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

Browse Source 
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
This commit is contained in:
Linus Torvalds 2015-09-17 11:01:34 -07:00
commit 42dc2a3048
12 changed files with 75 additions and 29 deletions
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23
arch/x86/Kconfig
View File

@ -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

1
arch/x86/include/asm/cpufeature.h
View File

@ -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 */

1
arch/x86/include/asm/paravirt_types.h
View File

@ -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 {

5
arch/x86/kernel/alternative.c
View File

@ -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);

7
arch/x86/kernel/apic/apic.c
View File

@ -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;
}

5
arch/x86/kernel/apic/io_apic.c
View File

@ -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

4
arch/x86/kernel/cpu/common.c
View File

@ -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");

4
arch/x86/kernel/ldt.c
View File

@ -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);
}

17
arch/x86/kernel/tsc.c
View File

@ -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;

27
arch/x86/kernel/vm86_32.c
View File

@ -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;

5
arch/x86/mm/srat.c
View File

@ -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))

5
tools/testing/selftests/x86/entry_from_vm86.c
View File

@ -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;
}