Sat Dec 22 08:59:45 2018 UTC ()

If the CPU is not vulnerable to SpectreV4, say it in the sysctl by default.
Apply some minor style while here.


(maxv)

diff -r1.19 -r1.20 src/sys/arch/x86/x86/spectre.c

--- src/sys/arch/x86/x86/spectre.c 2018/05/28 20:18:58	1.19
+++ src/sys/arch/x86/x86/spectre.c 2018/12/22 08:59:44	1.20

 @@ -1,14 +1,14 @@
-/*	$NetBSD: spectre.c,v 1.19 2018/05/28 20:18:58 maxv Exp $	*/
+/*	$NetBSD: spectre.c,v 1.20 2018/12/22 08:59:44 maxv Exp $	*/
 /*
  * Copyright (c) 2018 NetBSD Foundation, Inc.
  * All rights reserved.
+ *
  * This code is derived from software contributed to The NetBSD Foundation
  * by Maxime Villard.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
 @@ -24,27 +24,27 @@
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  */
 /*
  * Mitigations for the SpectreV2 and SpectreV4 CPU flaws.
  */
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: spectre.c,v 1.19 2018/05/28 20:18:58 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: spectre.c,v 1.20 2018/12/22 08:59:44 maxv Exp $");
 #include "opt_spectre.h"
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/cpu.h>
 #include <sys/sysctl.h>
 #include <sys/xcall.h>
 #include <machine/cpufunc.h>
 #include <machine/cpuvar.h>
 #include <machine/specialreg.h>
 #include <machine/frameasm.h>
 @@ -473,27 +473,28 @@ mitigation_v4_apply_cpu(bool enabled)
 		msr &= ~msrbit;
+	}
 	wrmsr(msrval, msr);
+}
 static void
 mitigation_v4_change_cpu(void *arg1, void *arg2)
+{
 	bool enabled = (bool)arg1;
 	mitigation_v4_apply_cpu(enabled);
+}
-static int mitigation_v4_change(bool enabled)
+static int
 mitigation_v4_change(bool enabled)
+{
 	struct cpu_info *ci = NULL;
 	CPU_INFO_ITERATOR cii;
 	uint64_t xc;
 	v4_detect_method();
 	mutex_enter(&cpu_lock);
 	/*
 	 * We expect all the CPUs to be online.
 	 */
 	for (CPU_INFO_FOREACH(cii, ci)) {
 @@ -599,37 +600,50 @@ cpu_speculation_init(struct cpu_info *ci
 		v2_mitigation_enabled =
 		    (v2_mitigation_method != V2_MITIGATION_NONE);
 		v2_set_name();
+	}
 	if (v2_mitigation_method != V2_MITIGATION_NONE) {
 		mitigation_v2_apply_cpu(ci, true);
+	}
 	/*
 	 * Spectre V4.
+	 *
 	 * cpu0 is the one that detects the method and sets the global
 	 * variable.
+	 *
 	 * Disabled by default, as recommended by AMD, but can be enabled
 	 * dynamically. We only detect if the CPU is not vulnerable, to
 	 * mark it as 'mitigated' in the sysctl.
 	 */
 #if 0
 	if (ci == &cpu_info_primary) {
 		v4_detect_method();
 		v4_mitigation_enabled =
 		    (v4_mitigation_method != V4_MITIGATION_NONE);
 		v4_set_name();
+	}
-	if (v4_mitigation_method != V4_MITIGATION_NONE) {
+	if (v4_mitigation_method != V4_MITIGATION_NONE &&
 	    v4_mitigation_method != V4_MITIGATION_INTEL_SSB_NO) {
 		mitigation_v4_apply_cpu(ci, true);
+	}
 #else
 	if (ci == &cpu_info_primary) {
 		v4_detect_method();
 		if (v4_mitigation_method == V4_MITIGATION_INTEL_SSB_NO) {
 			v4_mitigation_enabled = true;
 			v4_set_name();
+		}
+	}
 #endif
+}
 void sysctl_speculation_init(struct sysctllog **);
 void
 sysctl_speculation_init(struct sysctllog **clog)
+{
 	const struct sysctlnode *spec_rnode;
 	/* SpectreV1 */
 	spec_rnode = NULL;
 	sysctl_createv(clog, 0, NULL, &spec_rnode,