From: Brandon Philips Date: Wed, 2 Apr 2008 21:10:59 +0000 (-0300) Subject: V4L/DVB (7492): vivi: Simplify the vivi driver and avoid deadlocks X-Git-Tag: v2.6.26-rc1~1084^2~212 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=78718e5d44cd450431d5b16ee36d3a7de1db6dfa;p=linux-2.6 V4L/DVB (7492): vivi: Simplify the vivi driver and avoid deadlocks vivi previously had a very complex queuing system and held spinlocks while doing copy_to_user, kmalloc, etc. This caused the driver to easily deadlock when a multi-threaded application used it and revealed bugs in videobuf too. This replaces the copy_to_user with memcpy since we were never copying to user space addresses. And makes the kmalloc atomic. Signed-off-by: Brandon Philips Signed-off-by: Mauro Carvalho Chehab --- diff --git a/drivers/media/video/vivi.c b/drivers/media/video/vivi.c index 02a232768e..8353deb8a1 100644 --- a/drivers/media/video/vivi.c +++ b/drivers/media/video/vivi.c @@ -146,8 +146,6 @@ struct vivi_buffer { struct vivi_dmaqueue { struct list_head active; - struct list_head queued; - struct timer_list timeout; /* thread for generating video stream*/ struct task_struct *kthread; @@ -162,7 +160,6 @@ static LIST_HEAD(vivi_devlist); struct vivi_dev { struct list_head vivi_devlist; - struct mutex lock; spinlock_t slock; struct mutex mutex; @@ -323,24 +320,26 @@ static void gen_line(char *basep, int inipos, int wmax, end: return; } + static void vivi_fillbuff(struct vivi_dev *dev, struct vivi_buffer *buf) { int h , pos = 0; int hmax = buf->vb.height; int wmax = buf->vb.width; struct timeval ts; - char *tmpbuf = kmalloc(wmax * 2, GFP_KERNEL); + char *tmpbuf = kmalloc(wmax * 2, GFP_ATOMIC); void *vbuf = videobuf_to_vmalloc(&buf->vb); if (!tmpbuf) return; + if (!vbuf) + return; + for (h = 0; h < hmax; h++) { gen_line(tmpbuf, 0, wmax, hmax, h, dev->mv_count, dev->timestr); - /* FIXME: replacing to __copy_to_user */ - if (copy_to_user(vbuf + pos, tmpbuf, wmax * 2) != 0) - dprintk(dev, 2, "vivifill copy_to_user failed.\n"); + memcpy(vbuf + pos, tmpbuf, wmax * 2); pos += wmax*2; } @@ -373,67 +372,58 @@ static void vivi_fillbuff(struct vivi_dev *dev, struct vivi_buffer *buf) dev->timestr, (unsigned long)tmpbuf, pos); /* Advice that buffer was filled */ - buf->vb.state = VIDEOBUF_DONE; buf->vb.field_count++; do_gettimeofday(&ts); buf->vb.ts = ts; - - list_del(&buf->vb.queue); - wake_up(&buf->vb.done); + buf->vb.state = VIDEOBUF_DONE; } -static int restart_video_queue(struct vivi_dmaqueue *dma_q); - -static void vivi_thread_tick(struct vivi_dmaqueue *dma_q) +static void vivi_thread_tick(struct vivi_fh *fh) { - struct vivi_buffer *buf; - struct vivi_dev *dev = container_of(dma_q, struct vivi_dev, vidq); + struct vivi_buffer *buf; + struct vivi_dev *dev = fh->dev; + struct vivi_dmaqueue *dma_q = &dev->vidq; - int bc; + unsigned long flags = 0; - spin_lock(&dev->slock); - /* Announces videobuf that all went ok */ - for (bc = 0;; bc++) { - if (list_empty(&dma_q->active)) { - dprintk(dev, 1, "No active queue to serve\n"); - break; - } + dprintk(dev, 1, "Thread tick\n"); - buf = list_entry(dma_q->active.next, - struct vivi_buffer, vb.queue); + spin_lock_irqsave(&dev->slock, flags); + if (list_empty(&dma_q->active)) { + dprintk(dev, 1, "No active queue to serve\n"); + goto unlock; + } - /* Nobody is waiting something to be done, just return */ - if (!waitqueue_active(&buf->vb.done)) { - mod_timer(&dma_q->timeout, jiffies+BUFFER_TIMEOUT); - spin_unlock(&dev->slock); - return; - } + buf = list_entry(dma_q->active.next, + struct