diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu
index 0e77569bd5e099b91ed5819eef3a7427a8849187..fc20cde63d1eac1fd563385542c7659c965c5e18 100644
--- a/Documentation/ABI/testing/sysfs-devices-system-cpu
+++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
@@ -487,6 +487,7 @@ What: /sys/devices/system/cpu/vulnerabilities
/sys/devices/system/cpu/vulnerabilities/l1tf
/sys/devices/system/cpu/vulnerabilities/mds
/sys/devices/system/cpu/vulnerabilities/tsx_async_abort
+ /sys/devices/system/cpu/vulnerabilities/itlb_multihit
Date: January 2018
Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
Description: Information about CPU vulnerabilities
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 989e03544f18d91ed03f1817f898c375d8d73b73..c4fbe379cc0b2c1c47b93183c52eeea82ee9c734 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -400,5 +400,6 @@
#define X86_BUG_MSBDS_ONLY X86_BUG(20) /* CPU is only affected by the MSDBS variant of BUG_MDS */
#define X86_BUG_SWAPGS X86_BUG(21) /* CPU is affected by speculation through SWAPGS */
#define X86_BUG_TAA X86_BUG(22) /* CPU is affected by TSX Async Abort(TAA) */
+#define X86_BUG_ITLB_MULTIHIT X86_BUG(23) /* CPU may incur MCE during certain page attribute changes */
#endif /* _ASM_X86_CPUFEATURES_H */
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index b3a8bb2af0b6f3eb5e5e2271ef023990496cda01..6a3124664289adff0dd922a3b8e603e31fcf6c10 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -93,6 +93,13 @@
* Microarchitectural Data
* Sampling (MDS) vulnerabilities.
*/
+#define ARCH_CAP_PSCHANGE_MC_NO BIT(6) /*
+ * The processor is not susceptible to a
+ * machine check error due to modifying the
+ * code page size along with either the
+ * physical address or cache type
+ * without TLB invalidation.
+ */
#define ARCH_CAP_TSX_CTRL_MSR BIT(7) /* MSR for TSX control is available. */
#define ARCH_CAP_TAA_NO BIT(8) /*
* Not susceptible to
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 43c647e1943915b9d76b2a0c5c0a91652cea16ea..5364beda8c6148affb08d4cb6357586ac4511ad3 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -1419,6 +1419,11 @@ static ssize_t l1tf_show_state(char *buf)
}
#endif
+static ssize_t itlb_multihit_show_state(char *buf)
+{
+ return sprintf(buf, "Processor vulnerable\n");
+}
+
static ssize_t mds_show_state(char *buf)
{
if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) {
@@ -1524,6 +1529,9 @@ static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr
case X86_BUG_TAA:
return tsx_async_abort_show_state(buf);
+ case X86_BUG_ITLB_MULTIHIT:
+ return itlb_multihit_show_state(buf);
+
default:
break;
}
@@ -1565,4 +1573,9 @@ ssize_t cpu_show_tsx_async_abort(struct device *dev, struct device_attribute *at
{
return cpu_show_common(dev, attr, buf, X86_BUG_TAA);
}
+
+ssize_t cpu_show_itlb_multihit(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ return cpu_show_common(dev, attr, buf, X86_BUG_ITLB_MULTIHIT);
+}
#endif
