1 files changed, 157 insertions, 118 deletions

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 38ed3e92e393..26e9527ee464 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -22,6 +22,7 @@
  * License along with this program; if not,  see <http://www.gnu.org/licenses>
  */
 
+#define _GNU_SOURCE
 #include <stdlib.h>
 #include <stdio.h>
 #include <stdarg.h>
@@ -36,11 +37,13 @@
 #include <linux/err.h>
 #include <linux/kernel.h>
 #include <linux/bpf.h>
+#include <linux/btf.h>
 #include <linux/list.h>
 #include <linux/limits.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/vfs.h>
+#include <tools/libc_compat.h>
 #include <libelf.h>
 #include <gelf.h>
 
@@ -95,54 +98,6 @@ void libbpf_set_print(libbpf_print_fn_t warn,
 
 #define STRERR_BUFSIZE  128
 
-#define ERRNO_OFFSET(e)		((e) - __LIBBPF_ERRNO__START)
-#define ERRCODE_OFFSET(c)	ERRNO_OFFSET(LIBBPF_ERRNO__##c)
-#define NR_ERRNO	(__LIBBPF_ERRNO__END - __LIBBPF_ERRNO__START)
-
-static const char *libbpf_strerror_table[NR_ERRNO] = {
-	[ERRCODE_OFFSET(LIBELF)]	= "Something wrong in libelf",
-	[ERRCODE_OFFSET(FORMAT)]	= "BPF object format invalid",
-	[ERRCODE_OFFSET(KVERSION)]	= "'version' section incorrect or lost",
-	[ERRCODE_OFFSET(ENDIAN)]	= "Endian mismatch",
-	[ERRCODE_OFFSET(INTERNAL)]	= "Internal error in libbpf",
-	[ERRCODE_OFFSET(RELOC)]		= "Relocation failed",
-	[ERRCODE_OFFSET(VERIFY)]	= "Kernel verifier blocks program loading",
-	[ERRCODE_OFFSET(PROG2BIG)]	= "Program too big",
-	[ERRCODE_OFFSET(KVER)]		= "Incorrect kernel version",
-	[ERRCODE_OFFSET(PROGTYPE)]	= "Kernel doesn't support this program type",
-	[ERRCODE_OFFSET(WRNGPID)]	= "Wrong pid in netlink message",
-	[ERRCODE_OFFSET(INVSEQ)]	= "Invalid netlink sequence",
-};
-
-int libbpf_strerror(int err, char *buf, size_t size)
-{
-	if (!buf || !size)
-		return -1;
-
-	err = err > 0 ? err : -err;
-
-	if (err < __LIBBPF_ERRNO__START) {
-		int ret;
-
-		ret = strerror_r(err, buf, size);
-		buf[size - 1] = '\0';
-		return ret;
-	}
-
-	if (err < __LIBBPF_ERRNO__END) {
-		const char *msg;
-
-		msg = libbpf_strerror_table[ERRNO_OFFSET(err)];
-		snprintf(buf, size, "%s", msg);
-		buf[size - 1] = '\0';
-		return 0;
-	}
-
-	snprintf(buf, size, "Unknown libbpf error %d", err);
-	buf[size - 1] = '\0';
-	return -1;
-}
-
 #define CHECK_ERR(action, err, out) do {	\
 	err = action;			\
 	if (err)			\
@@ -216,8 +171,8 @@ struct bpf_map {
 	size_t offset;
 	int map_ifindex;
 	struct bpf_map_def def;
-	uint32_t btf_key_type_id;
-	uint32_t btf_value_type_id;
+	__u32 btf_key_type_id;
+	__u32 btf_value_type_id;
 	void *priv;
 	bpf_map_clear_priv_t clear_priv;
 };
@@ -369,7 +324,7 @@ bpf_object__add_program(struct bpf_object *obj, void *data, size_t size,
 	progs = obj->programs;
 	nr_progs = obj->nr_programs;
 
-	progs = realloc(progs, sizeof(progs[0]) * (nr_progs + 1));
+	progs = reallocarray(progs, nr_progs + 1, sizeof(progs[0]));
 	if (!progs) {
 		/*
 		 * In this case the original obj->programs
@@ -870,8 +825,8 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
 				continue;
 			}
 
