Commit 3d8e0090 authored by Zhang Rui's avatar Zhang Rui Committed by Rafael J. Wysocki
Browse files

ACPI: fix create_modalias() return value handling 



Currently, create_modalias() handles the output truncated case in
an improper way (return -EINVAL).
Plus, acpi_device_uevent() and acpi_device_modalias_show() do
improper check for the create_modalias() return value as well.

This patch fixes create_modalias() to
return -EINVAL if there is an output error,
return -ENOMEM if the output is truncated,
and also fixes both acpi_device_uevent() and acpi_device_modalias_show()
to do proper return value check.

Signed-off-by: default avatarZhang Rui <rui.zhang@intel.com>
Reviewed-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 7e22e911

drivers/acpi/scan.c

+10 −6
Original line number Diff line number Diff line
@@ -85,6 +85,9 @@ int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler, 
 * Creates hid/cid(s) string needed for modalias and uevent

 * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:

 * char *modalias: "acpi:IBM0001:ACPI0001"

 * Return: 0: no _HID and no _CID

 *         -EINVAL: output error

 *         -ENOMEM: output is truncated

*/

static int create_modalias(struct acpi_device *acpi_dev, char *modalias,

			   int size)
@@ -101,8 +104,10 @@ static int create_modalias(struct acpi_device *acpi_dev, char *modalias, 


	list_for_each_entry(id, &acpi_dev->pnp.ids, list) {

		count = snprintf(&modalias[len], size, "%s:", id->id);

		if (count < 0 || count >= size)

			return -EINVAL;

		if (count < 0)

			return EINVAL;

		if (count >= size)

			return -ENOMEM;

		len += count;

		size -= count;

	}
@@ -116,10 +121,9 @@ acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, cha 
	struct acpi_device *acpi_dev = to_acpi_device(dev);

	int len;



	/* Device has no HID and no CID or string is >1024 */

	len = create_modalias(acpi_dev, buf, 1024);

	if (len <= 0)

		return 0;

		return len;

	buf[len++] = '\n';

	return len;

}
@@ -782,8 +786,8 @@ static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env) 
		return -ENOMEM;

	len = create_modalias(acpi_dev, &env->buf[env->buflen - 1],

			      sizeof(env->buf) - env->buflen);

	if (len >= (sizeof(env->buf) - env->buflen))

		return -ENOMEM;

	if (len <= 0)

		return len;

	env->buflen += len;

	return 0;

}

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