Commit 069b188f authored by Chris Metcalf's avatar Chris Metcalf Committed by Greg Kroah-Hartman
Browse files

tile-srom: avoid krealloc(... __GFP_ZERO) pattern 

Joe Perches points out [1] that this pattern isn't currently safe.
This driver doesn't really need the zeroing semantic anyway;
by restructuring the code slightly we can initialize all the
fields of the structure up front instead.

[1] https://lkml.kernel.org/r/1469729491.3998.58.camel@perches.com



Signed-off-by: default avatarChris Metcalf <cmetcalf@mellanox.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent acde785e

drivers/char/tile-srom.c

+15 −13
Original line number Diff line number Diff line
@@ -331,13 +331,11 @@ static const struct file_operations srom_fops = { 
/**

 * srom_setup_minor() - Initialize per-minor information.

 * @srom: Per-device SROM state.

 * @index: Device to set up.

 * @devhdl: Partition device handle.

 */

static int srom_setup_minor(struct srom_dev *srom, int index)

static int srom_setup_minor(struct srom_dev *srom, int devhdl)

{

	struct device *dev;

	int devhdl = srom->hv_devhdl;



	srom->hv_devhdl = devhdl;

	mutex_init(&srom->lock);



	if (_srom_read(devhdl, &srom->total_size,
@@ -350,9 +348,7 @@ static int srom_setup_minor(struct srom_dev *srom, int index) 
		       SROM_PAGE_SIZE_OFF, sizeof(srom->page_size)) < 0)

		return -EIO;



	dev = device_create(srom_class, &srom_parent->dev,

			    MKDEV(srom_major, index), srom, "%d", index);

	return PTR_ERR_OR_ZERO(dev);

	return 0;

}



/** srom_init() - Initialize the driver's module. */
@@ -365,7 +361,7 @@ static int srom_init(void) 
	 * Start with a plausible number of partitions; the krealloc() call

	 * below will yield about log(srom_devs) additional allocations.

	 */

	srom_devices = kzalloc(4 * sizeof(struct srom_dev), GFP_KERNEL);

	srom_devices = kmalloc(4 * sizeof(struct srom_dev), GFP_KERNEL);



	/* Discover the number of srom partitions. */

	for (i = 0; ; i++) {
@@ -373,7 +369,7 @@ static int srom_init(void) 
		char buf[20];

		struct srom_dev *new_srom_devices =

			krealloc(srom_devices, (i+1) * sizeof(struct srom_dev),

				 GFP_KERNEL | __GFP_ZERO);

				 GFP_KERNEL);

		if (!new_srom_devices) {

			result = -ENOMEM;

			goto fail_mem;
@@ -387,7 +383,9 @@ static int srom_init(void) 
					  i, devhdl);

			break;

		}

		srom_devices[i].hv_devhdl = devhdl;

		result = srom_setup_minor(&srom_devices[i], devhdl);

		if (result != 0)

			goto fail_mem;

	}

	srom_devs = i;
@@ -431,9 +429,13 @@ static int srom_init(void) 
	srom_class->dev_groups = srom_dev_groups;

	srom_class->devnode = srom_devnode;



	/* Do per-partition initialization */

	/* Create per-partition devices */

	for (i = 0; i < srom_devs; i++) {

		result = srom_setup_minor(srom_devices + i, i);

		struct device *dev =

			device_create(srom_class, &srom_parent->dev,

				      MKDEV(srom_major, i), srom_devices + i,

				      "%d", i);

		result = PTR_ERR_OR_ZERO(dev);

		if (result < 0)

			goto fail_class;

	}

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