From ff102ea99099c36250e93a87a9794b5233801020 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Mon, 5 Nov 2007 11:43:31 -0500 Subject: 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 Acked-by: Zhang Rui Signed-off-by: Len Brown --- drivers/acpi/video.c | 71 +++++++++++++++++++++++++--------------------------- 1 file changed, 34 insertions(+), 37 deletions(-) (limited to 'drivers/acpi') 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; } -- cgit v1.2.3