Messages in this thread | | | Subject | Re: [PATCH v5 04/13] s390: vfio-ap: base implementation of VFIO AP device driver | From | Pierre Morel <> | Date | Wed, 13 Jun 2018 12:54:40 +0200 |
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On 13/06/2018 09:48, Cornelia Huck wrote: > On Wed, 13 Jun 2018 09:41:16 +0200 > Pierre Morel <pmorel@linux.ibm.com> wrote: > >> On 07/05/2018 17:11, Tony Krowiak wrote: >>> Introduces a new AP device driver. This device driver >>> is built on the VFIO mediated device framework. The framework >>> provides sysfs interfaces that facilitate passthrough >>> access by guests to devices installed on the linux host. >> ...snip... >> >>> +static int vfio_ap_matrix_dev_create(void) >>> +{ >>> + int ret; >>> + >>> + vfio_ap_root_device = root_device_register(VFIO_AP_ROOT_NAME); >>> + >>> + if (IS_ERR(vfio_ap_root_device)) { >>> + ret = PTR_ERR(vfio_ap_root_device); >>> + goto done; >>> + } >>> + >>> + ap_matrix = kzalloc(sizeof(*ap_matrix), GFP_KERNEL); >>> + if (!ap_matrix) { >>> + ret = -ENOMEM; >>> + goto matrix_alloc_err; >>> + } >>> + >>> + ap_matrix->device.type = &vfio_ap_dev_type; >>> + dev_set_name(&ap_matrix->device, "%s", VFIO_AP_DEV_NAME); >>> + ap_matrix->device.parent = vfio_ap_root_device; >>> + ap_matrix->device.release = vfio_ap_matrix_dev_release; >>> + ap_matrix->device.driver = &vfio_ap_drv.driver; >>> + >>> + ret = device_register(&ap_matrix->device); >>> + if (ret) >>> + goto matrix_reg_err; >>> + >>> + goto done; >>> + >>> +matrix_reg_err: >>> + put_device(&ap_matrix->device); >> Did not see this before but here you certainly want to >> do a kfree and not a put_device. > No, this must not be a kfree. Once you've tried to register something > embedding a struct device with the driver core, you need to use > put_device, as another path may have acquired a reference, even if > registering ultimately failed. See the comment for device_register(). > IOW, the code is correct.
learned something again :) , but still, a kfree is needed for the kzalloc. Does'nt it?
> >> >> >>> + >>> +matrix_alloc_err: >>> + root_device_unregister(vfio_ap_root_device); >>> + >>> +done: >>> + return ret; >>> +} >>> + >>> +static void vfio_ap_matrix_dev_destroy(struct ap_matrix *ap_matrix) >>> +{ >>> + device_unregister(&ap_matrix->device); >>> + root_device_unregister(vfio_ap_root_device); >> Also here you need a kfree(ap_matrix) too . > Same here. >
-- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany
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