vivi_buffer, vb.queue); - do_gettimeofday(&buf->vb.ts); - dprintk(dev, 2, "[%p/%d] wakeup\n", buf, buf->vb. i); + /* Nobody is waiting on this buffer, return */ + if (!waitqueue_active(&buf->vb.done)) + goto unlock; - /* Fill buffer */ - vivi_fillbuff(dev, buf); + list_del(&buf->vb.queue); - if (list_empty(&dma_q->active)) { - del_timer(&dma_q->timeout); - } else { - mod_timer(&dma_q->timeout, jiffies + BUFFER_TIMEOUT); - } - } - if (bc != 1) - dprintk(dev, 1, "%s: %d buffers handled (should be 1)\n", - __FUNCTION__, bc); - spin_unlock(&dev->slock); + do_gettimeofday(&buf->vb.ts); + + /* Fill buffer */ + vivi_fillbuff(dev, buf); + dprintk(dev, 1, "filled buffer %p\n", buf); + + wake_up(&buf->vb.done); + dprintk(dev, 2, "[%p/%d] wakeup\n", buf, buf->vb. i); +unlock: + spin_unlock_irqrestore(&dev->slock, flags); + return; } #define frames_to_ms(frames) \ ((frames * WAKE_NUMERATOR * 1000) / WAKE_DENOMINATOR) -static void vivi_sleep(struct vivi_dmaqueue *dma_q) +static void vivi_sleep(struct vivi_fh *fh) { - struct vivi_dev *dev = container_of(dma_q, struct vivi_dev, vidq); - int timeout, running_time; + struct vivi_dev *dev = fh->dev; + struct vivi_dmaqueue *dma_q = &dev->vidq; + int timeout; DECLARE_WAITQUEUE(wait, current); dprintk(dev, 1, "%s dma_q=0x%08lx\n", __FUNCTION__, @@ -443,37 +433,10 @@ static void vivi_sleep(struct vivi_dmaqueue *dma_q) if (kthread_should_stop()) goto stop_task; - running_time = jiffies - dma_q->ini_jiffies; - dma_q->frame++; - /* Calculate time to wake up */ - timeout = msecs_to_jiffies(frames_to_ms(dma_q->frame)) - running_time; + timeout = msecs_to_jiffies(frames_to_ms(1)); - if (timeout > msecs_to_jiffies(frames_to_ms(2)) || timeout <= 0) { - int old = dma_q->frame; - int nframes; - - dma_q->frame = (jiffies_to_msecs(running_time) / - frames_to_ms(1)) + 1; - - timeout = msecs_to_jiffies(frames_to_ms(dma_q->frame)) - - running_time; - - if (unlikely (timeout <= 0)) - timeout = 1; - - nframes = (dma_q->frame > old)? - dma_q->frame - old : old - dma_q->frame; - - dprintk(dev, 1, "%ld: %s %d frames. " - "Current frame is %d. Will sleep for %d jiffies\n", - jiffies, - (dma_q->frame > old)? "Underrun, losed" : "Overrun of", - nframes, dma_q->frame, timeout); - } else - dprintk(dev, 1, "will sleep for %d jiffies\n", timeout); - - vivi_thread_tick(dma_q); + vivi_thread_tick(fh); schedule_timeout_interruptible(timeout); @@ -484,16 +447,15 @@ stop_task: static int vivi_thread(void *data) { - struct vivi_dmaqueue *dma_q = data; - struct vivi_dev *dev = container_of(dma_q, struct vivi_dev, vidq); + struct vivi_fh *fh = data; + struct vivi_dev *dev = fh->dev; dprintk(dev, 1, "thread started\n"); - mod_timer(&dma_q->timeout, jiffies+BUFFER_TIMEOUT); set_freezable(); for (;;) { - vivi_sleep(dma_q); + vivi_sleep(fh); if (kthread_should_stop()) break; @@ -502,16 +464,17 @@ static int vivi_thread(void *data) return 0; } -static int vivi_start_thread(struct vivi_dmaqueue *dma_q) +static int vivi_start_thread(struct vivi_fh *fh) { - struct vivi_dev *dev = container_of(dma_q, struct vivi_dev, vidq); + struct vivi_dev *dev = fh->dev; + struct vivi_dmaqueue *dma_q = &dev->vidq; dma_q->frame = 0; dma_q->ini_jiffies = jiffies; dprintk(dev, 1, "%s\n", __FUNCTION__); - dma_q->kthread = kthread_run(vivi_thread, dma_q, "vivi"); + dma_q->kthread = kthread_run(vivi_thread, fh, "vivi"); if (IS_ERR(dma_q->kthread)) { printk(KERN_ERR "vivi: kernel_thread() failed\n"); @@ -536,91 +499,6 @@ static void vivi_stop_thread(struct vivi_dmaqueue *dma_q) } } -static int restart_video_queue(struct vivi_dmaqueue *dma_q) -{ - struct vivi_dev *dev = container_of(dma_q, struct vivi_dev, vidq); - struct vivi_buffer *buf, *prev; - - dprintk(dev, 1, "%s dma_q=0x%08lx\n", __FUNCTION__, - (unsigned long)dma_q); - - if (!list_empty(&dma_q->active)) { - buf = list_entry(dma_q->active.next, - struct vivi_buffer, vb.queue); - dprintk(dev, 2, "restart_queue [%p/%d]: restart dma\n", - buf, buf->vb.i); - - dprintk(dev, 1, "Restarting video dma\n"); - vivi_stop_thread(dma_q); - - /* cancel all outstanding capture / vbi requests */ - list_for_each_entry_safe(buf, prev, &dma_q->active, vb.queue) { - list_del(&buf->vb.queue); - buf->vb.state = VIDEOBUF_ERROR; - wake_up(&buf->vb.done); - } - mod_timer(&dma_q->timeout, jiffies+BUFFER_TIMEOUT); - - return 0; - } - - prev = NULL; - for (;;) { - if (list_empty(&dma_q->queued)) - return 0; - buf = list_entry(dma_q->queued.next, - struct vivi_buffer, vb.queue); - if (NULL == prev) { - list_del(&buf->vb.queue); - list_add_tail(&buf->vb.queue, &dma_q->active); - - dprintk(dev, 1, "Restarting video dma\n"); - vivi_stop_thread(dma_q); - vivi_start_thread(dma_q); - - buf->vb.state = VIDEOBUF_ACTIVE; - mod_timer(&dma_q->timeout, jiffies+BUFFER_TIMEOUT); - dprintk(dev, 2, - "[%p/%d] restart_queue - first active\n", - buf, buf->vb.i); - - } else if (prev->vb.width == buf->vb.width && - prev->vb.height == buf->vb.height && - prev->fmt == buf->fmt) { - list_del(&buf->vb.queue); - list_add_tail(&buf->vb.queue, &dma_q->active); - buf->vb.state = VIDEOBUF_ACTIVE; - dprintk(dev, 2, - "[%p/%d] restart_queue - move to active\n", - buf, buf->vb.i); - } else { - return 0; - } - prev = buf; - } -} - -static void vivi_vid_timeout(unsigned long data) -{ - struct vivi_dev *dev = (struct vivi_dev *)data; - struct vivi_dmaqueue *vidq = &dev->vidq; - struct vivi_buffer *buf; - - spin_lock(&dev->slock); - - while (!list_empty(&vidq->active)) { - buf = list_entry(vidq->active.next, - struct vivi_buffer, vb.queue); - list_del(&buf->vb.queue); - buf->vb.state = VIDEOBUF_ERROR; - wake_up(&buf->vb.done); - printk(KERN_INFO "vivi/0: [%p/%d] timeout\n", buf, buf->vb.i); - } - restart_video_queue(vidq); - - spin_unlock(&dev->slock); -} - /* ------------------------------------------------------------------ Videobuf operations ------------------------------------------------------------------*/ @@ -649,13 +527,13 @@ static void free_buffer(struct videobuf_queue *vq, struct vivi_buffer *buf) struct vivi_fh *fh = vq->priv_data; struct vivi_dev *dev = fh->dev; - dprintk(dev, 1, "%s\n", __FUNCTION__); + dprintk(dev, 1, "%s, state: %i\n", __FUNCTION__, buf->vb.state); if (in_interrupt()) BUG(); - videobuf_waiton(&buf->vb, 0, 0); videobuf_vmalloc_free(&buf->vb); + dprintk(dev, 1, "free_buffer: freed"); buf->vb.state = VIDEOBUF_NEEDS_INIT; } @@ -668,28 +546,25 @@ buffer_prepare(struct videobuf_queue *vq, struct videobuf_buffer *vb, struct vivi_fh *fh = vq->priv_data; struct vivi_dev *dev = fh->dev; struct vivi_buffer *buf = container_of(vb, struct vivi_buffer, vb); - int rc, init_buffer = 0; + int rc; dprintk(dev, 1, "%s, field=%d\n", __FUNCTION__, field); BUG_ON(NULL == fh->fmt); + if (fh->width < 48 || fh->width > norm_maxw() || fh->height < 32 || fh->height > norm_maxh()) return -EINVAL; + buf->vb.size = fh->width*fh->height*2; if (0 != buf->vb.baddr && buf->vb.bsize < buf->vb.size) return -EINVAL; - if (buf->fmt != fh->fmt || - buf->vb.width != fh->width || - buf->vb.height != fh->height || - buf->vb.field != field) { - buf->fmt = fh->fmt; - buf->vb.width = fh->width; - buf->vb.height = fh->height; - buf->vb.field = field; - init_buffer = 1; - } + /* These