mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-04 11:36:51 +07:00
5803b02388
The event handler in the virmidi sequencer code takes a read-lock for the linked list traverse, while it's calling snd_seq_dump_var_event() in the loop. The latter function may expand the user-space data depending on the event type. It eventually invokes copy_from_user(), which might be a potential dead-lock. The sequencer core guarantees that the user-space data is passed only with atomic=0 argument, but snd_virmidi_dev_receive_event() ignores it and always takes read-lock(). For avoiding the problem above, this patch introduces rwsem for non-atomic case, while keeping rwlock for atomic case. Also while we're at it: the superfluous irq flags is dropped in snd_virmidi_input_open(). Reported-by: Jia-Ju Bai <baijiaju1990@163.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
83 lines
2.7 KiB
C
83 lines
2.7 KiB
C
#ifndef __SOUND_SEQ_VIRMIDI_H
|
|
#define __SOUND_SEQ_VIRMIDI_H
|
|
|
|
/*
|
|
* Virtual Raw MIDI client on Sequencer
|
|
* Copyright (c) 2000 by Takashi Iwai <tiwai@suse.de>,
|
|
* 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
|
|
*
|
|
*/
|
|
|
|
#include <sound/rawmidi.h>
|
|
#include <sound/seq_midi_event.h>
|
|
|
|
/*
|
|
* device file instance:
|
|
* This instance is created at each time the midi device file is
|
|
* opened. Each instance has its own input buffer and MIDI parser
|
|
* (buffer), and is associated with the device instance.
|
|
*/
|
|
struct snd_virmidi {
|
|
struct list_head list;
|
|
int seq_mode;
|
|
int client;
|
|
int port;
|
|
unsigned int trigger: 1;
|
|
struct snd_midi_event *parser;
|
|
struct snd_seq_event event;
|
|
struct snd_virmidi_dev *rdev;
|
|
struct snd_rawmidi_substream *substream;
|
|
};
|
|
|
|
#define SNDRV_VIRMIDI_SUBSCRIBE (1<<0)
|
|
#define SNDRV_VIRMIDI_USE (1<<1)
|
|
|
|
/*
|
|
* device record:
|
|
* Each virtual midi device has one device instance. It contains
|
|
* common information and the linked-list of opened files,
|
|
*/
|
|
struct snd_virmidi_dev {
|
|
struct snd_card *card; /* associated card */
|
|
struct snd_rawmidi *rmidi; /* rawmidi device */
|
|
int seq_mode; /* SNDRV_VIRMIDI_XXX */
|
|
int device; /* sequencer device */
|
|
int client; /* created/attached client */
|
|
int port; /* created/attached port */
|
|
unsigned int flags; /* SNDRV_VIRMIDI_* */
|
|
rwlock_t filelist_lock;
|
|
struct rw_semaphore filelist_sem;
|
|
struct list_head filelist;
|
|
};
|
|
|
|
/* sequencer mode:
|
|
* ATTACH = input/output events from midi device are routed to the
|
|
* attached sequencer port. sequencer port is not created
|
|
* by virmidi itself.
|
|
* the input to rawmidi must be processed by passing the
|
|
* incoming events via snd_virmidi_receive()
|
|
* DISPATCH = input/output events are routed to subscribers.
|
|
* sequencer port is created in virmidi.
|
|
*/
|
|
#define SNDRV_VIRMIDI_SEQ_NONE 0
|
|
#define SNDRV_VIRMIDI_SEQ_ATTACH 1
|
|
#define SNDRV_VIRMIDI_SEQ_DISPATCH 2
|
|
|
|
int snd_virmidi_new(struct snd_card *card, int device, struct snd_rawmidi **rrmidi);
|
|
|
|
#endif /* __SOUND_SEQ_VIRMIDI */
|