WSL2-Linux-Kernel/sound/core/rawmidi.c

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C
Исходник Обычный вид История

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Abstract layer for MIDI v1.0 stream
* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
*/
#include <sound/core.h>
#include <linux/major.h>
#include <linux/init.h>
#include <linux/sched/signal.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/wait.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/mm.h>
#include <linux/nospec.h>
#include <sound/rawmidi.h>
#include <sound/info.h>
#include <sound/control.h>
#include <sound/minors.h>
#include <sound/initval.h>
MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
MODULE_DESCRIPTION("Midlevel RawMidi code for ALSA.");
MODULE_LICENSE("GPL");
#ifdef CONFIG_SND_OSSEMUL
static int midi_map[SNDRV_CARDS];
static int amidi_map[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS-1)] = 1};
module_param_array(midi_map, int, NULL, 0444);
MODULE_PARM_DESC(midi_map, "Raw MIDI device number assigned to 1st OSS device.");
module_param_array(amidi_map, int, NULL, 0444);
MODULE_PARM_DESC(amidi_map, "Raw MIDI device number assigned to 2nd OSS device.");
#endif /* CONFIG_SND_OSSEMUL */
static int snd_rawmidi_free(struct snd_rawmidi *rmidi);
static int snd_rawmidi_dev_free(struct snd_device *device);
static int snd_rawmidi_dev_register(struct snd_device *device);
static int snd_rawmidi_dev_disconnect(struct snd_device *device);
static LIST_HEAD(snd_rawmidi_devices);
static DEFINE_MUTEX(register_mutex);
#define rmidi_err(rmidi, fmt, args...) \
dev_err(&(rmidi)->dev, fmt, ##args)
#define rmidi_warn(rmidi, fmt, args...) \
dev_warn(&(rmidi)->dev, fmt, ##args)
#define rmidi_dbg(rmidi, fmt, args...) \
dev_dbg(&(rmidi)->dev, fmt, ##args)
struct snd_rawmidi_status32 {
s32 stream;
s32 tstamp_sec; /* Timestamp */
s32 tstamp_nsec;
u32 avail; /* available bytes */
u32 xruns; /* count of overruns since last status (in bytes) */
unsigned char reserved[16]; /* reserved for future use */
};
#define SNDRV_RAWMIDI_IOCTL_STATUS32 _IOWR('W', 0x20, struct snd_rawmidi_status32)
struct snd_rawmidi_status64 {
int stream;
u8 rsvd[4]; /* alignment */
s64 tstamp_sec; /* Timestamp */
s64 tstamp_nsec;
size_t avail; /* available bytes */
size_t xruns; /* count of overruns since last status (in bytes) */
unsigned char reserved[16]; /* reserved for future use */
};
#define SNDRV_RAWMIDI_IOCTL_STATUS64 _IOWR('W', 0x20, struct snd_rawmidi_status64)
static struct snd_rawmidi *snd_rawmidi_search(struct snd_card *card, int device)
{
struct snd_rawmidi *rawmidi;
list_for_each_entry(rawmidi, &snd_rawmidi_devices, list)
if (rawmidi->card == card && rawmidi->device == device)
return rawmidi;
return NULL;
}
static inline unsigned short snd_rawmidi_file_flags(struct file *file)
{
switch (file->f_mode & (FMODE_READ | FMODE_WRITE)) {
case FMODE_WRITE:
return SNDRV_RAWMIDI_LFLG_OUTPUT;
case FMODE_READ:
return SNDRV_RAWMIDI_LFLG_INPUT;
default:
return SNDRV_RAWMIDI_LFLG_OPEN;
}
}
static inline bool __snd_rawmidi_ready(struct snd_rawmidi_runtime *runtime)
{
return runtime->avail >= runtime->avail_min;
}
static bool snd_rawmidi_ready(struct snd_rawmidi_substream *substream)
{
unsigned long flags;
bool ready;
spin_lock_irqsave(&substream->lock, flags);
ready = __snd_rawmidi_ready(substream->runtime);
spin_unlock_irqrestore(&substream->lock, flags);
return ready;
}
static inline int snd_rawmidi_ready_append(struct snd_rawmidi_substream *substream,
size_t count)
{
struct snd_rawmidi_runtime *runtime = substream->runtime;
return runtime->avail >= runtime->avail_min &&
(!substream->append || runtime->avail >= count);
}
static void snd_rawmidi_input_event_work(struct work_struct *work)
{
struct snd_rawmidi_runtime *runtime =
container_of(work, struct snd_rawmidi_runtime, event_work);
if (runtime->event)
runtime->event(runtime->substream);
}
/* buffer refcount management: call with substream->lock held */
static inline void snd_rawmidi_buffer_ref(struct snd_rawmidi_runtime *runtime)
{
runtime->buffer_ref++;
}
static inline void snd_rawmidi_buffer_unref(struct snd_rawmidi_runtime *runtime)
{
runtime->buffer_ref--;
}
static void snd_rawmidi_buffer_ref_sync(struct snd_rawmidi_substream *substream)
{
int loop = HZ;
spin_lock_irq(&substream->lock);
while (substream->runtime->buffer_ref) {
spin_unlock_irq(&substream->lock);
if (!--loop) {
rmidi_err(substream->rmidi, "Buffer ref sync timeout\n");
return;
}
schedule_timeout_uninterruptible(1);
spin_lock_irq(&substream->lock);
}
spin_unlock_irq(&substream->lock);
}
static int snd_rawmidi_runtime_create(struct snd_rawmidi_substream *substream)
{
struct snd_rawmidi_runtime *runtime;
runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
if (!runtime)
return -ENOMEM;
runtime->substream = substream;
init_waitqueue_head(&runtime->sleep);
INIT_WORK(&runtime->event_work, snd_rawmidi_input_event_work);
runtime->event = NULL;
runtime->buffer_size = PAGE_SIZE;
runtime->avail_min = 1;
if (substream->stream == SNDRV_RAWMIDI_STREAM_INPUT)
runtime->avail = 0;
else
runtime->avail = runtime->buffer_size;
runtime->buffer = kvzalloc(runtime->buffer_size, GFP_KERNEL);
if (!runtime->buffer) {
kfree(runtime);
return -ENOMEM;
}
runtime->appl_ptr = runtime->hw_ptr = 0;
substream->runtime = runtime;
return 0;
}
static int snd_rawmidi_runtime_free(struct snd_rawmidi_substream *substream)
{
struct snd_rawmidi_runtime *runtime = substream->runtime;
kvfree(runtime->buffer);
kfree(runtime);
substream->runtime = NULL;
return 0;
}
static inline void snd_rawmidi_output_trigger(struct snd_rawmidi_substream *substream, int up)
{
if (!substream->opened)
return;
substream->ops->trigger(substream, up);
}
static void snd_rawmidi_input_trigger(struct snd_rawmidi_substream *substream, int up)
{
if (!substream->opened)
return;
substream->ops->trigger(substream, up);
if (!up)
cancel_work_sync(&substream->runtime->event_work);
}
static void __reset_runtime_ptrs(struct snd_rawmidi_runtime *runtime,
bool is_input)
{
runtime->drain = 0;
runtime->appl_ptr = runtime->hw_ptr = 0;
runtime->avail = is_input ? 0 : runtime->buffer_size;
}
static void reset_runtime_ptrs(struct snd_rawmidi_substream *substream,
bool is_input)
{
unsigned long flags;
spin_lock_irqsave(&substream->lock, flags);
if (substream->opened && substream->runtime)
__reset_runtime_ptrs(substream->runtime, is_input);
spin_unlock_irqrestore(&substream->lock, flags);
}
int snd_rawmidi_drop_output(struct snd_rawmidi_substream *substream)
{
snd_rawmidi_output_trigger(substream, 0);
reset_runtime_ptrs(substream, false);
return 0;
}
EXPORT_SYMBOL(snd_rawmidi_drop_output);
int snd_rawmidi_drain_output(struct snd_rawmidi_substream *substream)
{
int err = 0;
long timeout;
struct snd_rawmidi_runtime *runtime;
spin_lock_irq(&substream->lock);
runtime = substream->runtime;
if (!substream->opened || !runtime || !runtime->buffer) {
err = -EINVAL;
} else {
snd_rawmidi_buffer_ref(runtime);
runtime->drain = 1;
}
spin_unlock_irq(&substream->lock);
if (err < 0)
return err;
timeout = wait_event_interruptible_timeout(runtime->sleep,
(runtime->avail >= runtime->buffer_size),
10*HZ);
spin_lock_irq(&substream->lock);
if (signal_pending(current))
err = -ERESTARTSYS;
if (runtime->avail < runtime->buffer_size && !timeout) {
rmidi_warn(substream->rmidi,
"rawmidi drain error (avail = %li, buffer_size = %li)\n",
(long)runtime->avail, (long)runtime->buffer_size);
err = -EIO;
}
runtime->drain = 0;
spin_unlock_irq(&substream->lock);
if (err != -ERESTARTSYS) {
/* we need wait a while to make sure that Tx FIFOs are empty */
if (substream->ops->drain)
substream->ops->drain(substream);
else
msleep(50);
snd_rawmidi_drop_output(substream);
}
spin_lock_irq(&substream->lock);
snd_rawmidi_buffer_unref(runtime);
spin_unlock_irq(&substream->lock);
return err;
}
EXPORT_SYMBOL(snd_rawmidi_drain_output);
int snd_rawmidi_drain_input(struct snd_rawmidi_substream *substream)
{
snd_rawmidi_input_trigger(substream, 0);
reset_runtime_ptrs(substream, true);
return 0;
}
EXPORT_SYMBOL(snd_rawmidi_drain_input);
/* look for an available substream for the given stream direction;
* if a specific subdevice is given, try to assign it
*/
static int assign_substream(struct snd_rawmidi *rmidi, int subdevice,
int stream, int mode,
struct snd_rawmidi_substream **sub_ret)
{
struct snd_rawmidi_substream *substream;
struct snd_rawmidi_str *s = &rmidi->streams[stream];
static const unsigned int info_flags[2] = {
[SNDRV_RAWMIDI_STREAM_OUTPUT] = SNDRV_RAWMIDI_INFO_OUTPUT,
[SNDRV_RAWMIDI_STREAM_INPUT] = SNDRV_RAWMIDI_INFO_INPUT,
};
if (!(rmidi->info_flags & info_flags[stream]))
return -ENXIO;
if (subdevice >= 0 && subdevice >= s->substream_count)
return -ENODEV;
list_for_each_entry(substream, &s->substreams, list) {
if (substream->opened) {
if (stream == SNDRV_RAWMIDI_STREAM_INPUT ||
!(mode & SNDRV_RAWMIDI_LFLG_APPEND) ||
!substream->append)
continue;
}
if (subdevice < 0 || subdevice == substream->number) {
*sub_ret = substream;
return 0;
}
}
return -EAGAIN;
}
/* open and do ref-counting for the given substream */
static int open_substream(struct snd_rawmidi *rmidi,
struct snd_rawmidi_substream *substream,
int mode)
{
int err;
if (substream->use_count == 0) {
err = snd_rawmidi_runtime_create(substream);
if (err < 0)
return err;
err = substream->ops->open(substream);
if (err < 0) {
snd_rawmidi_runtime_free(substream);
return err;
}
spin_lock_irq(&substream->lock);
substream->opened = 1;
substream->active_sensing = 0;
if (mode & SNDRV_RAWMIDI_LFLG_APPEND)
substream->append = 1;
substream->pid = get_pid(task_pid(current));
rmidi->streams[substream->stream].substream_opened++;
spin_unlock_irq(&substream->lock);
}
substream->use_count++;
return 0;
}
static void close_substream(struct snd_rawmidi *rmidi,
struct snd_rawmidi_substream *substream,
int cleanup);
static int rawmidi_open_priv(struct snd_rawmidi *rmidi, int subdevice, int mode,
struct snd_rawmidi_file *rfile)
{
struct snd_rawmidi_substream *sinput = NULL, *soutput = NULL;
int err;
rfile->input = rfile->output = NULL;
if (mode & SNDRV_RAWMIDI_LFLG_INPUT) {
err = assign_substream(rmidi, subdevice,
SNDRV_RAWMIDI_STREAM_INPUT,
mode, &sinput);
if (err < 0)
return err;
}
if (mode & SNDRV_RAWMIDI_LFLG_OUTPUT) {
err = assign_substream(rmidi, subdevice,
SNDRV_RAWMIDI_STREAM_OUTPUT,
mode, &soutput);
if (err < 0)
return err;
}
if (sinput) {
err = open_substream(rmidi, sinput, mode);
if (err < 0)
return err;
}
if (soutput) {
err = open_substream(rmidi, soutput, mode);
if (err < 0) {
if (sinput)
close_substream(rmidi, sinput, 0);
return err;
}
}
rfile->rmidi = rmidi;
rfile->input = sinput;
rfile->output = soutput;
return 0;
}
/* called from sound/core/seq/seq_midi.c */
int snd_rawmidi_kernel_open(struct snd_card *card, int device, int subdevice,
int mode, struct snd_rawmidi_file *rfile)
{
struct snd_rawmidi *rmidi;
int err = 0;
if (snd_BUG_ON(!rfile))
return -EINVAL;
mutex_lock(&register_mutex);
rmidi = snd_rawmidi_search(card, device);
if (!rmidi)
err = -ENODEV;
else if (!try_module_get(rmidi->card->module))
err = -ENXIO;
mutex_unlock(&register_mutex);
if (err < 0)
return err;
mutex_lock(&rmidi->open_mutex);
err = rawmidi_open_priv(rmidi, subdevice, mode, rfile);
mutex_unlock(&rmidi->open_mutex);
if (err < 0)
module_put(rmidi->card->module);
return err;
}
EXPORT_SYMBOL(snd_rawmidi_kernel_open);
static int snd_rawmidi_open(struct inode *inode, struct file *file)
{
int maj = imajor(inode);
struct snd_card *card;
int subdevice;
unsigned short fflags;
int err;
struct snd_rawmidi *rmidi;
struct snd_rawmidi_file *rawmidi_file = NULL;
wait_queue_entry_t wait;
if ((file->f_flags & O_APPEND) && !(file->f_flags & O_NONBLOCK))
return -EINVAL; /* invalid combination */
*: convert stream-like files from nonseekable_open -> stream_open Using scripts/coccinelle/api/stream_open.cocci added in 10dce8af3422 ("fs: stream_open - opener for stream-like files so that read and write can run simultaneously without deadlock"), search and convert to stream_open all in-kernel nonseekable_open users for which read and write actually do not depend on ppos and where there is no other methods in file_operations which assume @offset access. I've verified each generated change manually - that it is correct to convert - and each other nonseekable_open instance left - that it is either not correct to convert there, or that it is not converted due to current stream_open.cocci limitations. The script also does not convert files that should be valid to convert, but that currently have .llseek = noop_llseek or generic_file_llseek for unknown reason despite file being opened with nonseekable_open (e.g. drivers/input/mousedev.c) Among cases converted 14 were potentially vulnerable to read vs write deadlock (see details in 10dce8af3422): drivers/char/pcmcia/cm4000_cs.c:1685:7-23: ERROR: cm4000_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/gnss/core.c:45:1-17: ERROR: gnss_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/hid/uhid.c:635:1-17: ERROR: uhid_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/infiniband/core/user_mad.c:988:1-17: ERROR: umad_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/input/evdev.c:527:1-17: ERROR: evdev_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/input/misc/uinput.c:401:1-17: ERROR: uinput_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/isdn/capi/capi.c:963:8-24: ERROR: capi_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/leds/uleds.c:77:1-17: ERROR: uleds_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/media/rc/lirc_dev.c:198:1-17: ERROR: lirc_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/s390/char/fs3270.c:488:1-17: ERROR: fs3270_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/usb/misc/ldusb.c:310:1-17: ERROR: ld_usb_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/xen/evtchn.c:667:8-24: ERROR: evtchn_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. net/batman-adv/icmp_socket.c:80:1-17: ERROR: batadv_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. net/rfkill/core.c:1146:8-24: ERROR: rfkill_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. and the rest were just safe to convert to stream_open because their read and write do not use ppos at all