Hi Julia,
sorry for the long delay until I finally responded.
Thanks a lot for your report and patch.
I'll queue this and send it for v3.6rcX hopefully soon.
On 07/08/2012 01:37 PM, Julia Lawall wrote:
> From: Julia Lawall <[email protected]>
>
> If list_for_each_entry, etc complete a traversal of the list, the iterator
> variable ends up pointing to an address at an offset from the list head,
> and not a meaningful structure. Thus this value should not be used after
> the end of the iterator. Replace port->adapter->scsi_host by
> adapter->scsi_host.
>
> This problem was found using Coccinelle (http://coccinelle.lip6.fr/).
>
> Signed-off-by: Julia Lawall <[email protected]>
>
> ---
> This is not tested, an I am not sure that this is the right change.
> Indeed, I'm not at all sure how the original code could have worked, since
> port->adapter->scsi_host should be a completely random value.
This is most probably a copy & paste oversight in
commit a1ca48319a9aa1c5b57ce142f538e76050bb8972
"[SCSI] zfcp: Move ACL/CFDC code to zfcp_cfdc.c"
v2.6.37
where the content of
static void zfcp_erp_port_access_changed(struct zfcp_port *port, char *id,
void *ref)
{
struct scsi_device *sdev;
int status = atomic_read(&port->status);
if (!(status & (ZFCP_STATUS_COMMON_ACCESS_DENIED |
ZFCP_STATUS_COMMON_ACCESS_BOXED))) {
shost_for_each_device(sdev, port->adapter->scsi_host)
^^^^
was merged into
zfcp_cfdc_adapter_access_changed(struct zfcp_adapter *adapter)
Since this code is for older hardware and users not using NPIV
and this is only executed on dynamic access changes,
nobody has noticed this so far I guess.
> drivers/s390/scsi/zfcp_cfdc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/s390/scsi/zfcp_cfdc.c b/drivers/s390/scsi/zfcp_cfdc.c
> index fab2c25..8ed63aa 100644
> --- a/drivers/s390/scsi/zfcp_cfdc.c
> +++ b/drivers/s390/scsi/zfcp_cfdc.c
> @@ -293,7 +293,7 @@ void zfcp_cfdc_adapter_access_changed(struct zfcp_adapter *adapter)
> }
> read_unlock_irqrestore(&adapter->port_list_lock, flags);
>
> - shost_for_each_device(sdev, port->adapter->scsi_host) {
> + shost_for_each_device(sdev, adapter->scsi_host) {
> zfcp_sdev = sdev_to_zfcp(sdev);
> status = atomic_read(&zfcp_sdev->status);
> if ((status & ZFCP_STATUS_COMMON_ACCESS_DENIED) ||
>
Steffen
Linux on System z Development
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