Re: Linux 4.9.140

[Greg KH]

diff --git a/Makefile b/Makefile
index a6959d96316d..a9aed2326233 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 VERSION = 4
 PATCHLEVEL = 9
-SUBLEVEL = 139
+SUBLEVEL = 140
 EXTRAVERSION =
 NAME = Roaring Lionus
 
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 647a702c29dc..6221166e3fca 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -33,10 +33,12 @@ static void __init spectre_v2_select_mitigation(void);
 static void __init ssb_select_mitigation(void);
 static void __init l1tf_select_mitigation(void);
 
-/* The base value of the SPEC_CTRL MSR that always has to be preserved. */
-u64 x86_spec_ctrl_base;
+/*
+ * Our boot-time value of the SPEC_CTRL MSR. We read it once so that any
+ * writes to SPEC_CTRL contain whatever reserved bits have been set.
+ */
+u64 __ro_after_init x86_spec_ctrl_base;
 EXPORT_SYMBOL_GPL(x86_spec_ctrl_base);
-static DEFINE_MUTEX(spec_ctrl_mutex);
 
 /*
  * The vendor and possibly platform specific bits which can be modified in
@@ -320,46 +322,6 @@ static enum spectre_v2_mitigation_cmd __init spectre_v2_parse_cmdline(void)
 	return cmd;
 }
 
-static bool stibp_needed(void)
-{
-	if (spectre_v2_enabled == SPECTRE_V2_NONE)
-		return false;
-
-	if (!boot_cpu_has(X86_FEATURE_STIBP))
-		return false;
-
-	return true;
-}
-
-static void update_stibp_msr(void *info)
-{
-	wrmsrl(MSR_IA32_SPEC_CTRL, x86_spec_ctrl_base);
-}
-
-void arch_smt_update(void)
-{
-	u64 mask;
-
-	if (!stibp_needed())
-		return;
-
-	mutex_lock(&spec_ctrl_mutex);
-	mask = x86_spec_ctrl_base;
-	if (cpu_smt_control == CPU_SMT_ENABLED)
-		mask |= SPEC_CTRL_STIBP;
-	else
-		mask &= ~SPEC_CTRL_STIBP;
-
-	if (mask != x86_spec_ctrl_base) {
-		pr_info("Spectre v2 cross-process SMT mitigation: %s STIBP\n",
-				cpu_smt_control == CPU_SMT_ENABLED ?
-				"Enabling" : "Disabling");
-		x86_spec_ctrl_base = mask;
-		on_each_cpu(update_stibp_msr, NULL, 1);
-	}
-	mutex_unlock(&spec_ctrl_mutex);
-}
-
 static void __init spectre_v2_select_mitigation(void)
 {
 	enum spectre_v2_mitigation_cmd cmd = spectre_v2_parse_cmdline();
@@ -459,9 +421,6 @@ static void __init spectre_v2_select_mitigation(void)
 		setup_force_cpu_cap(X86_FEATURE_USE_IBRS_FW);
 		pr_info("Enabling Restricted Speculation for firmware calls\n");
 	}
-
-	/* Enable STIBP if appropriate */
-	arch_smt_update();
 }
 
 #undef pr_fmt
@@ -854,8 +813,6 @@ static ssize_t l1tf_show_state(char *buf)
 static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr,
 			       char *buf, unsigned int bug)
 {
-	int ret;
-
 	if (!boot_cpu_has_bug(bug))
 		return sprintf(buf, "Not affected\n");
 