and corresponding file_operations do not have methods that assume @offset file access(*): arch/powerpc/platforms/52xx/mpc52xx_gpt.c:631:8-24: WARNING: mpc52xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_ibox_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_ibox_stat_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_mbox_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_mbox_stat_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_wbox_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_wbox_stat_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. arch/um/drivers/harddog_kern.c:88:8-24: WARNING: harddog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. arch/x86/kernel/cpu/microcode/core.c:430:33-49: WARNING: microcode_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/char/ds1620.c:215:8-24: WARNING: ds1620_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/char/dtlk.c:301:1-17: WARNING: dtlk_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/char/ipmi/ipmi_watchdog.c:840:9-25: WARNING: ipmi_wdog_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/char/pcmcia/scr24x_cs.c:95:8-24: WARNING: scr24x_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/char/tb0219.c:246:9-25: WARNING: tb0219_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/firewire/nosy.c:306:8-24: WARNING: nosy_ops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/hwmon/fschmd.c:840:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/hwmon/w83793.c:1344:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/infiniband/core/ucma.c:1747:8-24: WARNING: ucma_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/infiniband/core/ucm.c:1178:8-24: WARNING: ucm_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/infiniband/core/uverbs_main.c:1086:8-24: WARNING: uverbs_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/input/joydev.c:282:1-17: WARNING: joydev_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/pci/switch/switchtec.c:393:1-17: WARNING: switchtec_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/platform/chrome/cros_ec_debugfs.c:135:8-24: WARNING: cros_ec_console_log_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/rtc/rtc-ds1374.c:470:9-25: WARNING: ds1374_wdt_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/rtc/rtc-m41t80.c:805:9-25: WARNING: wdt_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/s390/char/tape_char.c:293:2-18: WARNING: tape_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/s390/char/zcore.c:194:8-24: WARNING: zcore_reipl_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/s390/crypto/zcrypt_api.c:528:8-24: WARNING: zcrypt_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/spi/spidev.c:594:1-17: WARNING: spidev_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/staging/pi433/pi433_if.c:974:1-17: WARNING: pi433_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/acquirewdt.c:203:8-24: WARNING: acq_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/advantechwdt.c:202:8-24: WARNING: advwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/alim1535_wdt.c:252:8-24: WARNING: ali_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/alim7101_wdt.c:217:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ar7_wdt.c:166:8-24: WARNING: ar7_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/at91rm9200_wdt.c:113:8-24: WARNING: at91wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ath79_wdt.c:135:8-24: WARNING: ath79_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/bcm63xx_wdt.c:119:8-24: WARNING: bcm63xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/cpu5wdt.c:143:8-24: WARNING: cpu5wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/cpwd.c:397:8-24: WARNING: cpwd_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/eurotechwdt.c:319:8-24: WARNING: eurwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/f71808e_wdt.c:528:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/gef_wdt.c:232:8-24: WARNING: gef_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/geodewdt.c:95:8-24: WARNING: geodewdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ib700wdt.c:241:8-24: WARNING: ibwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ibmasr.c:326:8-24: WARNING: asr_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/indydog.c:80:8-24: WARNING: indydog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/intel_scu_watchdog.c:307:8-24: WARNING: intel_scu_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/iop_wdt.c:104:8-24: WARNING: iop_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/it8712f_wdt.c:330:8-24: WARNING: it8712f_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ixp4xx_wdt.c:68:8-24: WARNING: ixp4xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ks8695_wdt.c:145:8-24: WARNING: ks8695wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/m54xx_wdt.c:88:8-24: WARNING: m54xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/machzwd.c:336:8-24: WARNING: zf_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/mixcomwd.c:153:8-24: WARNING: mixcomwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/mtx-1_wdt.c:121:8-24: WARNING: mtx1_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/mv64x60_wdt.c:136:8-24: WARNING: mv64x60_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/nuc900_wdt.c:134:8-24: WARNING: nuc900wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/nv_tco.c:164:8-24: WARNING: nv_tco_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pc87413_wdt.c:289:8-24: WARNING: pc87413_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd.c:698:8-24: WARNING: pcwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd.c:737:8-24: WARNING: pcwd_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd_pci.c:581:8-24: WARNING: pcipcwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd_pci.c:623:8-24: WARNING: pcipcwd_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd_usb.c:488:8-24: WARNING: usb_pcwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd_usb.c:527:8-24: WARNING: usb_pcwd_temperature_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pika_wdt.c:121:8-24: WARNING: pikawdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pnx833x_wdt.c:119:8-24: WARNING: pnx833x_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/rc32434_wdt.c:153:8-24: WARNING: rc32434_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/rdc321x_wdt.c:145:8-24: WARNING: rdc321x_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/riowd.c:79:1-17: WARNING: riowd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sa1100_wdt.c:62:8-24: WARNING: sa1100dog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sbc60xxwdt.c:211:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sbc7240_wdt.c:139:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sbc8360.c:274:8-24: WARNING: sbc8360_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sbc_epx_c3.c:81:8-24: WARNING: epx_c3_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sbc_fitpc2_wdt.c:78:8-24: WARNING: fitpc2_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sb_wdog.c:108:1-17: WARNING: sbwdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sc1200wdt.c:181:8-24: WARNING: sc1200wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sc520_wdt.c:261:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sch311x_wdt.c:319:8-24: WARNING: sch311x_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/scx200_wdt.c:105:8-24: WARNING: scx200_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/smsc37b787_wdt.c:369:8-24: WARNING: wb_smsc_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/w83877f_wdt.c:227:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/w83977f_wdt.c:301:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wafer5823wdt.c:200:8-24: WARNING: wafwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/watchdog_dev.c:828:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdrtas.c:379:8-24: WARNING: wdrtas_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdrtas.c:445:8-24: WARNING: wdrtas_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt285.c:104:1-17: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt977.c:276:8-24: WARNING: wdt977_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt.c:424:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt.c:484:8-24: WARNING: wdt_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt_pci.c:464:8-24: WARNING: wdtpci_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt_pci.c:527:8-24: WARNING: wdtpci_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. net/batman-adv/log.c:105:1-17: WARNING: batadv_log_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. sound/core/control.c:57:7-23: WARNING: snd_ctl_f_ops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. sound/core/rawmidi.c:385:7-23: WARNING: snd_rawmidi_f_ops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. sound/core/seq/seq_clientmgr.c:310:7-23: WARNING: snd_seq_f_ops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. sound/core/timer.c:1428:7-23: WARNING: snd_timer_f_ops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. One can also recheck/review the patch via generating it with explanation comments included via $ make coccicheck MODE=patch COCCI=scripts/coccinelle/api/stream_open.cocci SPFLAGS="-D explain" (*) This second group also contains cases with read/write deadlocks that stream_open.cocci don't yet detect, but which are still valid to convert to stream_open since ppos is not used. For example drivers/pci/switch/switchtec.c calls wait_for_completion_interruptible() in its .read, but stream_open.cocci currently detects only "wait_event*" as blocking. Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yongzhi Pan <panyongzhi@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Juergen Gross <jgross@suse.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Tejun Heo <tj@kernel.org> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Julia Lawall <Julia.Lawall@lip6.fr> Cc: Nikolaus Rath <Nikolaus@rath.org> Cc: Han-Wen Nienhuys <hanwen@google.com> Cc: Anatolij Gustschin <agust@denx.de> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James R. Van Zandt" <jrv@vanzandt.mv.com> Cc: Corey Minyard <minyard@acm.org> Cc: Harald Welte <laforge@gnumonks.org> Acked-by: Lubomir Rintel <lkundrak@v3.sk> [scr24x_cs] Cc: Stefan Richter <stefanr@s5r6.in-berlin.de> Cc: Johan Hovold <johan@kernel.org> Cc: David Herrmann <dh.herrmann@googlemail.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com> Cc: Jean Delvare <jdelvare@suse.com> Acked-by: Guenter Roeck <linux@roeck-us.net> [watchdog/* hwmon/*] Cc: Rudolf Marek <r.marek@assembler.cz> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Karsten Keil <isdn@linux-pingi.de> Cc: Jacek Anaszewski <jacek.anaszewski@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Kurt Schwemmer <kurt.schwemmer@microsemi.com> Acked-by: Logan Gunthorpe <logang@deltatee.com> [drivers/pci/switch/switchtec] Acked-by: Bjorn Helgaas <bhelgaas@google.com> [drivers/pci/switch/switchtec] Cc: Benson Leung <bleung@chromium.org> Acked-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> [platform/chrome] Cc: Alessandro Zummo <a.zummo@towertech.it> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> [rtc/*] Cc: Mark Brown <broonie@kernel.org> Cc: Wim Van Sebroeck <wim@linux-watchdog.org> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: bcm-kernel-feedback-list@broadcom.com Cc: Wan ZongShun <mcuos.com@gmail.com> Cc: Zwane Mwaikambo <zwanem@gmail.com> Cc: Marek Lindner <mareklindner@neomailbox.ch> Cc: Simon Wunderlich <sw@simonwunderlich.de> Cc: Antonio Quartulli <a@unstable.cc> Cc: "David S. Miller" <davem@davemloft.net> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Takashi Iwai <tiwai@suse.com> Signed-off-by: Kirill Smelkov <kirr@nexedi.com>
2019-03-26 23:51:19 +03:00
err = stream_open(inode, file);
if (err < 0)
return err;
if (maj == snd_major) {
rmidi = snd_lookup_minor_data(iminor(inode),
SNDRV_DEVICE_TYPE_RAWMIDI);
#ifdef CONFIG_SND_OSSEMUL
} else if (maj == SOUND_MAJOR) {
rmidi = snd_lookup_oss_minor_data(iminor(inode),
SNDRV_OSS_DEVICE_TYPE_MIDI);
#endif
} else
return -ENXIO;
if (rmidi == NULL)
return -ENODEV;
if (!try_module_get(rmidi->card->module)) {
snd_card_unref(rmidi->card);
return -ENXIO;
}
mutex_lock(&rmidi->open_mutex);
card = rmidi->card;
err = snd_card_file_add(card, file);
if (err < 0)
goto __error_card;
fflags = snd_rawmidi_file_flags(file);
if ((file->f_flags & O_APPEND) || maj == SOUND_MAJOR) /* OSS emul? */
fflags |= SNDRV_RAWMIDI_LFLG_APPEND;
rawmidi_file = kmalloc(sizeof(*rawmidi_file), GFP_KERNEL);
if (rawmidi_file == NULL) {
err = -ENOMEM;
goto __error;
}
rawmidi_file->user_pversion = 0;
init_waitqueue_entry(&wait, current);
add_wait_queue(&rmidi->open_wait, &wait);
while (1) {
subdevice = snd_ctl_get_preferred_subdevice(card, SND_CTL_SUBDEV_RAWMIDI);
err = rawmidi_open_priv(rmidi, subdevice, fflags, rawmidi_file);
if (err >= 0)
break;
if (err == -EAGAIN) {
if (file->f_flags & O_NONBLOCK) {
err = -EBUSY;
break;
}
} else
break;
set_current_state(TASK_INTERRUPTIBLE);
mutex_unlock(&rmidi->open_mutex);
schedule();
mutex_lock(&rmidi->open_mutex);
if (rmidi->card->shutdown) {
err = -ENODEV;
break;
}
if (signal_pending(current)) {
err = -ERESTARTSYS;
break;
}
}
remove_wait_queue(&rmidi->open_wait, &wait);
if (err < 0) {
kfree(rawmidi_file);
goto __error;
}
#ifdef CONFIG_SND_OSSEMUL
if (rawmidi_file->input && rawmidi_file->input->runtime)
rawmidi_file->input->runtime->oss = (maj == SOUND_MAJOR);
if (rawmidi_file->output && rawmidi_file->output->runtime)
rawmidi_file->output->runtime->oss = (maj == SOUND_MAJOR);
#endif
file->private_data = rawmidi_file;
mutex_unlock(&rmidi->open_mutex);
snd_card_unref(rmidi->card);
return 0;
__error:
snd_card_file_remove(card, file);
__error_card:
mutex_unlock(&rmidi->open_mutex);
module_put(rmidi->card->module);
snd_card_unref(rmidi->card);
return err;
}
static void close_substream(struct snd_rawmidi *rmidi,
struct snd_rawmidi_substream *substream,
int cleanup)
{
if (--substream->use_count)
return;
if (cleanup) {
if (substream->stream == SNDRV_RAWMIDI_STREAM_INPUT)
snd_rawmidi_input_trigger(substream, 0);
else {
if (substream->active_sensing) {
