Merging upstream version 5.10.216.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

6 files changed, 332 insertions, 191 deletions

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index f29c6bed9..3b02cb8b0 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -1049,11 +1049,11 @@ static bool cpu_has_zenbleed_microcode(void)
 	u32 good_rev = 0;
 
 	switch (boot_cpu_data.x86_model) {
-	case 0x30 ... 0x3f: good_rev = 0x0830107a; break;
-	case 0x60 ... 0x67: good_rev = 0x0860010b; break;
-	case 0x68 ... 0x6f: good_rev = 0x08608105; break;
-	case 0x70 ... 0x7f: good_rev = 0x08701032; break;
-	case 0xa0 ... 0xaf: good_rev = 0x08a00008; break;
+	case 0x30 ... 0x3f: good_rev = 0x0830107b; break;
+	case 0x60 ... 0x67: good_rev = 0x0860010c; break;
+	case 0x68 ... 0x6f: good_rev = 0x08608107; break;
+	case 0x70 ... 0x7f: good_rev = 0x08701033; break;
+	case 0xa0 ... 0xaf: good_rev = 0x08a00009; break;
 
 	default:
 		return false;
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index d9fda0b6e..d6e14190c 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -109,9 +109,6 @@ DEFINE_STATIC_KEY_FALSE(switch_mm_cond_ibpb);
 /* Control unconditional IBPB in switch_mm() */
 DEFINE_STATIC_KEY_FALSE(switch_mm_always_ibpb);
 
-/* Control MDS CPU buffer clear before returning to user space */
-DEFINE_STATIC_KEY_FALSE(mds_user_clear);
-EXPORT_SYMBOL_GPL(mds_user_clear);
 /* Control MDS CPU buffer clear before idling (halt, mwait) */
 DEFINE_STATIC_KEY_FALSE(mds_idle_clear);
 EXPORT_SYMBOL_GPL(mds_idle_clear);
@@ -249,7 +246,7 @@ static void __init mds_select_mitigation(void)
 		if (!boot_cpu_has(X86_FEATURE_MD_CLEAR))
 			mds_mitigation = MDS_MITIGATION_VMWERV;
 
-		static_branch_enable(&mds_user_clear);
+		setup_force_cpu_cap(X86_FEATURE_CLEAR_CPU_BUF);
 
 		if (!boot_cpu_has(X86_BUG_MSBDS_ONLY) &&
 		    (mds_nosmt || cpu_mitigations_auto_nosmt()))
@@ -353,7 +350,7 @@ static void __init taa_select_mitigation(void)
 	 * For guests that can't determine whether the correct microcode is
 	 * present on host, enable the mitigation for UCODE_NEEDED as well.
 	 */
-	static_branch_enable(&mds_user_clear);
+	setup_force_cpu_cap(X86_FEATURE_CLEAR_CPU_BUF);
 
 	if (taa_nosmt || cpu_mitigations_auto_nosmt())
 		cpu_smt_disable(false);
@@ -421,7 +418,14 @@ static void __init mmio_select_mitigation(void)
 	 */
 	if (boot_cpu_has_bug(X86_BUG_MDS) || (boot_cpu_has_bug(X86_BUG_TAA) &&
 					      boot_cpu_has(X86_FEATURE_RTM)))
-		static_branch_enable(&mds_user_clear);
+		setup_force_cpu_cap(X86_FEATURE_CLEAR_CPU_BUF);
+
+	/*
+	 * X86_FEATURE_CLEAR_CPU_BUF could be enabled by other VERW based
+	 * mitigations, disable KVM-only mitigation in that case.
+	 */
+	if (boot_cpu_has(X86_FEATURE_CLEAR_CPU_BUF))
+		static_branch_disable(&mmio_stale_data_clear);
 	else
 		static_branch_enable(&mmio_stale_data_clear);
 
@@ -474,6 +478,57 @@ static int __init mmio_stale_data_parse_cmdline(char *str)
 early_param("mmio_stale_data", mmio_stale_data_parse_cmdline);
 
 #undef pr_fmt
+#define pr_fmt(fmt)	"Register File Data Sampling: " fmt
+
+enum rfds_mitigations {
+	RFDS_MITIGATION_OFF,
+	RFDS_MITIGATION_VERW,
+	RFDS_MITIGATION_UCODE_NEEDED,
+};
+
+/* Default mitigation for Register File Data Sampling */
+static enum rfds_mitigations rfds_mitigation __ro_after_init =
+	IS_ENABLED(CONFIG_MITIGATION_RFDS) ? RFDS_MITIGATION_VERW : RFDS_MITIGATION_OFF;
+
+static const char * const rfds_strings[] = {
+	[RFDS_MITIGATION_OFF]			= "Vulnerable",
+	[RFDS_MITIGATION_VERW]			= "Mitigation: Clear Register File",
+	[RFDS_MITIGATION_UCODE_NEEDED]		= "Vulnerable: No microcode",
+};
+
+static void __init rfds_select_mitigation(void)
+{
+	if (!boot_cpu_has_bug(X86_BUG_RFDS) || cpu_mitigations_off()) {
+		rfds_mitigation = RFDS_MITIGATION_OFF;
+		return;
+	}
+	if (rfds_mitigation == RFDS_MITIGATION_OFF)
+		return;
+
+	if (x86_read_arch_cap_msr() & ARCH_CAP_RFDS_CLEAR)
+		setup_force_cpu_cap(X86_FEATURE_CLEAR_CPU_BUF);
+	else
+		rfds_mitigation = RFDS_MITIGATION_UCODE_NEEDED;
+}
+
+static __init int rfds_parse_cmdline(char *str)
+{
+	if (!str)
+		return -EINVAL;
+
+	if (!boot_cpu_has_bug(X86_BUG_RFDS))
+		return 0;
+
+	if (!strcmp(str, "off"))
+		rfds_mitigation = RFDS_MITIGATION_OFF;
+	else if (!strcmp(str, "on"))
+		rfds_mitigation = RFDS_MITIGATION_VERW;
+
+	return 0;
+}
+early_param("reg_file_data_sampling", rfds_parse_cmdline);
+
+#undef pr_fmt
 #define pr_fmt(fmt)     "" fmt
 
 static void __init md_clear_update_mitigation(void)
@@ -481,12 +536,12 @@ static void __init md_clear_update_mitigation(void)
 	if (cpu_mitigations_off())
 		return;
 
