Merge branch 'libbpf-api'

Andrii Nakryiko says:

====================
Add bpf_object__open_file() and bpf_object__open_mem() APIs that use a new
approach to providing future-proof non-ABI-breaking API changes. It relies on
APIs accepting optional self-describing "opts" struct, containing its own
size, filled out and provided by potentially outdated (as well as
newer-than-libbpf) user application. A set of internal helper macros
(OPTS_VALID, OPTS_HAS, and OPTS_GET) streamline and simplify a graceful
handling forward and backward compatibility for user applications dynamically
linked against different versions of libbpf shared library.

Users of libbpf are provided with convenience macro LIBBPF_OPTS that takes
care of populating correct structure size and zero-initializes options struct,
which helps avoid obscure issues of unitialized padding. Uninitialized padding
in a struct might turn into garbage-populated new fields understood by future
versions of libbpf.

Patch #1 removes enforcement of kern_version in libbpf and always populates
correct one on behalf of users.
Patch #2 defines necessary infrastructure for options and two new open APIs
relying on it.
Patch #3 fixes bug in bpf_object__name().
Patch #4 switches two of test_progs' tests to use new APIs as a validation
that they work as expected.

v2->v3:
- fix LIBBPF_OPTS() to ensure zero-initialization of padded bytes;
- pass through name override and relaxed maps flag for open_file() (Toke);
- fix bpf_object__name() to actually return object name;
- don't bother parsing and verifying version section (John);

v1->v2:
- use better approach for tracking last field in opts struct;
- convert few tests to new APIs for validation;
- fix bug with using offsetof(last_field) instead of offsetofend(last_field).
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

tools/lib/bpf/libbpf.c

@@ -33,6 +33,7 @@
 #include <linux/limits.h>
 #include <linux/perf_event.h>
 #include <linux/ring_buffer.h>
+#include <linux/version.h>
 #include <sys/epoll.h>
 #include <sys/ioctl.h>
 #include <sys/mman.h>
@@ -255,7 +256,7 @@ struct bpf_object {
 	 */
 	struct {
 		int fd;
-		void *obj_buf;
+		const void *obj_buf;
 		size_t obj_buf_sz;
 		Elf *elf;
 		GElf_Ehdr ehdr;
@@ -491,9 +492,21 @@ bpf_object__init_prog_names(struct bpf_object *obj)
 	return 0;
 }
 
+static __u32 get_kernel_version(void)
+{
+	__u32 major, minor, patch;
+	struct utsname info;
+
+	uname(&info);
+	if (sscanf(info.release, "%u.%u.%u", &major, &minor, &patch) != 3)
+		return 0;
+	return KERNEL_VERSION(major, minor, patch);
+}
+
 static struct bpf_object *bpf_object__new(const char *path,
-					  void *obj_buf,
-					  size_t obj_buf_sz)
+					  const void *obj_buf,
+					  size_t obj_buf_sz,
+					  const char *obj_name)
 {
 	struct bpf_object *obj;
 	char *end;
@@ -505,11 +518,17 @@ static struct bpf_object *bpf_object__new(const char *path,
 	}
 
 	strcpy(obj->path, path);
-	/* Using basename() GNU version which doesn't modify arg. */
-	strncpy(obj->name, basename((void *)path), sizeof(obj->name) - 1);
-	end = strchr(obj->name, '.');
-	if (end)
-		*end = 0;
+	if (obj_name) {
+		strncpy(obj->name, obj_name, sizeof(obj->name) - 1);
+		obj->name[sizeof(obj->name) - 1] = 0;
+	} else {
+		/* Using basename() GNU version which doesn't modify arg. */
+		strncpy(obj->name, basename((void *)path),
+			sizeof(obj->name) - 1);
+		end = strchr(obj->name, '.');
+		if (end)
+			*end = 0;
+	}
 
 	obj->efile.fd = -1;
 	/*
@@ -526,6 +545,7 @@ static struct bpf_object *bpf_object__new(const char *path,
 	obj->efile.rodata_shndx = -1;
 	obj->efile.bss_shndx = -1;
 
+	obj->kern_version = get_kernel_version();
 	obj->loaded = false;
 
