Merge tag 'v5.3-rc6' into x86/cpu, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/kernel/apic/apic.c

@@ -722,7 +722,7 @@ static __initdata unsigned long lapic_cal_pm1, lapic_cal_pm2;
 static __initdata unsigned long lapic_cal_j1, lapic_cal_j2;
 
 /*
- * Temporary interrupt handler.
+ * Temporary interrupt handler and polled calibration function.
  */
 static void __init lapic_cal_handler(struct clock_event_device *dev)
 {
@@ -851,7 +851,8 @@ bool __init apic_needs_pit(void)
 static int __init calibrate_APIC_clock(void)
 {
 	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
-	void (*real_handler)(struct clock_event_device *dev);
+	u64 tsc_perj = 0, tsc_start = 0;
+	unsigned long jif_start;
 	unsigned long deltaj;
 	long delta, deltatsc;
 	int pm_referenced = 0;
@@ -878,29 +879,65 @@ static int __init calibrate_APIC_clock(void)
 	apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
 		    "calibrating APIC timer ...\n");
 
+	/*
+	 * There are platforms w/o global clockevent devices. Instead of
+	 * making the calibration conditional on that, use a polling based
+	 * approach everywhere.
+	 */
 	local_irq_disable();
 
-	/* Replace the global interrupt handler */
-	real_handler = global_clock_event->event_handler;
-	global_clock_event->event_handler = lapic_cal_handler;
-
 	/*
 	 * Setup the APIC counter to maximum. There is no way the lapic
 	 * can underflow in the 100ms detection time frame
 	 */
 	__setup_APIC_LVTT(0xffffffff, 0, 0);
 
-	/* Let the interrupts run */
+	/*
+	 * Methods to terminate the calibration loop:
+	 *  1) Global clockevent if available (jiffies)
+	 *  2) TSC if available and frequency is known
+	 */
+	jif_start = READ_ONCE(jiffies);
+
+	if (tsc_khz) {
+		tsc_start = rdtsc();
+		tsc_perj = div_u64((u64)tsc_khz * 1000, HZ);
+	}
+
+	/*
+	 * Enable interrupts so the tick can fire, if a global
+	 * clockevent device is available
+	 */
 	local_irq_enable();
 
-	while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
-		cpu_relax();
+	while (lapic_cal_loops <= LAPIC_CAL_LOOPS) {
+		/* Wait for a tick to elapse */
+		while (1) {
+			if (tsc_khz) {
+				u64 tsc_now = rdtsc();
+				if ((tsc_now - tsc_start) >= tsc_perj) {
+					tsc_start += tsc_perj;
+					break;
+				}
+			} else {
+				unsigned long jif_now = READ_ONCE(jiffies);
+
+				if (time_after(jif_now, jif_start)) {
+					jif_start = jif_now;
+					break;
+				}
+			}
+			cpu_relax();
+		}
+
+		/* Invoke the calibration routine */
+		local_irq_disable();
+		lapic_cal_handler(NULL);
+		local_irq_enable();
+	}
 
 	local_irq_disable();
 
-	/* Restore the real event handler */
-	global_clock_event->event_handler = real_handler;
-
 	/* Build delta t1-t2 as apic timer counts down */
 	delta = lapic_cal_t1 - lapic_cal_t2;
 	apic_printk(APIC_VERBOSE, "... lapic delta = %ld\n", delta);
@@ -943,10 +980,11 @@ static int __init calibrate_APIC_clock(void)
 	levt->features &= ~CLOCK_EVT_FEAT_DUMMY;
 
 	/*
-	 * PM timer calibration failed or not turned on
-	 * so lets try APIC timer based calibration
+	 * PM timer calibration failed or not turned on so lets try APIC
+	 * timer based calibration, if a global clockevent device is
+	 * available.
 	 */
-	if (!pm_referenced) {
+	if (!pm_referenced && global_clock_event) {
 		apic_printk(APIC_VERBOSE, "... verify APIC timer\n");
 