-	if (!static_key_enabled(&mds_user_clear))
+	if (!boot_cpu_has(X86_FEATURE_CLEAR_CPU_BUF))
 		goto out;
 
 	/*
-	 * mds_user_clear is now enabled. Update MDS, TAA and MMIO Stale Data
-	 * mitigation, if necessary.
+	 * X86_FEATURE_CLEAR_CPU_BUF is now enabled. Update MDS, TAA and MMIO
+	 * Stale Data mitigation, if necessary.
 	 */
 	if (mds_mitigation == MDS_MITIGATION_OFF &&
 	    boot_cpu_has_bug(X86_BUG_MDS)) {
@@ -498,11 +553,19 @@ static void __init md_clear_update_mitigation(void)
 		taa_mitigation = TAA_MITIGATION_VERW;
 		taa_select_mitigation();
 	}
-	if (mmio_mitigation == MMIO_MITIGATION_OFF &&
-	    boot_cpu_has_bug(X86_BUG_MMIO_STALE_DATA)) {
+	/*
+	 * MMIO_MITIGATION_OFF is not checked here so that mmio_stale_data_clear
+	 * gets updated correctly as per X86_FEATURE_CLEAR_CPU_BUF state.
+	 */
+	if (boot_cpu_has_bug(X86_BUG_MMIO_STALE_DATA)) {
 		mmio_mitigation = MMIO_MITIGATION_VERW;
 		mmio_select_mitigation();
 	}
+	if (rfds_mitigation == RFDS_MITIGATION_OFF &&
+	    boot_cpu_has_bug(X86_BUG_RFDS)) {
+		rfds_mitigation = RFDS_MITIGATION_VERW;
+		rfds_select_mitigation();
+	}
 out:
 	if (boot_cpu_has_bug(X86_BUG_MDS))
 		pr_info("MDS: %s\n", mds_strings[mds_mitigation]);
@@ -512,6 +575,8 @@ out:
 		pr_info("MMIO Stale Data: %s\n", mmio_strings[mmio_mitigation]);
 	else if (boot_cpu_has_bug(X86_BUG_MMIO_UNKNOWN))
 		pr_info("MMIO Stale Data: Unknown: No mitigations\n");
+	if (boot_cpu_has_bug(X86_BUG_RFDS))
+		pr_info("Register File Data Sampling: %s\n", rfds_strings[rfds_mitigation]);
 }
 
 static void __init md_clear_select_mitigation(void)
@@ -519,11 +584,12 @@ static void __init md_clear_select_mitigation(void)
 	mds_select_mitigation();
 	taa_select_mitigation();
 	mmio_select_mitigation();
+	rfds_select_mitigation();
 
 	/*
-	 * As MDS, TAA and MMIO Stale Data mitigations are inter-related, update
-	 * and print their mitigation after MDS, TAA and MMIO Stale Data
-	 * mitigation selection is done.
+	 * As these mitigations are inter-related and rely on VERW instruction
+	 * to clear the microarchitural buffers, update and print their status
+	 * after mitigation selection is done for each of these vulnerabilities.
 	 */
 	md_clear_update_mitigation();
 }
@@ -1251,19 +1317,21 @@ spectre_v2_user_select_mitigation(void)
 	}
 
 	/*
-	 * If no STIBP, enhanced IBRS is enabled, or SMT impossible, STIBP
+	 * If no STIBP, Intel enhanced IBRS is enabled, or SMT impossible, STIBP
 	 * is not required.
 	 *
-	 * Enhanced IBRS also protects against cross-thread branch target
+	 * Intel's Enhanced IBRS also protects against cross-thread branch target
 	 * injection in user-mode as the IBRS bit remains always set which
 	 * implicitly enables cross-thread protections.  However, in legacy IBRS
 	 * mode, the IBRS bit is set only on kernel entry and cleared on return
-	 * to userspace. This disables the implicit cross-thread protection,
-	 * so allow for STIBP to be selected in that case.
+	 * to userspace.  AMD Automatic IBRS also does not protect userspace.
+	 * These modes therefore disable the implicit cross-thread protection,
+	 * so allow for STIBP to be selected in those cases.
 	 */
 	if (!boot_cpu_has(X86_FEATURE_STIBP) ||
 	    !smt_possible ||
-	    spectre_v2_in_eibrs_mode(spectre_v2_enabled))
+	    (spectre_v2_in_eibrs_mode(spectre_v2_enabled) &&
+	     !boot_cpu_has(X86_FEATURE_AUTOIBRS)))
 		return;
 
 	/*
@@ -1293,9 +1361,9 @@ static const char * const spectre_v2_strings[] = {
 	[SPECTRE_V2_NONE]			= "Vulnerable",
 	[SPECTRE_V2_RETPOLINE]			= "Mitigation: Retpolines",
 	[SPECTRE_V2_LFENCE]			= "Mitigation: LFENCE",
-	[SPECTRE_V2_EIBRS]			= "Mitigation: Enhanced IBRS",
-	[SPECTRE_V2_EIBRS_LFENCE]		= "Mitigation: Enhanced IBRS + LFENCE",
-	[SPECTRE_V2_EIBRS_RETPOLINE]		= "Mitigation: Enhanced IBRS + Retpolines",
+	[SPECTRE_V2_EIBRS]			= "Mitigation: Enhanced / Automatic IBRS",
+	[SPECTRE_V2_EIBRS_LFENCE]		= "Mitigation: Enhanced / Automatic IBRS + LFENCE",
+	[SPECTRE_V2_EIBRS_RETPOLINE]		= "Mitigation: Enhanced / Automatic IBRS + Retpolines",
 	[SPECTRE_V2_IBRS]			= "Mitigation: IBRS",
 };
 
