5 files changed, 83 insertions, 14 deletions

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 4684ad7ba793..2d23a448e72d 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -39,6 +39,7 @@ static void __init spectre_v2_select_mitigation(void);
 static void __init ssb_select_mitigation(void);
 static void __init l1tf_select_mitigation(void);
 static void __init mds_select_mitigation(void);
+static void __init mds_print_mitigation(void);
 static void __init taa_select_mitigation(void);
 
 /* The base value of the SPEC_CTRL MSR that always has to be preserved. */
@@ -108,6 +109,12 @@ void __init check_bugs(void)
 	mds_select_mitigation();
 	taa_select_mitigation();
 
+	/*
+	 * As MDS and TAA mitigations are inter-related, print MDS
+	 * mitigation until after TAA mitigation selection is done.
+	 */
+	mds_print_mitigation();
+
 	arch_smt_update();
 
 #ifdef CONFIG_X86_32
@@ -245,6 +252,12 @@ static void __init mds_select_mitigation(void)
 		    (mds_nosmt || cpu_mitigations_auto_nosmt()))
 			cpu_smt_disable(false);
 	}
+}
+
+static void __init mds_print_mitigation(void)
+{
+	if (!boot_cpu_has_bug(X86_BUG_MDS) || cpu_mitigations_off())
+		return;
 
 	pr_info("%s\n", mds_strings[mds_mitigation]);
 }
@@ -304,8 +317,12 @@ static void __init taa_select_mitigation(void)
 		return;
 	}
 
-	/* TAA mitigation is turned off on the cmdline (tsx_async_abort=off) */
-	if (taa_mitigation == TAA_MITIGATION_OFF)
+	/*
+	 * TAA mitigation via VERW is turned off if both
+	 * tsx_async_abort=off and mds=off are specified.
+	 */
+	if (taa_mitigation == TAA_MITIGATION_OFF &&
+	    mds_mitigation == MDS_MITIGATION_OFF)
 		goto out;
 
 	if (boot_cpu_has(X86_FEATURE_MD_CLEAR))
@@ -339,6 +356,15 @@ static void __init taa_select_mitigation(void)
 	if (taa_nosmt || cpu_mitigations_auto_nosmt())
 		cpu_smt_disable(false);
 
+	/*
+	 * Update MDS mitigation, if necessary, as the mds_user_clear is
+	 * now enabled for TAA mitigation.
+	 */
+	if (mds_mitigation == MDS_MITIGATION_OFF &&
+	    boot_cpu_has_bug(X86_BUG_MDS)) {
+		mds_mitigation = MDS_MITIGATION_FULL;
+		mds_select_mitigation();
+	}
 out:
 	pr_info("%s\n", taa_strings[taa_mitigation]);
 }
diff --git a/arch/x86/kernel/cpu/intel_rdt.c b/arch/x86/kernel/cpu/intel_rdt.c
index cc43c5abd187..b99a04da70f6 100644
--- a/arch/x86/kernel/cpu/intel_rdt.c
+++ b/arch/x86/kernel/cpu/intel_rdt.c
@@ -610,6 +610,13 @@ static void domain_remove_cpu(int cpu, struct rdt_resource *r)
 			cancel_delayed_work(&d->cqm_limbo);
 		}
 
+		/*
+		 * rdt_domain "d" is going to be freed below, so clear
+		 * its pointer from pseudo_lock_region struct.
+		 */
+		if (d->plr)
+			d->plr->d = NULL;
+
 		kfree(d->ctrl_val);
 		kfree(d->mbps_val);
 		kfree(d->rmid_busy_llc);
diff --git a/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
index 968ace3c6d73..c8b72aff55e0 100644
--- a/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
+++ b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
@@ -408,8 +408,16 @@ int rdtgroup_schemata_show(struct kernfs_open_file *of,
 			for_each_alloc_enabled_rdt_resource(r)
 				seq_printf(s, "%s:uninitialized\n", r->name);
 		} else if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
-			seq_printf(s, "%s:%d=%x\n", rdtgrp->plr->r->name,
-				   rdtgrp->plr->d->id, rdtgrp->plr->cbm);
+			if (!rdtgrp->plr->d) {
+				rdt_last_cmd_clear();
+				rdt_last_cmd_puts("Cache domain offline\n");
+				ret = -ENODEV;
+			} else {
+				seq_printf(s, "%s:%d=%x\n",
+					   rdtgrp->plr->r->name,
+					   rdtgrp->plr->d->id,
+					   rdtgrp->plr->cbm);
+			}
 		} else {
 			closid = rdtgrp->closid;
 			for_each_alloc_enabled_rdt_resource(r) {
diff --git a/arch/x86/kernel/cpu/intel_rdt_pseudo_lock.c b/arch/x86/kernel/cpu/intel_rdt_pseudo_lock.c
index 912d53939f4f..a999a58ca331 100644
--- a/arch/x86/kernel/cpu/intel_rdt_pseudo_lock.c
+++ b/arch/x86/kernel/cpu/intel_rdt_pseudo_lock.c
@@ -1116,6 +1116,11 @@ static int pseudo_lock_measure_cycles(struct rdtgroup *rdtgrp, int sel)
 		goto out;
 	}
 