unsigned char buf = 0xfe;
/* sending single active sensing message
* to shut the device up
*/
snd_rawmidi_kernel_write(substream, &buf, 1);
}
if (snd_rawmidi_drain_output(substream) == -ERESTARTSYS)
snd_rawmidi_output_trigger(substream, 0);
}
snd_rawmidi_buffer_ref_sync(substream);
}
spin_lock_irq(&substream->lock);
substream->opened = 0;
substream->append = 0;
spin_unlock_irq(&substream->lock);
substream->ops->close(substream);
if (substream->runtime->private_free)
substream->runtime->private_free(substream);
snd_rawmidi_runtime_free(substream);
put_pid(substream->pid);
substream->pid = NULL;
rmidi->streams[substream->stream].substream_opened--;
}
static void rawmidi_release_priv(struct snd_rawmidi_file *rfile)
{
struct snd_rawmidi *rmidi;
rmidi = rfile->rmidi;
mutex_lock(&rmidi->open_mutex);
if (rfile->input) {
close_substream(rmidi, rfile->input, 1);
rfile->input = NULL;
}
if (rfile->output) {
close_substream(rmidi, rfile->output, 1);
rfile->output = NULL;
}
rfile->rmidi = NULL;
mutex_unlock(&rmidi->open_mutex);
wake_up(&rmidi->open_wait);
}
/* called from sound/core/seq/seq_midi.c */
int snd_rawmidi_kernel_release(struct snd_rawmidi_file *rfile)
{
struct snd_rawmidi *rmidi;
if (snd_BUG_ON(!rfile))
return -ENXIO;
rmidi = rfile->rmidi;
rawmidi_release_priv(rfile);
module_put(rmidi->card->module);
return 0;
}
EXPORT_SYMBOL(snd_rawmidi_kernel_release);
static int snd_rawmidi_release(struct inode *inode, struct file *file)
{
struct snd_rawmidi_file *rfile;
struct snd_rawmidi *rmidi;
struct module *module;
rfile = file->private_data;
rmidi = rfile->rmidi;
rawmidi_release_priv(rfile);
kfree(rfile);
module = rmidi->card->module;
snd_card_file_remove(rmidi->card, file);
module_put(module);
return 0;
}
static int snd_rawmidi_info(struct snd_rawmidi_substream *substream,
struct snd_rawmidi_info *info)
{
struct snd_rawmidi *rmidi;
if (substream == NULL)
return -ENODEV;
rmidi = substream->rmidi;
memset(info, 0, sizeof(*info));
info->card = rmidi->card->number;
info->device = rmidi->device;
info->subdevice = substream->number;
info->stream = substream->stream;
info->flags = rmidi->info_flags;
strcpy(info->id, rmidi->id);
strcpy(info->name, rmidi->name);
strcpy(info->subname, substream->name);
info->subdevices_count = substream->pstr->substream_count;
info->subdevices_avail = (substream->pstr->substream_count -
substream->pstr->substream_opened);
return 0;
}
static int snd_rawmidi_info_user(struct snd_rawmidi_substream *substream,
struct snd_rawmidi_info __user *_info)
{
struct snd_rawmidi_info info;
int err;
err = snd_rawmidi_info(substream, &info);
if (err < 0)
return err;
if (copy_to_user(_info, &info, sizeof(struct snd_rawmidi_info)))
return -EFAULT;
return 0;
}
static int __snd_rawmidi_info_select(struct snd_card *card,
struct snd_rawmidi_info *info)
{
struct snd_rawmidi *rmidi;
struct snd_rawmidi_str *pstr;
struct snd_rawmidi_substream *substream;
rmidi = snd_rawmidi_search(card, info->device);
if (!rmidi)
return -ENXIO;
if (info->stream < 0 || info->stream > 1)
return -EINVAL;
info->stream = array_index_nospec(info->stream, 2);
pstr = &rmidi->streams[info->stream];
if (pstr->substream_count == 0)
return -ENOENT;
if (info->subdevice >= pstr->substream_count)
return -ENXIO;
list_for_each_entry(substream, &pstr->substreams, list) {
if ((unsigned int)substream->number == info->subdevice)
return snd_rawmidi_info(substream, info);
}
return -ENXIO;
}
int snd_rawmidi_info_select(struct snd_card *card, struct snd_rawmidi_info *info)
{
int ret;
mutex_lock(&register_mutex);
ret = __snd_rawmidi_info_select(card, info);
mutex_unlock(&register_mutex);
return ret;
}
EXPORT_SYMBOL(snd_rawmidi_info_select);
static int snd_rawmidi_info_select_user(struct snd_card *card,
struct snd_rawmidi_info __user *_info)
{
int err;
struct snd_rawmidi_info info;
if (get_user(info.device, &_info->device))
return -EFAULT;
if (get_user(info.stream, &_info->stream))
return -EFAULT;
if (get_user(info.subdevice, &_info->subdevice))
return -EFAULT;
err = snd_rawmidi_info_select(card, &info);
if (err < 0)
return err;
if (copy_to_user(_info, &info, sizeof(struct snd_rawmidi_info)))
return -EFAULT;
return 0;
}
static int resize_runtime_buffer(struct snd_rawmidi_substream *substream,
struct snd_rawmidi_params *params,
bool is_input)
{
struct snd_rawmidi_runtime *runtime = substream->runtime;
char *newbuf, *oldbuf;
unsigned int framing = params->mode & SNDRV_RAWMIDI_MODE_FRAMING_MASK;
if (params->buffer_size < 32 || params->buffer_size > 1024L * 1024L)
return -EINVAL;
if (framing == SNDRV_RAWMIDI_MODE_FRAMING_TSTAMP && (params->buffer_size & 0x1f) != 0)
return -EINVAL;
if (params->avail_min < 1 || params->avail_min > params->buffer_size)
return -EINVAL;
if (params->buffer_size != runtime->buffer_size) {
newbuf = kvzalloc(params->buffer_size, GFP_KERNEL);
if (!newbuf)
return -ENOMEM;
spin_lock_irq(&substream->lock);
if (runtime->buffer_ref) {
spin_unlock_irq(&substream->lock);
kvfree(newbuf);
return -EBUSY;
}
oldbuf = runtime->buffer;
runtime->buffer = newbuf;
runtime->buffer_size = params->buffer_size;
__reset_runtime_ptrs(runtime, is_input);
spin_unlock_irq(&substream->lock);
kvfree(oldbuf);
}
runtime->avail_min = params->avail_min;
return 0;
}
int snd_rawmidi_output_params(struct snd_rawmidi_substream *substream,
struct snd_rawmidi_params *params)
{
int err;
snd_rawmidi_drain_output(substream);
mutex_lock(&substream->rmidi->open_mutex);
if (substream->append && substream->use_count > 1)
err = -EBUSY;
else
err = resize_runtime_buffer(substream, params, false);
if (!err)
substream->active_sensing = !params->no_active_sensing;
mutex_unlock(&substream->rmidi->open_mutex);
return err;
}
EXPORT_SYMBOL(snd_rawmidi_output_params);
int snd_rawmidi_input_params(struct snd_rawmidi_substream *substream,
struct snd_rawmidi_params *params)
{
unsigned int framing = params->mode & SNDRV_RAWMIDI_MODE_FRAMING_MASK;
unsigned int clock_type = params->mode & SNDRV_RAWMIDI_MODE_CLOCK_MASK;
int err;
snd_rawmidi_drain_input(substream);
mutex_lock(&substream->rmidi->open_mutex);
if (framing == SNDRV_RAWMIDI_MODE_FRAMING_NONE && clock_type != SNDRV_RAWMIDI_MODE_CLOCK_NONE)
err = -EINVAL;
else if (clock_type > SNDRV_RAWMIDI_MODE_CLOCK_MONOTONIC_RAW)
err = -EINVAL;
else if (framing > SNDRV_RAWMIDI_MODE_FRAMING_TSTAMP)
err = -EINVAL;
else
err = resize_runtime_buffer(substream, params, true);
if (!err) {
substream->framing = framing;
substream->clock_type = clock_type;
}
mutex_unlock(&substream->rmidi->open_mutex);
return 0;
}
EXPORT_SYMBOL(snd_rawmidi_input_params);
static int snd_rawmidi_output_status(struct snd_rawmidi_substream *substream,
struct snd_rawmidi_status64 *status)
{
struct snd_rawmidi_runtime *runtime = substream->runtime;
memset(status, 0, sizeof(*status));
status->stream = SNDRV_RAWMIDI_STREAM_OUTPUT;
spin_lock_irq(&substream->lock);
status->avail = runtime->avail;
spin_unlock_irq(&substream->lock);
return 0;
}
static int snd_rawmidi_input_status(struct snd_rawmidi_substream *substream,
struct snd_rawmidi_status64 *status)
{
struct snd_rawmidi_runtime *runtime = substream->runtime;
memset(status, 0, sizeof(*status));
status->stream = SNDRV_RAWMIDI_STREAM_INPUT;
spin_lock_irq(&substream->lock);
status->avail = runtime->avail;
status->xruns = runtime->xruns;
runtime->xruns = 0;
spin_unlock_irq(&substream->lock);
return 0;
}
static int snd_rawmidi_ioctl_status32(struct snd_rawmidi_file *rfile,
struct snd_rawmidi_status32 __user *argp)
{
int err = 0;
struct snd_rawmidi_status32 __user *status = argp;
struct snd_rawmidi_status32 status32;
struct snd_rawmidi_status64 status64;
if (copy_from_user(&status32, argp,
sizeof(struct snd_rawmidi_status32)))
return -EFAULT;
switch (status32.stream) {
case SNDRV_RAWMIDI_STREAM_OUTPUT:
if (rfile->output == NULL)
return -EINVAL;
err = snd_rawmidi_output_status(rfile->output, &status64);
break;
case SNDRV_RAWMIDI_STREAM_INPUT:
if (rfile->input == NULL)
return -EINVAL;
err = snd_rawmidi_input_status(rfile->input, &status64);
break;
default:
return -EINVAL;
}
if (err < 0)
return err;
status32 = (struct snd_rawmidi_status32) {
.stream = status64.stream,
.tstamp_sec = status64.tstamp_sec,
.tstamp_nsec = status64.tstamp_nsec,
.avail = status64.avail,
.xruns = status64.xruns,
};
if (copy_to_user(status, &status32, sizeof(*status)))
return -EFAULT;
return 0;
}
static int snd_rawmidi_ioctl_status64(struct snd_rawmidi_file *rfile,
struct snd_rawmidi_status64 __user *argp)
{
int err = 0;
struct snd_rawmidi_status64 status;
if (copy_from_user(&status, argp, sizeof(struct snd_rawmidi_status64)))
return -EFAULT;
switch (status.stream) {
case SNDRV_RAWMIDI_STREAM_OUTPUT:
if (rfile->output == NULL)
return -EINVAL;
err = snd_rawmidi_output_status(rfile->output, &status);
break;
case SNDRV_RAWMIDI_STREAM_INPUT:
if (rfile->input == NULL)
return -EINVAL;
err = snd_rawmidi_input_status(rfile->input, &status);
break;
default:
return -EINVAL;
}
if (err < 0)
return err;
if (copy_to_user(argp, &status,
sizeof(struct snd_rawmidi_status64)))
return -EFAULT;
return 0;
}
static long snd_rawmidi_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct snd_rawmidi_file *rfile;
void __user *argp = (void __user *)arg;
rfile = file->private_data;
if (((cmd >> 8) & 0xff) != 'W')
return -ENOTTY;
switch (cmd) {
case SNDRV_RAWMIDI_IOCTL_PVERSION:
return put_user(SNDRV_RAWMIDI_VERSION, (int __user *)argp) ? -EFAULT : 0;
case SNDRV_RAWMIDI_IOCTL_INFO:
{
int stream;
struct snd_rawmidi_info __user *info = argp;
if (get_user(stream, &info->stream))
return -EFAULT;
switch (stream) {
case SNDRV_RAWMIDI_STREAM_INPUT:
return snd_rawmidi_info_user(rfile->input, info);
case SNDRV_RAWMIDI_STREAM_OUTPUT:
return snd_rawmidi_info_user(rfile->output, info);
default:
return -EINVAL;
}
}
case SNDRV_RAWMIDI_IOCTL_USER_PVERSION:
if (get_user(rfile->user_pversion, (unsigned int __user *)arg))
return -EFAULT;
return 0;
case SNDRV_RAWMIDI_IOCTL_PARAMS:
{
struct snd_rawmidi_params params;
if (copy_from_user(&params, argp, sizeof(struct snd_rawmidi_params)))
return -EFAULT;
if (rfile->user_pversion < SNDRV_PROTOCOL_VERSION(2, 0, 2)) {
params.mode = 0;
memset(params.reserved, 0, sizeof(params.reserved));
}
switch (params.stream) {
case SNDRV_RAWMIDI_STREAM_OUTPUT:
if (rfile->output == NULL)
return -EINVAL;
return snd_rawmidi_output_params(rfile->output, &params);
case SNDRV_RAWMIDI_STREAM_INPUT:
if (rfile->input == NULL)
return -EINVAL;
return snd_rawmidi_input_params(rfile->input, &params);
default:
return -EINVAL;
}
}
case SNDRV_RAWMIDI_IOCTL_STATUS32:
return snd_rawmidi_ioctl_status32(rfile, argp);
case SNDRV_RAWMIDI_IOCTL_STATUS64:
return snd_rawmidi_ioctl_status64(rfile, argp);
case SNDRV_RAWMIDI_IOCTL_DROP:
{
int val;
if (get_user(val, (int __user *) argp))
return -EFAULT;
switch (val) {
case SNDRV_RAWMIDI_STREAM_OUTPUT:
if (rfile->output == NULL)
return -EINVAL;
return snd_rawmidi_drop_output(rfile->output);
default:
return -EINVAL;
}
}
case SNDRV_RAWMIDI_IOCTL_DRAIN:
{
int val;
if (get_user(val, (int __user *) argp))
return -EFAULT;
switch (val) {
case SNDRV_RAWMIDI_STREAM_OUTPUT:
if (rfile->output == NULL)
return -EINVAL;
return snd_rawmidi_drain_output(rfile->output);
case SNDRV_RAWMIDI_STREAM_INPUT:
if (rfile->input == NULL)
return -EINVAL;
return snd_rawmidi_drain_input(rfile->input);
default:
return -EINVAL;
}
}
default:
rmidi_dbg(rfile->rmidi,
"rawmidi: unknown command = 0x%x\n", cmd);
}
return -ENOTTY;
}
static int snd_rawmidi_control_ioctl(struct snd_card *card,
struct snd_ctl_file *control,
unsigned int cmd,
unsigned long arg)
{
void __user *argp = (void __user *)arg;
switch (cmd) {
case SNDRV_CTL_IOCTL_RAWMIDI_NEXT_DEVICE:
{
int device;
if (get_user(device, (int __user *)argp))
return -EFAULT;
if (device >= SNDRV_RAWMIDI_DEVICES) /* next device is -1 */
device = SNDRV_RAWMIDI_DEVICES - 1;
mutex_lock(&register_mutex);
device = device < 0 ? 0 : device + 1;
while (device < SNDRV_RAWMIDI_DEVICES) {
if (snd_rawmidi_search(card, device))
break;
device++;
}
if (device == SNDRV_RAWMIDI_DEVICES)
device = -1;
mutex_unlock(&register_mutex);
if (put_user(device, (int __user *)argp))
return -EFAULT;
return 0;
}
case SNDRV_CTL_IOCTL_RAWMIDI_PREFER_SUBDEVICE:
{
int val;
if (get_user(val, (int __user *)argp))
return -EFAULT;
control->preferred_subdevice[SND_CTL_SUBDEV_RAWMIDI] = val;
return 0;
}
case SNDRV_CTL_IOCTL_RAWMIDI_INFO:
return snd_rawmidi_info_select_user(card, argp);
}
return -ENOIOCTLCMD;
}
static int receive_with_tstamp_framing(struct snd_rawmidi_substream *substream,
const unsigned char *buffer, int src_count, const struct timespec64 *tstamp)
{
struct snd_rawmidi_runtime *runtime = substream->runtime;
struct snd_rawmidi_framing_tstamp *dest_ptr;
struct snd_rawmidi_framing_tstamp frame = { .tv_sec = tstamp->tv_sec, .tv_nsec = tstamp->tv_nsec };
int orig_count = src_count;
int frame_size = sizeof(struct snd_rawmidi_framing_tstamp);
BUILD_BUG_ON(frame_size != 0x20);
if (snd_BUG_ON((runtime->hw_ptr & 0x1f) != 0))
return -EINVAL;
while (src_count > 0) {
if ((int)(runtime->buffer_size - runtime->avail) < frame_size) {
runtime->xruns += src_count;
break;
}
if (src_count >= SNDRV_RAWMIDI_FRAMING_DATA_LENGTH)
frame.length = SNDRV_RAWMIDI_FRAMING_DATA_LENGTH;
else {
frame.length = src_count;
memset(frame.data, 0, SNDRV_RAWMIDI_FRAMING_DATA_LENGTH);
}
memcpy(frame.data, buffer, frame.length);
buffer += frame.length;
src_count -= frame.length;
dest_ptr = (struct snd_rawmidi_framing_tstamp *) (runtime->buffer + runtime->hw_ptr);
*dest_ptr = frame;
runtime->avail += frame_size;
runtime->hw_ptr += frame_size;
runtime->hw_ptr %= runtime->buffer_size;
}
return orig_count - src_count;
}
static struct timespec64 get_framing_tstamp(struct snd_rawmidi_substream *substream)
{
struct timespec64 ts64 = {0, 0};
switch (substream->clock_type) {
case SNDRV_RAWMIDI_MODE_CLOCK_MONOTONIC_RAW:
ktime_get_raw_ts64(&ts64);
break;
case SNDRV_RAWMIDI_MODE_CLOCK_MONOTONIC:
ktime_get_ts64(&ts64);
break;
case SNDRV_RAWMIDI_MODE_CLOCK_REALTIME:
ktime_get_real_ts64(&ts64);
break;
}
return ts64;
}
/**
* snd_rawmidi_receive - receive the input data from the device
* @substream: the rawmidi substream
* @buffer: the buffer pointer
* @count: the data size to read
*
* Reads the data from the internal buffer.