 		/*

arch/x86/kernel/apic/probe_32.c

@@ -184,7 +184,8 @@ void __init default_setup_apic_routing(void)
 				def_to_bigsmp = 0;
 				break;
 			}
-			/* If P4 and above fall through */
+			/* P4 and above */
+			/* fall through */
 		case X86_VENDOR_HYGON:
 		case X86_VENDOR_AMD:
 			def_to_bigsmp = 1;

arch/x86/kernel/cpu/amd.c

@@ -804,6 +804,64 @@ static void init_amd_ln(struct cpuinfo_x86 *c)
 	msr_set_bit(MSR_AMD64_DE_CFG, 31);
 }
 
+static bool rdrand_force;
+
+static int __init rdrand_cmdline(char *str)
+{
+	if (!str)
+		return -EINVAL;
+
+	if (!strcmp(str, "force"))
+		rdrand_force = true;
+	else
+		return -EINVAL;
+
+	return 0;
+}
+early_param("rdrand", rdrand_cmdline);
+
+static void clear_rdrand_cpuid_bit(struct cpuinfo_x86 *c)
+{
+	/*
+	 * Saving of the MSR used to hide the RDRAND support during
+	 * suspend/resume is done by arch/x86/power/cpu.c, which is
+	 * dependent on CONFIG_PM_SLEEP.
+	 */
+	if (!IS_ENABLED(CONFIG_PM_SLEEP))
+		return;
+
+	/*
+	 * The nordrand option can clear X86_FEATURE_RDRAND, so check for
+	 * RDRAND support using the CPUID function directly.
+	 */
+	if (!(cpuid_ecx(1) & BIT(30)) || rdrand_force)
+		return;
+
+	msr_clear_bit(MSR_AMD64_CPUID_FN_1, 62);
+
+	/*
+	 * Verify that the CPUID change has occurred in case the kernel is
+	 * running virtualized and the hypervisor doesn't support the MSR.
+	 */
+	if (cpuid_ecx(1) & BIT(30)) {
+		pr_info_once("BIOS may not properly restore RDRAND after suspend, but hypervisor does not support hiding RDRAND via CPUID.\n");
+		return;
+	}
+
+	clear_cpu_cap(c, X86_FEATURE_RDRAND);
+	pr_info_once("BIOS may not properly restore RDRAND after suspend, hiding RDRAND via CPUID. Use rdrand=force to reenable.\n");
+}
+
+static void init_amd_jg(struct cpuinfo_x86 *c)
+{
+	/*
+	 * Some BIOS implementations do not restore proper RDRAND support
+	 * across suspend and resume. Check on whether to hide the RDRAND
+	 * instruction support via CPUID.
+	 */
+	clear_rdrand_cpuid_bit(c);
+}
+
 static void init_amd_bd(struct cpuinfo_x86 *c)
 {
 	u64 value;
@@ -818,6 +876,13 @@ static void init_amd_bd(struct cpuinfo_x86 *c)
 			wrmsrl_safe(MSR_F15H_IC_CFG, value);
 		}
 	}
+
+	/*
+	 * Some BIOS implementations do not restore proper RDRAND support
+	 * across suspend and resume. Check on whether to hide the RDRAND
+	 * instruction support via CPUID.
+	 */
+	clear_rdrand_cpuid_bit(c);
 }
 
 static void init_amd_zn(struct cpuinfo_x86 *c)
@@ -860,6 +925,7 @@ static void init_amd(struct cpuinfo_x86 *c)
 	case 0x10: init_amd_gh(c); break;
 	case 0x12: init_amd_ln(c); break;
 	case 0x15: init_amd_bd(c); break;
+	case 0x16: init_amd_jg(c); break;
 	case 0x17: init_amd_zn(c); break;
 	}
 

arch/x86/kernel/cpu/bugs.c

@@ -34,6 +34,7 @@
 
 #include "cpu.h"
 
