Merge tag 'x86-urgent-2020-06-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull more x86 updates from Thomas Gleixner:
 "A set of fixes and updates for x86:

   - Unbreak paravirt VDSO clocks.

     While the VDSO code was moved into lib for sharing a subtle check
     for the validity of paravirt clocks got replaced. While the
     replacement works perfectly fine for bare metal as the update of
     the VDSO clock mode is synchronous, it fails for paravirt clocks
     because the hypervisor can invalidate them asynchronously.

     Bring it back as an optional function so it does not inflict this
     on architectures which are free of PV damage.

   - Fix the jiffies to jiffies64 mapping on 64bit so it does not
     trigger an ODR violation on newer compilers

   - Three fixes for the SSBD and *IB* speculation mitigation maze to
     ensure consistency, not disabling of some *IB* variants wrongly and
     to prevent a rogue cross process shutdown of SSBD. All marked for
     stable.

   - Add yet more CPU models to the splitlock detection capable list
     !@#%$!

   - Bring the pr_info() back which tells that TSC deadline timer is
     enabled.

   - Reboot quirk for MacBook6,1"

* tag 'x86-urgent-2020-06-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/vdso: Unbreak paravirt VDSO clocks
  lib/vdso: Provide sanity check for cycles (again)
  clocksource: Remove obsolete ifdef
  x86_64: Fix jiffies ODR violation
  x86/speculation: PR_SPEC_FORCE_DISABLE enforcement for indirect branches.
  x86/speculation: Prevent rogue cross-process SSBD shutdown
  x86/speculation: Avoid force-disabling IBPB based on STIBP and enhanced IBRS.
  x86/cpu: Add Sapphire Rapids CPU model number
  x86/split_lock: Add Icelake microserver and Tigerlake CPU models
  x86/apic: Make TSC deadline timer detection message visible
  x86/reboot/quirks: Add MacBook6,1 reboot quirk

2 files changed, 57 insertions, 38 deletions

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index b6f887be440c..0b71970d2d3d 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -588,7 +588,9 @@ early_param("nospectre_v1", nospectre_v1_cmdline);
 static enum spectre_v2_mitigation spectre_v2_enabled __ro_after_init =
 	SPECTRE_V2_NONE;
 
-static enum spectre_v2_user_mitigation spectre_v2_user __ro_after_init =
+static enum spectre_v2_user_mitigation spectre_v2_user_stibp __ro_after_init =
+	SPECTRE_V2_USER_NONE;
+static enum spectre_v2_user_mitigation spectre_v2_user_ibpb __ro_after_init =
 	SPECTRE_V2_USER_NONE;
 
 #ifdef CONFIG_RETPOLINE
@@ -734,15 +736,6 @@ spectre_v2_user_select_mitigation(enum spectre_v2_mitigation_cmd v2_cmd)
 		break;
 	}
 
-	/*
-	 * At this point, an STIBP mode other than "off" has been set.
-	 * If STIBP support is not being forced, check if STIBP always-on
-	 * is preferred.
-	 */
-	if (mode != SPECTRE_V2_USER_STRICT &&
-	    boot_cpu_has(X86_FEATURE_AMD_STIBP_ALWAYS_ON))
-		mode = SPECTRE_V2_USER_STRICT_PREFERRED;
-
 	/* Initialize Indirect Branch Prediction Barrier */
 	if (boot_cpu_has(X86_FEATURE_IBPB)) {
 		setup_force_cpu_cap(X86_FEATURE_USE_IBPB);
@@ -765,23 +758,36 @@ spectre_v2_user_select_mitigation(enum spectre_v2_mitigation_cmd v2_cmd)
 		pr_info("mitigation: Enabling %s Indirect Branch Prediction Barrier\n",
 			static_key_enabled(&switch_mm_always_ibpb) ?
 			"always-on" : "conditional");
+
+		spectre_v2_user_ibpb = mode;
 	}
 
