From patchwork Thu Sep 16 00:56:37 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mauro Carvalho Chehab X-Patchwork-Id: 184252 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id o8G0xAQp032618 for ; Thu, 16 Sep 2010 00:59:10 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752733Ab0IPA7I (ORCPT ); Wed, 15 Sep 2010 20:59:08 -0400 Received: from mx1.redhat.com ([209.132.183.28]:18920 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752421Ab0IPA7H (ORCPT ); Wed, 15 Sep 2010 20:59:07 -0400 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o8G0x3tF005161 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 15 Sep 2010 20:59:03 -0400 Received: from pedra (vpn-238-101.phx2.redhat.com [10.3.238.101]) by int-mx01.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o8G0uodW016279 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); Wed, 15 Sep 2010 20:59:00 -0400 Date: Wed, 15 Sep 2010 21:56:37 -0300 From: Mauro Carvalho Chehab To: Linux Media Mailing List Cc: Arnd Bergmann Subject: [PATCH 4/8] V4L/DVB: bttv: fix driver lock and remove explicit calls to BKL Message-ID: <20100915215637.3b98ed56@pedra> In-Reply-To: References: Mime-Version: 1.0 X-Scanned-By: MIMEDefang 2.67 on 10.5.11.11 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.3 (demeter1.kernel.org [140.211.167.41]); Thu, 16 Sep 2010 00:59:10 +0000 (UTC) diff --git a/drivers/media/video/bt8xx/bttv-driver.c b/drivers/media/video/bt8xx/bttv-driver.c index fcafe2f..5f5cd4a 100644 --- a/drivers/media/video/bt8xx/bttv-driver.c +++ b/drivers/media/video/bt8xx/bttv-driver.c @@ -1859,21 +1859,25 @@ static int bttv_s_std(struct file *file, void *priv, v4l2_std_id *id) unsigned int i; int err; + mutex_lock(&btv->lock); err = v4l2_prio_check(&btv->prio, fh->prio); - if (0 != err) - return err; + if (err) + goto err; for (i = 0; i < BTTV_TVNORMS; i++) if (*id & bttv_tvnorms[i].v4l2_id) break; - if (i == BTTV_TVNORMS) - return -EINVAL; + if (i == BTTV_TVNORMS) { + err = -EINVAL; + goto err; + } - mutex_lock(&btv->lock); set_tvnorm(btv, i); + +err: mutex_unlock(&btv->lock); - return 0; + return err; } static int bttv_querystd(struct file *file, void *f, v4l2_std_id *id) @@ -1893,10 +1897,13 @@ static int bttv_enum_input(struct file *file, void *priv, { struct bttv_fh *fh = priv; struct bttv *btv = fh->btv; - int n; + int rc = 0; - if (i->index >= bttv_tvcards[btv->c.type].video_inputs) - return -EINVAL; + mutex_lock(&btv->lock); + if (i->index >= bttv_tvcards[btv->c.type].video_inputs) { + rc = -EINVAL; + goto err; + } i->type = V4L2_INPUT_TYPE_CAMERA; i->audioset = 1; @@ -1919,10 +1926,12 @@ static int bttv_enum_input(struct file *file, void *priv, i->status |= V4L2_IN_ST_NO_H_LOCK; } - for (n = 0; n < BTTV_TVNORMS; n++) - i->std |= bttv_tvnorms[n].v4l2_id; + i->std = BTTV_NORMS; - return 0; +err: + mutex_unlock(&btv->lock); + + return rc; } static int bttv_g_input(struct file *file, void *priv, unsigned int *i) @@ -1930,7 +1939,10 @@ static int bttv_g_input(struct file *file, void *priv, unsigned int *i) struct bttv_fh *fh = priv; struct bttv *btv = fh->btv; + mutex_lock(&btv->lock); *i = btv->input; + mutex_unlock(&btv->lock); + return 0; } @@ -1941,15 +1953,19 @@ static int bttv_s_input(struct file *file, void *priv, unsigned int i) int err; - err = v4l2_prio_check(&btv->prio, fh->prio); - if (0 != err) - return err; - - if (i > bttv_tvcards[btv->c.type].video_inputs) - return -EINVAL; - mutex_lock(&btv->lock); + err = v4l2_prio_check(&btv->prio, fh->prio); + if (unlikely(err)) + goto err; + + if (i > bttv_tvcards[btv->c.type].video_inputs) { + err = -EINVAL; + goto err; + } + set_input(btv, i, btv->tvnorm); + +err: mutex_unlock(&btv->lock); return 0; } @@ -1961,22 +1977,25 @@ static int bttv_s_tuner(struct file *file, void *priv, struct bttv *btv = fh->btv; int err; - err = v4l2_prio_check(&btv->prio, fh->prio); - if (0 != err) - return err; - - if (btv->tuner_type == TUNER_ABSENT) - return -EINVAL; - - if (0 != t->index) + if (unlikely(0 != t->index)) return -EINVAL; mutex_lock(&btv->lock); + if (unlikely(btv->tuner_type == TUNER_ABSENT)) { + err = -EINVAL; + goto err; + } + + err = v4l2_prio_check(&btv->prio, fh->prio); + if (unlikely(err)) + goto err; + bttv_call_all(btv, tuner, s_tuner, t); if (btv->audio_mode_gpio) btv->audio_mode_gpio(btv, t, 1); +err: mutex_unlock(&btv->lock); return 0; @@ -1988,8 +2007,10 @@ static int bttv_g_frequency(struct file *file, void *priv, struct bttv_fh *fh = priv; struct bttv *btv = fh->btv; + mutex_lock(&btv->lock); f->type = btv->radio_user ? V4L2_TUNER_RADIO : V4L2_TUNER_ANALOG_TV; f->frequency = btv->freq; + mutex_unlock(&btv->lock); return 0; } @@ -2001,21 +2022,26 @@ static int bttv_s_frequency(struct file *file, void *priv, struct bttv *btv = fh->btv; int err; - err = v4l2_prio_check(&btv->prio, fh->prio); - if (0 != err) - return err; - if (unlikely(f->tuner != 0)) return -EINVAL; + + mutex_lock(&btv->lock); + err = v4l2_prio_check(&btv->prio, fh->prio); + if (unlikely(err)) + goto err; + if (unlikely(f->type != (btv->radio_user - ? V4L2_TUNER_RADIO : V4L2_TUNER_ANALOG_TV))) - return -EINVAL; - mutex_lock(&btv->lock); + ? V4L2_TUNER_RADIO : V4L2_TUNER_ANALOG_TV))) { + err = -EINVAL; + goto err; + } btv->freq = f->frequency; bttv_call_all(btv, tuner, s_frequency, f); if (btv->has_matchbox && btv->radio_user) tea5757_set_freq(btv, btv->freq); +err: mutex_unlock(&btv->lock); + return 0; } @@ -2257,7 +2283,9 @@ verify_window_lock (struct bttv_fh * fh, if (V4L2_FIELD_ANY == field) { __s32 height2; + mutex_lock(&fh->btv->lock); height2 = fh->btv->crop[!!fh->do_crop].rect.height >> 1; + mutex_unlock(&fh->btv->lock); field = (win->w.height > height2) ? V4L2_FIELD_INTERLACED : V4L2_FIELD_TOP; @@ -2332,6 +2360,8 @@ static int setup_window_lock(struct bttv_fh *fh, struct bttv *btv, return -EFAULT; } } + + mutex_lock(&fh->cap.vb_lock); /* clip against screen */ if (NULL != btv->fbuf.base) n = btcx_screen_clips(btv->fbuf.fmt.width, btv->fbuf.fmt.height, @@ -2354,7 +2384,6 @@ static int setup_window_lock(struct bttv_fh *fh, struct bttv *btv, BUG(); } - mutex_lock(&fh->cap.vb_lock); kfree(fh->ov.clips); fh->ov.clips = clips; fh->ov.nclips = n; @@ -2362,6 +2391,14 @@ static int setup_window_lock(struct bttv_fh *fh, struct bttv *btv, fh->ov.w = win->w; fh->ov.field = win->field; fh->ov.setup_ok = 1; + + /* + * FIXME: btv is protected by btv->lock mutex, while btv->init + * is protected by fh->cap.vb_lock. This seems to open the + * possibility for some race situations. Maybe the better would + * be to unify those locks or to use another way to store the + * init values that will be consumed by videobuf callbacks + */ btv->init.ov.w.width = win->w.width; btv->init.ov.w.height = win->w.height; btv->init.ov.field = win->field; @@ -2490,7 +2527,9 @@ static int bttv_try_fmt_vid_cap(struct file *file, void *priv, if (V4L2_FIELD_ANY == field) { __s32 height2; + mutex_lock(&btv->lock); height2 = btv->crop[!!fh->do_crop].rect.height >> 1; + mutex_unlock(&btv->lock); field = (f->fmt.pix.height > height2) ? V4L2_FIELD_INTERLACED : V4L2_FIELD_BOTTOM; @@ -2651,11 +2690,15 @@ static int bttv_querycap(struct file *file, void *priv, V4L2_CAP_VBI_CAPTURE | V4L2_CAP_READWRITE | V4L2_CAP_STREAMING; - if (btv->has_saa6588) - cap->capabilities |= V4L2_CAP_RDS_CAPTURE; if (no_overlay <= 0) cap->capabilities |= V4L2_CAP_VIDEO_OVERLAY; + /* + * No need to lock here: those vars are initialized during board + * probe and remains untouched during the rest of the driver lifecycle + */ + if (btv->has_saa6588) + cap->capabilities |= V4L2_CAP_RDS_CAPTURE; if (btv->tuner_type != TUNER_ABSENT) cap->capabilities |= V4L2_CAP_TUNER; return 0; @@ -2730,16 +2773,22 @@ static int bttv_overlay(struct file *file, void *f, unsigned int on) struct bttv_fh *fh = f; struct bttv *btv = fh->btv; struct bttv_buffer *new; - int retval; + int retval = 0; if (on) { + mutex_lock(&fh->cap.vb_lock); /* verify args */ - if (NULL == btv->fbuf.base) + if (unlikely(!btv->fbuf.base)) { + mutex_unlock(&fh->cap.vb_lock); return -EINVAL; - if (!fh->ov.setup_ok) { + } + if (unlikely(!fh->ov.setup_ok)) { dprintk("bttv%d: overlay: !setup_ok\n", btv->c.nr); - return -EINVAL; + retval = -EINVAL; } + if (retval) + return retval; + mutex_unlock(&fh->cap.vb_lock); } if (!check_alloc_btres_lock(btv, fh, RESOURCE_OVERLAY)) @@ -2907,6 +2956,7 @@ static int bttv_queryctrl(struct file *file, void *priv, c->id >= V4L2_CID_PRIVATE_LASTP1)) return -EINVAL; + mutex_lock(&btv->lock); if (!btv->volume_gpio && (c->id == V4L2_CID_AUDIO_VOLUME)) *c = no_ctl; else { @@ -2914,6 +2964,7 @@ static int bttv_queryctrl(struct file *file, void *priv, *c = (NULL != ctrl) ? *ctrl : no_ctl; } + mutex_unlock(&btv->lock); return 0; } @@ -2924,8 +2975,11 @@ static int bttv_g_parm(struct file *file, void *f, struct bttv_fh *fh = f; struct bttv *btv = fh->btv; + mutex_lock(&btv->lock); v4l2_video_std_frame_period(bttv_tvnorms[btv->tvnorm].v4l2_id, &parm->parm.capture.timeperframe); + mutex_unlock(&btv->lock); + return 0; } @@ -2961,7 +3015,9 @@ static int bttv_g_priority(struct file *file, void *f, enum v4l2_priority *p) struct bttv_fh *fh = f; struct bttv *btv = fh->btv; + mutex_lock(&btv->lock); *p = v4l2_prio_max(&btv->prio); + mutex_unlock(&btv->lock); return 0; } @@ -2971,8 +3027,13 @@ static int bttv_s_priority(struct file *file, void *f, { struct bttv_fh *fh = f; struct bttv *btv = fh->btv; + int rc; - return v4l2_prio_change(&btv->prio, &fh->prio, prio); + mutex_lock(&btv->lock); + rc = v4l2_prio_change(&btv->prio, &fh->prio, prio); + mutex_unlock(&btv->lock); + + return rc; } static int bttv_cropcap(struct file *file, void *priv, @@ -2985,7 +3046,9 @@ static int bttv_cropcap(struct file *file, void *priv, cap->type != V4L2_BUF_TYPE_VIDEO_OVERLAY) return -EINVAL; + mutex_lock(&btv->lock); *cap = bttv_tvnorms[btv->tvnorm].cropcap; + mutex_unlock(&btv->lock); return 0; } @@ -3003,7 +3066,9 @@ static int bttv_g_crop(struct file *file, void *f, struct v4l2_crop *crop) inconsistent with fh->width or fh->height and apps do not expect a change here. */ + mutex_lock(&btv->lock); crop->c = btv->crop[!!fh->do_crop].rect; + mutex_unlock(&btv->lock); return 0; } @@ -3024,14 +3089,15 @@ static int bttv_s_crop(struct file *file, void *f, struct v4l2_crop *crop) crop->type != V4L2_BUF_TYPE_VIDEO_OVERLAY) return -EINVAL; - retval = v4l2_prio_check(&btv->prio, fh->prio); - if (0 != retval) - return retval; - /* Make sure tvnorm, vbi_end and the current cropping parameters remain