@@ -1364,7 +1432,7 @@ static enum spectre_v2_mitigation_cmd __init spectre_v2_parse_cmdline(void)
 	     cmd == SPECTRE_V2_CMD_EIBRS_LFENCE ||
 	     cmd == SPECTRE_V2_CMD_EIBRS_RETPOLINE) &&
 	    !boot_cpu_has(X86_FEATURE_IBRS_ENHANCED)) {
-		pr_err("%s selected but CPU doesn't have eIBRS. Switching to AUTO select\n",
+		pr_err("%s selected but CPU doesn't have Enhanced or Automatic IBRS. Switching to AUTO select\n",
 		       mitigation_options[i].option);
 		return SPECTRE_V2_CMD_AUTO;
 	}
@@ -1549,8 +1617,12 @@ static void __init spectre_v2_select_mitigation(void)
 		pr_err(SPECTRE_V2_EIBRS_EBPF_MSG);
 
 	if (spectre_v2_in_ibrs_mode(mode)) {
-		x86_spec_ctrl_base |= SPEC_CTRL_IBRS;
-		update_spec_ctrl(x86_spec_ctrl_base);
+		if (boot_cpu_has(X86_FEATURE_AUTOIBRS)) {
+			msr_set_bit(MSR_EFER, _EFER_AUTOIBRS);
+		} else {
+			x86_spec_ctrl_base |= SPEC_CTRL_IBRS;
+			update_spec_ctrl(x86_spec_ctrl_base);
+		}
 	}
 
 	switch (mode) {
@@ -1634,8 +1706,8 @@ static void __init spectre_v2_select_mitigation(void)
 	/*
 	 * Retpoline protects the kernel, but doesn't protect firmware.  IBRS
 	 * and Enhanced IBRS protect firmware too, so enable IBRS around
-	 * firmware calls only when IBRS / Enhanced IBRS aren't otherwise
-	 * enabled.
+	 * firmware calls only when IBRS / Enhanced / Automatic IBRS aren't
+	 * otherwise enabled.
 	 *
 	 * Use "mode" to check Enhanced IBRS instead of boot_cpu_has(), because
 	 * the user might select retpoline on the kernel command line and if
@@ -2432,74 +2504,74 @@ static const char * const l1tf_vmx_states[] = {
 static ssize_t l1tf_show_state(char *buf)
 {
 	if (l1tf_vmx_mitigation == VMENTER_L1D_FLUSH_AUTO)
-		return sprintf(buf, "%s\n", L1TF_DEFAULT_MSG);
+		return sysfs_emit(buf, "%s\n", L1TF_DEFAULT_MSG);
 
 	if (l1tf_vmx_mitigation == VMENTER_L1D_FLUSH_EPT_DISABLED ||
 	    (l1tf_vmx_mitigation == VMENTER_L1D_FLUSH_NEVER &&
 	     sched_smt_active())) {
-		return sprintf(buf, "%s; VMX: %s\n", L1TF_DEFAULT_MSG,
-			       l1tf_vmx_states[l1tf_vmx_mitigation]);
+		return sysfs_emit(buf, "%s; VMX: %s\n", L1TF_DEFAULT_MSG,
+				  l1tf_vmx_states[l1tf_vmx_mitigation]);
 	}
 
-	return sprintf(buf, "%s; VMX: %s, SMT %s\n", L1TF_DEFAULT_MSG,
-		       l1tf_vmx_states[l1tf_vmx_mitigation],
-		       sched_smt_active() ? "vulnerable" : "disabled");
+	return sysfs_emit(buf, "%s; VMX: %s, SMT %s\n", L1TF_DEFAULT_MSG,
+			  l1tf_vmx_states[l1tf_vmx_mitigation],
+			  sched_smt_active() ? "vulnerable" : "disabled");
 }
 
 static ssize_t itlb_multihit_show_state(char *buf)
 {
 	if (!boot_cpu_has(X86_FEATURE_MSR_IA32_FEAT_CTL) ||
 	    !boot_cpu_has(X86_FEATURE_VMX))
-		return sprintf(buf, "KVM: Mitigation: VMX unsupported\n");
+		return sysfs_emit(buf, "KVM: Mitigation: VMX unsupported\n");
 	else if (!(cr4_read_shadow() & X86_CR4_VMXE))
-		return sprintf(buf, "KVM: Mitigation: VMX disabled\n");
+		return sysfs_emit(buf, "KVM: Mitigation: VMX disabled\n");
 	else if (itlb_multihit_kvm_mitigation)
-		return sprintf(buf, "KVM: Mitigation: Split huge pages\n");
+		return sysfs_emit(buf, "KVM: Mitigation: Split huge pages\n");
 	else
-		return sprintf(buf, "KVM: Vulnerable\n");
+		return sysfs_emit(buf, "KVM: Vulnerable\n");
 }
 #else
 static ssize_t l1tf_show_state(char *buf)
 {
-	return sprintf(buf, "%s\n", L1TF_DEFAULT_MSG);
+	return sysfs_emit(buf, "%s\n", L1TF_DEFAULT_MSG);
 }
 
 static ssize_t itlb_multihit_show_state(char *buf)
 {
-	return sprintf(buf, "Processor vulnerable\n");
+	return sysfs_emit(buf, "Processor vulnerable\n");
 }
 #endif
 
 static ssize_t mds_show_state(char *buf)
 {
 	if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) {
-		return sprintf(buf, "%s; SMT Host state unknown\n",
-			       mds_strings[mds_mitigation]);
+		return sysfs_emit(buf, "%s; SMT Host state unknown\n",
+				  mds_strings[mds_mitigation]);
 	}
 
 	if (boot_cpu_has(X86_BUG_MSBDS_ONLY)) {
-		return sprintf(buf, "%s; SMT %s\n", mds_strings[mds_mitigation],
-			       (mds_mitigation == MDS_MITIGATION_OFF ? "vulnerable" :
-			        sched_smt_active() ? "mitigated" : "disabled"));
+		return sysfs_emit(buf, "%s; SMT %s\n", mds_strings[mds_mitigation],
+				  (mds_mitigation == MDS_MITIGATION_OFF ? "vulnerable" :
+				   sched_smt_active() ? "mitigated" : "disabled"));
 	}
 