+static void __init spectre_v1_select_mitigation(void);
 static void __init spectre_v2_select_mitigation(void);
 static void __init ssb_select_mitigation(void);
 static void __init l1tf_select_mitigation(void);
@@ -98,17 +99,11 @@ void __init check_bugs(void)
 	if (boot_cpu_has(X86_FEATURE_STIBP))
 		x86_spec_ctrl_mask |= SPEC_CTRL_STIBP;
 
-	/* Select the proper spectre mitigation before patching alternatives */
+	/* Select the proper CPU mitigations before patching alternatives: */
+	spectre_v1_select_mitigation();
 	spectre_v2_select_mitigation();
-
-	/*
-	 * Select proper mitigation for any exposure to the Speculative Store
-	 * Bypass vulnerability.
-	 */
 	ssb_select_mitigation();
-
 	l1tf_select_mitigation();
-
 	mds_select_mitigation();
 
 	arch_smt_update();
@@ -273,6 +268,98 @@ static int __init mds_cmdline(char *str)
 }
 early_param("mds", mds_cmdline);
 
+#undef pr_fmt
+#define pr_fmt(fmt)     "Spectre V1 : " fmt
+
+enum spectre_v1_mitigation {
+	SPECTRE_V1_MITIGATION_NONE,
+	SPECTRE_V1_MITIGATION_AUTO,
+};
+
+static enum spectre_v1_mitigation spectre_v1_mitigation __ro_after_init =
+	SPECTRE_V1_MITIGATION_AUTO;
+
+static const char * const spectre_v1_strings[] = {
+	[SPECTRE_V1_MITIGATION_NONE] = "Vulnerable: __user pointer sanitization and usercopy barriers only; no swapgs barriers",
+	[SPECTRE_V1_MITIGATION_AUTO] = "Mitigation: usercopy/swapgs barriers and __user pointer sanitization",
+};
+
+/*
+ * Does SMAP provide full mitigation against speculative kernel access to
+ * userspace?
+ */
+static bool smap_works_speculatively(void)
+{
+	if (!boot_cpu_has(X86_FEATURE_SMAP))
+		return false;
+
+	/*
+	 * On CPUs which are vulnerable to Meltdown, SMAP does not
+	 * prevent speculative access to user data in the L1 cache.
+	 * Consider SMAP to be non-functional as a mitigation on these
+	 * CPUs.
+	 */
+	if (boot_cpu_has(X86_BUG_CPU_MELTDOWN))
+		return false;
+
+	return true;
+}
+
+static void __init spectre_v1_select_mitigation(void)
+{
+	if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V1) || cpu_mitigations_off()) {
+		spectre_v1_mitigation = SPECTRE_V1_MITIGATION_NONE;
+		return;
+	}
+
+	if (spectre_v1_mitigation == SPECTRE_V1_MITIGATION_AUTO) {
+		/*
+		 * With Spectre v1, a user can speculatively control either
+		 * path of a conditional swapgs with a user-controlled GS
+		 * value.  The mitigation is to add lfences to both code paths.
+		 *
+		 * If FSGSBASE is enabled, the user can put a kernel address in
+		 * GS, in which case SMAP provides no protection.
+		 *
+		 * [ NOTE: Don't check for X86_FEATURE_FSGSBASE until the
+		 *	   FSGSBASE enablement patches have been merged. ]
+		 *
+		 * If FSGSBASE is disabled, the user can only put a user space
+		 * address in GS.  That makes an attack harder, but still
+		 * possible if there's no SMAP protection.
+		 */
+		if (!smap_works_speculatively()) {
+			/*
+			 * Mitigation can be provided from SWAPGS itself or
+			 * PTI as the CR3 write in the Meltdown mitigation
+			 * is serializing.
+			 *
+			 * If neither is there, mitigate with an LFENCE to
+			 * stop speculation through swapgs.
+			 */
+			if (boot_cpu_has_bug(X86_BUG_SWAPGS) &&
+			    !boot_cpu_has(X86_FEATURE_PTI))
+				setup_force_cpu_cap(X86_FEATURE_FENCE_SWAPGS_USER);
+
+			/*
+			 * Enable lfences in the kernel entry (non-swapgs)
+			 * paths, to prevent user entry from speculatively
+			 * skipping swapgs.
+			 */
+			setup_force_cpu_cap(X86_FEATURE_FENCE_SWAPGS_KERNEL);
+		}
+	}
+
+	pr_info("%s\n", spectre_v1_strings[spectre_v1_mitigation]);
+}
+
+static int __init nospectre_v1_cmdline(char *str)
+{
+	spectre_v1_mitigation = SPECTRE_V1_MITIGATION_NONE;
+	return 0;
+}
+early_param("nospectre_v1", nospectre_v1_cmdline);
+
 #undef pr_fmt
 #define pr_fmt(fmt)     "Spectre V2 : " fmt
 
