x86/bugs: Keep a per-CPU IA32_SPEC_CTRL value

stable inclusion
from stable-v4.19.266
commit 4b74a4f69682058fa79ccc9643ea69a0f1b955ee
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I5GZ2Z


CVE: CVE-2022-29901

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

commit caa0ff24 upstream.

Due to TIF_SSBD and TIF_SPEC_IB the actual IA32_SPEC_CTRL value can
differ from x86_spec_ctrl_base. As such, keep a per-CPU value
reflecting the current task's MSR content.

  [jpoimboe: rename]

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Suleiman Souhlal <suleiman@google.com>
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>
Reviewed-by: Liao Chang <liaochang1@huawei.com>
Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com>