-	return sprintf(buf, "%s; SMT %s\n", mds_strings[mds_mitigation],
-		       sched_smt_active() ? "vulnerable" : "disabled");
+	return sysfs_emit(buf, "%s; SMT %s\n", mds_strings[mds_mitigation],
+			  sched_smt_active() ? "vulnerable" : "disabled");
 }
 
 static ssize_t tsx_async_abort_show_state(char *buf)
 {
 	if ((taa_mitigation == TAA_MITIGATION_TSX_DISABLED) ||
 	    (taa_mitigation == TAA_MITIGATION_OFF))
-		return sprintf(buf, "%s\n", taa_strings[taa_mitigation]);
+		return sysfs_emit(buf, "%s\n", taa_strings[taa_mitigation]);
 
 	if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) {
-		return sprintf(buf, "%s; SMT Host state unknown\n",
-			       taa_strings[taa_mitigation]);
+		return sysfs_emit(buf, "%s; SMT Host state unknown\n",
+				  taa_strings[taa_mitigation]);
 	}
 
-	return sprintf(buf, "%s; SMT %s\n", taa_strings[taa_mitigation],
-		       sched_smt_active() ? "vulnerable" : "disabled");
+	return sysfs_emit(buf, "%s; SMT %s\n", taa_strings[taa_mitigation],
+			  sched_smt_active() ? "vulnerable" : "disabled");
 }
 
 static ssize_t mmio_stale_data_show_state(char *buf)
@@ -2519,9 +2591,15 @@ static ssize_t mmio_stale_data_show_state(char *buf)
 			  sched_smt_active() ? "vulnerable" : "disabled");
 }
 
+static ssize_t rfds_show_state(char *buf)
+{
+	return sysfs_emit(buf, "%s\n", rfds_strings[rfds_mitigation]);
+}
+
 static char *stibp_state(void)
 {
-	if (spectre_v2_in_eibrs_mode(spectre_v2_enabled))
+	if (spectre_v2_in_eibrs_mode(spectre_v2_enabled) &&
+	    !boot_cpu_has(X86_FEATURE_AUTOIBRS))
 		return "";
 
 	switch (spectre_v2_user_stibp) {
@@ -2567,47 +2645,46 @@ static char *pbrsb_eibrs_state(void)
 static ssize_t spectre_v2_show_state(char *buf)
 {
 	if (spectre_v2_enabled == SPECTRE_V2_LFENCE)
-		return sprintf(buf, "Vulnerable: LFENCE\n");
+		return sysfs_emit(buf, "Vulnerable: LFENCE\n");
 
 	if (spectre_v2_enabled == SPECTRE_V2_EIBRS && unprivileged_ebpf_enabled())
-		return sprintf(buf, "Vulnerable: eIBRS with unprivileged eBPF\n");
+		return sysfs_emit(buf, "Vulnerable: eIBRS with unprivileged eBPF\n");
 
 	if (sched_smt_active() && unprivileged_ebpf_enabled() &&
 	    spectre_v2_enabled == SPECTRE_V2_EIBRS_LFENCE)
-		return sprintf(buf, "Vulnerable: eIBRS+LFENCE with unprivileged eBPF and SMT\n");
+		return sysfs_emit(buf, "Vulnerable: eIBRS+LFENCE with unprivileged eBPF and SMT\n");
 
-	return sprintf(buf, "%s%s%s%s%s%s%s\n",
-		       spectre_v2_strings[spectre_v2_enabled],
-		       ibpb_state(),
-		       boot_cpu_has(X86_FEATURE_USE_IBRS_FW) ? ", IBRS_FW" : "",
-		       stibp_state(),
-		       boot_cpu_has(X86_FEATURE_RSB_CTXSW) ? ", RSB filling" : "",
-		       pbrsb_eibrs_state(),
-		       spectre_v2_module_string());
+	return sysfs_emit(buf, "%s%s%s%s%s%s%s\n",
+			  spectre_v2_strings[spectre_v2_enabled],
+			  ibpb_state(),
+			  boot_cpu_has(X86_FEATURE_USE_IBRS_FW) ? ", IBRS_FW" : "",
+			  stibp_state(),
+			  boot_cpu_has(X86_FEATURE_RSB_CTXSW) ? ", RSB filling" : "",
+			  pbrsb_eibrs_state(),
+			  spectre_v2_module_string());
 }
 
 static ssize_t srbds_show_state(char *buf)
 {
-	return sprintf(buf, "%s\n", srbds_strings[srbds_mitigation]);
+	return sysfs_emit(buf, "%s\n", srbds_strings[srbds_mitigation]);
 }
 
 static ssize_t retbleed_show_state(char *buf)
 {
 	if (retbleed_mitigation == RETBLEED_MITIGATION_UNRET ||
 	    retbleed_mitigation == RETBLEED_MITIGATION_IBPB) {
-	    if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD &&
-		boot_cpu_data.x86_vendor != X86_VENDOR_HYGON)
-		    return sprintf(buf, "Vulnerable: untrained return thunk / IBPB on non-AMD based uarch\n");
+		if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD &&
+		    boot_cpu_data.x86_vendor != X86_VENDOR_HYGON)
+			return sysfs_emit(buf, "Vulnerable: untrained return thunk / IBPB on non-AMD based uarch\n");
 
-	    return sprintf(buf, "%s; SMT %s\n",
-			   retbleed_strings[retbleed_mitigation],
-			   !sched_smt_active() ? "disabled" :
-			   spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT ||
-			   spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT_PREFERRED ?
-			   "enabled with STIBP protection" : "vulnerable");
+		return sysfs_emit(buf, "%s; SMT %s\n", retbleed_strings[retbleed_mitigation],
+				  !sched_smt_active() ? "disabled" :
+				  spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT ||
+				  spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT_PREFERRED ?
+				  "enabled with STIBP protection" : "vulnerable");
 	}
 
