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| author |   Takashi Iwai <tiwai@suse.de> | 2019-04-12 12:44:39 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2019-04-12 13:07:25 +0200 |
| commit | 6b580f523172f2c738b661069a57c23c74a75f88 (patch) | |
| tree | d772938f0958be15c9f097fecfdccc39609c9b7b /sound/core/seq/oss/seq_oss_device.h | |
| parent | ALSA: seq: Simplify snd_seq_kernel_client_enqueue() helper (diff) | |
| download | linux-dev-6b580f523172f2c738b661069a57c23c74a75f88.tar.xz linux-dev-6b580f523172f2c738b661069a57c23c74a75f88.zip | |
ALSA: seq: Protect racy pool manipulation from OSS sequencer
OSS sequencer emulation still allows to queue and issue the events
that manipulate the client pool concurrently in a racy way. This
patch serializes the access like the normal sequencer write / ioctl
via taking the client ioctl_mutex. Since the access to the sequencer
client is done indirectly via a client id number, a new helper to
take/release the mutex is introduced.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core/seq/oss/seq_oss_device.h')
| -rw-r--r-- | sound/core/seq/oss/seq_oss_device.h | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/sound/core/seq/oss/seq_oss_device.h b/sound/core/seq/oss/seq_oss_device.h index 2d0e9eaf13aa..77eb1fe1155c 100644 --- a/sound/core/seq/oss/seq_oss_device.h +++ b/sound/core/seq/oss/seq_oss_device.h @@ -30,6 +30,7 @@ #include <sound/rawmidi.h> #include <sound/seq_kernel.h> #include <sound/info.h> +#include "../seq_clientmgr.h" /* max. applications */ #define SNDRV_SEQ_OSS_MAX_CLIENTS 16 @@ -150,11 +151,16 @@ snd_seq_oss_dispatch(struct seq_oss_devinfo *dp, struct snd_seq_event *ev, int a return snd_seq_kernel_client_dispatch(dp->cseq, ev, atomic, hop); } -/* ioctl */ +/* ioctl for writeq */ static inline int snd_seq_oss_control(struct seq_oss_devinfo *dp, unsigned int type, void *arg) { - return snd_seq_kernel_client_ctl(dp->cseq, type, arg); + int err; + + snd_seq_client_ioctl_lock(dp->cseq); + err = snd_seq_kernel_client_ctl(dp->cseq, type, arg); + snd_seq_client_ioctl_unlock(dp->cseq); + return err; } /* fill the addresses in header */ |