perf/core: Fix narrow startup race when creating the perf nr_addr_filters sysfs file

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/2023061204-decal-flyable-6090@gregkh
This commit is contained in:
Greg KH 2023-06-12 15:09:09 +02:00 committed by Peter Zijlstra
parent 5d2d4a9f60
commit 652ffc2104

View File

@ -11408,9 +11408,32 @@ static DEVICE_ATTR_RW(perf_event_mux_interval_ms);
static struct attribute *pmu_dev_attrs[] = {
&dev_attr_type.attr,
&dev_attr_perf_event_mux_interval_ms.attr,
&dev_attr_nr_addr_filters.attr,
NULL,
};
static umode_t pmu_dev_is_visible(struct kobject *kobj, struct attribute *a, int n)
{
struct device *dev = kobj_to_dev(kobj);
struct pmu *pmu = dev_get_drvdata(dev);
if (!pmu->nr_addr_filters)
return 0;
return a->mode;
return 0;
}
static struct attribute_group pmu_dev_attr_group = {
.is_visible = pmu_dev_is_visible,
.attrs = pmu_dev_attrs,
};
static const struct attribute_group *pmu_dev_groups[] = {
&pmu_dev_attr_group,
NULL,
};
ATTRIBUTE_GROUPS(pmu_dev);
static int pmu_bus_running;
static struct bus_type pmu_bus = {
@ -11447,18 +11470,11 @@ static int pmu_dev_alloc(struct pmu *pmu)
if (ret)
goto free_dev;
/* For PMUs with address filters, throw in an extra attribute: */
if (pmu->nr_addr_filters)
ret = device_create_file(pmu->dev, &dev_attr_nr_addr_filters);
if (ret)
goto del_dev;
if (pmu->attr_update)
if (pmu->attr_update) {
ret = sysfs_update_groups(&pmu->dev->kobj, pmu->attr_update);
if (ret)
goto del_dev;
if (ret)
goto del_dev;
}
out:
return ret;