-	return sprintf(buf, "%s\n", retbleed_strings[retbleed_mitigation]);
+	return sysfs_emit(buf, "%s\n", retbleed_strings[retbleed_mitigation]);
 }
 
 static ssize_t gds_show_state(char *buf)
@@ -2629,26 +2706,26 @@ static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr
 			       char *buf, unsigned int bug)
 {
 	if (!boot_cpu_has_bug(bug))
-		return sprintf(buf, "Not affected\n");
+		return sysfs_emit(buf, "Not affected\n");
 
 	switch (bug) {
 	case X86_BUG_CPU_MELTDOWN:
 		if (boot_cpu_has(X86_FEATURE_PTI))
-			return sprintf(buf, "Mitigation: PTI\n");
+			return sysfs_emit(buf, "Mitigation: PTI\n");
 
 		if (hypervisor_is_type(X86_HYPER_XEN_PV))
-			return sprintf(buf, "Unknown (XEN PV detected, hypervisor mitigation required)\n");
+			return sysfs_emit(buf, "Unknown (XEN PV detected, hypervisor mitigation required)\n");
 
 		break;
 
 	case X86_BUG_SPECTRE_V1:
-		return sprintf(buf, "%s\n", spectre_v1_strings[spectre_v1_mitigation]);
+		return sysfs_emit(buf, "%s\n", spectre_v1_strings[spectre_v1_mitigation]);
 
 	case X86_BUG_SPECTRE_V2:
 		return spectre_v2_show_state(buf);
 
 	case X86_BUG_SPEC_STORE_BYPASS:
-		return sprintf(buf, "%s\n", ssb_strings[ssb_mode]);
+		return sysfs_emit(buf, "%s\n", ssb_strings[ssb_mode]);
 
 	case X86_BUG_L1TF:
 		if (boot_cpu_has(X86_FEATURE_L1TF_PTEINV))
@@ -2680,11 +2757,14 @@ static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr
 	case X86_BUG_SRSO:
 		return srso_show_state(buf);
 
+	case X86_BUG_RFDS:
+		return rfds_show_state(buf);
+
 	default:
 		break;
 	}
 
-	return sprintf(buf, "Vulnerable\n");
+	return sysfs_emit(buf, "Vulnerable\n");
 }
 
 ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, char *buf)
@@ -2754,4 +2834,9 @@ ssize_t cpu_show_spec_rstack_overflow(struct device *dev, struct device_attribut
 {
 	return cpu_show_common(dev, attr, buf, X86_BUG_SRSO);
 }
+
+ssize_t cpu_show_reg_file_data_sampling(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	return cpu_show_common(dev, attr, buf, X86_BUG_RFDS);
+}
 #endif
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 4ecc6072e..a496a9867 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -166,7 +166,6 @@ DEFINE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page) = { .gdt = {
 
 	[GDT_ENTRY_ESPFIX_SS]		= GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
 	[GDT_ENTRY_PERCPU]		= GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
-	GDT_STACK_CANARY_INIT
 #endif
 } };
 EXPORT_PER_CPU_SYMBOL_GPL(gdt_page);
@@ -600,7 +599,6 @@ void load_percpu_segment(int cpu)
 	__loadsegment_simple(gs, 0);
 	wrmsrl(MSR_GS_BASE, cpu_kernelmode_gs_base(cpu));
 #endif
-	load_stack_canary_segment();
 }
 
 #ifdef CONFIG_X86_32
@@ -1098,8 +1096,8 @@ static const __initconst struct x86_cpu_id cpu_vuln_whitelist[] = {
 	VULNWL_AMD(0x12,	NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT | NO_MMIO),
 
 	/* 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 | NO_ITLB_MULTIHIT | NO_MMIO),
-	VULNWL_HYGON(X86_FAMILY_ANY,	NO_MELTDOWN | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT | NO_MMIO),
+	VULNWL_AMD(X86_FAMILY_ANY,	NO_MELTDOWN | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT | NO_MMIO | NO_EIBRS_PBRSB),
+	VULNWL_HYGON(X86_FAMILY_ANY,	NO_MELTDOWN | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT | NO_MMIO | NO_EIBRS_PBRSB),
 
 	/* Zhaoxin Family 7 */
 	VULNWL(CENTAUR,	7, X86_MODEL_ANY,	NO_SPECTRE_V2 | NO_SWAPGS | NO_MMIO),
@@ -1134,6 +1132,8 @@ static const __initconst struct x86_cpu_id cpu_vuln_whitelist[] = {
 #define SRSO		BIT(5)
 /* CPU is affected by GDS */
 #define GDS		BIT(6)
+/* CPU is affected by Register File Data Sampling */
+#define RFDS		BIT(7)
 
 static const struct x86_cpu_id cpu_vuln_blacklist[] __initconst = {
 	VULNBL_INTEL_STEPPINGS(IVYBRIDGE,	X86_STEPPING_ANY,		SRBDS),
@@ -1161,14 +1161,23 @@ static const struct x86_cpu_id cpu_vuln_blacklist[] __initconst = {
 	VULNBL_INTEL_STEPPINGS(TIGERLAKE,	X86_STEPPING_ANY,		GDS),
 	VULNBL_INTEL_STEPPINGS(LAKEFIELD,	X86_STEPPING_ANY,		MMIO | MMIO_SBDS | RETBLEED),
 	VULNBL_INTEL_STEPPINGS(ROCKETLAKE,	X86_STEPPING_ANY,		MMIO | RETBLEED | GDS),
-	VULNBL_INTEL_STEPPINGS(ATOM_TREMONT,	X86_STEPPING_ANY,		MMIO | MMIO_SBDS),
-	VULNBL_INTEL_STEPPINGS(ATOM_TREMONT_D,	X86_STEPPING_ANY,		MMIO),
-	VULNBL_INTEL_STEPPINGS(ATOM_TREMONT_L,	X86_STEPPING_ANY,		MMIO | MMIO_SBDS),
+	VULNBL_INTEL_STEPPINGS(ALDERLAKE,	X86_STEPPING_ANY,		RFDS),
+	VULNBL_INTEL_STEPPINGS(ALDERLAKE_L,	X86_STEPPING_ANY,		RFDS),
+	VULNBL_INTEL_STEPPINGS(RAPTORLAKE,	X86_STEPPING_ANY,		RFDS),
+	VULNBL_INTEL_STEPPINGS(RAPTORLAKE_P,	X86_STEPPING_ANY,		RFDS),
+	VULNBL_INTEL_STEPPINGS(RAPTORLAKE_S,	X86_STEPPING_ANY,		RFDS),
+	VULNBL_INTEL_STEPPINGS(ALDERLAKE_N,	X86_STEPPING_ANY,		RFDS),
+	VULNBL_INTEL_STEPPINGS(ATOM_TREMONT,	X86_STEPPING_ANY,		MMIO | MMIO_SBDS | RFDS),
+	VULNBL_INTEL_STEPPINGS(ATOM_TREMONT_D,	X86_STEPPING_ANY,		MMIO | RFDS),
+	VULNBL_INTEL_STEPPINGS(ATOM_TREMONT_L,	X86_STEPPING_ANY,		MMIO | MMIO_SBDS | RFDS),
+	VULNBL_INTEL_STEPPINGS(ATOM_GOLDMONT,	X86_STEPPING_ANY,		RFDS),
+	VULNBL_INTEL_STEPPINGS(ATOM_GOLDMONT_D,	X86_STEPPING_ANY,		RFDS),
+	VULNBL_INTEL_STEPPINGS(ATOM_GOLDMONT_PLUS, X86_STEPPING_ANY,		RFDS),
 