*
* Return: The size of read data, or a negative error code on failure.
*/
int snd_rawmidi_receive(struct snd_rawmidi_substream *substream,
const unsigned char *buffer, int count)
{
unsigned long flags;
struct timespec64 ts64 = get_framing_tstamp(substream);
int result = 0, count1;
struct snd_rawmidi_runtime *runtime;
spin_lock_irqsave(&substream->lock, flags);
if (!substream->opened) {
result = -EBADFD;
goto unlock;
}
runtime = substream->runtime;
if (!runtime || !runtime->buffer) {
rmidi_dbg(substream->rmidi,
"snd_rawmidi_receive: input is not active!!!\n");
result = -EINVAL;
goto unlock;
}
if (substream->framing == SNDRV_RAWMIDI_MODE_FRAMING_TSTAMP) {
result = receive_with_tstamp_framing(substream, buffer, count, &ts64);
} else if (count == 1) { /* special case, faster code */
substream->bytes++;
if (runtime->avail < runtime->buffer_size) {
runtime->buffer[runtime->hw_ptr++] = buffer[0];
runtime->hw_ptr %= runtime->buffer_size;
runtime->avail++;
result++;
} else {
runtime->xruns++;
}
} else {
substream->bytes += count;
count1 = runtime->buffer_size - runtime->hw_ptr;
if (count1 > count)
count1 = count;
if (count1 > (int)(runtime->buffer_size - runtime->avail))
count1 = runtime->buffer_size - runtime->avail;
memcpy(runtime->buffer + runtime->hw_ptr, buffer, count1);
runtime->hw_ptr += count1;
runtime->hw_ptr %= runtime->buffer_size;
runtime->avail += count1;
count -= count1;
result += count1;
if (count > 0) {
buffer += count1;
count1 = count;
if (count1 > (int)(runtime->buffer_size - runtime->avail)) {
count1 = runtime->buffer_size - runtime->avail;
runtime->xruns += count - count1;
}
if (count1 > 0) {
memcpy(runtime->buffer, buffer, count1);
runtime->hw_ptr = count1;
runtime->avail += count1;
result += count1;
}
}
}
if (result > 0) {
if (runtime->event)
schedule_work(&runtime->event_work);
else if (__snd_rawmidi_ready(runtime))
wake_up(&runtime->sleep);
}
unlock:
spin_unlock_irqrestore(&substream->lock, flags);
return result;
}
EXPORT_SYMBOL(snd_rawmidi_receive);
static long snd_rawmidi_kernel_read1(struct snd_rawmidi_substream *substream,
unsigned char __user *userbuf,
unsigned char *kernelbuf, long count)
{
unsigned long flags;
long result = 0, count1;
struct snd_rawmidi_runtime *runtime = substream->runtime;
unsigned long appl_ptr;
int err = 0;
spin_lock_irqsave(&substream->lock, flags);
snd_rawmidi_buffer_ref(runtime);
while (count > 0 && runtime->avail) {
count1 = runtime->buffer_size - runtime->appl_ptr;
if (count1 > count)
count1 = count;
if (count1 > (int)runtime->avail)
count1 = runtime->avail;
/* update runtime->appl_ptr before unlocking for userbuf */
appl_ptr = runtime->appl_ptr;
runtime->appl_ptr += count1;
runtime->appl_ptr %= runtime->buffer_size;
runtime->avail -= count1;
if (kernelbuf)
memcpy(kernelbuf + result, runtime->buffer + appl_ptr, count1);
if (userbuf) {
spin_unlock_irqrestore(&substream->lock, flags);
if (copy_to_user(userbuf + result,
runtime->buffer + appl_ptr, count1))
err = -EFAULT;
spin_lock_irqsave(&substream->lock, flags);
if (err)
goto out;
}
result += count1;
count -= count1;
}
out:
snd_rawmidi_buffer_unref(runtime);
spin_unlock_irqrestore(&substream->lock, flags);
return result > 0 ? result : err;
}
long snd_rawmidi_kernel_read(struct snd_rawmidi_substream *substream,
unsigned char *buf, long count)
{
snd_rawmidi_input_trigger(substream, 1);
return snd_rawmidi_kernel_read1(substream, NULL/*userbuf*/, buf, count);
}
EXPORT_SYMBOL(snd_rawmidi_kernel_read);
static ssize_t snd_rawmidi_read(struct file *file, char __user *buf, size_t count,
loff_t *offset)
{
long result;
int count1;
struct snd_rawmidi_file *rfile;
struct snd_rawmidi_substream *substream;
struct snd_rawmidi_runtime *runtime;
rfile = file->private_data;
substream = rfile->input;
if (substream == NULL)
return -EIO;
runtime = substream->runtime;
snd_rawmidi_input_trigger(substream, 1);
result = 0;
while (count > 0) {
spin_lock_irq(&substream->lock);
while (!__snd_rawmidi_ready(runtime)) {
wait_queue_entry_t wait;
if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
spin_unlock_irq(&substream->lock);
return result > 0 ? result : -EAGAIN;
}
init_waitqueue_entry(&wait, current);
add_wait_queue(&runtime->sleep, &wait);
set_current_state(TASK_INTERRUPTIBLE);
spin_unlock_irq(&substream->lock);
schedule();
remove_wait_queue(&runtime->sleep, &wait);
if (rfile->rmidi->card->shutdown)
return -ENODEV;
if (signal_pending(current))
return result > 0 ? result : -ERESTARTSYS;
spin_lock_irq(&substream->lock);
if (!runtime->avail) {
spin_unlock_irq(&substream->lock);
return result > 0 ? result : -EIO;
}
}
spin_unlock_irq(&substream->lock);
count1 = snd_rawmidi_kernel_read1(substream,
(unsigned char __user *)buf,
NULL/*kernelbuf*/,
count);
if (count1 < 0)
return result > 0 ? result : count1;
result += count1;
buf += count1;
count -= count1;
}
return result;
}
/**
* snd_rawmidi_transmit_empty - check whether the output buffer is empty
* @substream: the rawmidi substream
*
* Return: 1 if the internal output buffer is empty, 0 if not.
*/
int snd_rawmidi_transmit_empty(struct snd_rawmidi_substream *substream)
{
struct snd_rawmidi_runtime *runtime;
int result;
unsigned long flags;
spin_lock_irqsave(&substream->lock, flags);
runtime = substream->runtime;
if (!substream->opened || !runtime || !runtime->buffer) {
rmidi_dbg(substream->rmidi,
"snd_rawmidi_transmit_empty: output is not active!!!\n");
result = 1;
} else {
result = runtime->avail >= runtime->buffer_size;
}
spin_unlock_irqrestore(&substream->lock, flags);
return result;
}
EXPORT_SYMBOL(snd_rawmidi_transmit_empty);
/*
ALSA: rawmidi: Make snd_rawmidi_transmit() race-free A kernel WARNING in snd_rawmidi_transmit_ack() is triggered by syzkaller fuzzer: WARNING: CPU: 1 PID: 20739 at sound/core/rawmidi.c:1136 Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff82999e2d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50 [<ffffffff81352089>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482 [<ffffffff813522b9>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515 [<ffffffff84f80bd5>] snd_rawmidi_transmit_ack+0x275/0x400 sound/core/rawmidi.c:1136 [<ffffffff84fdb3c1>] snd_virmidi_output_trigger+0x4b1/0x5a0 sound/core/seq/seq_virmidi.c:163 [< inline >] snd_rawmidi_output_trigger sound/core/rawmidi.c:150 [<ffffffff84f87ed9>] snd_rawmidi_kernel_write1+0x549/0x780 sound/core/rawmidi.c:1223 [<ffffffff84f89fd3>] snd_rawmidi_write+0x543/0xb30 sound/core/rawmidi.c:1273 [<ffffffff817b0323>] __vfs_write+0x113/0x480 fs/read_write.c:528 [<ffffffff817b1db7>] vfs_write+0x167/0x4a0 fs/read_write.c:577 [< inline >] SYSC_write fs/read_write.c:624 [<ffffffff817b50a1>] SyS_write+0x111/0x220 fs/read_write.c:616 [<ffffffff86336c36>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 Also a similar warning is found but in another path: Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff82be2c0d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50 [<ffffffff81355139>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482 [<ffffffff81355369>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515 [<ffffffff8527e69a>] rawmidi_transmit_ack+0x24a/0x3b0 sound/core/rawmidi.c:1133 [<ffffffff8527e851>] snd_rawmidi_transmit_ack+0x51/0x80 sound/core/rawmidi.c:1163 [<ffffffff852d9046>] snd_virmidi_output_trigger+0x2b6/0x570 sound/core/seq/seq_virmidi.c:185 [< inline >] snd_rawmidi_output_trigger sound/core/rawmidi.c:150 [<ffffffff85285a0b>] snd_rawmidi_kernel_write1+0x4bb/0x760 sound/core/rawmidi.c:1252 [<ffffffff85287b73>] snd_rawmidi_write+0x543/0xb30 sound/core/rawmidi.c:1302 [<ffffffff817ba5f3>] __vfs_write+0x113/0x480 fs/read_write.c:528 [<ffffffff817bc087>] vfs_write+0x167/0x4a0 fs/read_write.c:577 [< inline >] SYSC_write fs/read_write.c:624 [<ffffffff817bf371>] SyS_write+0x111/0x220 fs/read_write.c:616 [<ffffffff86660276>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 In the former case, the reason is that virmidi has an open code calling snd_rawmidi_transmit_ack() with the value calculated outside the spinlock. We may use snd_rawmidi_transmit() in a loop just for consuming the input data, but even there, there is a race between snd_rawmidi_transmit_peek() and snd_rawmidi_tranmit_ack(). Similarly in the latter case, it calls snd_rawmidi_transmit_peek() and snd_rawmidi_tranmit_ack() separately without protection, so they are racy as well. The patch tries to address these issues by the following ways: - Introduce the unlocked versions of snd_rawmidi_transmit_peek() and snd_rawmidi_transmit_ack() to be called inside the explicit lock. - Rewrite snd_rawmidi_transmit() to be race-free (the former case). - Make the split calls (the latter case) protected in the rawmidi spin lock. BugLink: http://lkml.kernel.org/r/CACT4Y+YPq1+cYLkadwjWa5XjzF1_Vki1eHnVn-Lm0hzhSpu5PA@mail.gmail.com BugLink: http://lkml.kernel.org/r/CACT4Y+acG4iyphdOZx47Nyq_VHGbpJQK-6xNpiqUjaZYqsXOGw@mail.gmail.com Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-01-31 13:57:41 +03:00
* __snd_rawmidi_transmit_peek - copy data from the internal buffer
* @substream: the rawmidi substream
* @buffer: the buffer pointer
* @count: data size to transfer
*
ALSA: rawmidi: Make snd_rawmidi_transmit() race-free A kernel WARNING in snd_rawmidi_transmit_ack() is triggered by syzkaller fuzzer: WARNING: CPU: 1 PID: 20739 at sound/core/rawmidi.c:1136 Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff82999e2d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50 [<ffffffff81352089>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482 [<ffffffff813522b9>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515 [<ffffffff84f80bd5>] snd_rawmidi_transmit_ack+0x275/0x400 sound/core/rawmidi.c:1136 [<ffffffff84fdb3c1>] snd_virmidi_output_trigger+0x4b1/0x5a0 sound/core/seq/seq_virmidi.c:163 [< inline >] snd_rawmidi_output_trigger sound/core/rawmidi.c:150 [<ffffffff84f87ed9>] snd_rawmidi_kernel_write1+0x549/0x780 sound/core/rawmidi.c:1223 [<ffffffff84f89fd3>] snd_rawmidi_write+0x543/0xb30 sound/core/rawmidi.c:1273 [<ffffffff817b0323>] __vfs_write+0x113/0x480 fs/read_write.c:528 [<ffffffff817b1db7>] vfs_write+0x167/0x4a0 fs/read_write.c:577 [< inline >] SYSC_write fs/read_write.c:624 [<ffffffff817b50a1>] SyS_write+0x111/0x220 fs/read_write.c:616 [<ffffffff86336c36>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 Also a similar warning is found but in another path: Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff82be2c0d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50 [<ffffffff81355139>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482 [<ffffffff81355369>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515 [<ffffffff8527e69a>] rawmidi_transmit_ack+0x24a/0x3b0 sound/core/rawmidi.c:1133 [<ffffffff8527e851>] snd_rawmidi_transmit_ack+0x51/0x80 sound/core/rawmidi.c:1163 [<ffffffff852d9046>] snd_virmidi_output_trigger+0x2b6/0x570 sound/core/seq/seq_virmidi.c:185 [< inline >] snd_rawmidi_output_trigger sound/core/rawmidi.c:150 [<ffffffff85285a0b>] snd_rawmidi_kernel_write1+0x4bb/0x760 sound/core/rawmidi.c:1252 [<ffffffff85287b73>] snd_rawmidi_write+0x543/0xb30 sound/core/rawmidi.c:1302 [<ffffffff817ba5f3>] __vfs_write+0x113/0x480 fs/read_write.c:528 [<ffffffff817bc087>] vfs_write+0x167/0x4a0 fs/read_write.c:577 [< inline >] SYSC_write fs/read_write.c:624 [<ffffffff817bf371>] SyS_write+0x111/0x220 fs/read_write.c:616 [<ffffffff86660276>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 In the former case, the reason is that virmidi has an open code calling snd_rawmidi_transmit_ack() with the value calculated outside the spinlock. We may use snd_rawmidi_transmit() in a loop just for consuming the input data, but even there, there is a race between snd_rawmidi_transmit_peek() and snd_rawmidi_tranmit_ack(). Similarly in the latter case, it calls snd_rawmidi_transmit_peek() and snd_rawmidi_tranmit_ack() separately without protection, so they are racy as well. The patch tries to address these issues by the following ways: - Introduce the unlocked versions of snd_rawmidi_transmit_peek() and snd_rawmidi_transmit_ack() to be called inside the explicit lock. - Rewrite snd_rawmidi_transmit() to be race-free (the former case). - Make the split calls (the latter case) protected in the rawmidi spin lock. BugLink: http://lkml.kernel.org/r/CACT4Y+YPq1+cYLkadwjWa5XjzF1_Vki1eHnVn-Lm0hzhSpu5PA@mail.gmail.com BugLink: http://lkml.kernel.org/r/CACT4Y+acG4iyphdOZx47Nyq_VHGbpJQK-6xNpiqUjaZYqsXOGw@mail.gmail.com Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-01-31 13:57:41 +03:00
* This is a variant of snd_rawmidi_transmit_peek() without spinlock.
