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

2221 строка
55 KiB
C
Исходник Обычный вид История

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Timers abstract layer
* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
*/
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/mutex.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/sched/signal.h>
#include <sound/core.h>
#include <sound/timer.h>
#include <sound/control.h>
#include <sound/info.h>
#include <sound/minors.h>
#include <sound/initval.h>
#include <linux/kmod.h>
ALSA: timer: Fix zero-division by continue of uninitialized instance When a user timer instance is continued without the explicit start beforehand, the system gets eventually zero-division error like: divide error: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN CPU: 1 PID: 27320 Comm: syz-executor Not tainted 4.8.0-rc3-next-20160825+ #8 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff88003c9b2280 task.stack: ffff880027280000 RIP: 0010:[<ffffffff858e1a6c>] [< inline >] ktime_divns include/linux/ktime.h:195 RIP: 0010:[<ffffffff858e1a6c>] [<ffffffff858e1a6c>] snd_hrtimer_callback+0x1bc/0x3c0 sound/core/hrtimer.c:62 Call Trace: <IRQ> [< inline >] __run_hrtimer kernel/time/hrtimer.c:1238 [<ffffffff81504335>] __hrtimer_run_queues+0x325/0xe70 kernel/time/hrtimer.c:1302 [<ffffffff81506ceb>] hrtimer_interrupt+0x18b/0x420 kernel/time/hrtimer.c:1336 [<ffffffff8126d8df>] local_apic_timer_interrupt+0x6f/0xe0 arch/x86/kernel/apic/apic.c:933 [<ffffffff86e13056>] smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:957 [<ffffffff86e1210c>] apic_timer_interrupt+0x8c/0xa0 arch/x86/entry/entry_64.S:487 <EOI> ..... Although a similar issue was spotted and a fix patch was merged in commit [6b760bb2c63a: ALSA: timer: fix division by zero after SNDRV_TIMER_IOCTL_CONTINUE], it seems covering only a part of iceberg. In this patch, we fix the issue a bit more drastically. Basically the continue of an uninitialized timer is supposed to be a fresh start, so we do it for user timers. For the direct snd_timer_continue() call, there is no way to pass the initial tick value, so we kick out for the uninitialized case. Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-09-07 16:45:31 +03:00
/* internal flags */
#define SNDRV_TIMER_IFLG_PAUSED 0x00010000
#define SNDRV_TIMER_IFLG_DEAD 0x00020000
ALSA: timer: Fix zero-division by continue of uninitialized instance When a user timer instance is continued without the explicit start beforehand, the system gets eventually zero-division error like: divide error: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN CPU: 1 PID: 27320 Comm: syz-executor Not tainted 4.8.0-rc3-next-20160825+ #8 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff88003c9b2280 task.stack: ffff880027280000 RIP: 0010:[<ffffffff858e1a6c>] [< inline >] ktime_divns include/linux/ktime.h:195 RIP: 0010:[<ffffffff858e1a6c>] [<ffffffff858e1a6c>] snd_hrtimer_callback+0x1bc/0x3c0 sound/core/hrtimer.c:62 Call Trace: <IRQ> [< inline >] __run_hrtimer kernel/time/hrtimer.c:1238 [<ffffffff81504335>] __hrtimer_run_queues+0x325/0xe70 kernel/time/hrtimer.c:1302 [<ffffffff81506ceb>] hrtimer_interrupt+0x18b/0x420 kernel/time/hrtimer.c:1336 [<ffffffff8126d8df>] local_apic_timer_interrupt+0x6f/0xe0 arch/x86/kernel/apic/apic.c:933 [<ffffffff86e13056>] smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:957 [<ffffffff86e1210c>] apic_timer_interrupt+0x8c/0xa0 arch/x86/entry/entry_64.S:487 <EOI> ..... Although a similar issue was spotted and a fix patch was merged in commit [6b760bb2c63a: ALSA: timer: fix division by zero after SNDRV_TIMER_IOCTL_CONTINUE], it seems covering only a part of iceberg. In this patch, we fix the issue a bit more drastically. Basically the continue of an uninitialized timer is supposed to be a fresh start, so we do it for user timers. For the direct snd_timer_continue() call, there is no way to pass the initial tick value, so we kick out for the uninitialized case. Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-09-07 16:45:31 +03:00
