From: Andreas Oberritter Date: Wed, 24 Sep 2008 08:00:37 +0000 (-0300) Subject: V4L/DVB (9029): Fix deadlock in demux code X-Git-Tag: v2.6.27-rc9~6^2~8 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=dda06a8e4610757def753ee3a541a0b1a1feb36b;p=linux-2.6-omap-h63xx.git V4L/DVB (9029): Fix deadlock in demux code The functions dvb_dmxdev_section_callback, dvb_dmxdev_ts_callback, dvb_dmx_swfilter_packet, dvb_dmx_swfilter_packets, dvb_dmx_swfilter and dvb_dmx_swfilter_204 may be called from both interrupt and process context. Therefore they need to be protected by spin_lock_irqsave() instead of spin_lock(). This fixes a deadlock discovered by lockdep. Signed-off-by: Andreas Oberritter Signed-off-by: Mauro Carvalho Chehab --- diff --git a/drivers/media/dvb/dvb-core/dmxdev.c b/drivers/media/dvb/dvb-core/dmxdev.c index 069d847ba88..0c733c66a44 100644 --- a/drivers/media/dvb/dvb-core/dmxdev.c +++ b/drivers/media/dvb/dvb-core/dmxdev.c @@ -364,15 +364,16 @@ static int dvb_dmxdev_section_callback(const u8 *buffer1, size_t buffer1_len, enum dmx_success success) { struct dmxdev_filter *dmxdevfilter = filter->priv; + unsigned long flags; int ret; if (dmxdevfilter->buffer.error) { wake_up(&dmxdevfilter->buffer.queue); return 0; } - spin_lock(&dmxdevfilter->dev->lock); + spin_lock_irqsave(&dmxdevfilter->dev->lock, flags); if (dmxdevfilter->state != DMXDEV_STATE_GO) { - spin_unlock(&dmxdevfilter->dev->lock); + spin_unlock_irqrestore(&dmxdevfilter->dev->lock, flags); return 0; } del_timer(&dmxdevfilter->timer); @@ -391,7 +392,7 @@ static int dvb_dmxdev_section_callback(const u8 *buffer1, size_t buffer1_len, } if (dmxdevfilter->params.sec.flags & DMX_ONESHOT) dmxdevfilter->state = DMXDEV_STATE_DONE; - spin_unlock(&dmxdevfilter->dev->lock); + spin_unlock_irqrestore(&dmxdevfilter->dev->lock, flags); wake_up(&dmxdevfilter->buffer.queue); return 0; } @@ -403,11 +404,12 @@ static int dvb_dmxdev_ts_callback(const u8 *buffer1, size_t buffer1_len, { struct dmxdev_filter *dmxdevfilter = feed->priv; struct dvb_ringbuffer *buffer; + unsigned long flags; int ret; - spin_lock(&dmxdevfilter->dev->lock); + spin_lock_irqsave(&dmxdevfilter->dev->lock, flags); if (dmxdevfilter->params.pes.output == DMX_OUT_DECODER) { - spin_unlock(&dmxdevfilter->dev->lock); + spin_unlock_irqrestore(&dmxdevfilter->dev->lock, flags); return 0; } @@ -417,7 +419,7 @@ static int dvb_dmxdev_ts_callback(const u8 *buffer1, size_t buffer1_len, else buffer = &dmxdevfilter->dev->dvr_buffer; if (buffer->error) { - spin_unlock(&dmxdevfilter->dev->lock); + spin_unlock_irqrestore(&dmxdevfilter->dev->lock, flags); wake_up(&buffer->queue); return 0; } @@ -428,7 +430,7 @@ static int dvb_dmxdev_ts_callback(const u8 *buffer1, size_t buffer1_len, dvb_ringbuffer_flush(buffer); buffer->error = ret; } - spin_unlock(&dmxdevfilter->dev->lock); + spin_unlock_irqrestore(&dmxdevfilter->dev->lock, flags); wake_up(&buffer->queue); return 0; } diff --git a/drivers/media/dvb/dvb-core/dvb_demux.c b/drivers/media/dvb/dvb-core/dvb_demux.c index e2eca0b1fe7..a2c1fd5d2f6 100644 --- a/drivers/media/dvb/dvb-core/dvb_demux.c +++ b/drivers/media/dvb/dvb-core/dvb_demux.c @@ -399,7 +399,9 @@ static void dvb_dmx_swfilter_packet(struct dvb_demux *demux, const u8 *buf) void dvb_dmx_swfilter_packets(struct dvb_demux *demux, const u8 *buf, size_t count) { - spin_lock(&demux->lock); + unsigned long flags; + + spin_lock_irqsave(&demux->lock, flags); while (count--) { if (buf[0] == 0x47) @@ -407,16 +409,17 @@ void dvb_dmx_swfilter_packets(struct dvb_demux *demux, const u8 *buf, buf += 188; } - spin_unlock(&demux->lock); + spin_unlock_irqrestore(&demux->lock, flags); } EXPORT_SYMBOL(dvb_dmx_swfilter_packets); void dvb_dmx_swfilter(struct dvb_demux *demux, const u8 *buf, size_t count) { + unsigned long flags; int p = 0, i, j; - spin_lock(&demux->lock); + spin_lock_irqsave(&demux->lock, flags); if (demux->tsbufp) { i = demux->tsbufp; @@ -449,17 +452,18 @@ void dvb_dmx_swfilter(struct dvb_demux *demux, const u8 *buf, size_t count) } bailout: - spin_unlock(&demux->lock); + spin_unlock_irqrestore(&demux->lock, flags); } EXPORT_SYMBOL(dvb_dmx_swfilter); void dvb_dmx_swfilter_204(struct dvb_demux *demux, const u8 *buf, size_t count) { + unsigned long flags; int p = 0, i, j; u8 tmppack[188]; - spin_lock(&demux->lock); + spin_lock_irqsave(&demux->lock, flags); if (demux->tsbufp) { i = demux->tsbufp; @@ -500,7 +504,7 @@ void dvb_dmx_swfilter_204(struct dvb_demux *demux, const u8 *buf, size_t count) } bailout: - spin_unlock(&demux->lock); + spin_unlock_irqrestore(&demux->lock, flags); } EXPORT_SYMBOL(dvb_dmx_swfilter_204);