*/
static int __snd_rawmidi_transmit_peek(struct snd_rawmidi_substream *substream,
unsigned char *buffer, int count)
{
int result, count1;
struct snd_rawmidi_runtime *runtime = substream->runtime;
if (runtime->buffer == NULL) {
rmidi_dbg(substream->rmidi,
"snd_rawmidi_transmit_peek: output is not active!!!\n");
return -EINVAL;
}
result = 0;
if (runtime->avail >= runtime->buffer_size) {
/* warning: lowlevel layer MUST trigger down the hardware */
goto __skip;
}
if (count == 1) { /* special case, faster code */
*buffer = runtime->buffer[runtime->hw_ptr];
result++;
} else {
count1 = runtime->buffer_size - runtime->hw_ptr;
if (count1 > count)
count1 = count;
if (count1 > (int)(runtime->buffer_size - runtime->avail))
count1 = runtime->buffer_size - runtime->avail;
memcpy(buffer, runtime->buffer + runtime->hw_ptr, count1);
count -= count1;
result += count1;
if (count > 0) {
if (count > (int)(runtime->buffer_size - runtime->avail - count1))
count = runtime->buffer_size - runtime->avail - count1;
memcpy(buffer + count1, runtime->buffer, count);
result += count;
}
}
__skip:
ALSA: rawmidi: Make snd_rawmidi_transmit() race-free A kernel WARNING in snd_rawmidi_transmit_ack() is triggered by syzkaller fuzzer: WARNING: CPU: 1 PID: 20739 at sound/core/rawmidi.c:1136 Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff82999e2d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50 [<ffffffff81352089>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482 [<ffffffff813522b9>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515 [<ffffffff84f80bd5>] snd_rawmidi_transmit_ack+0x275/0x400 sound/core/rawmidi.c:1136 [<ffffffff84fdb3c1>] snd_virmidi_output_trigger+0x4b1/0x5a0 sound/core/seq/seq_virmidi.c:163 [< inline >] snd_rawmidi_output_trigger sound/core/rawmidi.c:150 [<ffffffff84f87ed9>] snd_rawmidi_kernel_write1+0x549/0x780 sound/core/rawmidi.c:1223 [<ffffffff84f89fd3>] snd_rawmidi_write+0x543/0xb30 sound/core/rawmidi.c:1273 [<ffffffff817b0323>] __vfs_write+0x113/0x480 fs/read_write.c:528 [<ffffffff817b1db7>] vfs_write+0x167/0x4a0 fs/read_write.c:577 [< inline >] SYSC_write fs/read_write.c:624 [<ffffffff817b50a1>] SyS_write+0x111/0x220 fs/read_write.c:616 [<ffffffff86336c36>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 Also a similar warning is found but in another path: Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff82be2c0d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50 [<ffffffff81355139>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482 [<ffffffff81355369>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515 [<ffffffff8527e69a>] rawmidi_transmit_ack+0x24a/0x3b0 sound/core/rawmidi.c:1133 [<ffffffff8527e851>] snd_rawmidi_transmit_ack+0x51/0x80 sound/core/rawmidi.c:1163 [<ffffffff852d9046>] snd_virmidi_output_trigger+0x2b6/0x570 sound/core/seq/seq_virmidi.c:185 [< inline >] snd_rawmidi_output_trigger sound/core/rawmidi.c:150 [<ffffffff85285a0b>] snd_rawmidi_kernel_write1+0x4bb/0x760 sound/core/rawmidi.c:1252 [<ffffffff85287b73>] snd_rawmidi_write+0x543/0xb30 sound/core/rawmidi.c:1302 [<ffffffff817ba5f3>] __vfs_write+0x113/0x480 fs/read_write.c:528 [<ffffffff817bc087>] vfs_write+0x167/0x4a0 fs/read_write.c:577 [< inline >] SYSC_write fs/read_write.c:624 [<ffffffff817bf371>] SyS_write+0x111/0x220 fs/read_write.c:616 [<ffffffff86660276>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 In the former case, the reason is that virmidi has an open code calling snd_rawmidi_transmit_ack() with the value calculated outside the spinlock. We may use snd_rawmidi_transmit() in a loop just for consuming the input data, but even there, there is a race between snd_rawmidi_transmit_peek() and snd_rawmidi_tranmit_ack(). Similarly in the latter case, it calls snd_rawmidi_transmit_peek() and snd_rawmidi_tranmit_ack() separately without protection, so they are racy as well. The patch tries to address these issues by the following ways: - Introduce the unlocked versions of snd_rawmidi_transmit_peek() and snd_rawmidi_transmit_ack() to be called inside the explicit lock. - Rewrite snd_rawmidi_transmit() to be race-free (the former case). - Make the split calls (the latter case) protected in the rawmidi spin lock. BugLink: http://lkml.kernel.org/r/CACT4Y+YPq1+cYLkadwjWa5XjzF1_Vki1eHnVn-Lm0hzhSpu5PA@mail.gmail.com BugLink: http://lkml.kernel.org/r/CACT4Y+acG4iyphdOZx47Nyq_VHGbpJQK-6xNpiqUjaZYqsXOGw@mail.gmail.com Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-01-31 13:57:41 +03:00
return result;
}
/**
* snd_rawmidi_transmit_peek - copy data from the internal buffer
* @substream: the rawmidi substream
* @buffer: the buffer pointer
* @count: data size to transfer
*
* Copies data from the internal output buffer to the given buffer.
*
* Call this in the interrupt handler when the midi output is ready,
* and call snd_rawmidi_transmit_ack() after the transmission is
* finished.
*
* Return: The size of copied data, or a negative error code on failure.
*/
int snd_rawmidi_transmit_peek(struct snd_rawmidi_substream *substream,
unsigned char *buffer, int count)
{
int result;
unsigned long flags;
spin_lock_irqsave(&substream->lock, flags);
if (!substream->opened || !substream->runtime)
result = -EBADFD;
else
result = __snd_rawmidi_transmit_peek(substream, buffer, count);
spin_unlock_irqrestore(&substream->lock, flags);
return result;
}
EXPORT_SYMBOL(snd_rawmidi_transmit_peek);
/*
ALSA: rawmidi: Make snd_rawmidi_transmit() race-free A kernel WARNING in snd_rawmidi_transmit_ack() is triggered by syzkaller fuzzer: WARNING: CPU: 1 PID: 20739 at sound/core/rawmidi.c:1136 Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff82999e2d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50 [<ffffffff81352089>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482 [<ffffffff813522b9>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515 [<ffffffff84f80bd5>] snd_rawmidi_transmit_ack+0x275/0x400 sound/core/rawmidi.c:1136 [<ffffffff84fdb3c1>] snd_virmidi_output_trigger+0x4b1/0x5a0 sound/core/seq/seq_virmidi.c:163 [< inline >] snd_rawmidi_output_trigger sound/core/rawmidi.c:150 [<ffffffff84f87ed9>] snd_rawmidi_kernel_write1+0x549/0x780 sound/core/rawmidi.c:1223 [<ffffffff84f89fd3>] snd_rawmidi_write+0x543/0xb30 sound/core/rawmidi.c:1273 [<ffffffff817b0323>] __vfs_write+0x113/0x480 fs/read_write.c:528 [<ffffffff817b1db7>] vfs_write+0x167/0x4a0 fs/read_write.c:577 [< inline >] SYSC_write fs/read_write.c:624 [<ffffffff817b50a1>] SyS_write+0x111/0x220 fs/read_write.c:616 [<ffffffff86336c36>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 Also a similar warning is found but in another path: Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff82be2c0d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50 [<ffffffff81355139>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482 [<ffffffff81355369>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515 [<ffffffff8527e69a>] rawmidi_transmit_ack+0x24a/0x3b0 sound/core/rawmidi.c:1133 [<ffffffff8527e851>] snd_rawmidi_transmit_ack+0x51/0x80 sound/core/rawmidi.c:1163 [<ffffffff852d9046>] snd_virmidi_output_trigger+0x2b6/0x570 sound/core/seq/seq_virmidi.c:185 [< inline >] snd_rawmidi_output_trigger sound/core/rawmidi.c:150 [<ffffffff85285a0b>] snd_rawmidi_kernel_write1+0x4bb/0x760 sound/core/rawmidi.c:1252 [<ffffffff85287b73>] snd_rawmidi_write+0x543/0xb30 sound/core/rawmidi.c:1302 [<ffffffff817ba5f3>] __vfs_write+0x113/0x480 fs/read_write.c:528 [<ffffffff817bc087>] vfs_write+0x167/0x4a0 fs/read_write.c:577 [< inline >] SYSC_write fs/read_write.c:624 [<ffffffff817bf371>] SyS_write+0x111/0x220 fs/read_write.c:616 [<ffffffff86660276>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 In the former case, the reason is that virmidi has an open code calling snd_rawmidi_transmit_ack() with the value calculated outside the spinlock. We may use snd_rawmidi_transmit() in a loop just for consuming the input data, but even there, there is a race between snd_rawmidi_transmit_peek() and snd_rawmidi_tranmit_ack(). Similarly in the latter case, it calls snd_rawmidi_transmit_peek() and snd_rawmidi_tranmit_ack() separately without protection, so they are racy as well. The patch tries to address these issues by the following ways: - Introduce the unlocked versions of snd_rawmidi_transmit_peek() and snd_rawmidi_transmit_ack() to be called inside the explicit lock. - Rewrite snd_rawmidi_transmit() to be race-free (the former case). - Make the split calls (the latter case) protected in the rawmidi spin lock. BugLink: http://lkml.kernel.org/r/CACT4Y+YPq1+cYLkadwjWa5XjzF1_Vki1eHnVn-Lm0hzhSpu5PA@mail.gmail.com BugLink: http://lkml.kernel.org/r/CACT4Y+acG4iyphdOZx47Nyq_VHGbpJQK-6xNpiqUjaZYqsXOGw@mail.gmail.com Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-01-31 13:57:41 +03:00
* __snd_rawmidi_transmit_ack - acknowledge the transmission
* @substream: the rawmidi substream
* @count: the transferred count
*
ALSA: rawmidi: Make snd_rawmidi_transmit() race-free A kernel WARNING in snd_rawmidi_transmit_ack() is triggered by syzkaller fuzzer: WARNING: CPU: 1 PID: 20739 at sound/core/rawmidi.c:1136 Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff82999e2d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50 [<ffffffff81352089>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482 [<ffffffff813522b9>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515 [<ffffffff84f80bd5>] snd_rawmidi_transmit_ack+0x275/0x400 sound/core/rawmidi.c:1136 [<ffffffff84fdb3c1>] snd_virmidi_output_trigger+0x4b1/0x5a0 sound/core/seq/seq_virmidi.c:163 [< inline >] snd_rawmidi_output_trigger sound/core/rawmidi.c:150 [<ffffffff84f87ed9>] snd_rawmidi_kernel_write1+0x549/0x780 sound/core/rawmidi.c:1223 [<ffffffff84f89fd3>] snd_rawmidi_write+0x543/0xb30 sound/core/rawmidi.c:1273 [<ffffffff817b0323>] __vfs_write+0x113/0x480 fs/read_write.c:528 [<ffffffff817b1db7>] vfs_write+0x167/0x4a0 fs/read_write.c:577 [< inline >] SYSC_write fs/read_write.c:624 [<ffffffff817b50a1>] SyS_write+0x111/0x220 fs/read_write.c:616 [<ffffffff86336c36>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 Also a similar warning is found but in another path: Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff82be2c0d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50 [<ffffffff81355139>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482 [<ffffffff81355369>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515 [<ffffffff8527e69a>] rawmidi_transmit_ack+0x24a/0x3b0 sound/core/rawmidi.c:1133 [<ffffffff8527e851>] snd_rawmidi_transmit_ack+0x51/0x80 sound/core/rawmidi.c:1163 [<ffffffff852d9046>] snd_virmidi_output_trigger+0x2b6/0x570 sound/core/seq/seq_virmidi.c:185 [< inline >] snd_rawmidi_output_trigger sound/core/rawmidi.c:150 [<ffffffff85285a0b>] snd_rawmidi_kernel_write1+0x4bb/0x760 sound/core/rawmidi.c:1252 [<ffffffff85287b73>] snd_rawmidi_write+0x543/0xb30 sound/core/rawmidi.c:1302 [<ffffffff817ba5f3>] __vfs_write+0x113/0x480 fs/read_write.c:528 [<ffffffff817bc087>] vfs_write+0x167/0x4a0 fs/read_write.c:577 [< inline >] SYSC_write fs/read_write.c:624 [<ffffffff817bf371>] SyS_write+0x111/0x220 fs/read_write.c:616 [<ffffffff86660276>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 In the former case, the reason is that virmidi has an open code calling snd_rawmidi_transmit_ack() with the value calculated outside the spinlock. We may use snd_rawmidi_transmit() in a loop just for consuming the input data, but even there, there is a race between snd_rawmidi_transmit_peek() and snd_rawmidi_tranmit_ack(). Similarly in the latter case, it calls snd_rawmidi_transmit_peek() and snd_rawmidi_tranmit_ack() separately without protection, so they are racy as well. The patch tries to address these issues by the following ways: - Introduce the unlocked versions of snd_rawmidi_transmit_peek() and snd_rawmidi_transmit_ack() to be called inside the explicit lock. - Rewrite snd_rawmidi_transmit() to be race-free (the former case). - Make the split calls (the latter case) protected in the rawmidi spin lock. BugLink: http://lkml.kernel.org/r/CACT4Y+YPq1+cYLkadwjWa5XjzF1_Vki1eHnVn-Lm0hzhSpu5PA@mail.gmail.com BugLink: http://lkml.kernel.org/r/CACT4Y+acG4iyphdOZx47Nyq_VHGbpJQK-6xNpiqUjaZYqsXOGw@mail.gmail.com Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-01-31 13:57:41 +03:00
* This is a variant of __snd_rawmidi_transmit_ack() without spinlock.
*/
static int __snd_rawmidi_transmit_ack(struct snd_rawmidi_substream *substream,
int count)
{
struct snd_rawmidi_runtime *runtime = substream->runtime;
if (runtime->buffer == NULL) {
rmidi_dbg(substream->rmidi,
"snd_rawmidi_transmit_ack: output is not active!!!\n");
return -EINVAL;
}
snd_BUG_ON(runtime->avail + count > runtime->buffer_size);
runtime->hw_ptr += count;
runtime->hw_ptr %= runtime->buffer_size;
runtime->avail += count;
substream->bytes += count;
if (count > 0) {
if (runtime->drain || __snd_rawmidi_ready(runtime))
wake_up(&runtime->sleep);
}
return count;
}
ALSA: rawmidi: Make snd_rawmidi_transmit() race-free A kernel WARNING in snd_rawmidi_transmit_ack() is triggered by syzkaller fuzzer: WARNING: CPU: 1 PID: 20739 at sound/core/rawmidi.c:1136 Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff82999e2d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50 [<ffffffff81352089>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482 [<ffffffff813522b9>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515 [<ffffffff84f80bd5>] snd_rawmidi_transmit_ack+0x275/0x400 sound/core/rawmidi.c:1136 [<ffffffff84fdb3c1>] snd_virmidi_output_trigger+0x4b1/0x5a0 sound/core/seq/seq_virmidi.c:163 [< inline >] snd_rawmidi_output_trigger sound/core/rawmidi.c:150 [<ffffffff84f87ed9>] snd_rawmidi_kernel_write1+0x549/0x780 sound/core/rawmidi.c:1223 [<ffffffff84f89fd3>] snd_rawmidi_write+0x543/0xb30 sound/core/rawmidi.c:1273 [<ffffffff817b0323>] __vfs_write+0x113/0x480 fs/read_write.c:528 [<ffffffff817b1db7>] vfs_write+0x167/0x4a0 fs/read_write.c:577 [< inline >] SYSC_write fs/read_write.c:624 [<ffffffff817b50a1>] SyS_write+0x111/0x220 fs/read_write.c:616 [<ffffffff86336c36>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 Also a similar warning is found but in another path: Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff82be2c0d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50 [<ffffffff81355139>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482 [<ffffffff81355369>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515 [<ffffffff8527e69a>] rawmidi_transmit_ack+0x24a/0x3b0 sound/core/rawmidi.c:1133 [<ffffffff8527e851>] snd_rawmidi_transmit_ack+0x51/0x80 sound/core/rawmidi.c:1163 [<ffffffff852d9046>] snd_virmidi_output_trigger+0x2b6/0x570 sound/core/seq/seq_virmidi.c:185 [< inline >] snd_rawmidi_output_trigger sound/core/rawmidi.c:150 [<ffffffff85285a0b>] snd_rawmidi_kernel_write1+0x4bb/0x760 sound/core/rawmidi.c:1252 [<ffffffff85287b73>] snd_rawmidi_write+0x543/0xb30 sound/core/rawmidi.c:1302 [<ffffffff817ba5f3>] __vfs_write+0x113/0x480 fs/read_write.c:528 [<ffffffff817bc087>] vfs_write+0x167/0x4a0 fs/read_write.c:577 [< inline >] SYSC_write fs/read_write.c:624 [<ffffffff817bf371>] SyS_write+0x111/0x220 fs/read_write.c:616 [<ffffffff86660276>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 In the former case, the reason is that virmidi has an open code calling snd_rawmidi_transmit_ack() with the value calculated outside the spinlock. We may use snd_rawmidi_transmit() in a loop just for consuming the input data, but even there, there is a race between snd_rawmidi_transmit_peek() and snd_rawmidi_tranmit_ack(). Similarly in the latter case, it calls snd_rawmidi_transmit_peek() and snd_rawmidi_tranmit_ack() separately without protection, so they are racy as well. The patch tries to address these issues by the following ways: - Introduce the unlocked versions of snd_rawmidi_transmit_peek() and snd_rawmidi_transmit_ack() to be called inside the explicit lock. - Rewrite snd_rawmidi_transmit() to be race-free (the former case). - Make the split calls (the latter case) protected in the rawmidi spin lock. BugLink: http://lkml.kernel.org/r/CACT4Y+YPq1+cYLkadwjWa5XjzF1_Vki1eHnVn-Lm0hzhSpu5PA@mail.gmail.com BugLink: http://lkml.kernel.org/r/CACT4Y+acG4iyphdOZx47Nyq_VHGbpJQK-6xNpiqUjaZYqsXOGw@mail.gmail.com Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-01-31 13:57:41 +03:00
/**
* snd_rawmidi_transmit_ack - acknowledge the transmission
* @substream: the rawmidi substream
* @count: the transferred count
*
* Advances the hardware pointer for the internal output buffer with
* the given size and updates the condition.