@@ -1226,7 +1313,7 @@ static ssize_t l1tf_show_state(char *buf)
 
 static ssize_t mds_show_state(char *buf)
 {
-	if (!hypervisor_is_type(X86_HYPER_NATIVE)) {
+	if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) {
 		return sprintf(buf, "%s; SMT Host state unknown\n",
 			       mds_strings[mds_mitigation]);
 	}
@@ -1290,7 +1377,7 @@ static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr
 		break;
 
 	case X86_BUG_SPECTRE_V1:
-		return sprintf(buf, "Mitigation: __user pointer sanitization\n");
+		return sprintf(buf, "%s\n", spectre_v1_strings[spectre_v1_mitigation]);
 
 	case X86_BUG_SPECTRE_V2:
 		return sprintf(buf, "%s%s%s%s%s%s\n", spectre_v2_strings[spectre_v2_enabled],

arch/x86/kernel/cpu/common.c

@@ -1022,6 +1022,7 @@ static void identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
 #define NO_L1TF		BIT(3)
 #define NO_MDS		BIT(4)
 #define MSBDS_ONLY	BIT(5)
+#define NO_SWAPGS	BIT(6)
 
 #define VULNWL(_vendor, _family, _model, _whitelist)	\
 	{ X86_VENDOR_##_vendor, _family, _model, X86_FEATURE_ANY, _whitelist }
@@ -1048,30 +1049,38 @@ static const __initconst struct x86_cpu_id cpu_vuln_whitelist[] = {
 	VULNWL_INTEL(ATOM_BONNELL,		NO_SPECULATION),
 	VULNWL_INTEL(ATOM_BONNELL_MID,		NO_SPECULATION),
 
-	VULNWL_INTEL(ATOM_SILVERMONT,		NO_SSB | NO_L1TF | MSBDS_ONLY),
-	VULNWL_INTEL(ATOM_SILVERMONT_X,		NO_SSB | NO_L1TF | MSBDS_ONLY),
-	VULNWL_INTEL(ATOM_SILVERMONT_MID,	NO_SSB | NO_L1TF | MSBDS_ONLY),
-	VULNWL_INTEL(ATOM_AIRMONT,		NO_SSB | NO_L1TF | MSBDS_ONLY),
-	VULNWL_INTEL(XEON_PHI_KNL,		NO_SSB | NO_L1TF | MSBDS_ONLY),
-	VULNWL_INTEL(XEON_PHI_KNM,		NO_SSB | NO_L1TF | MSBDS_ONLY),
+	VULNWL_INTEL(ATOM_SILVERMONT,		NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS),
+	VULNWL_INTEL(ATOM_SILVERMONT_X,		NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS),
+	VULNWL_INTEL(ATOM_SILVERMONT_MID,	NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS),
+	VULNWL_INTEL(ATOM_AIRMONT,		NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS),
+	VULNWL_INTEL(XEON_PHI_KNL,		NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS),
+	VULNWL_INTEL(XEON_PHI_KNM,		NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS),
 