-	/* If enhanced IBRS is enabled no STIBP required */
-	if (spectre_v2_enabled == SPECTRE_V2_IBRS_ENHANCED)
+	/*
+	 * If enhanced IBRS is enabled or SMT impossible, STIBP is not
+	 * required.
+	 */
+	if (!smt_possible || spectre_v2_enabled == SPECTRE_V2_IBRS_ENHANCED)
 		return;
 
 	/*
-	 * If SMT is not possible or STIBP is not available clear the STIBP
-	 * mode.
+	 * At this point, an STIBP mode other than "off" has been set.
+	 * If STIBP support is not being forced, check if STIBP always-on
+	 * is preferred.
 	 */
-	if (!smt_possible || !boot_cpu_has(X86_FEATURE_STIBP))
+	if (mode != SPECTRE_V2_USER_STRICT &&
+	    boot_cpu_has(X86_FEATURE_AMD_STIBP_ALWAYS_ON))
+		mode = SPECTRE_V2_USER_STRICT_PREFERRED;
+
+	/*
+	 * If STIBP is not available, clear the STIBP mode.
+	 */
+	if (!boot_cpu_has(X86_FEATURE_STIBP))
 		mode = SPECTRE_V2_USER_NONE;
+
+	spectre_v2_user_stibp = mode;
+
 set_mode:
-	spectre_v2_user = mode;
-	/* Only print the STIBP mode when SMT possible */
-	if (smt_possible)
-		pr_info("%s\n", spectre_v2_user_strings[mode]);
+	pr_info("%s\n", spectre_v2_user_strings[mode]);
 }
 
 static const char * const spectre_v2_strings[] = {
@@ -1014,7 +1020,7 @@ void cpu_bugs_smt_update(void)
 {
 	mutex_lock(&spec_ctrl_mutex);
 
-	switch (spectre_v2_user) {
+	switch (spectre_v2_user_stibp) {
 	case SPECTRE_V2_USER_NONE:
 		break;
 	case SPECTRE_V2_USER_STRICT:
@@ -1257,14 +1263,19 @@ static int ib_prctl_set(struct task_struct *task, unsigned long ctrl)
 {
 	switch (ctrl) {
 	case PR_SPEC_ENABLE:
-		if (spectre_v2_user == SPECTRE_V2_USER_NONE)
+		if (spectre_v2_user_ibpb == SPECTRE_V2_USER_NONE &&
+		    spectre_v2_user_stibp == SPECTRE_V2_USER_NONE)
 			return 0;
 		/*
 		 * Indirect branch speculation is always disabled in strict
-		 * mode.
+		 * mode. It can neither be enabled if it was force-disabled
+		 * by a  previous prctl call.
+
 		 */
-		if (spectre_v2_user == SPECTRE_V2_USER_STRICT ||
-		    spectre_v2_user == SPECTRE_V2_USER_STRICT_PREFERRED)
+		if (spectre_v2_user_ibpb == SPECTRE_V2_USER_STRICT ||
+		    spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT ||
+		    spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT_PREFERRED ||
+		    task_spec_ib_force_disable(task))
 			return -EPERM;
 		task_clear_spec_ib_disable(task);
 		task_update_spec_tif(task);
@@ -1275,10 +1286,12 @@ static int ib_prctl_set(struct task_struct *task, unsigned long ctrl)
 		 * Indirect branch speculation is always allowed when
 		 * mitigation is force disabled.
 		 */
-		if (spectre_v2_user == SPECTRE_V2_USER_NONE)
+		if (spectre_v2_user_ibpb == SPECTRE_V2_USER_NONE &&
+		    spectre_v2_user_stibp == SPECTRE_V2_USER_NONE)
 			return -EPERM;
-		if (spectre_v2_user == SPECTRE_V2_USER_STRICT ||
-		    spectre_v2_user == SPECTRE_V2_USER_STRICT_PREFERRED)
+		if (spectre_v2_user_ibpb == SPECTRE_V2_USER_STRICT ||
+		    spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT ||
+		    spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT_PREFERRED)
 			return 0;
 		task_set_spec_ib_disable(task);
 		if (ctrl == PR_SPEC_FORCE_DISABLE)
@@ -1309,7 +1322,8 @@ void arch_seccomp_spec_mitigate(struct task_struct *task)
 {
 	if (ssb_mode == SPEC_STORE_BYPASS_SECCOMP)
 		ssb_prctl_set(task, PR_SPEC_FORCE_DISABLE);
-	if (spectre_v2_user == SPECTRE_V2_USER_SECCOMP)
+	if (spectre_v2_user_ibpb == SPECTRE_V2_USER_SECCOMP ||
+	    spectre_v2_user_stibp == SPECTRE_V2_USER_SECCOMP)
 		ib_prctl_set(task, PR_SPEC_FORCE_DISABLE);
 }
 #endif
@@ -1340,22 +1354,24 @@ static int ib_prctl_get(struct task_struct *task)
 	if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V2))
 		return PR_SPEC_NOT_AFFECTED;
 
