objtool: Fix elf_create_undef_symbol() endianness

stable inclusion
from stable-v5.10.133
commit fbf60f83e241f0ef967644ca06455f37fcea064b
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5PTAS
CVE: CVE-2022-29900,CVE-2022-23816,CVE-2022-29901

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=fbf60f83e241f0ef967644ca06455f37fcea064b

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

commit 46c7405d upstream.

Currently x86 cross-compilation fails on big endian system with:

  x86_64-cross-ld: init/main.o: invalid string offset 488112128 >= 6229 for section `.strtab'

Mark new ELF data in elf_create_undef_symbol() as symbol, so that libelf
does endianness handling correctly.

Fixes: 2f2f7e47 ("objtool: Add elf_create_undef_symbol()")
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: NIngo Molnar <mingo@kernel.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: https://lore.kernel.org/r/patch-1.thread-6c9df9.git-d39264656387.your-ad-here.call-01620841104-ext-2554@work.hoursSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NLin Yujun <linyujun809@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

tools/objtool/elf.c

@@ -758,6 +758,7 @@ static int elf_add_string(struct elf *elf, struct section *strtab, char *str)
 	data->d_buf = str;
 	data->d_size = strlen(str) + 1;
 	data->d_align = 1;
+	data->d_type = ELF_T_SYM;
 
 	len = strtab->len;
 	strtab->len += data->d_size;