Commit d3b2e775 authored by Borislav Petkov (AMD)'s avatar Borislav Petkov (AMD) Committed by Jialin Zhang
Browse files

x86/srso: Correct the mitigation status when SMT is disabled 

stable inclusion
from stable-v5.10.192
commit 0e8139f92304cef82ac769cfb51dda341a17fb1c
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I7RQ67

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=0e8139f92304cef82ac769cfb51dda341a17fb1c



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

commit 6405b72e upstream.

Specify how is SRSO mitigated when SMT is disabled. Also, correct the
SMT check for that.

Fixes: e9fbc47b ("x86/srso: Disable the mitigation on unaffected configurations")
Suggested-by: default avatarJosh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Acked-by: default avatarJosh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/20230814200813.p5czl47zssuej7nv@treble


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarJialin Zhang <zhangjialin11@huawei.com>
parent b2f4d82a

arch/x86/kernel/cpu/bugs.c

+2 −3
Original line number Diff line number Diff line
@@ -2377,8 +2377,7 @@ static void __init srso_select_mitigation(void) 
		 * Zen1/2 with SMT off aren't vulnerable after the right

		 * IBPB microcode has been applied.

		 */

		if ((boot_cpu_data.x86 < 0x19) &&

		    (!cpu_smt_possible() || (cpu_smt_control == CPU_SMT_DISABLED))) {

		if (boot_cpu_data.x86 < 0x19 && !cpu_smt_possible()) {

			setup_force_cpu_cap(X86_FEATURE_SRSO_NO);

			return;

		}
@@ -2668,7 +2667,7 @@ static ssize_t gds_show_state(char *buf) 
static ssize_t srso_show_state(char *buf)

{

	if (boot_cpu_has(X86_FEATURE_SRSO_NO))

		return sysfs_emit(buf, "Not affected\n");

		return sysfs_emit(buf, "Mitigation: SMT disabled\n");



	return sysfs_emit(buf, "%s%s\n",

			  srso_strings[srso_mitigation],