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index f8b8afc8f5b5541f06ab5f1bc1fca6bfd75bde33..d29b71ca3ca728a90659c9398ebb02b3c9447d66 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1016,13 +1016,14 @@ static void identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
#endif
}
-#define NO_SPECULATION BIT(0)
-#define NO_MELTDOWN BIT(1)
-#define NO_SSB BIT(2)
-#define NO_L1TF BIT(3)
-#define NO_MDS BIT(4)
-#define MSBDS_ONLY BIT(5)
-#define NO_SWAPGS BIT(6)
+#define NO_SPECULATION BIT(0)
+#define NO_MELTDOWN BIT(1)
+#define NO_SSB BIT(2)
+#define NO_L1TF BIT(3)
+#define NO_MDS BIT(4)
+#define MSBDS_ONLY BIT(5)
+#define NO_SWAPGS BIT(6)
+#define NO_ITLB_MULTIHIT BIT(7)
#define VULNWL(_vendor, _family, _model, _whitelist) \
{ X86_VENDOR_##_vendor, _family, _model, X86_FEATURE_ANY, _whitelist }
@@ -1043,27 +1044,27 @@ static const __initconst struct x86_cpu_id cpu_vuln_whitelist[] = {
VULNWL(NSC, 5, X86_MODEL_ANY, NO_SPECULATION),
/* Intel Family 6 */
- VULNWL_INTEL(ATOM_SALTWELL, NO_SPECULATION),
- VULNWL_INTEL(ATOM_SALTWELL_TABLET, NO_SPECULATION),
- VULNWL_INTEL(ATOM_SALTWELL_MID, NO_SPECULATION),
- VULNWL_INTEL(ATOM_BONNELL, NO_SPECULATION),
- VULNWL_INTEL(ATOM_BONNELL_MID, NO_SPECULATION),
-
- VULNWL_INTEL(ATOM_SILVERMONT, NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS),
- VULNWL_INTEL(ATOM_SILVERMONT_D, 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(ATOM_SALTWELL, NO_SPECULATION | NO_ITLB_MULTIHIT),
+ VULNWL_INTEL(ATOM_SALTWELL_TABLET, NO_SPECULATION | NO_ITLB_MULTIHIT),
+ VULNWL_INTEL(ATOM_SALTWELL_MID, NO_SPECULATION | NO_ITLB_MULTIHIT),
+ VULNWL_INTEL(ATOM_BONNELL, NO_SPECULATION | NO_ITLB_MULTIHIT),
+ VULNWL_INTEL(ATOM_BONNELL_MID, NO_SPECULATION | NO_ITLB_MULTIHIT),
+
+ VULNWL_INTEL(ATOM_SILVERMONT, NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS | NO_ITLB_MULTIHIT),
+ VULNWL_INTEL(ATOM_SILVERMONT_D, NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS | NO_ITLB_MULTIHIT),
+ VULNWL_INTEL(ATOM_SILVERMONT_MID, NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS | NO_ITLB_MULTIHIT),
+ VULNWL_INTEL(ATOM_AIRMONT, NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS | NO_ITLB_MULTIHIT),
+ VULNWL_INTEL(XEON_PHI_KNL, NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS | NO_ITLB_MULTIHIT),
+ VULNWL_INTEL(XEON_PHI_KNM, NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS | NO_ITLB_MULTIHIT),
VULNWL_INTEL(CORE_YONAH, NO_SSB),
- VULNWL_INTEL(ATOM_AIRMONT_MID, NO_L1TF | MSBDS_ONLY | NO_SWAPGS),
- VULNWL_INTEL(ATOM_AIRMONT_NP, NO_L1TF | NO_SWAPGS),
+ VULNWL_INTEL(ATOM_AIRMONT_MID, NO_L1TF | MSBDS_ONLY | NO_SWAPGS | NO_ITLB_MULTIHIT),
+ VULNWL_INTEL(ATOM_AIRMONT_NP, NO_L1TF | NO_SWAPGS | NO_ITLB_MULTIHIT),
- VULNWL_INTEL(ATOM_GOLDMONT, NO_MDS | NO_L1TF | NO_SWAPGS),
- VULNWL_INTEL(ATOM_GOLDMONT_D, NO_MDS | NO_L1TF | NO_SWAPGS),
- VULNWL_INTEL(ATOM_GOLDMONT_PLUS, NO_MDS | NO_L1TF | NO_SWAPGS),
+ VULNWL_INTEL(ATOM_GOLDMONT, NO_MDS | NO_L1TF | NO_SWAPGS | NO_ITLB_MULTIHIT),
+ VULNWL_INTEL(ATOM_GOLDMONT_D, NO_MDS | NO_L1TF | NO_SWAPGS | NO_ITLB_MULTIHIT),
+ VULNWL_INTEL(ATOM_GOLDMONT_PLUS, NO_MDS | NO_L1TF | NO_SWAPGS | NO_ITLB_MULTIHIT),
/*