 	VULNBL_AMD(0x15, RETBLEED),
 	VULNBL_AMD(0x16, RETBLEED),
 	VULNBL_AMD(0x17, RETBLEED | SRSO),
-	VULNBL_HYGON(0x18, RETBLEED),
+	VULNBL_HYGON(0x18, RETBLEED | SRSO),
 	VULNBL_AMD(0x19, SRSO),
 	{}
 };
@@ -1197,6 +1206,24 @@ static bool arch_cap_mmio_immune(u64 ia32_cap)
 		ia32_cap & ARCH_CAP_SBDR_SSDP_NO);
 }
 
+static bool __init vulnerable_to_rfds(u64 ia32_cap)
+{
+	/* The "immunity" bit trumps everything else: */
+	if (ia32_cap & ARCH_CAP_RFDS_NO)
+		return false;
+
+	/*
+	 * VMMs set ARCH_CAP_RFDS_CLEAR for processors not in the blacklist to
+	 * indicate that mitigation is needed because guest is running on a
+	 * vulnerable hardware or may migrate to such hardware:
+	 */
+	if (ia32_cap & ARCH_CAP_RFDS_CLEAR)
+		return true;
+
+	/* Only consult the blacklist when there is no enumeration: */
+	return cpu_matches(cpu_vuln_blacklist, RFDS);
+}
+
 static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
 {
 	u64 ia32_cap = x86_read_arch_cap_msr();
@@ -1219,8 +1246,16 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
 	   !cpu_has(c, X86_FEATURE_AMD_SSB_NO))
 		setup_force_cpu_bug(X86_BUG_SPEC_STORE_BYPASS);
 
-	if (ia32_cap & ARCH_CAP_IBRS_ALL)
+	/*
+	 * AMD's AutoIBRS is equivalent to Intel's eIBRS - use the Intel feature
+	 * flag and protect from vendor-specific bugs via the whitelist.
+	 */
+	if ((ia32_cap & ARCH_CAP_IBRS_ALL) || cpu_has(c, X86_FEATURE_AUTOIBRS)) {
 		setup_force_cpu_cap(X86_FEATURE_IBRS_ENHANCED);
+		if (!cpu_matches(cpu_vuln_whitelist, NO_EIBRS_PBRSB) &&
+		    !(ia32_cap & ARCH_CAP_PBRSB_NO))
+			setup_force_cpu_bug(X86_BUG_EIBRS_PBRSB);
+	}
 
 	if (!cpu_matches(cpu_vuln_whitelist, NO_MDS) &&
 	    !(ia32_cap & ARCH_CAP_MDS_NO)) {
@@ -1282,11 +1317,6 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
 			setup_force_cpu_bug(X86_BUG_RETBLEED);
 	}
 
-	if (cpu_has(c, X86_FEATURE_IBRS_ENHANCED) &&
-	    !cpu_matches(cpu_vuln_whitelist, NO_EIBRS_PBRSB) &&
-	    !(ia32_cap & ARCH_CAP_PBRSB_NO))
-		setup_force_cpu_bug(X86_BUG_EIBRS_PBRSB);
-
 	/*
 	 * Check if CPU is vulnerable to GDS. If running in a virtual machine on
 	 * an affected processor, the VMM may have disabled the use of GATHER by
@@ -1302,6 +1332,9 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
 			setup_force_cpu_bug(X86_BUG_SRSO);
 	}
 
+	if (vulnerable_to_rfds(ia32_cap))
+		setup_force_cpu_bug(X86_BUG_RFDS);
+
 	if (cpu_matches(cpu_vuln_whitelist, NO_MELTDOWN))
 		return;
 
@@ -1937,7 +1970,8 @@ DEFINE_PER_CPU(unsigned long, cpu_current_top_of_stack) =
 EXPORT_PER_CPU_SYMBOL(cpu_current_top_of_stack);
 
 #ifdef CONFIG_STACKPROTECTOR
-DEFINE_PER_CPU_ALIGNED(struct stack_canary, stack_canary);
+DEFINE_PER_CPU(unsigned long, __stack_chk_guard);
+EXPORT_PER_CPU_SYMBOL(__stack_chk_guard);
 #endif
 