* Call after the transmission is finished.
*
* Return: The advanced size if successful, or a negative error code on failure.
*/
int snd_rawmidi_transmit_ack(struct snd_rawmidi_substream *substream, int count)
{
int result;
unsigned long flags;
spin_lock_irqsave(&substream->lock, flags);
if (!substream->opened || !substream->runtime)
result = -EBADFD;
else
result = __snd_rawmidi_transmit_ack(substream, count);
spin_unlock_irqrestore(&substream->lock, flags);
ALSA: rawmidi: Make snd_rawmidi_transmit() race-free A kernel WARNING in snd_rawmidi_transmit_ack() is triggered by syzkaller fuzzer: WARNING: CPU: 1 PID: 20739 at sound/core/rawmidi.c:1136 Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff82999e2d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50 [<ffffffff81352089>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482 [<ffffffff813522b9>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515 [<ffffffff84f80bd5>] snd_rawmidi_transmit_ack+0x275/0x400 sound/core/rawmidi.c:1136 [<ffffffff84fdb3c1>] snd_virmidi_output_trigger+0x4b1/0x5a0 sound/core/seq/seq_virmidi.c:163 [< inline >] snd_rawmidi_output_trigger sound/core/rawmidi.c:150 [<ffffffff84f87ed9>] snd_rawmidi_kernel_write1+0x549/0x780 sound/core/rawmidi.c:1223 [<ffffffff84f89fd3>] snd_rawmidi_write+0x543/0xb30 sound/core/rawmidi.c:1273 [<ffffffff817b0323>] __vfs_write+0x113/0x480 fs/read_write.c:528 [<ffffffff817b1db7>] vfs_write+0x167/0x4a0 fs/read_write.c:577 [< inline >] SYSC_write fs/read_write.c:624 [<ffffffff817b50a1>] SyS_write+0x111/0x220 fs/read_write.c:616 [<ffffffff86336c36>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 Also a similar warning is found but in another path: Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff82be2c0d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50 [<ffffffff81355139>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482 [<ffffffff81355369>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515 [<ffffffff8527e69a>] rawmidi_transmit_ack+0x24a/0x3b0 sound/core/rawmidi.c:1133 [<ffffffff8527e851>] snd_rawmidi_transmit_ack+0x51/0x80 sound/core/rawmidi.c:1163 [<ffffffff852d9046>] snd_virmidi_output_trigger+0x2b6/0x570 sound/core/seq/seq_virmidi.c:185 [< inline >] snd_rawmidi_output_trigger sound/core/rawmidi.c:150 [<ffffffff85285a0b>] snd_rawmidi_kernel_write1+0x4bb/0x760 sound/core/rawmidi.c:1252 [<ffffffff85287b73>] snd_rawmidi_write+0x543/0xb30 sound/core/rawmidi.c:1302 [<ffffffff817ba5f3>] __vfs_write+0x113/0x480 fs/read_write.c:528 [<ffffffff817bc087>] vfs_write+0x167/0x4a0 fs/read_write.c:577 [< inline >] SYSC_write fs/read_write.c:624 [<ffffffff817bf371>] SyS_write+0x111/0x220 fs/read_write.c:616 [<ffffffff86660276>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 In the former case, the reason is that virmidi has an open code calling snd_rawmidi_transmit_ack() with the value calculated outside the spinlock. We may use snd_rawmidi_transmit() in a loop just for consuming the input data, but even there, there is a race between snd_rawmidi_transmit_peek() and snd_rawmidi_tranmit_ack(). Similarly in the latter case, it calls snd_rawmidi_transmit_peek() and snd_rawmidi_tranmit_ack() separately without protection, so they are racy as well. The patch tries to address these issues by the following ways: - Introduce the unlocked versions of snd_rawmidi_transmit_peek() and snd_rawmidi_transmit_ack() to be called inside the explicit lock. - Rewrite snd_rawmidi_transmit() to be race-free (the former case). - Make the split calls (the latter case) protected in the rawmidi spin lock. BugLink: http://lkml.kernel.org/r/CACT4Y+YPq1+cYLkadwjWa5XjzF1_Vki1eHnVn-Lm0hzhSpu5PA@mail.gmail.com BugLink: http://lkml.kernel.org/r/CACT4Y+acG4iyphdOZx47Nyq_VHGbpJQK-6xNpiqUjaZYqsXOGw@mail.gmail.com Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-01-31 13:57:41 +03:00
return result;
}
EXPORT_SYMBOL(snd_rawmidi_transmit_ack);
/**
* snd_rawmidi_transmit - copy from the buffer to the device
* @substream: the rawmidi substream
* @buffer: the buffer pointer
* @count: the data size to transfer
*
* Copies data from the buffer to the device and advances the pointer.
*
* Return: The copied size if successful, or a negative error code on failure.
*/
int snd_rawmidi_transmit(struct snd_rawmidi_substream *substream,
unsigned char *buffer, int count)
{
ALSA: rawmidi: Make snd_rawmidi_transmit() race-free A kernel WARNING in snd_rawmidi_transmit_ack() is triggered by syzkaller fuzzer: WARNING: CPU: 1 PID: 20739 at sound/core/rawmidi.c:1136 Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff82999e2d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50 [<ffffffff81352089>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482 [<ffffffff813522b9>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515 [<ffffffff84f80bd5>] snd_rawmidi_transmit_ack+0x275/0x400 sound/core/rawmidi.c:1136 [<ffffffff84fdb3c1>] snd_virmidi_output_trigger+0x4b1/0x5a0 sound/core/seq/seq_virmidi.c:163 [< inline >] snd_rawmidi_output_trigger sound/core/rawmidi.c:150 [<ffffffff84f87ed9>] snd_rawmidi_kernel_write1+0x549/0x780 sound/core/rawmidi.c:1223 [<ffffffff84f89fd3>] snd_rawmidi_write+0x543/0xb30 sound/core/rawmidi.c:1273 [<ffffffff817b0323>] __vfs_write+0x113/0x480 fs/read_write.c:528 [<ffffffff817b1db7>] vfs_write+0x167/0x4a0 fs/read_write.c:577 [< inline >] SYSC_write fs/read_write.c:624 [<ffffffff817b50a1>] SyS_write+0x111/0x220 fs/read_write.c:616 [<ffffffff86336c36>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 Also a similar warning is found but in another path: Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff82be2c0d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50 [<ffffffff81355139>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482 [<ffffffff81355369>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515 [<ffffffff8527e69a>] rawmidi_transmit_ack+0x24a/0x3b0 sound/core/rawmidi.c:1133 [<ffffffff8527e851>] snd_rawmidi_transmit_ack+0x51/0x80 sound/core/rawmidi.c:1163 [<ffffffff852d9046>] snd_virmidi_output_trigger+0x2b6/0x570 sound/core/seq/seq_virmidi.c:185 [< inline >] snd_rawmidi_output_trigger sound/core/rawmidi.c:150 [<ffffffff85285a0b>] snd_rawmidi_kernel_write1+0x4bb/0x760 sound/core/rawmidi.c:1252 [<ffffffff85287b73>] snd_rawmidi_write+0x543/0xb30 sound/core/rawmidi.c:1302 [<ffffffff817ba5f3>] __vfs_write+0x113/0x480 fs/read_write.c:528 [<ffffffff817bc087>] vfs_write+0x167/0x4a0 fs/read_write.c:577 [< inline >] SYSC_write fs/read_write.c:624 [<ffffffff817bf371>] SyS_write+0x111/0x220 fs/read_write.c:616 [<ffffffff86660276>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 In the former case, the reason is that virmidi has an open code calling snd_rawmidi_transmit_ack() with the value calculated outside the spinlock. We may use snd_rawmidi_transmit() in a loop just for consuming the input data, but even there, there is a race between snd_rawmidi_transmit_peek() and snd_rawmidi_tranmit_ack(). Similarly in the latter case, it calls snd_rawmidi_transmit_peek() and snd_rawmidi_tranmit_ack() separately without protection, so they are racy as well. The patch tries to address these issues by the following ways: - Introduce the unlocked versions of snd_rawmidi_transmit_peek() and snd_rawmidi_transmit_ack() to be called inside the explicit lock. - Rewrite snd_rawmidi_transmit() to be race-free (the former case). - Make the split calls (the latter case) protected in the rawmidi spin lock. BugLink: http://lkml.kernel.org/r/CACT4Y+YPq1+cYLkadwjWa5XjzF1_Vki1eHnVn-Lm0hzhSpu5PA@mail.gmail.com BugLink: http://lkml.kernel.org/r/CACT4Y+acG4iyphdOZx47Nyq_VHGbpJQK-6xNpiqUjaZYqsXOGw@mail.gmail.com Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-01-31 13:57:41 +03:00
int result;
unsigned long flags;
spin_lock_irqsave(&substream->lock, flags);
if (!substream->opened)
ALSA: rawmidi: Make snd_rawmidi_transmit() race-free A kernel WARNING in snd_rawmidi_transmit_ack() is triggered by syzkaller fuzzer: WARNING: CPU: 1 PID: 20739 at sound/core/rawmidi.c:1136 Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff82999e2d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50 [<ffffffff81352089>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482 [<ffffffff813522b9>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515 [<ffffffff84f80bd5>] snd_rawmidi_transmit_ack+0x275/0x400 sound/core/rawmidi.c:1136 [<ffffffff84fdb3c1>] snd_virmidi_output_trigger+0x4b1/0x5a0 sound/core/seq/seq_virmidi.c:163 [< inline >] snd_rawmidi_output_trigger sound/core/rawmidi.c:150 [<ffffffff84f87ed9>] snd_rawmidi_kernel_write1+0x549/0x780 sound/core/rawmidi.c:1223 [<ffffffff84f89fd3>] snd_rawmidi_write+0x543/0xb30 sound/core/rawmidi.c:1273 [<ffffffff817b0323>] __vfs_write+0x113/0x480 fs/read_write.c:528 [<ffffffff817b1db7>] vfs_write+0x167/0x4a0 fs/read_write.c:577 [< inline >] SYSC_write fs/read_write.c:624 [<ffffffff817b50a1>] SyS_write+0x111/0x220 fs/read_write.c:616 [<ffffffff86336c36>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 Also a similar warning is found but in another path: Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff82be2c0d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50 [<ffffffff81355139>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482 [<ffffffff81355369>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515 [<ffffffff8527e69a>] rawmidi_transmit_ack+0x24a/0x3b0 sound/core/rawmidi.c:1133 [<ffffffff8527e851>] snd_rawmidi_transmit_ack+0x51/0x80 sound/core/rawmidi.c:1163 [<ffffffff852d9046>] snd_virmidi_output_trigger+0x2b6/0x570 sound/core/seq/seq_virmidi.c:185 [< inline >] snd_rawmidi_output_trigger sound/core/rawmidi.c:150 [<ffffffff85285a0b>] snd_rawmidi_kernel_write1+0x4bb/0x760 sound/core/rawmidi.c:1252 [<ffffffff85287b73>] snd_rawmidi_write+0x543/0xb30 sound/core/rawmidi.c:1302 [<ffffffff817ba5f3>] __vfs_write+0x113/0x480 fs/read_write.c:528 [<ffffffff817bc087>] vfs_write+0x167/0x4a0 fs/read_write.c:577 [< inline >] SYSC_write fs/read_write.c:624 [<ffffffff817bf371>] SyS_write+0x111/0x220 fs/read_write.c:616 [<ffffffff86660276>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 In the former case, the reason is that virmidi has an open code calling snd_rawmidi_transmit_ack() with the value calculated outside the spinlock. We may use snd_rawmidi_transmit() in a loop just for consuming the input data, but even there, there is a race between snd_rawmidi_transmit_peek() and snd_rawmidi_tranmit_ack(). Similarly in the latter case, it calls snd_rawmidi_transmit_peek() and snd_rawmidi_tranmit_ack() separately without protection, so they are racy as well. The patch tries to address these issues by the following ways: - Introduce the unlocked versions of snd_rawmidi_transmit_peek() and snd_rawmidi_transmit_ack() to be called inside the explicit lock. - Rewrite snd_rawmidi_transmit() to be race-free (the former case). - Make the split calls (the latter case) protected in the rawmidi spin lock. BugLink: http://lkml.kernel.org/r/CACT4Y+YPq1+cYLkadwjWa5XjzF1_Vki1eHnVn-Lm0hzhSpu5PA@mail.gmail.com BugLink: http://lkml.kernel.org/r/CACT4Y+acG4iyphdOZx47Nyq_VHGbpJQK-6xNpiqUjaZYqsXOGw@mail.gmail.com Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-01-31 13:57:41 +03:00
result = -EBADFD;
else {
count = __snd_rawmidi_transmit_peek(substream, buffer, count);
if (count <= 0)
result = count;
else
result = __snd_rawmidi_transmit_ack(substream, count);
}
spin_unlock_irqrestore(&substream->lock, flags);
