mirror of
https://github.com/torvalds/linux.git
synced 2024-12-29 14:21:47 +00:00
40cab6e88c
OSS PCM stream management isn't modal but it allows ioctls issued at
any time for changing the parameters. In the previous hardening
patch ("ALSA: pcm: Avoid potential races between OSS ioctls and
read/write"), we covered these races and prevent the corruption by
protecting the concurrent accesses via params_lock mutex. However,
this means that some ioctls that try to change the stream parameter
(e.g. channels or format) would be blocked until the read/write
finishes, and it may take really long.
Basically changing the parameter while reading/writing is an invalid
operation, hence it's even more user-friendly from the API POV if it
returns -EBUSY in such a situation.
This patch adds such checks in the relevant ioctls with the addition
of read/write access refcount.
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
91 lines
2.7 KiB
C
91 lines
2.7 KiB
C
#ifndef __SOUND_PCM_OSS_H
|
|
#define __SOUND_PCM_OSS_H
|
|
|
|
/*
|
|
* Digital Audio (PCM) - OSS compatibility abstract layer
|
|
* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
|
|
*
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*
|
|
*/
|
|
|
|
struct snd_pcm_oss_setup {
|
|
char *task_name;
|
|
unsigned int disable:1,
|
|
direct:1,
|
|
block:1,
|
|
nonblock:1,
|
|
partialfrag:1,
|
|
nosilence:1,
|
|
buggyptr:1;
|
|
unsigned int periods;
|
|
unsigned int period_size;
|
|
struct snd_pcm_oss_setup *next;
|
|
};
|
|
|
|
struct snd_pcm_oss_runtime {
|
|
unsigned params: 1, /* format/parameter change */
|
|
prepare: 1, /* need to prepare the operation */
|
|
trigger: 1, /* trigger flag */
|
|
sync_trigger: 1; /* sync trigger flag */
|
|
int rate; /* requested rate */
|
|
int format; /* requested OSS format */
|
|
unsigned int channels; /* requested channels */
|
|
unsigned int fragshift;
|
|
unsigned int maxfrags;
|
|
unsigned int subdivision; /* requested subdivision */
|
|
size_t period_bytes; /* requested period size */
|
|
size_t period_frames; /* period frames for poll */
|
|
size_t period_ptr; /* actual write pointer to period */
|
|
unsigned int periods;
|
|
size_t buffer_bytes; /* requested buffer size */
|
|
size_t bytes; /* total # bytes processed */
|
|
size_t mmap_bytes;
|
|
char *buffer; /* vmallocated period */
|
|
size_t buffer_used; /* used length from period buffer */
|
|
struct mutex params_lock;
|
|
atomic_t rw_ref; /* concurrent read/write accesses */
|
|
#ifdef CONFIG_SND_PCM_OSS_PLUGINS
|
|
struct snd_pcm_plugin *plugin_first;
|
|
struct snd_pcm_plugin *plugin_last;
|
|
#endif
|
|
unsigned int prev_hw_ptr_period;
|
|
};
|
|
|
|
struct snd_pcm_oss_file {
|
|
struct snd_pcm_substream *streams[2];
|
|
};
|
|
|
|
struct snd_pcm_oss_substream {
|
|
unsigned oss: 1; /* oss mode */
|
|
struct snd_pcm_oss_setup setup; /* active setup */
|
|
};
|
|
|
|
struct snd_pcm_oss_stream {
|
|
struct snd_pcm_oss_setup *setup_list; /* setup list */
|
|
struct mutex setup_mutex;
|
|
#ifdef CONFIG_SND_VERBOSE_PROCFS
|
|
struct snd_info_entry *proc_entry;
|
|
#endif
|
|
};
|
|
|
|
struct snd_pcm_oss {
|
|
int reg;
|
|
unsigned int reg_mask;
|
|
};
|
|
|
|
#endif /* __SOUND_PCM_OSS_H */
|