Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Ingo Molnar:
 - misc fixes all around the map
 - block non-root vm86(old) if mmap_min_addr != 0
 - two small debuggability improvements
 - removal of obsolete paravirt op

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/platform: Fix Geode LX timekeeping in the generic x86 build
  x86/apic: Serialize LVTT and TSC_DEADLINE writes
  x86/ioapic: Force affinity setting in setup_ioapic_dest()
  x86/paravirt: Remove the unused pv_time_ops::get_tsc_khz method
  x86/ldt: Fix small LDT allocation for Xen
  x86/vm86: Fix the misleading CONFIG_VM86 Kconfig help text
  x86/cpu: Print family/model/stepping in hex
  x86/vm86: Block non-root vm86(old) if mmap_min_addr != 0
  x86/alternatives: Make optimize_nops() interrupt safe and synced
  x86/mm/srat: Print non-volatile flag in SRAT
  x86/cpufeatures: Enable cpuid for Intel SHA extensions

12 files changed, 75 insertions, 29 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 7aef2d52daa0..328c8352480c 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1006,7 +1006,7 @@ config X86_THERMAL_VECTOR
         depends on X86_MCE_INTEL
 
 config X86_LEGACY_VM86
-        bool "Legacy VM86 support (obsolete)"
+        bool "Legacy VM86 support"
         default n
         depends on X86_32
         ---help---
@@ -1018,19 +1018,20 @@ config X86_LEGACY_VM86
           available to accelerate real mode DOS programs.  However, any
           recent version of DOSEMU, X, or vbetool should be fully
           functional even without kernel VM86 support, as they will all
-          fall back to (pretty well performing) software emulation.
+          fall back to software emulation. Nevertheless, if you are using
+          a 16-bit DOS program where 16-bit performance matters, vm86
+          mode might be faster than emulation and you might want to
+          enable this option.
 
-          Anything that works on a 64-bit kernel is unlikely to need
-          this option, as 64-bit kernels don't, and can't, support V8086
-          mode.  This option is also unrelated to 16-bit protected mode
-          and is not needed to run most 16-bit programs under Wine.
+          Note that any app that works on a 64-bit kernel is unlikely to
+          need this option, as 64-bit kernels don't, and can't, support
+          V8086 mode. This option is also unrelated to 16-bit protected
+          mode and is not needed to run most 16-bit programs under Wine.
 
-          Enabling this option adds considerable attack surface to the
-          kernel and slows down system calls and exception handling.
+          Enabling this option increases the complexity of the kernel
+          and slows down exception handling a tiny bit.
 
-          Unless you use very old userspace or need the last drop of
-          performance in your real mode DOS games and can't use KVM,
-          say N here.
+          If unsure, say N here.
 
 config VM86
        bool
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 477fc28050e4..e6cf2ad350d1 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -241,6 +241,7 @@
 #define X86_FEATURE_AVX512PF    ( 9*32+26) /* AVX-512 Prefetch */
 #define X86_FEATURE_AVX512ER    ( 9*32+27) /* AVX-512 Exponential and Reciprocal */
 #define X86_FEATURE_AVX512CD    ( 9*32+28) /* AVX-512 Conflict Detection */
+#define X86_FEATURE_SHA_NI      ( 9*32+29) /* SHA1/SHA256 Instruction Extensions */
 
 /* Extended state features, CPUID level 0x0000000d:1 (eax), word 10 */
 #define X86_FEATURE_XSAVEOPT    (10*32+ 0) /* XSAVEOPT */
diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
index ce029e4fa7c6..31247b5bff7c 100644
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -97,7 +97,6 @@ struct pv_lazy_ops {
 struct pv_time_ops {
         unsigned long long (*sched_clock)(void);
         unsigned long long (*steal_clock)(int cpu);
-        unsigned long (*get_tsc_khz)(void);
 };
 
 struct pv_cpu_ops {
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index c42827eb86cf..25f909362b7a 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -338,10 +338,15 @@ done:
 
 static void __init_or_module optimize_nops(struct alt_instr *a, u8 *instr)
 {
+        unsigned long flags;
+
         if (instr[0] != 0x90)
                 return;
 
+        local_irq_save(flags);
         add_nops(instr + (a->instrlen - a->padlen), a->padlen);
+        sync_core();
+        local_irq_restore(flags);
 