ALSA: rawmidi: Make snd_rawmidi_transmit() race-free A kernel WARNING in snd_rawmidi_transmit_ack() is triggered by syzkaller fuzzer: WARNING: CPU: 1 PID: 20739 at sound/core/rawmidi.c:1136 Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff82999e2d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50 [<ffffffff81352089>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482 [<ffffffff813522b9>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515 [<ffffffff84f80bd5>] snd_rawmidi_transmit_ack+0x275/0x400 sound/core/rawmidi.c:1136 [<ffffffff84fdb3c1>] snd_virmidi_output_trigger+0x4b1/0x5a0 sound/core/seq/seq_virmidi.c:163 [< inline >] snd_rawmidi_output_trigger sound/core/rawmidi.c:150 [<ffffffff84f87ed9>] snd_rawmidi_kernel_write1+0x549/0x780 sound/core/rawmidi.c:1223 [<ffffffff84f89fd3>] snd_rawmidi_write+0x543/0xb30 sound/core/rawmidi.c:1273 [<ffffffff817b0323>] __vfs_write+0x113/0x480 fs/read_write.c:528 [<ffffffff817b1db7>] vfs_write+0x167/0x4a0 fs/read_write.c:577 [< inline >] SYSC_write fs/read_write.c:624 [<ffffffff817b50a1>] SyS_write+0x111/0x220 fs/read_write.c:616 [<ffffffff86336c36>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 Also a similar warning is found but in another path: Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff82be2c0d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50 [<ffffffff81355139>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482 [<ffffffff81355369>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515 [<ffffffff8527e69a>] rawmidi_transmit_ack+0x24a/0x3b0 sound/core/rawmidi.c:1133 [<ffffffff8527e851>] snd_rawmidi_transmit_ack+0x51/0x80 sound/core/rawmidi.c:1163 [<ffffffff852d9046>] snd_virmidi_output_trigger+0x2b6/0x570 sound/core/seq/seq_virmidi.c:185 [< inline >] snd_rawmidi_output_trigger sound/core/rawmidi.c:150 [<ffffffff85285a0b>] snd_rawmidi_kernel_write1+0x4bb/0x760 sound/core/rawmidi.c:1252 [<ffffffff85287b73>] snd_rawmidi_write+0x543/0xb30 sound/core/rawmidi.c:1302 [<ffffffff817ba5f3>] __vfs_write+0x113/0x480 fs/read_write.c:528 [<ffffffff817bc087>] vfs_write+0x167/0x4a0 fs/read_write.c:577 [< inline >] SYSC_write fs/read_write.c:624 [<ffffffff817bf371>] SyS_write+0x111/0x220 fs/read_write.c:616 [<ffffffff86660276>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 In the former case, the reason is that virmidi has an open code calling snd_rawmidi_transmit_ack() with the value calculated outside the spinlock. We may use snd_rawmidi_transmit() in a loop just for consuming the input data, but even there, there is a race between snd_rawmidi_transmit_peek() and snd_rawmidi_tranmit_ack(). Similarly in the latter case, it calls snd_rawmidi_transmit_peek() and snd_rawmidi_tranmit_ack() separately without protection, so they are racy as well. The patch tries to address these issues by the following ways: - Introduce the unlocked versions of snd_rawmidi_transmit_peek() and snd_rawmidi_transmit_ack() to be called inside the explicit lock. - Rewrite snd_rawmidi_transmit() to be race-free (the former case). - Make the split calls (the latter case) protected in the rawmidi spin lock. BugLink: http://lkml.kernel.org/r/CACT4Y+YPq1+cYLkadwjWa5XjzF1_Vki1eHnVn-Lm0hzhSpu5PA@mail.gmail.com BugLink: http://lkml.kernel.org/r/CACT4Y+acG4iyphdOZx47Nyq_VHGbpJQK-6xNpiqUjaZYqsXOGw@mail.gmail.com Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-01-31 13:57:41 +03:00
return result;
}
EXPORT_SYMBOL(snd_rawmidi_transmit);
/**
* snd_rawmidi_proceed - Discard the all pending bytes and proceed
* @substream: rawmidi substream
*
* Return: the number of discarded bytes
*/
int snd_rawmidi_proceed(struct snd_rawmidi_substream *substream)
{
struct snd_rawmidi_runtime *runtime;
unsigned long flags;
int count = 0;
spin_lock_irqsave(&substream->lock, flags);
runtime = substream->runtime;
if (substream->opened && runtime &&
runtime->avail < runtime->buffer_size) {
count = runtime->buffer_size - runtime->avail;
__snd_rawmidi_transmit_ack(substream, count);
}
spin_unlock_irqrestore(&substream->lock, flags);
return count;
}
EXPORT_SYMBOL(snd_rawmidi_proceed);
static long snd_rawmidi_kernel_write1(struct snd_rawmidi_substream *substream,
const unsigned char __user *userbuf,
const unsigned char *kernelbuf,
long count)
{
unsigned long flags;
long count1, result;
struct snd_rawmidi_runtime *runtime = substream->runtime;
unsigned long appl_ptr;
if (!kernelbuf && !userbuf)
return -EINVAL;
if (snd_BUG_ON(!runtime->buffer))
return -EINVAL;
result = 0;
spin_lock_irqsave(&substream->lock, flags);
if (substream->append) {
if ((long)runtime->avail < count) {
spin_unlock_irqrestore(&substream->lock, flags);
return -EAGAIN;
}
}
snd_rawmidi_buffer_ref(runtime);
while (count > 0 && runtime->avail > 0) {
count1 = runtime->buffer_size - runtime->appl_ptr;
if (count1 > count)
count1 = count;
if (count1 > (long)runtime->avail)
count1 = runtime->avail;
/* update runtime->appl_ptr before unlocking for userbuf */
appl_ptr = runtime->appl_ptr;
runtime->appl_ptr += count1;
runtime->appl_ptr %= runtime->buffer_size;
runtime->avail -= count1;
if (kernelbuf)
memcpy(runtime->buffer + appl_ptr,
kernelbuf + result, count1);
else if (userbuf) {
spin_unlock_irqrestore(&substream->lock, flags);
if (copy_from_user(runtime->buffer + appl_ptr,
userbuf + result, count1)) {
spin_lock_irqsave(&substream->lock, flags);
result = result > 0 ? result : -EFAULT;
goto __end;
}
spin_lock_irqsave(&substream->lock, flags);
}
result += count1;
count -= count1;
}
__end:
count1 = runtime->avail < runtime->buffer_size;
snd_rawmidi_buffer_unref(runtime);
spin_unlock_irqrestore(&substream->lock, flags);
if (count1)
snd_rawmidi_output_trigger(substream, 1);
return result;
}
long snd_rawmidi_kernel_write(struct snd_rawmidi_substream *substream,
const unsigned char *buf, long count)
{
return snd_rawmidi_kernel_write1(substream, NULL, buf, count);
}
EXPORT_SYMBOL(snd_rawmidi_kernel_write);
static ssize_t snd_rawmidi_write(struct file *file, const char __user *buf,
size_t count, loff_t *offset)
{
long result, timeout;
int count1;
struct snd_rawmidi_file *rfile;
struct snd_rawmidi_runtime *runtime;
struct snd_rawmidi_substream *substream;
rfile = file->private_data;
substream = rfile->output;
runtime = substream->runtime;
/* we cannot put an atomic message to our buffer */
if (substream->append && count > runtime->buffer_size)
return -EIO;
result = 0;
while (count > 0) {
spin_lock_irq(&substream->lock);
while (!snd_rawmidi_ready_append(substream, count)) {
wait_queue_entry_t wait;
if (file->f_flags & O_NONBLOCK) {
spin_unlock_irq(&substream->lock);
return result > 0 ? result : -EAGAIN;
}
init_waitqueue_entry(&wait, current);
add_wait_queue(&runtime->sleep, &wait);
set_current_state(TASK_INTERRUPTIBLE);
spin_unlock_irq(&substream->lock);
timeout = schedule_timeout(30 * HZ);
remove_wait_queue(&runtime->sleep, &wait);
if (rfile->rmidi->card->shutdown)
return -ENODEV;
if (signal_pending(current))
return result > 0 ? result : -ERESTARTSYS;
spin_lock_irq(&substream->lock);
if (!runtime->avail && !timeout) {
spin_unlock_irq(&substream->lock);
return result > 0 ? result : -EIO;
}
}
spin_unlock_irq(&substream->lock);
count1 = snd_rawmidi_kernel_write1(substream, buf, NULL, count);
if (count1 < 0)
return result > 0 ? result : count1;
result += count1;
buf += count1;
if ((size_t)count1 < count && (file->f_flags & O_NONBLOCK))
break;
count -= count1;
}
vfs: Implement proper O_SYNC semantics While Linux provided an O_SYNC flag basically since day 1, it took until Linux 2.4.0-test12pre2 to actually get it implemented for filesystems, since that day we had generic_osync_around with only minor changes and the great "For now, when the user asks for O_SYNC, we'll actually give O_DSYNC" comment. This patch intends to actually give us real O_SYNC semantics in addition to the O_DSYNC semantics. After Jan's O_SYNC patches which are required before this patch it's actually surprisingly simple, we just need to figure out when to set the datasync flag to vfs_fsync_range and when not. This patch renames the existing O_SYNC flag to O_DSYNC while keeping it's numerical value to keep binary compatibility, and adds a new real O_SYNC flag. To guarantee backwards compatiblity it is defined as expanding to both the O_DSYNC and the new additional binary flag (__O_SYNC) to make sure we are backwards-compatible when compiled against the new headers. This also means that all places that don't care about the differences can just check O_DSYNC and get the right behaviour for O_SYNC, too - only places that actuall care need to check __O_SYNC in addition. Drivers and network filesystems have been updated in a fail safe way to always do the full sync magic if O_DSYNC is set. The few places setting O_SYNC for lower layers are kept that way for now to stay failsafe. We enforce that O_DSYNC is set when __O_SYNC is set early in the open path to make sure we always get these sane options. Note that parisc really screwed up their headers as they already define a O_DSYNC that has always been a no-op. We try to repair it by using it for the new O_DSYNC and redefinining O_SYNC to send both the traditional O_SYNC numerical value _and_ the O_DSYNC one. Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Grant Grundler <grundler@parisc-linux.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Dilger <adilger@sun.com> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Kyle McMartin <kyle@mcmartin.ca> Acked-by: Ulrich Drepper <drepper@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jan Kara <jack@suse.cz>
2009-10-27 13:05:28 +03:00
if (file->f_flags & O_DSYNC) {
spin_lock_irq(&substream->lock);
while (runtime->avail != runtime->buffer_size) {
wait_queue_entry_t wait;
unsigned int last_avail = runtime->avail;
init_waitqueue_entry(&wait, current);
add_wait_queue(&runtime->sleep, &wait);
set_current_state(TASK_INTERRUPTIBLE);
spin_unlock_irq(&substream->lock);
timeout = schedule_timeout(30 * HZ);
remove_wait_queue(&runtime->sleep, &wait);
if (signal_pending(current))
return result > 0 ? result : -ERESTARTSYS;
if (runtime->avail == last_avail && !timeout)
return result > 0 ? result : -EIO;
spin_lock_irq(&substream->lock);
}
spin_unlock_irq(&substream->lock);
}
return result;
}
static __poll_t snd_rawmidi_poll(struct file *file, poll_table *wait)
{
struct snd_rawmidi_file *rfile;
struct snd_rawmidi_runtime *runtime;
__poll_t mask;
rfile = file->private_data;
if (rfile->input != NULL) {
runtime = rfile->input->runtime;
snd_rawmidi_input_trigger(rfile->input, 1);
poll_wait(file, &runtime->sleep, wait);
}
if (rfile->output != NULL) {
runtime = rfile->output->runtime;
poll_wait(file, &runtime->sleep, wait);
}
mask = 0;
if (rfile->input != NULL) {
if (snd_rawmidi_ready(rfile->input))
mask |= EPOLLIN | EPOLLRDNORM;
}
if (rfile->output != NULL) {
if (snd_rawmidi_ready(rfile->output))
mask |= EPOLLOUT | EPOLLWRNORM;
}
return mask;
}
/*
*/
#ifdef CONFIG_COMPAT
#include "rawmidi_compat.c"
#else
#define snd_rawmidi_ioctl_compat NULL
#endif
/*
*/
static void snd_rawmidi_proc_info_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
struct snd_rawmidi *rmidi;
struct snd_rawmidi_substream *substream;
struct snd_rawmidi_runtime *runtime;
unsigned long buffer_size, avail, xruns;
unsigned int clock_type;
static const char *clock_names[4] = { "none", "realtime", "monotonic", "monotonic raw" };
rmidi = entry->private_data;
snd_iprintf(buffer, "%s\n\n", rmidi->name);
mutex_lock(&rmidi->open_mutex);
if (rmidi->info_flags & SNDRV_RAWMIDI_INFO_OUTPUT) {
list_for_each_entry(substream,
&rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT].substreams,
list) {
snd_iprintf(buffer,
"Output %d\n"
" Tx bytes : %lu\n",
substream->number,
(unsigned long) substream->bytes);
if (substream->opened) {
snd_iprintf(buffer,
" Owner PID : %d\n",
pid_vnr(substream->pid));
runtime = substream->runtime;
spin_lock_irq(&substream->lock);
buffer_size = runtime->buffer_size;
avail = runtime->avail;
spin_unlock_irq(&substream->lock);
snd_iprintf(buffer,
" Mode : %s\n"
" Buffer size : %lu\n"
" Avail : %lu\n",
runtime->oss ? "OSS compatible" : "native",
buffer_size, avail);
}
}
}
if (rmidi->info_flags & SNDRV_RAWMIDI_INFO_INPUT) {
list_for_each_entry(substream,
&rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT].substreams,
list) {
snd_iprintf(buffer,
"Input %d\n"
" Rx bytes : %lu\n",
substream->number,
(unsigned long) substream->bytes);
if (substream->opened) {
snd_iprintf(buffer,
" Owner PID : %d\n",
pid_vnr(substream->pid));
runtime = substream->runtime;
spin_lock_irq(&substream->lock);
buffer_size = runtime->buffer_size;
avail = runtime->avail;
xruns = runtime->xruns;
spin_unlock_irq(&substream->lock);
snd_iprintf(buffer,
" Buffer size : %lu\n"
" Avail : %lu\n"
" Overruns : %lu\n",
buffer_size, avail, xruns);
if (substream->framing == SNDRV_RAWMIDI_MODE_FRAMING_TSTAMP) {
clock_type = substream->clock_type >> SNDRV_RAWMIDI_MODE_CLOCK_SHIFT;
if (!snd_BUG_ON(clock_type >= ARRAY_SIZE(clock_names)))
snd_iprintf(buffer,
" Framing : tstamp\n"
" Clock type : %s\n",
clock_names[clock_type]);
}
}
}
}
mutex_unlock(&rmidi->open_mutex);
}
/*
* Register functions
*/
static const struct file_operations snd_rawmidi_f_ops = {
.owner = THIS_MODULE,
.read = snd_rawmidi_read,
.write = snd_rawmidi_write,
.open = snd_rawmidi_open,
.release = snd_rawmidi_release,
.llseek = no_llseek,
.poll = snd_rawmidi_poll,
.unlocked_ioctl = snd_rawmidi_ioctl,
.compat_ioctl = snd_rawmidi_ioctl_compat,
};
static int snd_rawmidi_alloc_substreams(struct snd_rawmidi *rmidi,
struct snd_rawmidi_str *stream,
int direction,
int count)
{
struct snd_rawmidi_substream *substream;
int idx;
for (idx = 0; idx < count; idx++) {
substream = kzalloc(sizeof(*substream), GFP_KERNEL);
if (!substream)
return -ENOMEM;
substream->stream = direction;
substream->number = idx;
substream->rmidi = rmidi;
substream->pstr = stream;
spin_lock_init(&substream->lock);
list_add_tail(&substream->list, &stream->substreams);
stream->substream_count++;
}
return 0;
}
static void release_rawmidi_device(struct device *dev)
{
kfree(container_of(dev, struct snd_rawmidi, dev));
}
/**
* snd_rawmidi_new - create a rawmidi instance
* @card: the card instance
* @id: the id string
* @device: the device index
* @output_count: the number of output streams
* @input_count: the number of input streams
* @rrawmidi: the pointer to store the new rawmidi instance
*
* Creates a new rawmidi instance.
* Use snd_rawmidi_set_ops() to set the operators to the new instance.
