From 814173380135834d8e520cb2fa45951205744cf3 Mon Sep 17 00:00:00 2001 From: Greg KH Date: Mon, 12 Jun 2023 15:09:09 +0200 Subject: [PATCH] perf/core: Fix narrow startup race when creating the perf nr_addr_filters sysfs file [ Upstream commit 652ffc2104ec1f69dd4a46313888c33527145ccf ] Signed-off-by: Greg Kroah-Hartman Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/2023061204-decal-flyable-6090@gregkh Signed-off-by: Sasha Levin --- kernel/events/core.c | 40 ++++++++++++++++++++++++++++------------ 1 file changed, 28 insertions(+), 12 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 58ecb1c..f22c540 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -11413,9 +11413,32 @@ 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 = { @@ -11452,18 +11475,11 @@ 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; -- 2.7.4