Messages in this thread Patch in this message | | | From | "JiSheng Zhang" <> | Date | Fri, 18 Jul 2008 20:31:16 +0800 | Subject | Re: PATCH] firewire: add padding to some struct |
| |
Hi, >From: Stefan Richter <stefanr@s5r6.in-berlin.de> >Reply-To: >To: JiSheng Zhang <jszhang3@mail.ustc.edu.cn> >Subject: Re: PATCH] firewire: add padding to some struct >Date:Fri, 18 Jul 2008 13:38:25 +0200 > >JiSheng Zhang wrote: > > If p is a pointer to struct fw_cdev_event_response), p->data will point to the > > padding data rather than the right place, it will cause problem under some > > platforms. For example, in the function handle_device_event of libraw1394(ported > > to juju stack): > > ..... > > case FW_CDEV_EVENT_RESPONSE: > > rc = u64_to_ptr(u->response.closure); > > if (rc->data != NULL) > > memcpy(rc->data, u->response.data, rc->length);//here it will lost the last four > > bytes > > errcode = juju_to_raw1394_errcode(u->response.rcode); > > ..... > > > > Although this problem can be solved by add the offset to the pointer, but the > > member:__u32 data[0] lost its original meaning. > > I don't understand what the problem is. As long as both kernel and > library use "response.data" or "&response + offsetof(typeof(response), > data)", they will write and read at the correct location. > This patch can fix the problem while not changing the struct definition.
Thanks in advance, JiSheng
--- old/drivers/firewire/fw-cdev.c 2008-07-14 05:51:29.000000000 +0800 +++ new/drivers/firewire/fw-cdev.c 2008-07-18 20:20:45.841328585 +0800 @@ -382,9 +382,9 @@ response->response.type = FW_CDEV_EVENT_RESPONSE; response->response.rcode = rcode; - queue_event(client, &response->event, - &response->response, sizeof(response->response), - response->response.data, response->response.length); + queue_event(client, &response->event, &response->response, + sizeof(response->response) + response->response.length, + NULL, 0); } static int ioctl_send_request(struct client *client, void *buffer)
| |