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authorDmitry Torokhov <dmitry.torokhov@gmail.com>2007-11-05 11:43:31 -0500
committerLen Brown <len.brown@intel.com>2007-11-14 12:14:28 -0500
commitff102ea99099c36250e93a87a9794b5233801020 (patch)
tree19cf2ac073458b8337e9514589ad2c284407f50b
parentf51e83916a0a022d3d0ea39ae2f877c703032923 (diff)
ACPI: video - remove unsafe uses of list_for_each_safe()
list_for_each_safe() only protects list from list alterations performed by the same thread. One still needs to implement proper locking when list is being accessed from several threads. Signed-off-by: Dmitry Torokhov <dtor@mail.ru> Acked-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
-rw-r--r--drivers/acpi/video.c71
1 files changed, 34 insertions, 37 deletions
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index be66a7c04d3..36b64a75167 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -1462,12 +1462,14 @@ acpi_video_bus_get_one_device(struct acpi_device *device,
static void acpi_video_device_rebind(struct acpi_video_bus *video)
{
- struct list_head *node, *next;
- list_for_each_safe(node, next, &video->video_device_list) {
- struct acpi_video_device *dev =
- container_of(node, struct acpi_video_device, entry);
+ struct acpi_video_device *dev;
+
+ down(&video->sem);
+
+ list_for_each_entry(dev, &video->video_device_list, entry)
acpi_video_device_bind(video, dev);
- }
+
+ up(&video->sem);
}
/*
@@ -1592,30 +1594,33 @@ static int acpi_video_device_enumerate(struct acpi_video_bus *video)
static int acpi_video_switch_output(struct acpi_video_bus *video, int event)
{
- struct list_head *node, *next;
+ struct list_head *node;
struct acpi_video_device *dev = NULL;
struct acpi_video_device *dev_next = NULL;
struct acpi_video_device *dev_prev = NULL;
unsigned long state;
int status = 0;
+ down(&video->sem);
- list_for_each_safe(node, next, &video->video_device_list) {
+ list_for_each(node, &video->video_device_list) {
dev = container_of(node, struct acpi_video_device, entry);
status = acpi_video_device_get_state(dev, &state);
if (state & 0x2) {
- dev_next =
- container_of(node->next, struct acpi_video_device,
- entry);
- dev_prev =
- container_of(node->prev, struct acpi_video_device,
- entry);
+ dev_next = container_of(node->next,
+ struct acpi_video_device, entry);
+ dev_prev = container_of(node->prev,
+ struct acpi_video_device, entry);
goto out;
}
}
+
dev_next = container_of(node->next, struct acpi_video_device, entry);
dev_prev = container_of(node->prev, struct acpi_video_device, entry);
- out:
+
+ out:
+ up(&video->sem);
+
switch (event) {
case ACPI_VIDEO_NOTIFY_CYCLE:
case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:
@@ -1691,24 +1696,17 @@ acpi_video_bus_get_devices(struct acpi_video_bus *video,
struct acpi_device *device)
{
int status = 0;
- struct list_head *node, *next;
-
+ struct acpi_device *dev;
acpi_video_device_enumerate(video);
- list_for_each_safe(node, next, &device->children) {
- struct acpi_device *dev =
- list_entry(node, struct acpi_device, node);
-
- if (!dev)
- continue;
+ list_for_each_entry(dev, &device->children, node) {
status = acpi_video_bus_get_one_device(dev, video);
if (ACPI_FAILURE(status)) {
ACPI_EXCEPTION((AE_INFO, status, "Cant attach device"));
continue;
}
-
}
return status;
}
@@ -1724,9 +1722,6 @@ static int acpi_video_bus_put_one_device(struct acpi_video_device *device)
video = device->video;
- down(&video->sem);
- list_del(&device->entry);
- up(&video->sem);
acpi_video_device_remove_fs(device->dev);
status = acpi_remove_notify_handler(device->dev->handle,
@@ -1734,32 +1729,34 @@ static int acpi_video_bus_put_one_device(struct acpi_video_device *device)
acpi_video_device_notify);
backlight_device_unregister(device->backlight);
video_output_unregister(device->output_dev);
+
return 0;
}
static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
{
int status;
- struct list_head *node, *next;
+ struct acpi_video_device *dev, *next;
+ down(&video->sem);
- list_for_each_safe(node, next, &video->video_device_list) {
- struct acpi_video_device *data =
- list_entry(node, struct acpi_video_device, entry);
- if (!data)
- continue;
+ list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
- status = acpi_video_bus_put_one_device(data);
+ status = acpi_video_bus_put_one_device(dev);
if (ACPI_FAILURE(status))
printk(KERN_WARNING PREFIX
"hhuuhhuu bug in acpi video driver.\n");
- if (data->brightness)
- kfree(data->brightness->levels);
- kfree(data->brightness);
- kfree(data);
+ if (dev->brightness) {
+ kfree(dev->brightness->levels);
+ kfree(dev->brightness);
+ }
+ list_del(&dev->entry);
+ kfree(dev);
}
+ up(&video->sem);
+
return 0;
}