-			reloc = realloc(reloc,
-					sizeof(*obj->efile.reloc) * nr_reloc);
+			reloc = reallocarray(reloc, nr_reloc,
+					     sizeof(*obj->efile.reloc));
 			if (!reloc) {
 				pr_warning("realloc failed\n");
 				err = -ENOMEM;
@@ -1015,70 +970,121 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr,
 
 static int bpf_map_find_btf_info(struct bpf_map *map, const struct btf *btf)
 {
+	const struct btf_type *container_type;
+	const struct btf_member *key, *value;
 	struct bpf_map_def *def = &map->def;
 	const size_t max_name = 256;
-	int64_t key_size, value_size;
-	int32_t key_id, value_id;
-	char name[max_name];
+	char container_name[max_name];
+	__s64 key_size, value_size;
+	__s32 container_id;
 
-	/* Find key type by name from BTF */
-	if (snprintf(name, max_name, "%s_key", map->name) == max_name) {
-		pr_warning("map:%s length of BTF key_type:%s_key is too long\n",
+	if (snprintf(container_name, max_name, "____btf_map_%s", map->name) ==
+	    max_name) {
+		pr_warning("map:%s length of '____btf_map_%s' is too long\n",
 			   map->name, map->name);
 		return -EINVAL;
 	}
 
-	key_id = btf__find_by_name(btf, name);
-	if (key_id < 0) {
-		pr_debug("map:%s key_type:%s cannot be found in BTF\n",
-			 map->name, name);
-		return key_id;
+	container_id = btf__find_by_name(btf, container_name);
+	if (container_id < 0) {
+		pr_debug("map:%s container_name:%s cannot be found in BTF. Missing BPF_ANNOTATE_KV_PAIR?\n",
+			 map->name, container_name);
+		return container_id;
 	}
 
-	key_size = btf__resolve_size(btf, key_id);
-	if (key_size < 0) {
-		pr_warning("map:%s key_type:%s cannot get the BTF type_size\n",
-			   map->name, name);
-		return key_size;
+	container_type = btf__type_by_id(btf, container_id);
+	if (!container_type) {
+		pr_warning("map:%s cannot find BTF type for container_id:%u\n",
+			   map->name, container_id);
+		return -EINVAL;
 	}
 
-	if (def->key_size != key_size) {
-		pr_warning("map:%s key_type:%s has BTF type_size:%u != key_size:%u\n",
-			   map->name, name, (unsigned int)key_size, def->key_size);
+	if (BTF_INFO_KIND(container_type->info) != BTF_KIND_STRUCT ||
+	    BTF_INFO_VLEN(container_type->info) < 2) {
+		pr_warning("map:%s container_name:%s is an invalid container struct\n",
+			   map->name, container_name);
 		return -EINVAL;
 	}
 
-	/* Find value type from BTF */
-	if (snprintf(name, max_name, "%s_value", map->name) == max_name) {
-		pr_warning("map:%s length of BTF value_type:%s_value is too long\n",
-			  map->name, map->name);
-		return -EINVAL;
+	key = (struct btf_member *)(container_type + 1);
+	value = key + 1;
+
+	key_size = btf__resolve_size(btf, key->type);
+	if (key_size < 0) {
+		pr_warning("map:%s invalid BTF key_type_size\n",
+			   map->name);
+		return key_size;
 	}
 
-	value_id = btf__find_by_name(btf, name);
-	if (value_id < 0) {
-		pr_debug("map:%s value_type:%s cannot be found in BTF\n",
-			 map->name, name);
-		return value_id;
+	if (def->key_size != key_size) {
+		pr_warning("map:%s btf_key_type_size:%u != map_def_key_size:%u\n",
+			   map->name, (__u32)key_size, def->key_size);
+		return -EINVAL;
 	}
 
-	value_size = btf__resolve_size(btf, value_id);
+	value_size = btf__resolve_size(btf, value->type);
 	if (value_size < 0) {
-		pr_warning("map:%s value_type:%s cannot get the BTF type_size\n",
-			   map->name, name);
+		pr_warning("map:%s invalid BTF value_type_size\n", map->name);
 		return value_size;
 	}
 
 	if (def->value_size != value_size) {
-		pr_warning("map:%s value_type:%s has BTF type_size:%u != value_size:%u\n",
-			   map->name, name, (unsigned int)value_size, def->value_size);
+		pr_warning("map:%s btf_value_type_size:%u != map_def_value_size:%u\n",
+			   map->name, (__u32)value_size, def->value_size);
 		return -EINVAL;
 	}
 