consistent until we're done. Note read() may change vbi_end in check_alloc_btres_lock(). */ mutex_lock(&btv->lock); + retval = v4l2_prio_check(&btv->prio, fh->prio); + if (0 != retval) { + mutex_unlock(&btv->lock); + return retval; + } retval = -EBUSY; @@ -3221,21 +3287,32 @@ static int bttv_open(struct file *file) return -ENODEV; } - lock_kernel(); - dprintk(KERN_DEBUG "bttv%d: open called (type=%s)\n", btv->c.nr,v4l2_type_names[type]); /* allocate per filehandle data */ - fh = kmalloc(sizeof(*fh),GFP_KERNEL); - if (NULL == fh) { - unlock_kernel(); + fh = kmalloc(sizeof(*fh), GFP_KERNEL); + if (unlikely(!fh)) return -ENOMEM; - } file->private_data = fh; + + /* + * btv is protected by btv->lock mutex, while btv->init and other + * streaming vars are protected by fh->cap.vb_lock. We need to take + * care of both locks to avoid troubles. However, vb_lock is used also + * inside videobuf, without calling buf->lock. So, it is a very bad + * idea to hold both locks at the same time. + * Let's first copy btv->init at fh, holding cap.vb_lock, and then work + * with the rest of init, holding btv->lock. + */ + mutex_lock(&fh->cap.vb_lock); *fh = btv->init; + mutex_unlock(&fh->cap.vb_lock); + fh->type = type; fh->ov.setup_ok = 0; + + mutex_lock(&btv->lock); v4l2_prio_open(&btv->prio, &fh->prio); videobuf_queue_sg_init(&fh->cap, &bttv_video_qops, @@ -3272,7 +3349,7 @@ static int bttv_open(struct file *file) bttv_vbi_fmt_reset(&fh->vbi_fmt, btv->tvnorm); bttv_field_count(btv); - unlock_kernel(); + mutex_unlock(&btv->lock); return 0; } @@ -3281,6 +3358,7 @@ static int bttv_release(struct file *file) struct bttv_fh *fh = file->private_data; struct bttv *btv = fh->btv; + mutex_lock(&btv->lock); /* turn off overlay */ if (check_btres(fh, RESOURCE_OVERLAY)) bttv_switch_overlay(btv,fh,NULL); @@ -3305,8 +3383,15 @@ static int bttv_release(struct file *file) } /* free stuff */ + + /* + * videobuf uses cap.vb_lock - we should avoid holding btv->lock, + * otherwise we may have dead lock conditions + */ + mutex_unlock(&btv->lock); videobuf_mmap_free(&fh->cap); videobuf_mmap_free(&fh->vbi); + mutex_lock(&btv->lock); v4l2_prio_close(&btv->prio, fh->prio); file->private_data = NULL; kfree(fh); @@ -3316,6 +3401,7 @@ static int bttv_release(struct file *file) if (!btv->users) audio_mute(btv, 1); + mutex_unlock(&btv->lock); return 0; } @@ -3412,21 +3498,19 @@ static int radio_open(struct file *file) dprintk("bttv: open dev=%s\n", video_device_node_name(vdev)); - lock_kernel(); - dprintk("bttv%d: open called (radio)\n",btv->c.nr); /* allocate per filehandle data */ fh = kmalloc(sizeof(*fh), GFP_KERNEL); - if (NULL == fh) { - unlock_kernel(); + if (unlikely(!fh)) return -ENOMEM; - } file->private_data = fh; + mutex_lock(&fh->cap.vb_lock); *fh = btv->init; - v4l2_prio_open(&btv->prio, &fh->prio); + mutex_unlock(&fh->cap.vb_lock); mutex_lock(&btv->lock); + v4l2_prio_open(&btv->prio, &fh->prio); btv->radio_user++; @@ -3434,7 +3518,6 @@ static int radio_open(struct file *file) audio_input(btv,TVAUDIO_INPUT_RADIO); mutex_unlock(&btv->lock); - unlock_kernel(); return 0; } @@ -3444,6 +3527,7 @@ static int radio_release(struct file *file) struct bttv *btv = fh->btv; struct rds_command cmd; + mutex_lock(&btv->lock); v4l2_prio_close(&btv->prio, fh->prio); file->private_data = NULL; kfree(fh); @@ -3451,6 +3535,7 @@ static int radio_release(struct file *file) btv->radio_user--; bttv_call_all(btv, core, ioctl, RDS_CMD_CLOSE, &cmd); + mutex_unlock(&btv->lock); return 0; }