#if IS_ENABLED(CONFIG_SND_HRTIMER)
#define DEFAULT_TIMER_LIMIT 4
#else
#define DEFAULT_TIMER_LIMIT 1
#endif
static int timer_limit = DEFAULT_TIMER_LIMIT;
static int timer_tstamp_monotonic = 1;
MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.de>");
MODULE_DESCRIPTION("ALSA timer interface");
MODULE_LICENSE("GPL");
module_param(timer_limit, int, 0444);
MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
module_param(timer_tstamp_monotonic, int, 0444);
MODULE_PARM_DESC(timer_tstamp_monotonic, "Use posix monotonic clock source for timestamps (default).");
MODULE_ALIAS_CHARDEV(CONFIG_SND_MAJOR, SNDRV_MINOR_TIMER);
MODULE_ALIAS("devname:snd/timer");
struct snd_timer_user {
struct snd_timer_instance *timeri;
int tread; /* enhanced read with timestamps and events */
unsigned long ticks;
unsigned long overrun;
int qhead;
int qtail;
int qused;
int queue_size;
bool disconnected;
struct snd_timer_read *queue;
struct snd_timer_tread *tqueue;
spinlock_t qlock;
unsigned long last_resolution;
unsigned int filter;
struct timespec64 tstamp; /* trigger tstamp */
wait_queue_head_t qchange_sleep;
struct fasync_struct *fasync;
struct mutex ioctl_lock;
};
/* list of timers */
static LIST_HEAD(snd_timer_list);
/* list of slave instances */
static LIST_HEAD(snd_timer_slave_list);
/* lock for slave active lists */
static DEFINE_SPINLOCK(slave_active_lock);
#define MAX_SLAVE_INSTANCES 1000
static int num_slaves;
static DEFINE_MUTEX(register_mutex);
static int snd_timer_free(struct snd_timer *timer);
static int snd_timer_dev_free(struct snd_device *device);
static int snd_timer_dev_register(struct snd_device *device);
static int snd_timer_dev_disconnect(struct snd_device *device);
static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left);
/*
* create a timer instance with the given owner string.
*/
struct snd_timer_instance *snd_timer_instance_new(const char *owner)
{
struct snd_timer_instance *timeri;
timeri = kzalloc(sizeof(*timeri), GFP_KERNEL);
if (timeri == NULL)
return NULL;
timeri->owner = kstrdup(owner, GFP_KERNEL);
if (! timeri->owner) {
kfree(timeri);
return NULL;
}
INIT_LIST_HEAD(&timeri->open_list);
INIT_LIST_HEAD(&timeri->active_list);
INIT_LIST_HEAD(&timeri->ack_list);
INIT_LIST_HEAD(&timeri->slave_list_head);
INIT_LIST_HEAD(&timeri->slave_active_head);
return timeri;
}
EXPORT_SYMBOL(snd_timer_instance_new);
void snd_timer_instance_free(struct snd_timer_instance *timeri)
{
if (timeri) {
if (timeri->private_free)
timeri->private_free(timeri);
kfree(timeri->owner);
kfree(timeri);
}
}
EXPORT_SYMBOL(snd_timer_instance_free);
/*
* find a timer instance from the given timer id
*/
static struct snd_timer *snd_timer_find(struct snd_timer_id *tid)
{
struct snd_timer *timer = NULL;
list_for_each_entry(timer, &snd_timer_list, device_list) {
if (timer->tmr_class != tid->dev_class)
continue;
if ((timer->tmr_class == SNDRV_TIMER_CLASS_CARD ||
timer->tmr_class == SNDRV_TIMER_CLASS_PCM) &&
(timer->card == NULL ||
timer->card->number != tid->card))
continue;
if (timer->tmr_device != tid->device)
continue;
if (timer->tmr_subdevice != tid->subdevice)
continue;
return timer;
