lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20251013143444.3999-14-david.kaplan@amd.com>
Date: Mon, 13 Oct 2025 09:34:01 -0500
From: David Kaplan <david.kaplan@....com>
To: Thomas Gleixner <tglx@...utronix.de>, Borislav Petkov <bp@...en8.de>,
	Peter Zijlstra <peterz@...radead.org>, Josh Poimboeuf <jpoimboe@...nel.org>,
	Pawan Gupta <pawan.kumar.gupta@...ux.intel.com>, Ingo Molnar
	<mingo@...hat.com>, Dave Hansen <dave.hansen@...ux.intel.com>,
	<x86@...nel.org>, "H . Peter Anvin" <hpa@...or.com>
CC: Alexander Graf <graf@...zon.com>, Boris Ostrovsky
	<boris.ostrovsky@...cle.com>, <linux-kernel@...r.kernel.org>
Subject: [RFC PATCH 13/56] x86/bugs: Reset SRSO mitigations

Add function to reset SRSO mitigations back to their boot-time defaults.

Signed-off-by: David Kaplan <david.kaplan@....com>
---
 arch/x86/kernel/cpu/bugs.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 9a9d5309aa56..112553058ccc 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -3312,6 +3312,21 @@ static void __init srso_apply_mitigation(void)
 	}
 }
 
+#ifdef CONFIG_DYNAMIC_MITIGATIONS
+static void srso_reset_mitigation(void)
+{
+	setup_clear_cpu_cap(X86_FEATURE_RETHUNK);
+	setup_clear_cpu_cap(X86_FEATURE_UNRET);
+	setup_clear_cpu_cap(X86_FEATURE_SRSO_ALIAS);
+	setup_clear_cpu_cap(X86_FEATURE_SRSO);
+	setup_clear_cpu_cap(X86_FEATURE_ENTRY_IBPB);
+	setup_clear_cpu_cap(X86_FEATURE_IBPB_ON_VMEXIT);
+	x86_pred_cmd = PRED_CMD_IBPB;
+	x86_return_thunk = __x86_return_thunk;
+	srso_mitigation = SRSO_MITIGATION_AUTO;
+}
+#endif
+
 #undef pr_fmt
 #define pr_fmt(fmt)	"VMSCAPE: " fmt
 
@@ -3925,5 +3940,6 @@ void arch_cpu_reset_mitigations(void)
 	mds_reset_mitigation();
 	mmio_reset_mitigation();
 	srbds_reset_mitigation();
+	srso_reset_mitigation();
 }
 #endif
-- 
2.34.1


Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