kabi: Fix "Intel: perf/core: Add attr_groups_update into struct pmu"

hulk inclusion
category: Bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I47H3V
CVE: NA

-------------------------------------------------

Use the new pmu_attr_update_notifier_chain to update attribute groups
to fix kabi broken introduced by the following commit:
"Intel: perf/core: Add attr_groups_update into struct pmu"
"Intel: perf/x86: Use the new pmu::update_attrs attribute group".
Signed-off-by: NWei Li <liwei391@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: NYang Jihong <yangjihong1@huawei.com>
Reviewed-by: NXie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

arch/x86/events/core.c

@@ -1810,6 +1810,22 @@ ssize_t x86_event_sysfs_show(char *page, u64 config, u64 event)
 static struct attribute_group x86_pmu_attr_group;
 static struct attribute_group x86_pmu_caps_group;
 
+static int x86_pmu_attr_update_notify(struct notifier_block *nb,
+					unsigned long ret, void *group)
+{
+	struct pmu *tmp = group;
+
+	if (tmp != &pmu)
+		return NOTIFY_DONE;
+
+	*(int *)ret = sysfs_update_groups(&tmp->dev->kobj, x86_pmu.attr_update);
+	return NOTIFY_STOP;
+}
+
+static struct notifier_block x86_pmu_attr_update_notifier = {
+	.notifier_call = &x86_pmu_attr_update_notify,
+};
+
 static int __init init_hw_perf_events(void)
 {
 	struct x86_pmu_quirk *quirk;
@@ -1868,7 +1884,7 @@ static int __init init_hw_perf_events(void)
 	if (!x86_pmu.events_sysfs_show)
 		x86_pmu_events_group.attrs = &empty_attrs;
 
-	pmu.attr_update = x86_pmu.attr_update;
+	pmu_attr_update_register_notifier(&x86_pmu_attr_update_notifier);
 
 	pr_info("... version:                %d\n",     x86_pmu.version);
 	pr_info("... bit width:              %d\n",     x86_pmu.cntval_bits);

include/linux/perf_event.h

@@ -279,7 +279,6 @@ struct pmu {
 	struct module			*module;
 	struct device			*dev;
 	const struct attribute_group	**attr_groups;
-	const struct attribute_group	**attr_update;
 	const char			*name;
 	int				type;
 
@@ -897,6 +896,9 @@ extern void perf_event_itrace_started(struct perf_event *event);
 extern int perf_pmu_register(struct pmu *pmu, const char *name, int type);
 extern void perf_pmu_unregister(struct pmu *pmu);
 
+extern int pmu_attr_update_register_notifier(struct notifier_block *nb);
+extern int pmu_attr_update_unregister_notifier(struct notifier_block *nb);
+
 extern int perf_num_counters(void);
 extern const char *perf_pmu_name(void);
 extern void __perf_event_task_sched_in(struct task_struct *prev,

kernel/events/core.c

@@ -9690,6 +9690,30 @@ static struct bus_type pmu_bus = {
 	.name		= "event_source",
 	.dev_groups	= pmu_dev_groups,
 };
+static BLOCKING_NOTIFIER_HEAD(pmu_attr_update_notifier_chain);
+
+int pmu_attr_update_register_notifier(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_register(
+		&pmu_attr_update_notifier_chain, nb);
+}
+EXPORT_SYMBOL_GPL(pmu_attr_update_register_notifier);
+
+int pmu_attr_update_unregister_notifier(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_unregister(
+		&pmu_attr_update_notifier_chain, nb);
+}
+EXPORT_SYMBOL_GPL(pmu_attr_update_unregister_notifier);
+
+static int pmu_attr_update_notifier_call_chain(struct pmu *pmu)
+{
+	int ret = 0;
+
+	blocking_notifier_call_chain(&pmu_attr_update_notifier_chain,
+		(unsigned long)&ret, (void *)pmu);
+	return ret;
+}
 
 static void pmu_dev_release(struct device *dev)
 {
@@ -9724,9 +9748,7 @@ static int pmu_dev_alloc(struct pmu *pmu)
 	if (ret)
 		goto del_dev;
 
-	if (pmu->attr_update)
-		ret = sysfs_update_groups(&pmu->dev->kobj, pmu->attr_update);
-
+	ret = pmu_attr_update_notifier_call_chain(pmu);
 	if (ret)
 		goto del_dev;