diff options
author | Soeren Moch <smoch@web.de> | 2013-06-05 20:26:23 -0400 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-07-28 19:30:21 -0400 |
commit | 61eeaa1b66e47443f27f4cf0809940fbe08142f8 (patch) | |
tree | e53df49a046094fe9bbc6e3096e3e9e783ae2cd8 | |
parent | b534f8f9f56d5e800d4529f54e38be960fd064a2 (diff) |
media: dmxdev: remove dvb_ringbuffer_flush() on writer side
commit 414abbd2cd4c2618895f02ed3a76ec6647281436 upstream.
In dvb_ringbuffer lock-less synchronizationof reader and writer threads is done
with separateread and write pointers. Sincedvb_ringbuffer_flush() modifies the
read pointer, this function must not be called from the writer thread.
This patch removes the dvb_ringbuffer_flush() calls in the dmxdev ringbuffer
write functions, this fixes Oopses "Unable to handle kernel paging request"
I could observe for the call chaindvb_demux_read ->dvb_dmxdev_buffer_read ->
dvb_ringbuffer_read_user -> __copy_to_user (the reader side of the ringbuffer).
The flush calls at the write side are not necessary anyway since ringbuffer_flush
is also called in dvb_dmxdev_buffer_read() when an error condition is set in the
ringbuffer.
This patch should also be applied to stable kernels.
Signed-off-by: Soeren Moch <smoch@web.de>
Reviewed-by: Sakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | drivers/media/dvb-core/dmxdev.c | 8 |
1 files changed, 2 insertions, 6 deletions
diff --git a/drivers/media/dvb-core/dmxdev.c b/drivers/media/dvb-core/dmxdev.c index a1a3a5159d71..0b4616b87195 100644 --- a/drivers/media/dvb-core/dmxdev.c +++ b/drivers/media/dvb-core/dmxdev.c | |||
@@ -377,10 +377,8 @@ static int dvb_dmxdev_section_callback(const u8 *buffer1, size_t buffer1_len, | |||
377 | ret = dvb_dmxdev_buffer_write(&dmxdevfilter->buffer, buffer2, | 377 | ret = dvb_dmxdev_buffer_write(&dmxdevfilter->buffer, buffer2, |
378 | buffer2_len); | 378 | buffer2_len); |
379 | } | 379 | } |
380 | if (ret < 0) { | 380 | if (ret < 0) |
381 | dvb_ringbuffer_flush(&dmxdevfilter->buffer); | ||
382 | dmxdevfilter->buffer.error = ret; | 381 | dmxdevfilter->buffer.error = ret; |
383 | } | ||
384 | if (dmxdevfilter->params.sec.flags & DMX_ONESHOT) | 382 | if (dmxdevfilter->params.sec.flags & DMX_ONESHOT) |
385 | dmxdevfilter->state = DMXDEV_STATE_DONE; | 383 | dmxdevfilter->state = DMXDEV_STATE_DONE; |
386 | spin_unlock(&dmxdevfilter->dev->lock); | 384 | spin_unlock(&dmxdevfilter->dev->lock); |
@@ -416,10 +414,8 @@ static int dvb_dmxdev_ts_callback(const u8 *buffer1, size_t buffer1_len, | |||
416 | ret = dvb_dmxdev_buffer_write(buffer, buffer1, buffer1_len); | 414 | ret = dvb_dmxdev_buffer_write(buffer, buffer1, buffer1_len); |
417 | if (ret == buffer1_len) | 415 | if (ret == buffer1_len) |
418 | ret = dvb_dmxdev_buffer_write(buffer, buffer2, buffer2_len); | 416 | ret = dvb_dmxdev_buffer_write(buffer, buffer2, buffer2_len); |
419 | if (ret < 0) { | 417 | if (ret < 0) |
420 | dvb_ringbuffer_flush(buffer); | ||
421 | buffer->error = ret; | 418 | buffer->error = ret; |
422 | } | ||
423 | spin_unlock(&dmxdevfilter->dev->lock); | 419 | spin_unlock(&dmxdevfilter->dev->lock); |
424 | wake_up(&buffer->queue); | 420 | wake_up(&buffer->queue); |
425 | return 0; | 421 | return 0; |