 	INIT_LIST_HEAD(&obj->list);
@@ -569,7 +589,7 @@ 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(obj->efile.obj_buf,
+		obj->efile.elf = elf_memory((char *)obj->efile.obj_buf,
 					    obj->efile.obj_buf_sz);
 	} else {
 		obj->efile.fd = open(obj->path, O_RDONLY);
@@ -636,21 +656,6 @@ bpf_object__init_license(struct bpf_object *obj, void *data, size_t size)
 	return 0;
 }
 
-static int
-bpf_object__init_kversion(struct bpf_object *obj, void *data, size_t size)
-{
-	__u32 kver;
-
-	if (size != sizeof(kver)) {
-		pr_warning("invalid kver section in %s\n", obj->path);
-		return -LIBBPF_ERRNO__FORMAT;
-	}
-	memcpy(&kver, data, sizeof(kver));
-	obj->kern_version = kver;
-	pr_debug("kernel version of %s is %x\n", obj->path, obj->kern_version);
-	return 0;
-}
-
 static int compare_bpf_map(const void *_a, const void *_b)
 {
 	const struct bpf_map *a = _a;
@@ -1568,11 +1573,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
 			if (err)
 				return err;
 		} else if (strcmp(name, "version") == 0) {
-			err = bpf_object__init_kversion(obj,
-							data->d_buf,
-							data->d_size);
-			if (err)
-				return err;
+			/* skip, we don't need it anymore */
 		} else if (strcmp(name, "maps") == 0) {
 			obj->efile.maps_shndx = idx;
 		} else if (strcmp(name, MAPS_ELF_SEC) == 0) {
@@ -3551,54 +3552,9 @@ bpf_object__load_progs(struct bpf_object *obj, int log_level)
 	return 0;
 }
 
-static bool bpf_prog_type__needs_kver(enum bpf_prog_type type)
-{
-	switch (type) {
-	case BPF_PROG_TYPE_SOCKET_FILTER:
-	case BPF_PROG_TYPE_SCHED_CLS:
-	case BPF_PROG_TYPE_SCHED_ACT:
-	case BPF_PROG_TYPE_XDP:
-	case BPF_PROG_TYPE_CGROUP_SKB:
-	case BPF_PROG_TYPE_CGROUP_SOCK:
-	case BPF_PROG_TYPE_LWT_IN:
-	case BPF_PROG_TYPE_LWT_OUT:
-	case BPF_PROG_TYPE_LWT_XMIT:
-	case BPF_PROG_TYPE_LWT_SEG6LOCAL:
-	case BPF_PROG_TYPE_SOCK_OPS:
-	case BPF_PROG_TYPE_SK_SKB:
-	case BPF_PROG_TYPE_CGROUP_DEVICE:
-	case BPF_PROG_TYPE_SK_MSG:
-	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
-	case BPF_PROG_TYPE_LIRC_MODE2:
-	case BPF_PROG_TYPE_SK_REUSEPORT:
-	case BPF_PROG_TYPE_FLOW_DISSECTOR:
-	case BPF_PROG_TYPE_UNSPEC:
-	case BPF_PROG_TYPE_TRACEPOINT:
-	case BPF_PROG_TYPE_RAW_TRACEPOINT:
-	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
-	case BPF_PROG_TYPE_PERF_EVENT:
-	case BPF_PROG_TYPE_CGROUP_SYSCTL:
-	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
-		return false;
-	case BPF_PROG_TYPE_KPROBE:
-	default:
-		return true;
-	}
-}
-
-static int bpf_object__validate(struct bpf_object *obj, bool needs_kver)
-{
-	if (needs_kver && obj->kern_version == 0) {
-		pr_warning("%s doesn't provide kernel version\n",
-			   obj->path);
-		return -LIBBPF_ERRNO__KVERSION;
-	}
-	return 0;
-}
-
 static struct bpf_object *
-__bpf_object__open(const char *path, void *obj_buf, size_t obj_buf_sz,
-		   bool needs_kver, int flags)
+__bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz,
+		   const char *obj_name, int flags)
 {
 	struct bpf_object *obj;
 	int err;
@@ -3608,7 +3564,7 @@ __bpf_object__open(const char *path, void *obj_buf, size_t obj_buf_sz,
 		return ERR_PTR(-LIBBPF_ERRNO__LIBELF);
 	}
 
-	obj = bpf_object__new(path, obj_buf, obj_buf_sz);
+	obj = bpf_object__new(path, obj_buf, obj_buf_sz, obj_name);
 	if (IS_ERR(obj))
 		return obj;
 