properties only change when queue is idle, see s_fmt */ + buf->fmt = fh->fmt; + buf->vb.width = fh->width; + buf->vb.height = fh->height; + buf->vb.field = field; if (VIDEOBUF_NEEDS_INIT == buf->vb.state) { rc = videobuf_iolock(vq, &buf->vb, NULL); @@ -712,45 +587,12 @@ buffer_queue(struct videobuf_queue *vq, struct videobuf_buffer *vb) struct vivi_buffer *buf = container_of(vb, struct vivi_buffer, vb); struct vivi_fh *fh = vq->priv_data; struct vivi_dev *dev = fh->dev; - struct vivi_dmaqueue *vidq = &dev->vidq; - struct vivi_buffer *prev; - - if (!list_empty(&vidq->queued)) { - dprintk(dev, 1, "adding vb queue=0x%08lx\n", - (unsigned long)&buf->vb.queue); - list_add_tail(&buf->vb.queue, &vidq->queued); - buf->vb.state = VIDEOBUF_QUEUED; - dprintk(dev, 2, "[%p/%d] buffer_queue - append to queued\n", - buf, buf->vb.i); - } else if (list_empty(&vidq->active)) { - list_add_tail(&buf->vb.queue, &vidq->active); - - buf->vb.state = VIDEOBUF_ACTIVE; - mod_timer(&vidq->timeout, jiffies+BUFFER_TIMEOUT); - dprintk(dev, 2, "[%p/%d] buffer_queue - first active\n", - buf, buf->vb.i); - - vivi_start_thread(vidq); - } else { - prev = list_entry(vidq->active.prev, - struct vivi_buffer, vb.queue); - if (prev->vb.width == buf->vb.width && - prev->vb.height == buf->vb.height && - prev->fmt == buf->fmt) { - list_add_tail(&buf->vb.queue, &vidq->active); - buf->vb.state = VIDEOBUF_ACTIVE; - dprintk(dev, 2, - "[%p/%d] buffer_queue - append to active\n", - buf, buf->vb.i); - - } else { - list_add_tail(&buf->vb.queue, &vidq->queued); - buf->vb.state = VIDEOBUF_QUEUED; - dprintk(dev, 2, - "[%p/%d] buffer_queue - first queued\n", - buf, buf->vb.i); - } - } + struct vivi_dmaqueue *vidq = &dev->vidq; + + dprintk(dev, 1, "%s\n", __FUNCTION__); + + buf->vb.state = VIDEOBUF_QUEUED; + list_add_tail(&buf->vb.queue, &vidq->active); } static void buffer_release(struct videobuf_queue *vq, @@ -759,12 +601,9 @@ static void buffer_release(struct videobuf_queue *vq, struct vivi_buffer *buf = container_of(vb, struct vivi_buffer, vb); struct vivi_fh *fh = vq->priv_data; struct vivi_dev *dev = (struct vivi_dev *)fh->dev; - struct vivi_dmaqueue *vidq = &dev->vidq; dprintk(dev, 1, "%s\n", __FUNCTION__); - vivi_stop_thread(vidq); - free_buffer(vq, buf); } @@ -870,17 +709,31 @@ static int vidioc_s_fmt_cap(struct file *file, void *priv, struct v4l2_format *f) { struct vivi_fh *fh = priv; + struct videobuf_queue *q = &fh->vb_vidq; + int ret = vidioc_try_fmt_cap(file, fh, f); if (ret < 0) return (ret); + mutex_lock(&q->vb_lock); + + if (videobuf_queue_is_busy(&fh->vb_vidq)) { + dprintk(fh->dev, 1, "%s queue busy\n", __FUNCTION__); + ret = -EBUSY; + goto out; + } + fh->fmt = &format; fh->width = f->fmt.pix.width; fh->height = f->fmt.pix.height; fh->vb_vidq.field = f->fmt.pix.field; fh->type = f->type; - return (0); + ret = 0; +out: + mutex_unlock(&q->vb_lock); + + return (ret); } static int vidioc_reqbufs(struct file *file, void *priv, @@ -1097,6 +950,8 @@ unlock: NULL, &dev->slock, fh->type, V4L2_FIELD_INTERLACED, sizeof(struct vivi_buffer), fh); + vivi_start_thread(fh); + return 0; } @@ -1252,18 +1107,12 @@ static int __init vivi_init(void) /* init video dma queues */ INIT_LIST_HEAD(&dev->vidq.active); - INIT_LIST_HEAD(&dev->vidq.queued); init_waitqueue_head(&dev->vidq.wq); /* initialize locks */ - mutex_init(&dev->lock); spin_lock_init(&dev->slock); mutex_init(&dev->mutex); - dev->vidq.timeout.function = vivi_vid_timeout; - dev->vidq.timeout.data = (unsigned long)dev; - init_timer(&dev->vidq.timeout); - vfd = video_device_alloc(); if (NULL == vfd) break;