-	switch (spectre_v2_user) {
-	case SPECTRE_V2_USER_NONE:
+	if (spectre_v2_user_ibpb == SPECTRE_V2_USER_NONE &&
+	    spectre_v2_user_stibp == SPECTRE_V2_USER_NONE)
 		return PR_SPEC_ENABLE;
-	case SPECTRE_V2_USER_PRCTL:
-	case SPECTRE_V2_USER_SECCOMP:
+	else if (spectre_v2_user_ibpb == SPECTRE_V2_USER_STRICT ||
+	    spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT ||
+	    spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT_PREFERRED)
+		return PR_SPEC_DISABLE;
+	else if (spectre_v2_user_ibpb == SPECTRE_V2_USER_PRCTL ||
+	    spectre_v2_user_ibpb == SPECTRE_V2_USER_SECCOMP ||
+	    spectre_v2_user_stibp == SPECTRE_V2_USER_PRCTL ||
+	    spectre_v2_user_stibp == SPECTRE_V2_USER_SECCOMP) {
 		if (task_spec_ib_force_disable(task))
 			return PR_SPEC_PRCTL | PR_SPEC_FORCE_DISABLE;
 		if (task_spec_ib_disable(task))
 			return PR_SPEC_PRCTL | PR_SPEC_DISABLE;
 		return PR_SPEC_PRCTL | PR_SPEC_ENABLE;
-	case SPECTRE_V2_USER_STRICT:
-	case SPECTRE_V2_USER_STRICT_PREFERRED:
-		return PR_SPEC_DISABLE;
-	default:
+	} else
 		return PR_SPEC_NOT_AFFECTED;
-	}
 }
 
 int arch_prctl_spec_ctrl_get(struct task_struct *task, unsigned long which)
@@ -1594,7 +1610,7 @@ static char *stibp_state(void)
 	if (spectre_v2_enabled == SPECTRE_V2_IBRS_ENHANCED)
 		return "";
 
-	switch (spectre_v2_user) {
+	switch (spectre_v2_user_stibp) {
 	case SPECTRE_V2_USER_NONE:
 		return ", STIBP: disabled";
 	case SPECTRE_V2_USER_STRICT:
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 63926c94eb5f..c25a67a34bd3 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -1142,9 +1142,12 @@ void switch_to_sld(unsigned long tifn)
 static const struct x86_cpu_id split_lock_cpu_ids[] __initconst = {
 	X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_X,		0),
 	X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_L,		0),
+	X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_D,		0),
 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT,	1),
 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT_D,	1),
 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT_L,	1),
+	X86_MATCH_INTEL_FAM6_MODEL(TIGERLAKE_L,		1),
+	X86_MATCH_INTEL_FAM6_MODEL(TIGERLAKE,		1),
 	{}
 };