@@ -3617,7 +3573,6 @@ __bpf_object__open(const char *path, void *obj_buf, size_t obj_buf_sz,
 	CHECK_ERR(bpf_object__probe_caps(obj), err, out);
 	CHECK_ERR(bpf_object__elf_collect(obj, flags), err, out);
 	CHECK_ERR(bpf_object__collect_reloc(obj), err, out);
-	CHECK_ERR(bpf_object__validate(obj, needs_kver), err, out);
 
 	bpf_object__elf_finish(obj);
 	return obj;
@@ -3626,8 +3581,8 @@ __bpf_object__open(const char *path, void *obj_buf, size_t obj_buf_sz,
 	return ERR_PTR(err);
 }
 
-struct bpf_object *__bpf_object__open_xattr(struct bpf_object_open_attr *attr,
-					    int flags)
+static struct bpf_object *
+__bpf_object__open_xattr(struct bpf_object_open_attr *attr, int flags)
 {
 	/* param validation */
 	if (!attr->file)
@@ -3635,9 +3590,7 @@ struct bpf_object *__bpf_object__open_xattr(struct bpf_object_open_attr *attr,
 
 	pr_debug("loading %s\n", attr->file);
 
-	return __bpf_object__open(attr->file, NULL, 0,
-				  bpf_prog_type__needs_kver(attr->prog_type),
-				  flags);
+	return __bpf_object__open(attr->file, NULL, 0, NULL, flags);
 }
 
 struct bpf_object *bpf_object__open_xattr(struct bpf_object_open_attr *attr)
@@ -3655,25 +3608,67 @@ struct bpf_object *bpf_object__open(const char *path)
 	return bpf_object__open_xattr(&attr);
 }
 
-struct bpf_object *bpf_object__open_buffer(void *obj_buf,
-					   size_t obj_buf_sz,
-					   const char *name)
+struct bpf_object *
+bpf_object__open_file(const char *path, struct bpf_object_open_opts *opts)
+{
+	const char *obj_name;
+	bool relaxed_maps;
+
+	if (!OPTS_VALID(opts, bpf_object_open_opts))
+		return ERR_PTR(-EINVAL);
+	if (!path)
+		return ERR_PTR(-EINVAL);
+
+	pr_debug("loading %s\n", path);
+
+	obj_name = OPTS_GET(opts, object_name, path);
+	relaxed_maps = OPTS_GET(opts, relaxed_maps, false);
+	return __bpf_object__open(path, NULL, 0, obj_name,
+				  relaxed_maps ? MAPS_RELAX_COMPAT : 0);
+}
+
+struct bpf_object *
+bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz,
+		     struct bpf_object_open_opts *opts)
 {
 	char tmp_name[64];
+	const char *obj_name;
+	bool relaxed_maps;
 
-	/* param validation */
-	if (!obj_buf || obj_buf_sz <= 0)
-		return NULL;
+	if (!OPTS_VALID(opts, bpf_object_open_opts))
+		return ERR_PTR(-EINVAL);
+	if (!obj_buf || obj_buf_sz == 0)
+		return ERR_PTR(-EINVAL);
 
-	if (!name) {
+	obj_name = OPTS_GET(opts, object_name, NULL);
+	if (!obj_name) {
 		snprintf(tmp_name, sizeof(tmp_name), "%lx-%lx",
 			 (unsigned long)obj_buf,
 			 (unsigned long)obj_buf_sz);
-		name = tmp_name;
+		obj_name = tmp_name;
 	}
-	pr_debug("loading object '%s' from buffer\n", name);
+	pr_debug("loading object '%s' from buffer\n", obj_name);
+
+	relaxed_maps = OPTS_GET(opts, relaxed_maps, false);
+	return __bpf_object__open(obj_name, obj_buf, obj_buf_sz, obj_name,
+				  relaxed_maps ? MAPS_RELAX_COMPAT : 0);
+}
+
+struct bpf_object *
+bpf_object__open_buffer(const void *obj_buf, size_t obj_buf_sz,
+			const char *name)
+{
+	LIBBPF_OPTS(bpf_object_open_opts, opts,
+		.object_name = name,
+		/* wrong default, but backwards-compatible */
+		.relaxed_maps = true,
+	);
+
+	/* returning NULL is wrong, but backwards-compatible */
+	if (!obj_buf || obj_buf_sz == 0)
+		return NULL;
 
