Mirrors_Framework/ethercat
1
0
Fork 0
mirror of https://gitlab.com/etherlab.org/ethercat.git synced 2026-09-24 02:53:57 +08:00
Code Issues Actions Packages Projects Releases Wiki Activity

Sii write wait_event() deadlock fixed: use wait_event_interruptible and refcount ec_master_sii_write_request_t objects with kref

Browse Source
This commit is contained in:
Martin Troxler
2011-01-05 11:33:31 +01:00
parent 273be9d362
commit 74762f3bca
4 changed files with 47 additions and 28 deletions
Download Patch File Download Diff File Expand all files Collapse all files
master/cdev.c
+28 -28
View File
@@ -1072,7 +1072,8 @@ int ec_cdev_ioctl_slave_sii_write(
ec_slave_t *slave;
unsigned int byte_size;
uint16_t *words;
ec_sii_write_request_t request;
ec_sii_write_request_t* request;
int retval;
if (copy_from_user(&data, (void __user *) arg, sizeof(data))) {
return -EFAULT;
@@ -1088,58 +1089,57 @@ int ec_cdev_ioctl_slave_sii_write(
return -ENOMEM;
}
request = kmalloc(sizeof(*request), GFP_KERNEL);
if (!request)
return -ENOMEM;
kref_init(&request->refcount);
// init SII write request
INIT_LIST_HEAD(&request->list);
request->words = words; // now "owned" by request, see ec_master_sii_write_request_release
request->offset = data.offset;
request->nwords = data.nwords;
if (copy_from_user(words,
(void __user *) data.words, byte_size)) {
kfree(words);
kref_put(&request->refcount,ec_master_sii_write_request_release);
return -EFAULT;
}
if (ec_mutex_lock_interruptible(&master->master_mutex))
if (ec_mutex_lock_interruptible(&master->master_mutex)) {
kref_put(&request->refcount,ec_master_sii_write_request_release);
return -EINTR;
}
if (!(slave = ec_master_find_slave(
master, 0, data.slave_position))) {
ec_mutex_unlock(&master->master_mutex);
EC_MASTER_ERR(master, "Slave %u does not exist!\n",
data.slave_position);
kfree(words);
kref_put(&request->refcount,ec_master_sii_write_request_release);
return -EINVAL;
}
// init SII write request
INIT_LIST_HEAD(&request.list);
request.slave = slave;
request.words = words;
request.offset = data.offset;
request.nwords = data.nwords;
request.state = EC_INT_REQUEST_QUEUED;
request->slave = slave;
request->state = EC_INT_REQUEST_QUEUED;
// schedule SII write request.
list_add_tail(&request.list, &master->sii_requests);
list_add_tail(&request->list, &master->sii_requests);
kref_get(&request->refcount);
ec_mutex_unlock(&master->master_mutex);
// wait for processing through FSM
if (wait_event_interruptible(master->sii_queue,
request.state != EC_INT_REQUEST_QUEUED)) {
// interrupted by signal
ec_mutex_lock(&master->master_mutex);
if (request.state == EC_INT_REQUEST_QUEUED) {
// abort request
list_del(&request.list);
ec_mutex_unlock(&master->master_mutex);
kfree(words);
return -EINTR;
}
ec_mutex_unlock(&master->master_mutex);
((request->state == EC_INT_REQUEST_SUCCESS) || (request->state == EC_INT_REQUEST_FAILURE)))) {
// interrupted by signal
kref_put(&request->refcount,ec_master_sii_write_request_release);
return -EINTR;
}
// wait until master FSM has finished processing
wait_event(master->sii_queue, request.state != EC_INT_REQUEST_BUSY);
kfree(words);
retval = request->state == EC_INT_REQUEST_SUCCESS ? 0 : -EIO;
kref_put(&request->refcount,ec_master_sii_write_request_release);
return request.state == EC_INT_REQUEST_SUCCESS ? 0 : -EIO;
return retval;
}
/*****************************************************************************/