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Commit 33ab3490 authored by Dennis Dalessandro's avatar Dennis Dalessandro Committed by Greg Kroah-Hartman
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staging/rdma/hfi1: Reduce snoop locking scope in IOCTL handler. 



This patch avoids issues while calling into copy from/to user while holding the
lock by only taking the lock when it is absolutely required.

The only commands which require the snoop lock are: *Set Filter *Clear Filter
*Clear Queue

Reviewed-by: default avatarMike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: default avatarDennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: default avatarIra Weiny <ira.weiny@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f1811cf6

drivers/staging/rdma/hfi1/diag.c

+6 −4
Original line number Diff line number Diff line
@@ -1012,8 +1012,6 @@ static long hfi1_ioctl(struct file *fp, unsigned int cmd, unsigned long arg) 
		 */

		return -EINVAL;



	spin_lock_irqsave(&dd->hfi1_snoop.snoop_lock, flags);



	switch (cmd) {

	case HFI1_SNOOP_IOCSETLINKSTATE_EXTRA:

		memset(&link_info, 0, sizeof(link_info));
@@ -1130,11 +1128,14 @@ static long hfi1_ioctl(struct file *fp, unsigned int cmd, unsigned long arg) 


	case HFI1_SNOOP_IOCCLEARQUEUE:

		snoop_dbg("Clearing snoop queue");

		spin_lock_irqsave(&dd->hfi1_snoop.snoop_lock, flags);

		drain_snoop_list(&dd->hfi1_snoop.queue);

		spin_unlock_irqrestore(&dd->hfi1_snoop.snoop_lock, flags);

		break;



	case HFI1_SNOOP_IOCCLEARFILTER:

		snoop_dbg("Clearing filter");

		spin_lock_irqsave(&dd->hfi1_snoop.snoop_lock, flags);

		if (dd->hfi1_snoop.filter_callback) {

			/* Drain packets first */

			drain_snoop_list(&dd->hfi1_snoop.queue);
@@ -1142,6 +1143,7 @@ static long hfi1_ioctl(struct file *fp, unsigned int cmd, unsigned long arg) 
		}

		kfree(dd->hfi1_snoop.filter_value);

		dd->hfi1_snoop.filter_value = NULL;

		spin_unlock_irqrestore(&dd->hfi1_snoop.snoop_lock, flags);

		break;



	case HFI1_SNOOP_IOCSETFILTER:
@@ -1178,13 +1180,14 @@ static long hfi1_ioctl(struct file *fp, unsigned int cmd, unsigned long arg) 
			break;

		}

		/* Drain packets first */

		spin_lock_irqsave(&dd->hfi1_snoop.snoop_lock, flags);

		drain_snoop_list(&dd->hfi1_snoop.queue);

		dd->hfi1_snoop.filter_callback =

			hfi1_filters[filter_cmd.opcode].filter;

		/* just in case we see back to back sets */

		kfree(dd->hfi1_snoop.filter_value);

		dd->hfi1_snoop.filter_value = filter_value;



		spin_unlock_irqrestore(&dd->hfi1_snoop.snoop_lock, flags);

		break;

	case HFI1_SNOOP_IOCGETVERSION:

		value = SNOOP_CAPTURE_VERSION;
@@ -1208,7 +1211,6 @@ static long hfi1_ioctl(struct file *fp, unsigned int cmd, unsigned long arg) 
		break;

	}

done:

	spin_unlock_irqrestore(&dd->hfi1_snoop.snoop_lock, flags);

	return ret;

}