-	return __bpf_object__open(name, obj_buf, obj_buf_sz, true, true);
+	return bpf_object__open_mem(obj_buf, obj_buf_sz, &opts);
 }
 
 int bpf_object__unload(struct bpf_object *obj)
@@ -4236,7 +4231,7 @@ bpf_object__next(struct bpf_object *prev)
 
 const char *bpf_object__name(const struct bpf_object *obj)
 {
-	return obj ? obj->path : ERR_PTR(-EINVAL);
+	return obj ? obj->name : ERR_PTR(-EINVAL);
 }
 
 unsigned int bpf_object__kversion(const struct bpf_object *obj)

tools/lib/bpf/libbpf.h

@@ -67,14 +67,52 @@ struct bpf_object_open_attr {
 	enum bpf_prog_type prog_type;
 };
 
+/* Helper macro to declare and initialize libbpf options struct
+ *
+ * This dance with uninitialized declaration, followed by memset to zero,
+ * followed by assignment using compound literal syntax is done to preserve
+ * ability to use a nice struct field initialization syntax and **hopefully**
+ * have all the padding bytes initialized to zero. It's not guaranteed though,
+ * when copying literal, that compiler won't copy garbage in literal's padding
+ * bytes, but that's the best way I've found and it seems to work in practice.
+ */
+#define LIBBPF_OPTS(TYPE, NAME, ...)					    \
+	struct TYPE NAME;						    \
+	memset(&NAME, 0, sizeof(struct TYPE));				    \
+	NAME = (struct TYPE) {						    \
+		.sz = sizeof(struct TYPE),				    \
+		__VA_ARGS__						    \
+	}
+
+struct bpf_object_open_opts {
+	/* size of this struct, for forward/backward compatiblity */
+	size_t sz;
+	/* object name override, if provided:
+	 * - for object open from file, this will override setting object
+	 *   name from file path's base name;
+	 * - for object open from memory buffer, this will specify an object
+	 *   name and will override default "<addr>-<buf-size>" name;
+	 */
+	const char *object_name;
+	/* parse map definitions non-strictly, allowing extra attributes/data */
+	bool relaxed_maps;
+};
+#define bpf_object_open_opts__last_field relaxed_maps
+
 LIBBPF_API struct bpf_object *bpf_object__open(const char *path);
 LIBBPF_API struct bpf_object *
+bpf_object__open_file(const char *path, struct bpf_object_open_opts *opts);
+LIBBPF_API struct bpf_object *
+bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz,
+		     struct bpf_object_open_opts *opts);
+
+/* deprecated bpf_object__open variants */
+LIBBPF_API struct bpf_object *
+bpf_object__open_buffer(const void *obj_buf, size_t obj_buf_sz,
+			const char *name);
+LIBBPF_API struct bpf_object *
 bpf_object__open_xattr(struct bpf_object_open_attr *attr);
-struct bpf_object *__bpf_object__open_xattr(struct bpf_object_open_attr *attr,
-					    int flags);
-LIBBPF_API struct bpf_object *bpf_object__open_buffer(void *obj_buf,
-						      size_t obj_buf_sz,
-						      const char *name);
+
 int bpf_object__section_size(const struct bpf_object *obj, const char *name,
 			     __u32 *size);
 int bpf_object__variable_offset(const struct bpf_object *obj, const char *name,

tools/lib/bpf/libbpf.map

@@ -192,4 +192,7 @@ LIBBPF_0.0.5 {
 } LIBBPF_0.0.4;
 
 LIBBPF_0.0.6 {
+	global:
+		bpf_object__open_file;
+		bpf_object__open_mem;
 } LIBBPF_0.0.5;

tools/lib/bpf/libbpf_internal.h

@@ -47,6 +47,38 @@ do {				\
 #define pr_info(fmt, ...)	__pr(LIBBPF_INFO, fmt, ##__VA_ARGS__)
 #define pr_debug(fmt, ...)	__pr(LIBBPF_DEBUG, fmt, ##__VA_ARGS__)
 