-	map->btf_key_type_id = key_id;
-	map->btf_value_type_id = value_id;
+	map->btf_key_type_id = key->type;
+	map->btf_value_type_id = value->type;
+
+	return 0;
+}
+
+int bpf_map__reuse_fd(struct bpf_map *map, int fd)
+{
+	struct bpf_map_info info = {};
+	__u32 len = sizeof(info);
+	int new_fd, err;
+	char *new_name;
+
+	err = bpf_obj_get_info_by_fd(fd, &info, &len);
+	if (err)
+		return err;
+
+	new_name = strdup(info.name);
+	if (!new_name)
+		return -errno;
+
+	new_fd = open("/", O_RDONLY | O_CLOEXEC);
+	if (new_fd < 0)
+		goto err_free_new_name;
+
+	new_fd = dup3(fd, new_fd, O_CLOEXEC);
+	if (new_fd < 0)
+		goto err_close_new_fd;
+
+	err = zclose(map->fd);
+	if (err)
+		goto err_close_new_fd;
+	free(map->name);
+
+	map->fd = new_fd;
+	map->name = new_name;
+	map->def.type = info.type;
+	map->def.key_size = info.key_size;
+	map->def.value_size = info.value_size;
+	map->def.max_entries = info.max_entries;
+	map->def.map_flags = info.map_flags;
+	map->btf_key_type_id = info.btf_key_type_id;
+	map->btf_value_type_id = info.btf_value_type_id;
 
 	return 0;
+
+err_close_new_fd:
+	close(new_fd);
+err_free_new_name:
+	free(new_name);
+	return -errno;
 }
 
 static int
@@ -1093,6 +1099,12 @@ bpf_object__create_maps(struct bpf_object *obj)
 		struct bpf_map_def *def = &map->def;
 		int *pfd = &map->fd;
 
+		if (map->fd >= 0) {
+			pr_debug("skip map create (preset) %s: fd=%d\n",
+				 map->name, map->fd);
+			continue;
+		}
+
 		create_attr.name = map->name;
 		create_attr.map_ifindex = map->map_ifindex;
 		create_attr.map_type = def->type;
@@ -1163,7 +1175,7 @@ bpf_program__reloc_text(struct bpf_program *prog, struct bpf_object *obj,
 			return -LIBBPF_ERRNO__RELOC;
 		}
 		new_cnt = prog->insns_cnt + text->insns_cnt;
-		new_insn = realloc(prog->insns, new_cnt * sizeof(*insn));
+		new_insn = reallocarray(prog->insns, new_cnt, sizeof(*insn));
 		if (!new_insn) {
 			pr_warning("oom in prog realloc\n");
 			return -ENOMEM;
@@ -1520,15 +1532,26 @@ out:
 	return ERR_PTR(err);
 }
 
-struct bpf_object *bpf_object__open(const char *path)
+struct bpf_object *bpf_object__open_xattr(struct bpf_object_open_attr *attr)
 {
 	/* param validation */
-	if (!path)
+	if (!attr->file)
 		return NULL;
 
-	pr_debug("loading %s\n", path);
+	pr_debug("loading %s\n", attr->file);
 
-	return __bpf_object__open(path, NULL, 0, true);
+	return __bpf_object__open(attr->file, NULL, 0,
+				  bpf_prog_type__needs_kver(attr->prog_type));
+}
+
+struct bpf_object *bpf_object__open(const char *path)
+{
+	struct bpf_object_open_attr attr = {
+		.file		= path,
+		.prog_type	= BPF_PROG_TYPE_UNSPEC,
+	};
+
+	return bpf_object__open_xattr(&attr);
 }
 
 struct bpf_object *bpf_object__open_buffer(void *obj_buf,
@@ -2081,23 +2104,31 @@ static const struct {
 #undef BPF_S_PROG_SEC
 #undef BPF_SA_PROG_SEC
 
-static int bpf_program__identify_section(struct bpf_program *prog)
+int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
+			     enum bpf_attach_type *expected_attach_type)
 {
 	int i;
 
-	if (!prog->section_name)
-		goto err;
-
-	for (i = 0; i < ARRAY_SIZE(section_names); i++)
-		if (strncmp(prog->section_name, section_names[i].sec,
-			    section_names[i].len) == 0)
-			return i;
+	if (!name)
+		return -EINVAL;
 
