From 3d8e00909df96c2d3eace3996748be9c0a437e5a Mon Sep 17 00:00:00 2001 From: Zhang Rui Date: Tue, 14 Jan 2014 16:46:35 +0800 Subject: [PATCH] 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: Zhang Rui Reviewed-by: Mika Westerberg Signed-off-by: Rafael J. Wysocki --- drivers/acpi/scan.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index fd39459926b1..c92532158195 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -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; } -- 2.34.1