+static inline bool libbpf_validate_opts(const char *opts,
+					size_t opts_sz, size_t user_sz,
+					const char *type_name)
+{
+	if (user_sz < sizeof(size_t)) {
+		pr_warning("%s size (%zu) is too small\n", type_name, user_sz);
+		return false;
+	}
+	if (user_sz > opts_sz) {
+		size_t i;
+
+		for (i = opts_sz; i < user_sz; i++) {
+			if (opts[i]) {
+				pr_warning("%s has non-zero extra bytes",
+					   type_name);
+				return false;
+			}
+		}
+	}
+	return true;
+}
+
+#define OPTS_VALID(opts, type)						      \
+	(!(opts) || libbpf_validate_opts((const char *)opts,		      \
+					 offsetofend(struct type,	      \
+						     type##__last_field),     \
+					 (opts)->sz, #type))
+#define OPTS_HAS(opts, field) \
+	((opts) && opts->sz >= offsetofend(typeof(*(opts)), field))
+#define OPTS_GET(opts, field, fallback_value) \
+	(OPTS_HAS(opts, field) ? (opts)->field : fallback_value)
+
 int libbpf__load_raw_btf(const char *raw_types, size_t types_len,
 			 const char *str_sec, size_t str_len);
 

tools/testing/selftests/bpf/Makefile

@@ -160,7 +160,7 @@ $(OUTPUT)/test_queue_map.o: test_queue_stack_map.h
 $(OUTPUT)/test_stack_map.o: test_queue_stack_map.h
 
 $(OUTPUT)/flow_dissector_load.o: flow_dissector_load.h
-$(OUTPUT)/test_progs.o: flow_dissector_load.h
+$(OUTPUT)/test_progs.o: flow_dissector_load.h $(OUTPUT)/test_attach_probe.o
 
 BTF_LLC_PROBE := $(shell $(LLC) -march=bpf -mattr=help 2>&1 | grep dwarfris)
 BTF_PAHOLE_PROBE := $(shell $(BTF_PAHOLE) --help 2>&1 | grep BTF)

tools/testing/selftests/bpf/prog_tests/attach_probe.c

 // SPDX-License-Identifier: GPL-2.0
 #include <test_progs.h>
 
+#define EMBED_FILE(NAME, PATH)						    \
+asm (									    \
+"      .pushsection \".rodata\", \"a\", @progbits              \n"	    \
+"      .global "#NAME"_data                                    \n"	    \
+#NAME"_data:                                                   \n"	    \
+"      .incbin \"" PATH "\"                                    \n"	    \
+#NAME"_data_end:                                               \n"	    \
+"      .global "#NAME"_size                                    \n"	    \
+"      .type "#NAME"_size, @object                             \n"	    \
+"      .size "#NAME"_size, 4                                   \n"	    \
+"      .align 4,                                               \n"	    \
+#NAME"_size:                                                   \n"	    \
+"      .int "#NAME"_data_end - "#NAME"_data                    \n"	    \
+"      .popsection                                             \n"	    \
+);									    \
+extern char NAME##_data[];						    \
+extern int NAME##_size;
+
 ssize_t get_base_addr() {
 	size_t start;
 	char buf[256];
@@ -21,6 +39,8 @@ ssize_t get_base_addr() {
 	return -EINVAL;
 }
 
+EMBED_FILE(probe, "test_attach_probe.o");
+
 void test_attach_probe(void)
 {
 	const char *kprobe_name = "kprobe/sys_nanosleep";
@@ -29,11 +49,15 @@ void test_attach_probe(void)
 	const char *uretprobe_name = "uretprobe/trigger_func";
 	const int kprobe_idx = 0, kretprobe_idx = 1;
 	const int uprobe_idx = 2, uretprobe_idx = 3;
-	const char *file = "./test_attach_probe.o";
+	const char *obj_name = "attach_probe";
+	LIBBPF_OPTS(bpf_object_open_opts, open_opts,
+		.object_name = obj_name,
+		.relaxed_maps = true,
+	);
 	struct bpf_program *kprobe_prog, *kretprobe_prog;
 	struct bpf_program *uprobe_prog, *uretprobe_prog;
 	struct bpf_object *obj;
-	int err, prog_fd, duration = 0, res;
+	int err, duration = 0, res;
 	struct bpf_link *kprobe_link = NULL;
 	struct bpf_link *kretprobe_link = NULL;
 	struct bpf_link *uprobe_link = NULL;
@@ -48,11 +72,16 @@ void test_attach_probe(void)
 		return;
 	uprobe_offset = (size_t)&get_base_addr - base_addr;
 
