diff options
author | Logan Gunthorpe <logang@deltatee.com> | 2017-03-17 12:48:22 -0600 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-03-21 06:44:33 +0100 |
commit | ac1ddc584e9817d9d0a4572f3245305d907c6e61 (patch) | |
tree | 73b664e8d4a109d05db0fd947c3f9ac5811d209f /drivers/scsi | |
parent | d5ed9177f64fe95d9de79e6504d41612d9127e8a (diff) | |
download | linux-ac1ddc584e9817d9d0a4572f3245305d907c6e61.tar.bz2 |
scsi: utilize new cdev_device_add helper function
This driver did not set kobj.parent so it likely suffered from
a potential use after free race if the user unregistered the
device while it was in use.
This was not so straightforward a conversion but I think this patch
cleans up its probe's error path significantly.
This patch adds device_initialize, which is required for
cdev_device_add. Then it switches to put_device instead of kfree as
recommended by device_initialize's documentation. This removes a lot
from the error path which was already in __remove.
A couple things needed to be re-ordered to be entirely correct, though.
ida_remove is also moved out of __remove and into unregister to
simplify things and follow the pattern other devices are using.
This also drop an extra unnecessary get_device/put_device in the code.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/scsi')
-rw-r--r-- | drivers/scsi/osd/osd_uld.c | 56 |
1 files changed, 20 insertions, 36 deletions
diff --git a/drivers/scsi/osd/osd_uld.c b/drivers/scsi/osd/osd_uld.c index e0ce5d2fd14d..4101c3178411 100644 --- a/drivers/scsi/osd/osd_uld.c +++ b/drivers/scsi/osd/osd_uld.c @@ -400,9 +400,6 @@ static void __remove(struct device *dev) kfree(oud->odi.osdname); - if (oud->cdev.owner) - cdev_del(&oud->cdev); - osd_dev_fini(&oud->od); scsi_device_put(scsi_device); @@ -411,7 +408,6 @@ static void __remove(struct device *dev) if (oud->disk) put_disk(oud->disk); - ida_remove(&osd_minor_ida, oud->minor); kfree(oud); } @@ -446,8 +442,20 @@ static int osd_probe(struct device *dev) if (NULL == oud) goto err_retract_minor; + /* class device member */ + device_initialize(&oud->class_dev); dev_set_drvdata(dev, oud); oud->minor = minor; + oud->class_dev.devt = MKDEV(SCSI_OSD_MAJOR, oud->minor); + oud->class_dev.class = &osd_uld_class; + oud->class_dev.parent = dev; + oud->class_dev.release = __remove; + + /* hold one more reference to the scsi_device that will get released + * in __release, in case a logout is happening while fs is mounted + */ + scsi_device_get(scsi_device); + osd_dev_init(&oud->od, scsi_device); /* allocate a disk and set it up */ /* FIXME: do we need this since sg has already done that */ @@ -461,59 +469,34 @@ static int osd_probe(struct device *dev) sprintf(disk->disk_name, "osd%d", oud->minor); oud->disk = disk; - /* hold one more reference to the scsi_device that will get released - * in __release, in case a logout is happening while fs is mounted - */ - scsi_device_get(scsi_device); - osd_dev_init(&oud->od, scsi_device); - /* Detect the OSD Version */ error = __detect_osd(oud); if (error) { OSD_ERR("osd detection failed, non-compatible OSD device\n"); - goto err_put_disk; + goto err_free_osd; } /* init the char-device for communication with user-mode */ cdev_init(&oud->cdev, &osd_fops); oud->cdev.owner = THIS_MODULE; - error = cdev_add(&oud->cdev, - MKDEV(SCSI_OSD_MAJOR, oud->minor), 1); - if (error) { - OSD_ERR("cdev_add failed\n"); - goto err_put_disk; - } - /* class device member */ - oud->class_dev.devt = oud->cdev.dev; - oud->class_dev.class = &osd_uld_class; - oud->class_dev.parent = dev; - oud->class_dev.release = __remove; error = dev_set_name(&oud->class_dev, "%s", disk->disk_name); if (error) { OSD_ERR("dev_set_name failed => %d\n", error); - goto err_put_cdev; + goto err_free_osd; } - error = device_register(&oud->class_dev); + error = cdev_device_add(&oud->cdev, &oud->class_dev); if (error) { OSD_ERR("device_register failed => %d\n", error); - goto err_put_cdev; + goto err_free_osd; } - get_device(&oud->class_dev); - OSD_INFO("osd_probe %s\n", disk->disk_name); return 0; -err_put_cdev: - cdev_del(&oud->cdev); -err_put_disk: - scsi_device_put(scsi_device); - put_disk(disk); err_free_osd: - dev_set_drvdata(dev, NULL); - kfree(oud); + put_device(&oud->class_dev); err_retract_minor: ida_remove(&osd_minor_ida, minor); return error; @@ -530,9 +513,10 @@ static int osd_remove(struct device *dev) scsi_device); } - device_unregister(&oud->class_dev); - + cdev_device_del(&oud->cdev, &oud->class_dev); + ida_remove(&osd_minor_ida, oud->minor); put_device(&oud->class_dev); + return 0; } |