Commit 292888c8 authored by Heiko Carstens's avatar Heiko Carstens Committed by Martin Schwidefsky
Browse files

[S390] cio: kernel stack overflow. 



Use different kind of assignment to make sure gcc doesn't create code
that creates temp variables on the stack, assigns values to it and
copies the content of the whole temp variable to the destination.
This reduces stack usage of e.g. ccwgroup_driver_register from 976
to 48 bytes instead.

Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 8f61701b

drivers/s390/cio/ccwgroup.c

+5 −9
Original line number Diff line number Diff line
@@ -183,11 +183,9 @@ ccwgroup_create(struct device *root, 


	gdev->creator_id = creator_id;

	gdev->count = argc;

	gdev->dev = (struct device ) {

		.bus = &ccwgroup_bus_type,

		.parent = root,

		.release = ccwgroup_release,

	};

	gdev->dev.bus = &ccwgroup_bus_type;

	gdev->dev.parent = root;

	gdev->dev.release = ccwgroup_release;



	snprintf (gdev->dev.bus_id, BUS_ID_SIZE, "%s",

			gdev->cdev[0]->dev.bus_id);
@@ -391,10 +389,8 @@ int 
ccwgroup_driver_register (struct ccwgroup_driver *cdriver)

{

	/* register our new driver with the core */

	cdriver->driver = (struct device_driver) {

		.bus = &ccwgroup_bus_type,

		.name = cdriver->name,

	};

	cdriver->driver.bus = &ccwgroup_bus_type;

	cdriver->driver.name = cdriver->name;



	return driver_register(&cdriver->driver);

}

drivers/s390/cio/chsc.c

+2 −4
Original line number Diff line number Diff line
@@ -1391,10 +1391,8 @@ new_channel_path(int chpid) 
	/* fill in status, etc. */

	chp->id = chpid;

	chp->state = 1;

	chp->dev = (struct device) {

		.parent  = &css[0]->device,

		.release = chp_release,

	};

	chp->dev.parent = &css[0]->device;

	chp->dev.release = chp_release;

	snprintf(chp->dev.bus_id, BUS_ID_SIZE, "chp0.%x", chpid);



	/* Obtain channel path description and fill it in. */

drivers/s390/cio/device.c

+7 −12
Original line number Diff line number Diff line
@@ -556,12 +556,11 @@ get_disc_ccwdev_by_devno(unsigned int devno, unsigned int ssid, 
			 struct ccw_device *sibling)

{

	struct device *dev;

	struct match_data data = {

		.devno   = devno,

		.ssid    = ssid,

		.sibling = sibling,

	};

	struct match_data data;



	data.devno = devno;

	data.ssid = ssid;

	data.sibling = sibling;

	dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);



	return dev ? to_ccwdev(dev) : NULL;
@@ -835,10 +834,8 @@ io_subchannel_probe (struct subchannel *sch) 
		return -ENOMEM;

	}

	atomic_set(&cdev->private->onoff, 0);

	cdev->dev = (struct device) {

		.parent = &sch->dev,

		.release = ccw_device_release,

	};

	cdev->dev.parent = &sch->dev;

	cdev->dev.release = ccw_device_release;

	INIT_LIST_HEAD(&cdev->private->kick_work.entry);

	/* Do first half of device_register. */

	device_initialize(&cdev->dev);
@@ -977,9 +974,7 @@ ccw_device_console_enable (struct ccw_device *cdev, struct subchannel *sch) 
	int rc;



	/* Initialize the ccw_device structure. */

	cdev->dev = (struct device) {

		.parent = &sch->dev,

	};

	cdev->dev.parent= &sch->dev;

	rc = io_subchannel_recog(cdev, sch);

	if (rc)

		return rc;

drivers/s390/cio/device_fsm.c

+8 −12
Original line number Diff line number Diff line
@@ -267,12 +267,10 @@ ccw_device_recog_done(struct ccw_device *cdev, int state) 
			notify = 1;

		}

		/* fill out sense information */

		cdev->id = (struct ccw_device_id) {

			.cu_type   = cdev->private->senseid.cu_type,

			.cu_model  = cdev->private->senseid.cu_model,

			.dev_type  = cdev->private->senseid.dev_type,

			.dev_model = cdev->private->senseid.dev_model,

		};

		cdev->id.cu_type   = cdev->private->senseid.cu_type;

		cdev->id.cu_model  = cdev->private->senseid.cu_model;

		cdev->id.dev_type  = cdev->private->senseid.dev_type;

		cdev->id.dev_model = cdev->private->senseid.dev_model;

		if (notify) {

			cdev->private->state = DEV_STATE_OFFLINE;

			if (same_dev) {
@@ -566,12 +564,10 @@ ccw_device_verify_done(struct ccw_device *cdev, int err) 
		/* Deliver fake irb to device driver, if needed. */

		if (cdev->private->flags.fake_irb) {

			memset(&cdev->private->irb, 0, sizeof(struct irb));

			cdev->private->irb.scsw = (struct scsw) {

				.cc = 1,

				.fctl = SCSW_FCTL_START_FUNC,

				.actl = SCSW_ACTL_START_PEND,

				.stctl = SCSW_STCTL_STATUS_PEND,

			};

			cdev->private->irb.scsw.cc = 1;

			cdev->private->irb.scsw.fctl = SCSW_FCTL_START_FUNC;

			cdev->private->irb.scsw.actl = SCSW_ACTL_START_PEND;

			cdev->private->irb.scsw.stctl = SCSW_STCTL_STATUS_PEND;

			cdev->private->flags.fake_irb = 0;

			if (cdev->handler)

				cdev->handler(cdev, cdev->private->intparm,

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