x86/kexec: Disable RET on kexec

stable inclusion
from stable-v5.10.133
commit c2ca992144281917cfae19d231b1195c02906a4e
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=c2ca992144281917cfae19d231b1195c02906a4e



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

commit 697977d8 upstream.

All the invocations unroll to __x86_return_thunk and this file
must be PIC independent.

This fixes kexec on 64-bit AMD boxes.

  [ bp: Fix 32-bit build. ]

Reported-by: Edward Tran <edward.tran@oracle.com>
Reported-by: Awais Tanveer <awais.tanveer@oracle.com>
Suggested-by: Ankur Arora <ankur.a.arora@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Lin Yujun <linyujun809@huawei.com>
Reviewed-by: Zhang Jianhua <chris.zjh@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>