         DUMP_BYTES(instr, a->instrlen, "%p: [%d:%d) optimized NOPs: ",
                    instr, a->instrlen - a->padlen, a->padlen);
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 3ca3e46aa405..24e94ce454e2 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -336,6 +336,13 @@ static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
         apic_write(APIC_LVTT, lvtt_value);
 
         if (lvtt_value & APIC_LVT_TIMER_TSCDEADLINE) {
+                /*
+                 * See Intel SDM: TSC-Deadline Mode chapter. In xAPIC mode,
+                 * writing to the APIC LVTT and TSC_DEADLINE MSR isn't serialized.
+                 * According to Intel, MFENCE can do the serialization here.
+                 */
+                asm volatile("mfence" : : : "memory");
+
                 printk_once(KERN_DEBUG "TSC deadline timer enabled\n");
                 return;
         }
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 38a76f826530..5c60bb162622 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -2522,6 +2522,7 @@ void __init setup_ioapic_dest(void)
         int pin, ioapic, irq, irq_entry;
         const struct cpumask *mask;
         struct irq_data *idata;
+        struct irq_chip *chip;
 
         if (skip_ioapic_setup == 1)
                 return;
@@ -2545,9 +2546,9 @@ void __init setup_ioapic_dest(void)
                 else
                         mask = apic->target_cpus();
 
-                irq_set_affinity(irq, mask);
+                chip = irq_data_get_irq_chip(idata);
+                chip->irq_set_affinity(idata, mask, false);
         }
-
 }
 #endif
 
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 07ce52c22ec8..de22ea7ff82f 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1110,10 +1110,10 @@ void print_cpu_info(struct cpuinfo_x86 *c)
         else
                 printk(KERN_CONT "%d86", c->x86);
 
-        printk(KERN_CONT " (fam: %02x, model: %02x", c->x86, c->x86_model);
+        printk(KERN_CONT " (family: 0x%x, model: 0x%x", c->x86, c->x86_model);
 
         if (c->x86_mask || c->cpuid_level >= 0)
-                printk(KERN_CONT ", stepping: %02x)\n", c->x86_mask);
+                printk(KERN_CONT ", stepping: 0x%x)\n", c->x86_mask);
         else
                 printk(KERN_CONT ")\n");
 
diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c
index 2bcc0525f1c1..6acc9dd91f36 100644
--- a/arch/x86/kernel/ldt.c
+++ b/arch/x86/kernel/ldt.c
@@ -58,7 +58,7 @@ static struct ldt_struct *alloc_ldt_struct(int size)
         if (alloc_size > PAGE_SIZE)
                 new_ldt->entries = vzalloc(alloc_size);
         else
-                new_ldt->entries = kzalloc(PAGE_SIZE, GFP_KERNEL);
+                new_ldt->entries = (void *)get_zeroed_page(GFP_KERNEL);
 
         if (!new_ldt->entries) {
                 kfree(new_ldt);
@@ -95,7 +95,7 @@ static void free_ldt_struct(struct ldt_struct *ldt)
         if (ldt->size * LDT_ENTRY_SIZE > PAGE_SIZE)
                 vfree(ldt->entries);
         else
-                kfree(ldt->entries);
+                free_page((unsigned long)ldt->entries);
         kfree(ldt);
 }
 
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index c8d52cb4cb6e..c3f7602cd038 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -21,6 +21,7 @@
 #include <asm/hypervisor.h>
 #include <asm/nmi.h>
 #include <asm/x86_init.h>
+#include <asm/geode.h>
 
 unsigned int __read_mostly cpu_khz;     /* TSC clocks / usec, not used here */
 EXPORT_SYMBOL(cpu_khz);
@@ -1013,15 +1014,17 @@ EXPORT_SYMBOL_GPL(mark_tsc_unstable);
 
 static void __init check_system_tsc_reliable(void)
 {
-#ifdef CONFIG_MGEODE_LX
-        /* RTSC counts during suspend */
+#if defined(CONFIG_MGEODEGX1) || defined(CONFIG_MGEODE_LX) || defined(CONFIG_X86_GENERIC)
+        if (is_geode_lx()) {
+                /* RTSC counts during suspend */
 #define RTSC_SUSP 0x100
-        unsigned long res_low, res_high;
+                unsigned long res_low, res_high;
 