 	VULNWL_INTEL(CORE_YONAH,		NO_SSB),
 
-	VULNWL_INTEL(ATOM_AIRMONT_MID,		NO_L1TF | MSBDS_ONLY),
+	VULNWL_INTEL(ATOM_AIRMONT_MID,		NO_L1TF | MSBDS_ONLY | NO_SWAPGS),
 
-	VULNWL_INTEL(ATOM_GOLDMONT,		NO_MDS | NO_L1TF),
-	VULNWL_INTEL(ATOM_GOLDMONT_X,		NO_MDS | NO_L1TF),
-	VULNWL_INTEL(ATOM_GOLDMONT_PLUS,	NO_MDS | NO_L1TF),
+	VULNWL_INTEL(ATOM_GOLDMONT,		NO_MDS | NO_L1TF | NO_SWAPGS),
+	VULNWL_INTEL(ATOM_GOLDMONT_X,		NO_MDS | NO_L1TF | NO_SWAPGS),
+	VULNWL_INTEL(ATOM_GOLDMONT_PLUS,	NO_MDS | NO_L1TF | NO_SWAPGS),
+
+	/*
+	 * Technically, swapgs isn't serializing on AMD (despite it previously
+	 * being documented as such in the APM).  But according to AMD, %gs is
+	 * updated non-speculatively, and the issuing of %gs-relative memory
+	 * operands will be blocked until the %gs update completes, which is
+	 * good enough for our purposes.
+	 */
 
 	/* AMD Family 0xf - 0x12 */
-	VULNWL_AMD(0x0f,	NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS),
-	VULNWL_AMD(0x10,	NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS),
-	VULNWL_AMD(0x11,	NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS),
-	VULNWL_AMD(0x12,	NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS),
+	VULNWL_AMD(0x0f,	NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS | NO_SWAPGS),
+	VULNWL_AMD(0x10,	NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS | NO_SWAPGS),
+	VULNWL_AMD(0x11,	NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS | NO_SWAPGS),
+	VULNWL_AMD(0x12,	NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS | NO_SWAPGS),
 
 	/* FAMILY_ANY must be last, otherwise 0x0f - 0x12 matches won't work */
-	VULNWL_AMD(X86_FAMILY_ANY,	NO_MELTDOWN | NO_L1TF | NO_MDS),
-	VULNWL_HYGON(X86_FAMILY_ANY,	NO_MELTDOWN | NO_L1TF | NO_MDS),
+	VULNWL_AMD(X86_FAMILY_ANY,	NO_MELTDOWN | NO_L1TF | NO_MDS | NO_SWAPGS),
+	VULNWL_HYGON(X86_FAMILY_ANY,	NO_MELTDOWN | NO_L1TF | NO_MDS | NO_SWAPGS),
 	{}
 };
 
@@ -1108,6 +1117,9 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
 			setup_force_cpu_bug(X86_BUG_MSBDS_ONLY);
 	}
 
+	if (!cpu_matches(NO_SWAPGS))
+		setup_force_cpu_bug(X86_BUG_SWAPGS);
+
 	if (cpu_matches(NO_MELTDOWN))
 		return;
 

arch/x86/kernel/cpu/mtrr/cyrix.c

@@ -98,6 +98,7 @@ cyrix_get_free_region(unsigned long base, unsigned long size, int replace_reg)
 	case 7:
 		if (size < 0x40)
 			break;
+		/* Else, fall through */
 	case 6:
 	case 5:
 	case 4:

arch/x86/kernel/cpu/umwait.c

@@ -17,6 +17,12 @@
  */
 static u32 umwait_control_cached = UMWAIT_CTRL_VAL(100000, UMWAIT_C02_ENABLE);
 