* Technically, swapgs isn't serializing on AMD (despite it previously
@@ -1074,14 +1075,14 @@ static const __initconst struct x86_cpu_id cpu_vuln_whitelist[] = {
*/
/* AMD Family 0xf - 0x12 */
- 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),
+ VULNWL_AMD(0x0f, NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT),
+ VULNWL_AMD(0x10, NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT),
+ VULNWL_AMD(0x11, NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT),
+ VULNWL_AMD(0x12, NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT),
/* FAMILY_ANY must be last, otherwise 0x0f - 0x12 matches won't work */
- 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),
+ VULNWL_AMD(X86_FAMILY_ANY, NO_MELTDOWN | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT),
+ VULNWL_HYGON(X86_FAMILY_ANY, NO_MELTDOWN | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT),
{}
};
@@ -1106,6 +1107,10 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
{
u64 ia32_cap = x86_read_arch_cap_msr();
+ /* Set ITLB_MULTIHIT bug if cpu is not in the whitelist and not mitigated */
+ if (!cpu_matches(NO_ITLB_MULTIHIT) && !(ia32_cap & ARCH_CAP_PSCHANGE_MC_NO))
+ setup_force_cpu_bug(X86_BUG_ITLB_MULTIHIT);
+
if (cpu_matches(NO_SPECULATION))
return;
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 0fccd8c0312eaeed577b3a49bb9474254d1b81b7..6265871a4af2ec09951e3d8343400c1d9ef2619c 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -561,6 +561,12 @@ ssize_t __weak cpu_show_tsx_async_abort(struct device *dev,
return sprintf(buf, "Not affected\n");
}
+ssize_t __weak cpu_show_itlb_multihit(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "Not affected\n");
+}
+
static DEVICE_ATTR(meltdown, 0444, cpu_show_meltdown, NULL);
static DEVICE_ATTR(spectre_v1, 0444, cpu_show_spectre_v1, NULL);
static DEVICE_ATTR(spectre_v2, 0444, cpu_show_spectre_v2, NULL);
@@ -568,6 +574,7 @@ static DEVICE_ATTR(spec_store_bypass, 0444, cpu_show_spec_store_bypass, NULL);
static DEVICE_ATTR(l1tf, 0444, cpu_show_l1tf, NULL);
static DEVICE_ATTR(mds, 0444, cpu_show_mds, NULL);
static DEVICE_ATTR(tsx_async_abort, 0444, cpu_show_tsx_async_abort, NULL);
+static DEVICE_ATTR(itlb_multihit, 0444, cpu_show_itlb_multihit, NULL);
static struct attribute *cpu_root_vulnerabilities_attrs[] = {
&dev_attr_meltdown.attr,
@@ -577,6 +584,7 @@ static struct attribute *cpu_root_vulnerabilities_attrs[] = {
&dev_attr_l1tf.attr,
&dev_attr_mds.attr,
&dev_attr_tsx_async_abort.attr,
+ &dev_attr_itlb_multihit.attr,
NULL
};
diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index f35369f79771714e34865844bc0725fde7c636f8..2a093434e97560360885aaa489185f087196606c 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -62,6 +62,8 @@ extern ssize_t cpu_show_mds(struct device *dev,
extern ssize_t cpu_show_tsx_async_abort(struct device *dev,
struct device_attribute *attr,
char *buf);
+extern ssize_t cpu_show_itlb_multihit(struct device *dev,
+ struct device_attribute *attr, char *buf);
extern __printf(4, 5)
struct device *cpu_device_create(struct device *parent, void *drvdata,