+	if (!plr->d) {
+		ret = -ENODEV;
+		goto out;
+	}
+
 	plr->thread_done = 0;
 	cpu = cpumask_first(&plr->d->cpu_mask);
 	if (!cpu_online(cpu)) {
@@ -1429,6 +1434,11 @@ static int pseudo_lock_dev_mmap(struct file *filp, struct vm_area_struct *vma)
 
 	plr = rdtgrp->plr;
 
+	if (!plr->d) {
+		mutex_unlock(&rdtgroup_mutex);
+		return -ENODEV;
+	}
+
 	/*
 	 * Task is required to run with affinity to the cpus associated
 	 * with the pseudo-locked region. If this is not the case the task
diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index ad64031e82dc..a2d7e6646cce 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -268,17 +268,27 @@ static int rdtgroup_cpus_show(struct kernfs_open_file *of,
 			      struct seq_file *s, void *v)
 {
 	struct rdtgroup *rdtgrp;
+	struct cpumask *mask;
 	int ret = 0;
 
 	rdtgrp = rdtgroup_kn_lock_live(of->kn);
 
 	if (rdtgrp) {
-		if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)
-			seq_printf(s, is_cpu_list(of) ? "%*pbl\n" : "%*pb\n",
-				   cpumask_pr_args(&rdtgrp->plr->d->cpu_mask));
-		else
+		if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
+			if (!rdtgrp->plr->d) {
+				rdt_last_cmd_clear();
+				rdt_last_cmd_puts("Cache domain offline\n");
+				ret = -ENODEV;
+			} else {
+				mask = &rdtgrp->plr->d->cpu_mask;
+				seq_printf(s, is_cpu_list(of) ?
+					   "%*pbl\n" : "%*pb\n",
+					   cpumask_pr_args(mask));
+			}
+		} else {
 			seq_printf(s, is_cpu_list(of) ? "%*pbl\n" : "%*pb\n",
 				   cpumask_pr_args(&rdtgrp->cpu_mask));
+		}
 	} else {
 		ret = -ENOENT;
 	}
@@ -1286,6 +1296,7 @@ static int rdtgroup_size_show(struct kernfs_open_file *of,
 	struct rdt_resource *r;
 	struct rdt_domain *d;
 	unsigned int size;
+	int ret = 0;
 	bool sep;
 	u32 ctrl;
 
@@ -1296,11 +1307,18 @@ static int rdtgroup_size_show(struct kernfs_open_file *of,
 	}
 
 	if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
-		seq_printf(s, "%*s:", max_name_width, rdtgrp->plr->r->name);
-		size = rdtgroup_cbm_to_size(rdtgrp->plr->r,
-					    rdtgrp->plr->d,
-					    rdtgrp->plr->cbm);
-		seq_printf(s, "%d=%u\n", rdtgrp->plr->d->id, size);
+		if (!rdtgrp->plr->d) {
+			rdt_last_cmd_clear();
+			rdt_last_cmd_puts("Cache domain offline\n");
+			ret = -ENODEV;
+		} else {
+			seq_printf(s, "%*s:", max_name_width,
+				   rdtgrp->plr->r->name);
+			size = rdtgroup_cbm_to_size(rdtgrp->plr->r,
+						    rdtgrp->plr->d,
+						    rdtgrp->plr->cbm);
+			seq_printf(s, "%d=%u\n", rdtgrp->plr->d->id, size);
+		}
 		goto out;
 	}
 
@@ -1330,7 +1348,7 @@ static int rdtgroup_size_show(struct kernfs_open_file *of,
 out:
 	rdtgroup_kn_unlock(of->kn);
 
-	return 0;
+	return ret;
 }
 
 /* rdtgroup information files for one cache resource. */