+/*
+ * Cache the original IA32_UMWAIT_CONTROL MSR value which is configured by
+ * hardware or BIOS before kernel boot.
+ */
+static u32 orig_umwait_control_cached __ro_after_init;
+
 /*
  * Serialize access to umwait_control_cached and IA32_UMWAIT_CONTROL MSR in
  * the sysfs write functions.
@@ -52,6 +58,23 @@ static int umwait_cpu_online(unsigned int cpu)
 	return 0;
 }
 
+/*
+ * The CPU hotplug callback sets the control MSR to the original control
+ * value.
+ */
+static int umwait_cpu_offline(unsigned int cpu)
+{
+	/*
+	 * This code is protected by the CPU hotplug already and
+	 * orig_umwait_control_cached is never changed after it caches
+	 * the original control MSR value in umwait_init(). So there
+	 * is no race condition here.
+	 */
+	wrmsr(MSR_IA32_UMWAIT_CONTROL, orig_umwait_control_cached, 0);
+
+	return 0;
+}
+
 /*
  * On resume, restore IA32_UMWAIT_CONTROL MSR on the boot processor which
  * is the only active CPU at this time. The MSR is set up on the APs via the
@@ -185,8 +208,22 @@ static int __init umwait_init(void)
 	if (!boot_cpu_has(X86_FEATURE_WAITPKG))
 		return -ENODEV;
 
+	/*
+	 * Cache the original control MSR value before the control MSR is
+	 * changed. This is the only place where orig_umwait_control_cached
+	 * is modified.
+	 */
+	rdmsrl(MSR_IA32_UMWAIT_CONTROL, orig_umwait_control_cached);
+
 	ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "umwait:online",
-				umwait_cpu_online, NULL);
+				umwait_cpu_online, umwait_cpu_offline);
+	if (ret < 0) {
+		/*
+		 * On failure, the control MSR on all CPUs has the
+		 * original control value.
+		 */
+		return ret;
+	}
 
 	register_syscore_ops(&umwait_syscore_ops);
 

arch/x86/kernel/head_64.S

@@ -193,10 +193,10 @@ ENTRY(secondary_startup_64)
 
 	/* Set up %gs.
 	 *
-	 * The base of %gs always points to the bottom of the irqstack
-	 * union.  If the stack protector canary is enabled, it is
-	 * located at %gs:40.  Note that, on SMP, the boot cpu uses
-	 * init data section till per cpu areas are set up.
+	 * The base of %gs always points to fixed_percpu_data. If the
+	 * stack protector canary is enabled, it is located at %gs:40.
+	 * Note that, on SMP, the boot cpu uses init data section until
+	 * the per cpu areas are set up.
 	 */
 	movl	$MSR_GS_BASE,%ecx
 	movl	initial_gs(%rip),%eax

arch/x86/kernel/hpet.c

@@ -827,10 +827,6 @@ int __init hpet_enable(void)
 	if (!hpet_cfg_working())
 		goto out_nohpet;
 
-	/* Validate that the counter is counting */
-	if (!hpet_counting())
-		goto out_nohpet;
-
 	/*
 	 * Read the period and check for a sane value:
 	 */
@@ -896,6 +892,14 @@ int __init hpet_enable(void)
 	}
 	hpet_print_config();
 
+	/*
+	 * Validate that the counter is counting. This needs to be done
+	 * after sanitizing the config registers to properly deal with
+	 * force enabled HPETs.
+	 */
+	if (!hpet_counting())
+		goto out_nohpet;
+
 	clocksource_register_hz(&clocksource_hpet, (u32)hpet_freq);
 
 	if (id & HPET_ID_LEGSUP) {

arch/x86/kernel/kvm.c

@@ -308,9 +308,6 @@ static notrace void kvm_guest_apic_eoi_write(u32 reg, u32 val)
 
 static void kvm_guest_cpu_init(void)
 {
-	if (!kvm_para_available())
-		return;
-
 	if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF) && kvmapf) {
 		u64 pa = slow_virt_to_phys(this_cpu_ptr(&apf_reason));
 