-err:
-	pr_warning("failed to guess program type based on section name %s\n",
-		   prog->section_name);
+	for (i = 0; i < ARRAY_SIZE(section_names); i++) {
+		if (strncmp(name, section_names[i].sec, section_names[i].len))
+			continue;
+		*prog_type = section_names[i].prog_type;
+		*expected_attach_type = section_names[i].expected_attach_type;
+		return 0;
+	}
+	return -EINVAL;
+}
 
-	return -1;
+static int
+bpf_program__identify_section(struct bpf_program *prog,
+			      enum bpf_prog_type *prog_type,
+			      enum bpf_attach_type *expected_attach_type)
+{
+	return libbpf_prog_type_by_name(prog->section_name, prog_type,
+					expected_attach_type);
 }
 
 int bpf_map__fd(struct bpf_map *map)
@@ -2115,12 +2146,12 @@ const char *bpf_map__name(struct bpf_map *map)
 	return map ? map->name : NULL;
 }
 
-uint32_t bpf_map__btf_key_type_id(const struct bpf_map *map)
+__u32 bpf_map__btf_key_type_id(const struct bpf_map *map)
 {
 	return map ? map->btf_key_type_id : 0;
 }
 
-uint32_t bpf_map__btf_value_type_id(const struct bpf_map *map)
+__u32 bpf_map__btf_value_type_id(const struct bpf_map *map)
 {
 	return map ? map->btf_value_type_id : 0;
 }
@@ -2146,6 +2177,11 @@ void *bpf_map__priv(struct bpf_map *map)
 	return map ? map->priv : ERR_PTR(-EINVAL);
 }
 
+bool bpf_map__is_offload_neutral(struct bpf_map *map)
+{
+	return map->def.type == BPF_MAP_TYPE_PERF_EVENT_ARRAY;
+}
+
 void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex)
 {
 	map->map_ifindex = ifindex;
@@ -2225,12 +2261,15 @@ int bpf_prog_load(const char *file, enum bpf_prog_type type,
 int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
 			struct bpf_object **pobj, int *prog_fd)
 {
+	struct bpf_object_open_attr open_attr = {
+		.file		= attr->file,
+		.prog_type	= attr->prog_type,
+	};
 	struct bpf_program *prog, *first_prog = NULL;
 	enum bpf_attach_type expected_attach_type;
 	enum bpf_prog_type prog_type;
 	struct bpf_object *obj;
 	struct bpf_map *map;
-	int section_idx;
 	int err;
 
 	if (!attr)
@@ -2238,8 +2277,7 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
 	if (!attr->file)
 		return -EINVAL;
 
-	obj = __bpf_object__open(attr->file, NULL, 0,
-				 bpf_prog_type__needs_kver(attr->prog_type));
+	obj = bpf_object__open_xattr(&open_attr);
 	if (IS_ERR_OR_NULL(obj))
 		return -ENOENT;
 
@@ -2252,14 +2290,14 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
 		prog->prog_ifindex = attr->ifindex;
 		expected_attach_type = attr->expected_attach_type;
 		if (prog_type == BPF_PROG_TYPE_UNSPEC) {
-			section_idx = bpf_program__identify_section(prog);
-			if (section_idx < 0) {
+			err = bpf_program__identify_section(prog, &prog_type,
+							    &expected_attach_type);
+			if (err < 0) {
+				pr_warning("failed to guess program type based on section name %s\n",
+					   prog->section_name);
 				bpf_object__close(obj);
 				return -EINVAL;
 			}
-			prog_type = section_names[section_idx].prog_type;
-			expected_attach_type =
-				section_names[section_idx].expected_attach_type;
 		}
 
 		bpf_program__set_type(prog, prog_type);
@@ -2271,7 +2309,8 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
 	}
 
 	bpf_map__for_each(map, obj) {
-		map->map_ifindex = attr->ifindex;
+		if (!bpf_map__is_offload_neutral(map))
+			map->map_ifindex = attr->ifindex;
 	}
 
 	if (!first_prog) {
@@ -2299,8 +2338,8 @@ bpf_perf_event_read_simple(void *mem, unsigned long size,
 	volatile struct perf_event_mmap_page *header = mem;
 	__u64 data_tail = header->data_tail;
 	__u64 data_head = header->data_head;
+	int ret = LIBBPF_PERF_EVENT_ERROR;
 	void *base, *begin, *end;
-	int ret;
 
 	asm volatile("" ::: "memory"); /* in real code it should be smp_rmb() */
 	if (data_head == data_tail)