@@ -870,12 +827,10 @@ static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr
 		return sprintf(buf, "Mitigation: __user pointer sanitization\n");
 
 	case X86_BUG_SPECTRE_V2:
-		ret = sprintf(buf, "%s%s%s%s%s\n", spectre_v2_strings[spectre_v2_enabled],
+		return sprintf(buf, "%s%s%s%s\n", spectre_v2_strings[spectre_v2_enabled],
 			       boot_cpu_has(X86_FEATURE_USE_IBPB) ? ", IBPB" : "",
 			       boot_cpu_has(X86_FEATURE_USE_IBRS_FW) ? ", IBRS_FW" : "",
-			       (x86_spec_ctrl_base & SPEC_CTRL_STIBP) ? ", STIBP" : "",
 			       spectre_v2_module_string());
-		return ret;
 
 	case X86_BUG_SPEC_STORE_BYPASS:
 		return sprintf(buf, "%s\n", ssb_strings[ssb_mode]);
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 8d7bace9a7b2..b5a0165b7300 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -1970,12 +1970,6 @@ static void cpuhp_online_cpu_device(unsigned int cpu)
 	kobject_uevent(&dev->kobj, KOBJ_ONLINE);
 }
 
-/*
- * Architectures that need SMT-specific errata handling during SMT hotplug
- * should override this.
- */
-void __weak arch_smt_update(void) { };
-
 static int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval)
 {
 	int cpu, ret = 0;
@@ -2002,10 +1996,8 @@ static int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval)
 		 */
 		cpuhp_offline_cpu_device(cpu);
 	}
-	if (!ret) {
+	if (!ret)
 		cpu_smt_control = ctrlval;
-		arch_smt_update();
-	}
 	cpu_maps_update_done();
 	return ret;
 }
@@ -2016,7 +2008,6 @@ static int cpuhp_smt_enable(void)
 
 	cpu_maps_update_begin();
 	cpu_smt_control = CPU_SMT_ENABLED;
-	arch_smt_update();
 	for_each_present_cpu(cpu) {
 		/* Skip online CPUs and CPUs on offline nodes */
 		if (cpu_online(cpu) || !node_online(cpu_to_node(cpu)))
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 0db120d2a4fe..b0a72677b7e5 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -2292,7 +2292,6 @@ static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_bu
 	if (on_link)
 		nrt->rt6i_flags &= ~RTF_GATEWAY;
 
-	nrt->rt6i_protocol = RTPROT_REDIRECT;
 	nrt->rt6i_gateway = *(struct in6_addr *)neigh->primary_key;
 
 	if (ip6_ins_rt(nrt))
@@ -2397,7 +2396,6 @@ static struct rt6_info *rt6_add_route_info(struct net *net,
 		.fc_dst_len	= prefixlen,
 		.fc_flags	= RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO |
 				  RTF_UP | RTF_PREF(pref),
-		.fc_protocol = RTPROT_RA,
 		.fc_nlinfo.portid = 0,
 		.fc_nlinfo.nlh = NULL,
 		.fc_nlinfo.nl_net = net,
@@ -2450,7 +2448,6 @@ struct rt6_info *rt6_add_dflt_router(const struct in6_addr *gwaddr,
 		.fc_ifindex	= dev->ifindex,
 		.fc_flags	= RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT |
 				  RTF_UP | RTF_EXPIRES | RTF_PREF(pref),
-		.fc_protocol = RTPROT_RA,
 		.fc_nlinfo.portid = 0,
 		.fc_nlinfo.nlh = NULL,
 		.fc_nlinfo.nl_net = dev_net(dev),
@@ -3247,6 +3244,14 @@ static int rt6_fill_node(struct net *net,
 	}
 	rtm->rtm_scope = RT_SCOPE_UNIVERSE;
 	rtm->rtm_protocol = rt->rt6i_protocol;
+	if (rt->rt6i_flags & RTF_DYNAMIC)
+		rtm->rtm_protocol = RTPROT_REDIRECT;
+	else if (rt->rt6i_flags & RTF_ADDRCONF) {
+		if (rt->rt6i_flags & (RTF_DEFAULT | RTF_ROUTEINFO))
+			rtm->rtm_protocol = RTPROT_RA;
+		else
+			rtm->rtm_protocol = RTPROT_KERNEL;
+	}
 
 	if (rt->rt6i_flags & RTF_CACHE)
 		rtm->rtm_flags |= RTM_F_CLONED;