@@ -625,9 +622,6 @@ static void __init kvm_guest_init(void)
 {
 	int i;
 
-	if (!kvm_para_available())
-		return;
-
 	paravirt_ops_setup();
 	register_reboot_notifier(&kvm_pv_reboot_nb);
 	for (i = 0; i < KVM_TASK_SLEEP_HASHSIZE; i++)
@@ -848,8 +842,6 @@ asm(
  */
 void __init kvm_spinlock_init(void)
 {
-	if (!kvm_para_available())
-		return;
 	/* Does host kernel support KVM_FEATURE_PV_UNHALT? */
 	if (!kvm_para_has_feature(KVM_FEATURE_PV_UNHALT))
 		return;

arch/x86/kernel/ptrace.c

@@ -201,6 +201,7 @@ static int set_segment_reg(struct task_struct *task,
 	case offsetof(struct user_regs_struct, ss):
 		if (unlikely(value == 0))
 			return -EIO;
+		/* Else, fall through */
 
 	default:
 		*pt_regs_access(task_pt_regs(task), offset) = value;

arch/x86/kernel/stacktrace.c

@@ -100,7 +100,7 @@ copy_stack_frame(const void __user *fp, struct stack_frame_user *frame)
 {
 	int ret;
 
-	if (!access_ok(fp, sizeof(*frame)))
+	if (__range_not_ok(fp, sizeof(*frame), TASK_SIZE))
 		return 0;
 
 	ret = 1;

arch/x86/kernel/sysfb_efi.c

@@ -230,9 +230,55 @@ static const struct dmi_system_id efifb_dmi_system_table[] __initconst = {
 	{},
 };
 
+/*
+ * Some devices have a portrait LCD but advertise a landscape resolution (and
+ * pitch). We simply swap width and height for these devices so that we can
+ * correctly deal with some of them coming with multiple resolutions.
+ */
+static const struct dmi_system_id efifb_dmi_swap_width_height[] __initconst = {
+	{
+		/*
+		 * Lenovo MIIX310-10ICR, only some batches have the troublesome
+		 * 800x1280 portrait screen. Luckily the portrait version has
+		 * its own BIOS version, so we match on that.
+		 */
+		.matches = {
+			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+			DMI_EXACT_MATCH(DMI_PRODUCT_VERSION, "MIIX 310-10ICR"),
+			DMI_EXACT_MATCH(DMI_BIOS_VERSION, "1HCN44WW"),
+		},
+	},
+	{
+		/* Lenovo MIIX 320-10ICR with 800x1280 portrait screen */
+		.matches = {
+			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+			DMI_EXACT_MATCH(DMI_PRODUCT_VERSION,
+					"Lenovo MIIX 320-10ICR"),
+		},
+	},
+	{
+		/* Lenovo D330 with 800x1280 or 1200x1920 portrait screen */
+		.matches = {
+			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+			DMI_EXACT_MATCH(DMI_PRODUCT_VERSION,
+					"Lenovo ideapad D330-10IGM"),
+		},
+	},
+	{},
+};
+
 __init void sysfb_apply_efi_quirks(void)
 {
 	if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI ||
 	    !(screen_info.capabilities & VIDEO_CAPABILITY_SKIP_QUIRKS))
 		dmi_check_system(efifb_dmi_system_table);
+
+	if (screen_info.orig_video_isVGA == VIDEO_TYPE_EFI &&
+	    dmi_check_system(efifb_dmi_swap_width_height)) {
+		u16 temp = screen_info.lfb_width;
+
+		screen_info.lfb_width = screen_info.lfb_height;
+		screen_info.lfb_height = temp;
+		screen_info.lfb_linelength = 4 * screen_info.lfb_width;
+	}
 }