firewire:queue the right number of data
PATCH 1/1 firewire:queue the right number of data
Hi,
There will be 4 padding bytes in struct fw_cdev_event_response on some platforms The member:__u32 data will point to these padding bytes. While queue the response and data in complete_transaction in fw-cdev.c, it will queue like this:
|response(excluding padding bytes)|4 padding bytes|4 padding bytes|data. It queue 4 extra bytes. That is to say it use "&response + sizeof(response)" while other place of kernel and userspace library use "&response + offsetof (typeof(response), data)". So it will lost the last 4 bytes of data.This patch can fix it while not changing the struct definition.
Sorry for open a new ticket.
drivers/firewire/fw-cdev.c +3 -3
@@ -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)
JiSheng Zhang wrote at LKML:
Quoted 18 lines
Hi,
There will be 4 padding bytes in struct
fw_cdev_event_responseon some platforms
The member:__u32 data will point to these padding bytes. While queue the
response and data incomplete_transactioninfw-cdev.c, it will queue like this:
|response(excluding padding bytes)|4 padding bytes|4 padding bytes|data. It queue 4 extra bytes. That is to say it use "&response + sizeof(response)" while other place of kernel and userspace library use "&response + offsetof
(typeof(response), data)". So it will lost the last 4 bytes of data.This patch can fix it while not changing the struct definition.Sorry for open a new ticket.
Signed-off-by JiSheng Zhang <[email protected]>drivers/firewire/fw-cdev.c +0
-0@@ -382,9 +382,9 @@ response->response.type =FW_CDEV_EVENT_RESPONSE ;
drivers/firewire/fw-cdev.c line 390
Quoted 10 lines
drivers/firewire/fw-cdev.c +3
-3response->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)
I tested it now on i686, x86-64, and x86-64 with i686 userland, using firecontrol and gscanbus. As discussed, they got corrupted block read responses on x86-64 and on x86-64 with i686 userland. The patch fixes this.
I committed it to linux1394-2.6.git#fixes and intend to send it upstream at the end of the week or so. Thanks for spotting this bug.
One point about which I am not sure about yet is what happens if there are multiple events queued up before the client can read() them. The tests which I did so far involved only a single event queued and dequeued at a time.
PS:
I removed a rule from linux1394-devel's header filters which matched your previous posts. (Message has priority, but no X-Mailer/User-Agent)
Signature · 3 lines
Stefan Richter -=====-==--- -=== =-=-- http://arcgraph.de/sr/
A message that is not in the archive (sent off-list or not yet received): [email protected]
on Sun, 20 Jul 2008 16:00:32 +0200
Quoted 30 lines · Stefan Richter
JiSheng Zhang wrote at LKML:
Quoted 29 lines
Hi,
There will be 4 padding bytes in struct
fw_cdev_event_responseon some platforms The member:__u32 data will point to these padding bytes. While queue the response and data incomplete_transactioninfw-cdev.c, it will queue like this:
|response(excluding padding bytes)|4 padding bytes|4 padding bytes|data. It queue 4 extra bytes. That is to say it use "&response + sizeof(response)" while other place of kernel and userspace library use "&response + offsetof (typeof(response), data)". So it will lost the last 4 bytes of data.This patch can fix it while not changing the struct definition.Sorry for open a new ticket.
Signed-off-by JiSheng Zhang <[email protected]>drivers/firewire/fw-cdev.c +3
-3@@ -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 ); }
Quoted 8 lines
drivers/firewire/fw-cdev.c line 390
Quoted 1 line
drivers/firewire/fw-cdev.c +0
-0static int ioctl_send_request (struct client *client,void *buffer)I tested it now on i686, x86-64, and x86-64 with i686 userland, using firecontrol and gscanbus. As discussed, they got corrupted block read responses on x86-64 and on x86-64 with i686 userland. The patch fixes this.
I committed it to linux1394-2.6.git#fixes and intend to send it upstream at the end of the week or so. Thanks for spotting this bug.
Thanks for committing.
Quoted 5 lines
One point about which I am not sure about yet is what happens if there are multiple events queued up before the client can
read()them. The tests which I did so far involved only a single event queued and dequeued at a time.
IMHO, even there are multiple events queued, it should work OK because events are put into event_list rather than a ring buffer, there is no padding bytes problem between events.
Quoted 5 lines
PS:
I removed a rule from linux1394-devel's header filters which matched your previous posts. (Message has priority, but no X-Mailer/User-Agent)
Thanks very much
Regards,
JiSheng