android/android_kernel_samsung_sm8650
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vfio/mdev: Use the driver core to create the 'remove' file

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The device creator is supposed to use the dev.groups value to add sysfs
files before device_add is called, not call sysfs_create_files() after
device_add() returns. This creates a race with uevent delivery where the
extra attribute will not be visible.

This was being done because the groups had been co-opted by the mdev
driver, now that prior patches have moved the driver's groups to the
struct device_driver the dev.group is properly free for use here.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20220411141403.86980-34-hch@lst.de
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Zhi Wang <zhi.a.wang@intel.com>
This commit is contained in:
Jason Gunthorpe 2022-04-11 16:14:02 +02:00 committed by Zhi Wang
parent 6b42f491e1
commit 2aa72ec97c
3 changed files with 13 additions and 9 deletions
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1
drivers/vfio/mdev/mdev_core.c
View File

@ -269,6 +269,7 @@ int mdev_device_create(struct mdev_type *type, const guid_t *uuid)
mdev->dev.parent = parent->dev;
mdev->dev.bus = &mdev_bus_type;
mdev->dev.release = mdev_device_release;
mdev->dev.groups = mdev_device_groups;
mdev->type = type;
/* Pairs with the put in mdev_device_release() */
kobject_get(&type->kobj);

2
drivers/vfio/mdev/mdev_private.h
View File

@ -32,6 +32,8 @@ struct mdev_type {
unsigned int type_group_id;
};
extern const struct attribute_group *mdev_device_groups[];
#define to_mdev_type_attr(_attr) \
container_of(_attr, struct mdev_type_attribute, attr)
#define to_mdev_type(_kobj) \

19
drivers/vfio/mdev/mdev_sysfs.c
View File

@ -244,11 +244,20 @@ static ssize_t remove_store(struct device *dev, struct device_attribute *attr,
static DEVICE_ATTR_WO(remove);
static const struct attribute *mdev_device_attrs[] = {
static struct attribute *mdev_device_attrs[] = {
&dev_attr_remove.attr,
NULL,
};
static const struct attribute_group mdev_device_group = {
.attrs = mdev_device_attrs,
};
const struct attribute_group *mdev_device_groups[] = {
&mdev_device_group,
NULL
};
int mdev_create_sysfs_files(struct mdev_device *mdev)
{
struct mdev_type *type = mdev->type;
@ -262,15 +271,8 @@ int mdev_create_sysfs_files(struct mdev_device *mdev)
ret = sysfs_create_link(kobj, &type->kobj, "mdev_type");
if (ret)
goto type_link_failed;
ret = sysfs_create_files(kobj, mdev_device_attrs);
if (ret)
goto create_files_failed;
return ret;
create_files_failed:
sysfs_remove_link(kobj, "mdev_type");
type_link_failed:
sysfs_remove_link(mdev->type->devices_kobj, dev_name(&mdev->dev));
return ret;
@ -280,7 +282,6 @@ void mdev_remove_sysfs_files(struct mdev_device *mdev)
{
struct kobject *kobj = &mdev->dev.kobj;
sysfs_remove_files(kobj, mdev_device_attrs);
sysfs_remove_link(kobj, "mdev_type");
sysfs_remove_link(mdev->type->devices_kobj, dev_name(&mdev->dev));
}