 #endif	/* CONFIG_X86_64 */
diff --git a/arch/x86/kernel/cpu/cpuid-deps.c b/arch/x86/kernel/cpu/cpuid-deps.c
index d50224199..24fca3d56 100644
--- a/arch/x86/kernel/cpu/cpuid-deps.c
+++ b/arch/x86/kernel/cpu/cpuid-deps.c
@@ -44,7 +44,10 @@ static const struct cpuid_dep cpuid_deps[] = {
 	{ X86_FEATURE_F16C,			X86_FEATURE_XMM2,     },
 	{ X86_FEATURE_AES,			X86_FEATURE_XMM2      },
 	{ X86_FEATURE_SHA_NI,			X86_FEATURE_XMM2      },
+	{ X86_FEATURE_GFNI,			X86_FEATURE_XMM2      },
 	{ X86_FEATURE_FMA,			X86_FEATURE_AVX       },
+	{ X86_FEATURE_VAES,			X86_FEATURE_AVX       },
+	{ X86_FEATURE_VPCLMULQDQ,		X86_FEATURE_AVX       },
 	{ X86_FEATURE_AVX2,			X86_FEATURE_AVX,      },
 	{ X86_FEATURE_AVX512F,			X86_FEATURE_AVX,      },
 	{ X86_FEATURE_AVX512IFMA,		X86_FEATURE_AVX512F   },
@@ -56,9 +59,6 @@ static const struct cpuid_dep cpuid_deps[] = {
 	{ X86_FEATURE_AVX512VL,			X86_FEATURE_AVX512F   },
 	{ X86_FEATURE_AVX512VBMI,		X86_FEATURE_AVX512F   },
 	{ X86_FEATURE_AVX512_VBMI2,		X86_FEATURE_AVX512VL  },
-	{ X86_FEATURE_GFNI,			X86_FEATURE_AVX512VL  },
-	{ X86_FEATURE_VAES,			X86_FEATURE_AVX512VL  },
-	{ X86_FEATURE_VPCLMULQDQ,		X86_FEATURE_AVX512VL  },
 	{ X86_FEATURE_AVX512_VNNI,		X86_FEATURE_AVX512VL  },
 	{ X86_FEATURE_AVX512_BITALG,		X86_FEATURE_AVX512VL  },
 	{ X86_FEATURE_AVX512_4VNNIW,		X86_FEATURE_AVX512F   },
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index c6ad53e38..a7a8c7731 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -178,6 +178,90 @@ static bool bad_spectre_microcode(struct cpuinfo_x86 *c)
 	return false;
 }
 
+#define MSR_IA32_TME_ACTIVATE		0x982
+
+/* Helpers to access TME_ACTIVATE MSR */
+#define TME_ACTIVATE_LOCKED(x)		(x & 0x1)
+#define TME_ACTIVATE_ENABLED(x)		(x & 0x2)
+
+#define TME_ACTIVATE_POLICY(x)		((x >> 4) & 0xf)	/* Bits 7:4 */
+#define TME_ACTIVATE_POLICY_AES_XTS_128	0
+
+#define TME_ACTIVATE_KEYID_BITS(x)	((x >> 32) & 0xf)	/* Bits 35:32 */
+
+#define TME_ACTIVATE_CRYPTO_ALGS(x)	((x >> 48) & 0xffff)	/* Bits 63:48 */
+#define TME_ACTIVATE_CRYPTO_AES_XTS_128	1
+
+/* Values for mktme_status (SW only construct) */
+#define MKTME_ENABLED			0
+#define MKTME_DISABLED			1
+#define MKTME_UNINITIALIZED		2
+static int mktme_status = MKTME_UNINITIALIZED;
+
+static void detect_tme_early(struct cpuinfo_x86 *c)
+{
+	u64 tme_activate, tme_policy, tme_crypto_algs;
+	int keyid_bits = 0, nr_keyids = 0;
+	static u64 tme_activate_cpu0 = 0;
+
+	rdmsrl(MSR_IA32_TME_ACTIVATE, tme_activate);
+
+	if (mktme_status != MKTME_UNINITIALIZED) {
+		if (tme_activate != tme_activate_cpu0) {
+			/* Broken BIOS? */
+			pr_err_once("x86/tme: configuration is inconsistent between CPUs\n");
+			pr_err_once("x86/tme: MKTME is not usable\n");
+			mktme_status = MKTME_DISABLED;
+
+			/* Proceed. We may need to exclude bits from x86_phys_bits. */
+		}
+	} else {
+		tme_activate_cpu0 = tme_activate;
+	}
+
+	if (!TME_ACTIVATE_LOCKED(tme_activate) || !TME_ACTIVATE_ENABLED(tme_activate)) {
+		pr_info_once("x86/tme: not enabled by BIOS\n");
+		mktme_status = MKTME_DISABLED;
+		return;
+	}
+
+	if (mktme_status != MKTME_UNINITIALIZED)
+		goto detect_keyid_bits;
+
+	pr_info("x86/tme: enabled by BIOS\n");
+
+	tme_policy = TME_ACTIVATE_POLICY(tme_activate);
+	if (tme_policy != TME_ACTIVATE_POLICY_AES_XTS_128)
+		pr_warn("x86/tme: Unknown policy is active: %#llx\n", tme_policy);
+
+	tme_crypto_algs = TME_ACTIVATE_CRYPTO_ALGS(tme_activate);
+	if (!(tme_crypto_algs & TME_ACTIVATE_CRYPTO_AES_XTS_128)) {
+		pr_err("x86/mktme: No known encryption algorithm is supported: %#llx\n",
+				tme_crypto_algs);
+		mktme_status = MKTME_DISABLED;
+	}
+detect_keyid_bits:
+	keyid_bits = TME_ACTIVATE_KEYID_BITS(tme_activate);
+	nr_keyids = (1UL << keyid_bits) - 1;
+	if (nr_keyids) {
+		pr_info_once("x86/mktme: enabled by BIOS\n");
+		pr_info_once("x86/mktme: %d KeyIDs available\n", nr_keyids);
+	} else {
+		pr_info_once("x86/mktme: disabled by BIOS\n");
+	}
+
+	if (mktme_status == MKTME_UNINITIALIZED) {
+		/* MKTME is usable */
+		mktme_status = MKTME_ENABLED;
+	}
+
+	/*
+	 * KeyID bits effectively lower the number of physical address
+	 * bits.  Update cpuinfo_x86::x86_phys_bits accordingly.
+	 */
+	c->x86_phys_bits -= keyid_bits;
+}
+
 static void early_init_intel(struct cpuinfo_x86 *c)
 {
 	u64 misc_enable;
@@ -329,6 +413,13 @@ static void early_init_intel(struct cpuinfo_x86 *c)
 	 */
 	if (detect_extended_topology_early(c) < 0)
 		detect_ht_early(c);
+
+	/*
+	 * Adjust the number of physical bits early because it affects the
+	 * valid bits of the MTRR mask registers.
+	 */
+	if (cpu_has(c, X86_FEATURE_TME))
+		detect_tme_early(c);
 }
 
 static void bsp_init_intel(struct cpuinfo_x86 *c)
@@ -489,90 +580,6 @@ static void srat_detect_node(struct cpuinfo_x86 *c)
 #endif
 }
 