-	/* load programs */
-	err = bpf_prog_load(file, BPF_PROG_TYPE_KPROBE, &obj, &prog_fd);
-	if (CHECK(err, "obj_load", "err %d errno %d\n", err, errno))
+	/* open object */
+	obj = bpf_object__open_mem(probe_data, probe_size, &open_opts);
+	if (CHECK(IS_ERR(obj), "obj_open_mem", "err %ld\n", PTR_ERR(obj)))
 		return;
 
+	if (CHECK(strcmp(bpf_object__name(obj), obj_name), "obj_name",
+		  "wrong obj name '%s', expected '%s'\n",
+		  bpf_object__name(obj), obj_name))
+		goto cleanup;
+
 	kprobe_prog = bpf_object__find_program_by_title(obj, kprobe_name);
 	if (CHECK(!kprobe_prog, "find_probe",
 		  "prog '%s' not found\n", kprobe_name))
@@ -70,6 +99,16 @@ void test_attach_probe(void)
 		  "prog '%s' not found\n", uretprobe_name))
 		goto cleanup;
 
+	bpf_program__set_kprobe(kprobe_prog);
+	bpf_program__set_kprobe(kretprobe_prog);
+	bpf_program__set_kprobe(uprobe_prog);
+	bpf_program__set_kprobe(uretprobe_prog);
+
+	/* create maps && load programs */
+	err = bpf_object__load(obj);
+	if (CHECK(err, "obj_load", "err %d\n", err))
+		goto cleanup;
+
 	/* load maps */
 	results_map_fd = bpf_find_map(__func__, obj, "results_map");
 	if (CHECK(results_map_fd < 0, "find_results_map",

tools/testing/selftests/bpf/prog_tests/reference_tracking.c

@@ -3,16 +3,26 @@
 
 void test_reference_tracking(void)
 {
-	const char *file = "./test_sk_lookup_kern.o";
+	const char *file = "test_sk_lookup_kern.o";
+	const char *obj_name = "ref_track";
+	LIBBPF_OPTS(bpf_object_open_opts, open_opts,
+		.object_name = obj_name,
+		.relaxed_maps = true,
+	);
 	struct bpf_object *obj;
 	struct bpf_program *prog;
 	__u32 duration = 0;
 	int err = 0;
 
-	obj = bpf_object__open(file);
+	obj = bpf_object__open_file(file, &open_opts);
 	if (CHECK_FAIL(IS_ERR(obj)))
 		return;
 
+	if (CHECK(strcmp(bpf_object__name(obj), obj_name), "obj_name",
+		  "wrong obj name '%s', expected '%s'\n",
+		  bpf_object__name(obj), obj_name))
+		goto cleanup;
+
 	bpf_object__for_each_program(prog, obj) {
 		const char *title;
 
@@ -35,5 +45,7 @@ void test_reference_tracking(void)
 		}
 		CHECK(err, title, "\n");
 	}
+
+cleanup:
 	bpf_object__close(obj);
 }

tools/testing/selftests/bpf/progs/test_attach_probe.c

@@ -49,4 +49,3 @@ int handle_uprobe_return(struct pt_regs *ctx)
 }
 
 char _license[] SEC("license") = "GPL";
-__u32 _version SEC("version") = 1;

tools/testing/selftests/bpf/progs/test_get_stack_rawtp.c

@@ -99,4 +99,3 @@ int bpf_prog1(void *ctx)
 }
 
 char _license[] SEC("license") = "GPL";
-__u32 _version SEC("version") = 1; /* ignored by tracepoints, required by libbpf.a */

tools/testing/selftests/bpf/progs/test_perf_buffer.c

@@ -22,4 +22,3 @@ int handle_sys_nanosleep_entry(struct pt_regs *ctx)
 }
 
 char _license[] SEC("license") = "GPL";
-__u32 _version SEC("version") = 1;

tools/testing/selftests/bpf/progs/test_stacktrace_map.c

@@ -74,4 +74,3 @@ int oncpu(struct sched_switch_args *ctx)
 }
 
 char _license[] SEC("license") = "GPL";
-__u32 _version SEC("version") = 1; /* ignored by tracepoints, required by libbpf.a */