x86/speculation: Include unprivileged eBPF status in Spectre v2 mitigation reporting

stable inclusion
from stable-v5.10.105
commit afc2d635b5e18e2b33116d8e121ee149882e33eb
category: bugfix
bugzilla: 186453 https://gitee.com/src-openeuler/kernel/issues/I50WBM
CVE: CVE-2022-0001

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=afc2d635b5e1



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

commit 44a3918c upstream.

With unprivileged eBPF enabled, eIBRS (without retpoline) is vulnerable
to Spectre v2 BHB-based attacks.

When both are enabled, print a warning message and report it in the
'spectre_v2' sysfs vulnerabilities file.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
[fllinden@amazon.com: backported to 5.10]
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Chen Jiahao <chenjiahao16@huawei.com>
Reviewed-by: Liao Chang <liaochang1@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>