-#define MSR_IA32_TME_ACTIVATE		0x982
-
-/* Helpers to access TME_ACTIVATE MSR */
-#define TME_ACTIVATE_LOCKED(x)		(x & 0x1)
-#define TME_ACTIVATE_ENABLED(x)		(x & 0x2)
-
-#define TME_ACTIVATE_POLICY(x)		((x >> 4) & 0xf)	/* Bits 7:4 */
-#define TME_ACTIVATE_POLICY_AES_XTS_128	0
-
-#define TME_ACTIVATE_KEYID_BITS(x)	((x >> 32) & 0xf)	/* Bits 35:32 */
-
-#define TME_ACTIVATE_CRYPTO_ALGS(x)	((x >> 48) & 0xffff)	/* Bits 63:48 */
-#define TME_ACTIVATE_CRYPTO_AES_XTS_128	1
-
-/* Values for mktme_status (SW only construct) */
-#define MKTME_ENABLED			0
-#define MKTME_DISABLED			1
-#define MKTME_UNINITIALIZED		2
-static int mktme_status = MKTME_UNINITIALIZED;
-
-static void detect_tme(struct cpuinfo_x86 *c)
-{
-	u64 tme_activate, tme_policy, tme_crypto_algs;
-	int keyid_bits = 0, nr_keyids = 0;
-	static u64 tme_activate_cpu0 = 0;
-
-	rdmsrl(MSR_IA32_TME_ACTIVATE, tme_activate);
-
-	if (mktme_status != MKTME_UNINITIALIZED) {
-		if (tme_activate != tme_activate_cpu0) {
-			/* Broken BIOS? */
-			pr_err_once("x86/tme: configuration is inconsistent between CPUs\n");
-			pr_err_once("x86/tme: MKTME is not usable\n");
-			mktme_status = MKTME_DISABLED;
-
-			/* Proceed. We may need to exclude bits from x86_phys_bits. */
-		}
-	} else {
-		tme_activate_cpu0 = tme_activate;
-	}
-
-	if (!TME_ACTIVATE_LOCKED(tme_activate) || !TME_ACTIVATE_ENABLED(tme_activate)) {
-		pr_info_once("x86/tme: not enabled by BIOS\n");
-		mktme_status = MKTME_DISABLED;
-		return;
-	}
-
-	if (mktme_status != MKTME_UNINITIALIZED)
-		goto detect_keyid_bits;
-
-	pr_info("x86/tme: enabled by BIOS\n");
-
-	tme_policy = TME_ACTIVATE_POLICY(tme_activate);
-	if (tme_policy != TME_ACTIVATE_POLICY_AES_XTS_128)
-		pr_warn("x86/tme: Unknown policy is active: %#llx\n", tme_policy);
-
-	tme_crypto_algs = TME_ACTIVATE_CRYPTO_ALGS(tme_activate);
-	if (!(tme_crypto_algs & TME_ACTIVATE_CRYPTO_AES_XTS_128)) {
-		pr_err("x86/mktme: No known encryption algorithm is supported: %#llx\n",
-				tme_crypto_algs);
-		mktme_status = MKTME_DISABLED;
-	}
-detect_keyid_bits:
-	keyid_bits = TME_ACTIVATE_KEYID_BITS(tme_activate);
-	nr_keyids = (1UL << keyid_bits) - 1;
-	if (nr_keyids) {
-		pr_info_once("x86/mktme: enabled by BIOS\n");
-		pr_info_once("x86/mktme: %d KeyIDs available\n", nr_keyids);
-	} else {
-		pr_info_once("x86/mktme: disabled by BIOS\n");
-	}
-
-	if (mktme_status == MKTME_UNINITIALIZED) {
-		/* MKTME is usable */
-		mktme_status = MKTME_ENABLED;
-	}
-
-	/*
-	 * KeyID bits effectively lower the number of physical address
-	 * bits.  Update cpuinfo_x86::x86_phys_bits accordingly.
-	 */
-	c->x86_phys_bits -= keyid_bits;
-}
-
 static void init_cpuid_fault(struct cpuinfo_x86 *c)
 {
 	u64 msr;
@@ -708,9 +715,6 @@ static void init_intel(struct cpuinfo_x86 *c)
 
 	init_ia32_feat_ctl(c);
 
-	if (cpu_has(c, X86_FEATURE_TME))
-		detect_tme(c);
-
 	init_intel_misc_features(c);
 
 	if (tsx_ctrl_state == TSX_CTRL_ENABLE)
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 0b7c81389..97ab29429 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -44,6 +44,7 @@
 #include <linux/sync_core.h>
 #include <linux/task_work.h>
 #include <linux/hardirq.h>
+#include <linux/kexec.h>
 
 #include <asm/intel-family.h>
 #include <asm/processor.h>
@@ -274,6 +275,7 @@ static noinstr void mce_panic(const char *msg, struct mce *final, char *exp)
 	struct llist_node *pending;
 	struct mce_evt_llist *l;
 	int apei_err = 0;
+	struct page *p;
 
 	/*
 	 * Allow instrumentation around external facilities usage. Not that it
@@ -329,6 +331,20 @@ static noinstr void mce_panic(const char *msg, struct mce *final, char *exp)
 	if (!fake_panic) {
 		if (panic_timeout == 0)
 			panic_timeout = mca_cfg.panic_timeout;
+
+		/*
+		 * Kdump skips the poisoned page in order to avoid
+		 * touching the error bits again. Poison the page even
+		 * if the error is fatal and the machine is about to
+		 * panic.
+		 */
+		if (kexec_crash_loaded()) {
+			if (final && (final->status & MCI_STATUS_ADDRV)) {
+				p = pfn_to_online_page(final->addr >> PAGE_SHIFT);
+				if (p)
+					SetPageHWPoison(p);
+			}
+		}
 		panic(msg);
 	} else
 		pr_emerg(HW_ERR "Fake kernel panic: %s\n", msg);
@@ -2373,12 +2389,14 @@ static ssize_t set_bank(struct device *s, struct device_attribute *attr,
 		return -EINVAL;
 
 	b = &per_cpu(mce_banks_array, s->id)[bank];
-
 	if (!b->init)
 		return -ENODEV;
 
 	b->ctl = new;
+
+	mutex_lock(&mce_sysfs_mutex);
 	mce_restart();
+	mutex_unlock(&mce_sysfs_mutex);
 
 	return size;
 }