpf_program__bpil_offs_to_addr(struct bpf_prog_info_linear *info_linear);
  *     }
  *     long values[ncpus];
  *     bpf_map_lookup_elem(per_cpu_map_fd, key, values);
- *
  */
 LIBBPF_API int libbpf_num_possible_cpus(void);
 
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index ceb0c98979bc..ec79400517d4 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h
@@ -89,6 +89,13 @@
 	(offsetof(TYPE, FIELD) + sizeof(((TYPE *)0)->FIELD))
 #endif
 
+/* Check whether a string `str` has prefix `pfx`, regardless if `pfx` is
+ * a string literal known at compilation time or char * pointer known only at
+ * runtime.
+ */
+#define str_has_pfx(str, pfx) \
+	(strncmp(str, pfx, __builtin_constant_p(pfx) ? sizeof(pfx) - 1 : strlen(pfx)) == 0)
+
 /* Symbol versioning is different between static and shared library.
  * Properly versioned symbols are needed for shared library, but
  * only the symbol of the new version is needed for static library.
diff --git a/tools/lib/bpf/libbpf_legacy.h b/tools/lib/bpf/libbpf_legacy.h
index df0d03dcffab..74e6f860f703 100644
--- a/tools/lib/bpf/libbpf_legacy.h
+++ b/tools/lib/bpf/libbpf_legacy.h
@@ -46,6 +46,15 @@ enum libbpf_strict_mode {
 	 */
 	LIBBPF_STRICT_DIRECT_ERRS = 0x02,
 
+	/*
+	 * Enforce strict BPF program section (SEC()) names.
+	 * E.g., while prefiously SEC("xdp_whatever") or SEC("perf_event_blah") were
+	 * allowed, with LIBBPF_STRICT_SEC_PREFIX this will become
+	 * unrecognized by libbpf and would have to be just SEC("xdp") and
+	 * SEC("xdp") and SEC("perf_event").
+	 */
+	LIBBPF_STRICT_SEC_NAME = 0x04,
+
 	__LIBBPF_STRICT_LAST,
 };
 
diff --git a/tools/lib/bpf/skel_internal.h b/tools/lib/bpf/skel_internal.h
index b22b50c1b173..9cf66702fa8d 100644
--- a/tools/lib/bpf/skel_internal.h
+++ b/tools/lib/bpf/skel_internal.h
@@ -105,10 +105,12 @@ static inline int bpf_load_and_run(struct bpf_load_and_run_opts *opts)
 	err = skel_sys_bpf(BPF_PROG_RUN, &attr, sizeof(attr));
 	if (err < 0 || (int)attr.test.retval < 0) {
 		opts->errstr = "failed to execute loader prog";
-		if (err < 0)
+		if (err < 0) {
 			err = -errno;
-		else
+		} else {
 			err = (int)attr.test.retval;
+			errno = -err;
+		}
 		goto out;
 	}
 	err = 0;