-        rdmsr_safe(MSR_GEODE_BUSCONT_CONF0, &res_low, &res_high);
-        /* Geode_LX - the OLPC CPU has a very reliable TSC */
-        if (res_low & RTSC_SUSP)
-                tsc_clocksource_reliable = 1;
+                rdmsr_safe(MSR_GEODE_BUSCONT_CONF0, &res_low, &res_high);
+                /* Geode_LX - the OLPC CPU has a very reliable TSC */
+                if (res_low & RTSC_SUSP)
+                        tsc_clocksource_reliable = 1;
+        }
 #endif
         if (boot_cpu_has(X86_FEATURE_TSC_RELIABLE))
                 tsc_clocksource_reliable = 1;
diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c
index abd8b856bd2b..524619351961 100644
--- a/arch/x86/kernel/vm86_32.c
+++ b/arch/x86/kernel/vm86_32.c
@@ -45,6 +45,7 @@
 #include <linux/audit.h>
 #include <linux/stddef.h>
 #include <linux/slab.h>
+#include <linux/security.h>
 
 #include <asm/uaccess.h>
 #include <asm/io.h>
@@ -232,6 +233,32 @@ static long do_sys_vm86(struct vm86plus_struct __user *user_vm86, bool plus)
         struct pt_regs *regs = current_pt_regs();
         unsigned long err = 0;
 
+        err = security_mmap_addr(0);
+        if (err) {
+                /*
+                 * vm86 cannot virtualize the address space, so vm86 users
+                 * need to manage the low 1MB themselves using mmap.  Given
+                 * that BIOS places important data in the first page, vm86
+                 * is essentially useless if mmap_min_addr != 0.  DOSEMU,
+                 * for example, won't even bother trying to use vm86 if it
+                 * can't map a page at virtual address 0.
+                 *
+                 * To reduce the available kernel attack surface, simply
+                 * disallow vm86(old) for users who cannot mmap at va 0.
+                 *
+                 * The implementation of security_mmap_addr will allow
+                 * suitably privileged users to map va 0 even if
+                 * vm.mmap_min_addr is set above 0, and we want this
+                 * behavior for vm86 as well, as it ensures that legacy
+                 * tools like vbetool will not fail just because of
+                 * vm.mmap_min_addr.
+                 */
+                pr_info_once("Denied a call to vm86(old) from %s[%d] (uid: %d).  Set the vm.mmap_min_addr sysctl to 0 and/or adjust LSM mmap_min_addr policy to enable vm86 if you are using a vm86-based DOS emulator.\n",
+                             current->comm, task_pid_nr(current),
+                             from_kuid_munged(&init_user_ns, current_uid()));
+                return -EPERM;
+        }
+
         if (!vm86) {
                 if (!(vm86 = kzalloc(sizeof(*vm86), GFP_KERNEL)))
                         return -ENOMEM;
diff --git a/arch/x86/mm/srat.c b/arch/x86/mm/srat.c
index 66338a60aa6e..c2aea63bee20 100644
--- a/arch/x86/mm/srat.c
+++ b/arch/x86/mm/srat.c
@@ -192,10 +192,11 @@ acpi_numa_memory_affinity_init(struct acpi_srat_mem_affinity *ma)
 
         node_set(node, numa_nodes_parsed);
 
-        pr_info("SRAT: Node %u PXM %u [mem %#010Lx-%#010Lx]%s\n",
+        pr_info("SRAT: Node %u PXM %u [mem %#010Lx-%#010Lx]%s%s\n",
                 node, pxm,
                 (unsigned long long) start, (unsigned long long) end - 1,
-                hotpluggable ? " hotplug" : "");
+                hotpluggable ? " hotplug" : "",
+                ma->flags & ACPI_SRAT_MEM_NON_VOLATILE ? " non-volatile" : "");
 
         /* Mark hotplug range in memblock. */
         if (hotpluggable && memblock_mark_hotplug(start, ma->length))
diff --git a/tools/testing/selftests/x86/entry_from_vm86.c b/tools/testing/selftests/x86/entry_from_vm86.c
index 9a43a59a9bb4..421c607a8856 100644
--- a/tools/testing/selftests/x86/entry_from_vm86.c
+++ b/tools/testing/selftests/x86/entry_from_vm86.c
@@ -116,8 +116,9 @@ static bool do_test(struct vm86plus_struct *v86, unsigned long eip,
         v86->regs.eip = eip;
         ret = vm86(VM86_ENTER, v86);
 
-        if (ret == -1 && errno == ENOSYS) {
-                printf("[SKIP]\tvm86 not supported\n");
+        if (ret == -1 && (errno == ENOSYS || errno == EPERM)) {
+                printf("[SKIP]\tvm86 %s\n",
+                       errno == ENOSYS ? "not supported" : "not allowed");
                 return false;
         }