external/alsa-lib
Revision | 7cea8c156204ebae7c0dc60801dde5ddfa5bb7d0 (tree) |
---|---|
Time | 2019-02-12 22:37:44 |
Author | Brendan Shanks <brendan.shanks@tera...> |
Commiter | Takashi Iwai |
pcm: dshare: Fix overflow when slave_hw_ptr rolls over boundary
In snd_pcm_dshare_sync_area() when 'slave_hw_ptr' rolls over
'slave_boundary', the wrong variable is checked ('dshare->slave_hw_ptr' vs
the local 'slave_hw_ptr'). In some cases, this results in 'slave_hw_ptr'
not rolling over correctly. 'slave_size' and 'size' are then much too
large, and the for loop blocks for several minutes copying samples.
This was likely only triggered on 32-bit systems, since the PCM boundary
is computed based on LONG_MAX and is much larger on 64-bit systems.
This same change was made to pcm_dmix in commit
6c7f60f7a982fdba828e4530a9d7aa0aa2b704ae ("Fix boundary overlap”) from
June 2005.
Signed-off-by: Brendan Shanks <brendan.shanks@teradek.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
@@ -121,7 +121,7 @@ static void snd_pcm_dshare_sync_area(snd_pcm_t *pcm) | ||
121 | 121 | */ |
122 | 122 | slave_hw_ptr -= slave_hw_ptr % dshare->slave_period_size; |
123 | 123 | slave_hw_ptr += dshare->slave_buffer_size; |
124 | - if (dshare->slave_hw_ptr > dshare->slave_boundary) | |
124 | + if (slave_hw_ptr >= dshare->slave_boundary) | |
125 | 125 | slave_hw_ptr -= dshare->slave_boundary; |
126 | 126 | if (slave_hw_ptr < dshare->slave_appl_ptr) |
127 | 127 | slave_size = slave_hw_ptr + (dshare->slave_boundary - dshare->slave_appl_ptr); |