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_rawmidi_new(struct snd_card *card, char *id, int device,
int output_count, int input_count,
struct snd_rawmidi **rrawmidi)
{
struct snd_rawmidi *rmidi;
int err;
static const struct snd_device_ops ops = {
.dev_free = snd_rawmidi_dev_free,
.dev_register = snd_rawmidi_dev_register,
.dev_disconnect = snd_rawmidi_dev_disconnect,
};
if (snd_BUG_ON(!card))
return -ENXIO;
if (rrawmidi)
*rrawmidi = NULL;
rmidi = kzalloc(sizeof(*rmidi), GFP_KERNEL);
if (!rmidi)
return -ENOMEM;
rmidi->card = card;
rmidi->device = device;
mutex_init(&rmidi->open_mutex);
init_waitqueue_head(&rmidi->open_wait);
INIT_LIST_HEAD(&rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT].substreams);
INIT_LIST_HEAD(&rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT].substreams);
if (id != NULL)
strscpy(rmidi->id, id, sizeof(rmidi->id));
snd_device_initialize(&rmidi->dev, card);
rmidi->dev.release = release_rawmidi_device;
dev_set_name(&rmidi->dev, "midiC%iD%i", card->number, device);
err = snd_rawmidi_alloc_substreams(rmidi,
&rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT],
SNDRV_RAWMIDI_STREAM_INPUT,
input_count);
if (err < 0)
goto error;
err = snd_rawmidi_alloc_substreams(rmidi,
&rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT],
SNDRV_RAWMIDI_STREAM_OUTPUT,
output_count);
if (err < 0)
goto error;
err = snd_device_new(card, SNDRV_DEV_RAWMIDI, rmidi, &ops);
if (err < 0)
goto error;
if (rrawmidi)
*rrawmidi = rmidi;
return 0;
error:
snd_rawmidi_free(rmidi);
return err;
}
EXPORT_SYMBOL(snd_rawmidi_new);
static void snd_rawmidi_free_substreams(struct snd_rawmidi_str *stream)
{
struct snd_rawmidi_substream *substream;
while (!list_empty(&stream->substreams)) {
substream = list_entry(stream->substreams.next, struct snd_rawmidi_substream, list);
list_del(&substream->list);
kfree(substream);
}
}
static int snd_rawmidi_free(struct snd_rawmidi *rmidi)
{
if (!rmidi)
return 0;
snd_info_free_entry(rmidi->proc_entry);
rmidi->proc_entry = NULL;
if (rmidi->ops && rmidi->ops->dev_unregister)
rmidi->ops->dev_unregister(rmidi);
snd_rawmidi_free_substreams(&rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT]);
snd_rawmidi_free_substreams(&rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT]);
if (rmidi->private_free)
rmidi->private_free(rmidi);
put_device(&rmidi->dev);
return 0;
}
static int snd_rawmidi_dev_free(struct snd_device *device)
{
struct snd_rawmidi *rmidi = device->device_data;
return snd_rawmidi_free(rmidi);
}
#if IS_ENABLED(CONFIG_SND_SEQUENCER)
static void snd_rawmidi_dev_seq_free(struct snd_seq_device *device)
{
struct snd_rawmidi *rmidi = device->private_data;
rmidi->seq_dev = NULL;
}
#endif
static int snd_rawmidi_dev_register(struct snd_device *device)
{
int err;
struct snd_info_entry *entry;
char name[16];
struct snd_rawmidi *rmidi = device->device_data;
if (rmidi->device >= SNDRV_RAWMIDI_DEVICES)
return -ENOMEM;
err = 0;
mutex_lock(&register_mutex);
if (snd_rawmidi_search(rmidi->card, rmidi->device))
err = -EBUSY;
else
list_add_tail(&rmidi->list, &snd_rawmidi_devices);
ALSA: rawmidi: Fix possible deadlock with virmidi registration When a seq-virmidi driver is initialized, it registers a rawmidi instance with its callback to create an associated seq kernel client. Currently it's done throughly in rawmidi's register_mutex context. Recently it was found that this may lead to a deadlock another rawmidi device that is being attached with the sequencer is accessed, as both open with the same register_mutex. This was actually triggered by syzkaller, as Dmitry Vyukov reported: ====================================================== [ INFO: possible circular locking dependency detected ] 4.8.0-rc1+ #11 Not tainted ------------------------------------------------------- syz-executor/7154 is trying to acquire lock: (register_mutex#5){+.+.+.}, at: [<ffffffff84fd6d4b>] snd_rawmidi_kernel_open+0x4b/0x260 sound/core/rawmidi.c:341 but task is already holding lock: (&grp->list_mutex){++++.+}, at: [<ffffffff850138bb>] check_and_subscribe_port+0x5b/0x5c0 sound/core/seq/seq_ports.c:495 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&grp->list_mutex){++++.+}: [<ffffffff8147a3a8>] lock_acquire+0x208/0x430 kernel/locking/lockdep.c:3746 [<ffffffff863f6199>] down_read+0x49/0xc0 kernel/locking/rwsem.c:22 [< inline >] deliver_to_subscribers sound/core/seq/seq_clientmgr.c:681 [<ffffffff85005c5e>] snd_seq_deliver_event+0x35e/0x890 sound/core/seq/seq_clientmgr.c:822 [<ffffffff85006e96>] > snd_seq_kernel_client_dispatch+0x126/0x170 sound/core/seq/seq_clientmgr.c:2418 [<ffffffff85012c52>] snd_seq_system_broadcast+0xb2/0xf0 sound/core/seq/seq_system.c:101 [<ffffffff84fff70a>] snd_seq_create_kernel_client+0x24a/0x330 sound/core/seq/seq_clientmgr.c:2297 [< inline >] snd_virmidi_dev_attach_seq sound/core/seq/seq_virmidi.c:383 [<ffffffff8502d29f>] snd_virmidi_dev_register+0x29f/0x750 sound/core/seq/seq_virmidi.c:450 [<ffffffff84fd208c>] snd_rawmidi_dev_register+0x30c/0xd40 sound/core/rawmidi.c:1645 [<ffffffff84f816d3>] __snd_device_register.part.0+0x63/0xc0 sound/core/device.c:164 [< inline >] __snd_device_register sound/core/device.c:162 [<ffffffff84f8235d>] snd_device_register_all+0xad/0x110 sound/core/device.c:212 [<ffffffff84f7546f>] snd_card_register+0xef/0x6c0 sound/core/init.c:749 [<ffffffff85040b7f>] snd_virmidi_probe+0x3ef/0x590 sound/drivers/virmidi.c:123 [<ffffffff833ebf7b>] platform_drv_probe+0x8b/0x170 drivers/base/platform.c:564 ...... -> #0 (register_mutex#5){+.+.+.}: [< inline >] check_prev_add kernel/locking/lockdep.c:1829 [< inline >] check_prevs_add kernel/locking/lockdep.c:1939 [< inline >] validate_chain kernel/locking/lockdep.c:2266 [<ffffffff814791f4>] __lock_acquire+0x4d44/0x4d80 kernel/locking/lockdep.c:3335 [<ffffffff8147a3a8>] lock_acquire+0x208/0x430 kernel/locking/lockdep.c:3746 [< inline >] __mutex_lock_common kernel/locking/mutex.c:521 [<ffffffff863f0ef1>] mutex_lock_nested+0xb1/0xa20 kernel/locking/mutex.c:621 [<ffffffff84fd6d4b>] snd_rawmidi_kernel_open+0x4b/0x260 sound/core/rawmidi.c:341 [<ffffffff8502e7c7>] midisynth_subscribe+0xf7/0x350 sound/core/seq/seq_midi.c:188 [< inline >] subscribe_port sound/core/seq/seq_ports.c:427 [<ffffffff85013cc7>] check_and_subscribe_port+0x467/0x5c0 sound/core/seq/seq_ports.c:510 [<ffffffff85015da9>] snd_seq_port_connect+0x2c9/0x500 sound/core/seq/seq_ports.c:579 [<ffffffff850079b8>] snd_seq_ioctl_subscribe_port+0x1d8/0x2b0 sound/core/seq/seq_clientmgr.c:1480 [<ffffffff84ffe9e4>] snd_seq_do_ioctl+0x184/0x1e0 sound/core/seq/seq_clientmgr.c:2225 [<ffffffff84ffeae8>] snd_seq_kernel_client_ctl+0xa8/0x110 sound/core/seq/seq_clientmgr.c:2440 [<ffffffff85027664>] snd_seq_oss_midi_open+0x3b4/0x610 sound/core/seq/oss/seq_oss_midi.c:375 [<ffffffff85023d67>] snd_seq_oss_synth_setup_midi+0x107/0x4c0 sound/core/seq/oss/seq_oss_synth.c:281 [<ffffffff8501b0a8>] snd_seq_oss_open+0x748/0x8d0 sound/core/seq/oss/seq_oss_init.c:274 [<ffffffff85019d8a>] odev_open+0x6a/0x90 sound/core/seq/oss/seq_oss.c:138 [<ffffffff84f7040f>] soundcore_open+0x30f/0x640 sound/sound_core.c:639 ...... other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&grp->list_mutex); lock(register_mutex#5); lock(&grp->list_mutex); lock(register_mutex#5); *** DEADLOCK *** ====================================================== The fix is to simply move the registration parts in snd_rawmidi_dev_register() to the outside of the register_mutex lock. The lock is needed only to manage the linked list, and it's not necessarily to cover the whole initialization process. Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-08-30 15:45:46 +03:00
mutex_unlock(&register_mutex);
if (err < 0)
return err;
err = snd_register_device(SNDRV_DEVICE_TYPE_RAWMIDI,
rmidi->card, rmidi->device,
&snd_rawmidi_f_ops, rmidi, &rmidi->dev);
if (err < 0) {
rmidi_err(rmidi, "unable to register\n");
goto error;
}
if (rmidi->ops && rmidi->ops->dev_register) {
err = rmidi->ops->dev_register(rmidi);
if (err < 0)
goto error_unregister;
}
#ifdef CONFIG_SND_OSSEMUL
rmidi->ossreg = 0;
if ((int)rmidi->device == midi_map[rmidi->card->number]) {
if (snd_register_oss_device(SNDRV_OSS_DEVICE_TYPE_MIDI,
rmidi->card, 0, &snd_rawmidi_f_ops,
rmidi) < 0) {
rmidi_err(rmidi,
"unable to register OSS rawmidi device %i:%i\n",
rmidi->card->number, 0);
} else {
rmidi->ossreg++;
#ifdef SNDRV_OSS_INFO_DEV_MIDI
snd_oss_info_register(SNDRV_OSS_INFO_DEV_MIDI, rmidi->card->number, rmidi->name);
#endif
}
}
if ((int)rmidi->device == amidi_map[rmidi->card->number]) {
if (snd_register_oss_device(SNDRV_OSS_DEVICE_TYPE_MIDI,
rmidi->card, 1, &snd_rawmidi_f_ops,
rmidi) < 0) {
rmidi_err(rmidi,
"unable to register OSS rawmidi device %i:%i\n",
rmidi->card->number, 1);
} else {
rmidi->ossreg++;
}
}
#endif /* CONFIG_SND_OSSEMUL */
sprintf(name, "midi%d", rmidi->device);
entry = snd_info_create_card_entry(rmidi->card, name, rmidi->card->proc_root);
if (entry) {
entry->private_data = rmidi;
entry->c.text.read = snd_rawmidi_proc_info_read;
if (snd_info_register(entry) < 0) {
snd_info_free_entry(entry);
entry = NULL;
}
}
rmidi->proc_entry = entry;
#if IS_ENABLED(CONFIG_SND_SEQUENCER)
if (!rmidi->ops || !rmidi->ops->dev_register) { /* own registration mechanism */
if (snd_seq_device_new(rmidi->card, rmidi->device, SNDRV_SEQ_DEV_ID_MIDISYNTH, 0, &rmidi->seq_dev) >= 0) {
rmidi->seq_dev->private_data = rmidi;
rmidi->seq_dev->private_free = snd_rawmidi_dev_seq_free;
sprintf(rmidi->seq_dev->name, "MIDI %d-%d", rmidi->card->number, rmidi->device);
snd_device_register(rmidi->card, rmidi->seq_dev);
}
}
#endif
return 0;
error_unregister:
snd_unregister_device(&rmidi->dev);
error:
mutex_lock(&register_mutex);
list_del(&rmidi->list);
mutex_unlock(&register_mutex);
return err;
}
static int snd_rawmidi_dev_disconnect(struct snd_device *device)
{
struct snd_rawmidi *rmidi = device->device_data;
int dir;
mutex_lock(&register_mutex);
mutex_lock(&rmidi->open_mutex);
wake_up(&rmidi->open_wait);
list_del_init(&rmidi->list);
for (dir = 0; dir < 2; dir++) {
struct snd_rawmidi_substream *s;
list_for_each_entry(s, &rmidi->streams[dir].substreams, list) {
if (s->runtime)
wake_up(&s->runtime->sleep);
}
}
#ifdef CONFIG_SND_OSSEMUL
if (rmidi->ossreg) {
if ((int)rmidi->device == midi_map[rmidi->card->number]) {
snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_MIDI, rmidi->card, 0);
#ifdef SNDRV_OSS_INFO_DEV_MIDI
snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_MIDI, rmidi->card->number);
#endif
}
if ((int)rmidi->device == amidi_map[rmidi->card->number])
snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_MIDI, rmidi->card, 1);
rmidi->ossreg = 0;
}
#endif /* CONFIG_SND_OSSEMUL */
snd_unregister_device(&rmidi->dev);
mutex_unlock(&rmidi->open_mutex);
mutex_unlock(&register_mutex);
return 0;
}
/**
* snd_rawmidi_set_ops - set the rawmidi operators
* @rmidi: the rawmidi instance
* @stream: the stream direction, SNDRV_RAWMIDI_STREAM_XXX
* @ops: the operator table
*
* Sets the rawmidi operators for the given stream direction.
*/
void snd_rawmidi_set_ops(struct snd_rawmidi *rmidi, int stream,
const struct snd_rawmidi_ops *ops)
{
struct snd_rawmidi_substream *substream;
list_for_each_entry(substream, &rmidi->streams[stream].substreams, list)
substream->ops = ops;
}
EXPORT_SYMBOL(snd_rawmidi_set_ops);
/*
* ENTRY functions
*/
static int __init alsa_rawmidi_init(void)
{
snd_ctl_register_ioctl(snd_rawmidi_control_ioctl);
snd_ctl_register_ioctl_compat(snd_rawmidi_control_ioctl);
#ifdef CONFIG_SND_OSSEMUL
{ int i;
/* check device map table */
for (i = 0; i < SNDRV_CARDS; i++) {
if (midi_map[i] < 0 || midi_map[i] >= SNDRV_RAWMIDI_DEVICES) {
pr_err("ALSA: rawmidi: invalid midi_map[%d] = %d\n",
i, midi_map[i]);
midi_map[i] = 0;
}
if (amidi_map[i] < 0 || amidi_map[i] >= SNDRV_RAWMIDI_DEVICES) {
pr_err("ALSA: rawmidi: invalid amidi_map[%d] = %d\n",
i, amidi_map[i]);
amidi_map[i] = 1;
}
}
}
#endif /* CONFIG_SND_OSSEMUL */
return 0;
}
static void __exit alsa_rawmidi_exit(void)
{
snd_ctl_unregister_ioctl(snd_rawmidi_control_ioctl);
snd_ctl_unregister_ioctl_compat(snd_rawmidi_control_ioctl);
}
module_init(alsa_rawmidi_init)
module_exit(alsa_rawmidi_exit)