libbpf: Extract ELF processing state into separate struct

mainline inclusion
from mainline-5.16-rc1
commit 29a30ff5
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=29a30ff501518a49282754909543cef1ef49e4bc

-------------------------------------------------

Name currently anonymous internal struct that keeps ELF-related state
for bpf_object. Just a bit of clean up, no functional changes.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NSong Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211021014404.2635234-3-andrii@kernel.org
(cherry picked from commit 29a30ff5)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

tools/lib/bpf/libbpf.c

@@ -442,33 +442,7 @@ struct module_btf {
 	int fd_array_idx;
 };
 
-struct bpf_object {
-	char name[BPF_OBJ_NAME_LEN];
-	char license[64];
-	__u32 kern_version;
-
-	struct bpf_program *programs;
-	size_t nr_programs;
-	struct bpf_map *maps;
-	size_t nr_maps;
-	size_t maps_cap;
-
-	char *kconfig;
-	struct extern_desc *externs;
-	int nr_extern;
-	int kconfig_map_idx;
-	int rodata_map_idx;
-
-	bool loaded;
-	bool has_subcalls;
-
-	struct bpf_gen *gen_loader;
-
-	/*
-	 * Information when doing elf related work. Only valid if fd
-	 * is valid.
-	 */
-	struct {
+struct elf_state {
 	int fd;
 	const void *obj_buf;
 	size_t obj_buf_sz;
@@ -495,9 +469,34 @@ struct bpf_object {
 	int rodata_shndx;
 	int bss_shndx;
 	int st_ops_shndx;
-	} efile;
+};
+
+struct bpf_object {
+	char name[BPF_OBJ_NAME_LEN];
+	char license[64];
+	__u32 kern_version;
+
+	struct bpf_program *programs;
+	size_t nr_programs;
+	struct bpf_map *maps;
+	size_t nr_maps;
+	size_t maps_cap;
+
+	char *kconfig;
+	struct extern_desc *externs;
+	int nr_extern;
+	int kconfig_map_idx;
+	int rodata_map_idx;
+
+	bool loaded;
+	bool has_subcalls;
+
+	struct bpf_gen *gen_loader;
+
+	/* Information when doing ELF related work. Only valid if efile.elf is not NULL */
+	struct elf_state efile;
 	/*
-	 * All loaded bpf_object is linked in a list, which is
+	 * All loaded bpf_object are linked in a list, which is
 	 * hidden to caller. bpf_objects__<func> handlers deal with
 	 * all objects.
 	 */
@@ -531,7 +530,6 @@ struct bpf_object {
 
 	char path[];
 };
-#define obj_elf_valid(o)	((o)->efile.elf)
 
 static const char *elf_sym_str(const struct bpf_object *obj, size_t off);
 static const char *elf_sec_str(const struct bpf_object *obj, size_t off);
@@ -1165,7 +1163,7 @@ static struct bpf_object *bpf_object__new(const char *path,
 
 static void bpf_object__elf_finish(struct bpf_object *obj)
 {
-	if (!obj_elf_valid(obj))
+	if (!obj->efile.elf)
 		return;
 
 	if (obj->efile.elf) {
@@ -1190,7 +1188,7 @@ static int bpf_object__elf_init(struct bpf_object *obj)
 	int err = 0;
 	GElf_Ehdr *ep;
 
-	if (obj_elf_valid(obj)) {
+	if (obj->efile.elf) {
 		pr_warn("elf: init internal error\n");
 		return -LIBBPF_ERRNO__LIBELF;
 	}