1 files changed, 34 insertions, 9 deletions

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 5f4829f10129..106911b603bd 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -1033,6 +1033,27 @@ static inline void x86_assign_hw_event(struct perf_event *event,
 	}
 }
 
+/**
+ * x86_perf_rdpmc_index - Return PMC counter used for event
+ * @event: the perf_event to which the PMC counter was assigned
+ *
+ * The counter assigned to this performance event may change if interrupts
+ * are enabled. This counter should thus never be used while interrupts are
+ * enabled. Before this function is used to obtain the assigned counter the
+ * event should be checked for validity using, for example,
+ * perf_event_read_local(), within the same interrupt disabled section in
+ * which this counter is planned to be used.
+ *
+ * Return: The index of the performance monitoring counter assigned to
+ * @perf_event.
+ */
+int x86_perf_rdpmc_index(struct perf_event *event)
+{
+	lockdep_assert_irqs_disabled();
+
+	return event->hw.event_base_rdpmc;
+}
+
 static inline int match_prev_assignment(struct hw_perf_event *hwc,
 					struct cpu_hw_events *cpuc,
 					int i)
@@ -1584,7 +1605,7 @@ static void __init pmu_check_apic(void)
 
 }
 
-static struct attribute_group x86_pmu_format_group = {
+static struct attribute_group x86_pmu_format_group __ro_after_init = {
 	.name = "format",
 	.attrs = NULL,
 };
@@ -1631,9 +1652,9 @@ __init struct attribute **merge_attr(struct attribute **a, struct attribute **b)
 	struct attribute **new;
 	int j, i;
 
-	for (j = 0; a[j]; j++)
+	for (j = 0; a && a[j]; j++)
 		;
-	for (i = 0; b[i]; i++)
+	for (i = 0; b && b[i]; i++)
 		j++;
 	j++;
 
@@ -1642,9 +1663,9 @@ __init struct attribute **merge_attr(struct attribute **a, struct attribute **b)
 		return NULL;
 
 	j = 0;
-	for (i = 0; a[i]; i++)
+	for (i = 0; a && a[i]; i++)
 		new[j++] = a[i];
-	for (i = 0; b[i]; i++)
+	for (i = 0; b && b[i]; i++)
 		new[j++] = b[i];
 	new[j] = NULL;
 
@@ -1715,7 +1736,7 @@ static struct attribute *events_attr[] = {
 	NULL,
 };
 
-static struct attribute_group x86_pmu_events_group = {
+static struct attribute_group x86_pmu_events_group __ro_after_init = {
 	.name = "events",
 	.attrs = events_attr,
 };
@@ -1776,6 +1797,10 @@ static int __init init_hw_perf_events(void)
 	case X86_VENDOR_AMD:
 		err = amd_pmu_init();
 		break;
+	case X86_VENDOR_HYGON:
+		err = amd_pmu_init();
+		x86_pmu.name = "HYGON";
+		break;
 	default:
 		err = -ENOTSUPP;
 	}
@@ -2230,7 +2255,7 @@ static struct attribute *x86_pmu_attrs[] = {
 	NULL,
 };
 
-static struct attribute_group x86_pmu_attr_group = {
+static struct attribute_group x86_pmu_attr_group __ro_after_init = {
 	.attrs = x86_pmu_attrs,
 };
 
@@ -2248,7 +2273,7 @@ static struct attribute *x86_pmu_caps_attrs[] = {
 	NULL
 };
 
-static struct attribute_group x86_pmu_caps_group = {
+static struct attribute_group x86_pmu_caps_group __ro_after_init = {
 	.name = "caps",
 	.attrs = x86_pmu_caps_attrs,
 };
@@ -2465,7 +2490,7 @@ perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs
 
 	perf_callchain_store(entry, regs->ip);
 
-	if (!current->mm)
+	if (!nmi_uaccess_okay())
 		return;
 
 	if (perf_callchain_user32(regs, entry))