}
return NULL;
}
#ifdef CONFIG_MODULES
static void snd_timer_request(struct snd_timer_id *tid)
{
switch (tid->dev_class) {
case SNDRV_TIMER_CLASS_GLOBAL:
if (tid->device < timer_limit)
request_module("snd-timer-%i", tid->device);
break;
case SNDRV_TIMER_CLASS_CARD:
case SNDRV_TIMER_CLASS_PCM:
if (tid->card < snd_ecards_limit)
request_module("snd-card-%i", tid->card);
break;
default:
break;
}
}
#endif
/* move the slave if it belongs to the master; return 1 if match */
static int check_matching_master_slave(struct snd_timer_instance *master,
struct snd_timer_instance *slave)
{
if (slave->slave_class != master->slave_class ||
slave->slave_id != master->slave_id)
return 0;
if (master->timer->num_instances >= master->timer->max_instances)
return -EBUSY;
list_move_tail(&slave->open_list, &master->slave_list_head);
master->timer->num_instances++;
spin_lock_irq(&slave_active_lock);
spin_lock(&master->timer->lock);
slave->master = master;
slave->timer = master->timer;
if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
list_add_tail(&slave->active_list, &master->slave_active_head);
spin_unlock(&master->timer->lock);
spin_unlock_irq(&slave_active_lock);
return 1;
}
/*
* look for a master instance matching with the slave id of the given slave.
* when found, relink the open_link of the slave.
*
* call this with register_mutex down.
*/
static int snd_timer_check_slave(struct snd_timer_instance *slave)
{
struct snd_timer *timer;
struct snd_timer_instance *master;
int err = 0;
/* FIXME: it's really dumb to look up all entries.. */
list_for_each_entry(timer, &snd_timer_list, device_list) {
list_for_each_entry(master, &timer->open_list_head, open_list) {
err = check_matching_master_slave(master, slave);
if (err != 0) /* match found or error */
goto out;
}
}
out:
return err < 0 ? err : 0;
}
/*
* look for slave instances matching with the slave id of the given master.
* when found, relink the open_link of slaves.
*
* call this with register_mutex down.
*/
static int snd_timer_check_master(struct snd_timer_instance *master)
{
struct snd_timer_instance *slave, *tmp;
int err = 0;
/* check all pending slaves */
list_for_each_entry_safe(slave, tmp, &snd_timer_slave_list, open_list) {
err = check_matching_master_slave(master, slave);
if (err < 0)
break;
}
return err < 0 ? err : 0;
}
static void snd_timer_close_locked(struct snd_timer_instance *timeri,
struct device **card_devp_to_put);
/*
* open a timer instance
* when opening a master, the slave id must be here given.
*/
int snd_timer_open(struct snd_timer_instance *timeri,
struct snd_timer_id *tid,
unsigned int slave_id)
{
struct snd_timer *timer;
struct device *card_dev_to_put = NULL;
int err;
mutex_lock(&register_mutex);
if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
/* open a slave instance */
if (tid->dev_sclass <= SNDRV_TIMER_SCLASS_NONE ||
tid->dev_sclass > SNDRV_TIMER_SCLASS_OSS_SEQUENCER) {
pr_debug("ALSA: timer: invalid slave class %i\n",
tid->dev_sclass);
err = -EINVAL;
goto unlock;
}
if (num_slaves >= MAX_SLAVE_INSTANCES) {
err = -EBUSY;
goto unlock;
}
timeri->slave_class = tid->dev_sclass;
timeri->slave_id = tid->device;
timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
list_add_tail(&timeri->open_list, &snd_timer_slave_list);
num_slaves++;
err = snd_timer_check_slave(timeri);
goto list_added;
}
/* open a master instance */
timer = snd_timer_find(tid);
#ifdef CONFIG_MODULES
if (!timer) {
mutex_unlock(&register_mutex);
snd_timer_request(tid);
mutex_lock(&register_mutex);
timer = snd_timer_find(tid);
}
#endif
if (!timer) {
err = -ENODEV;
goto unlock;
}
if (!list_empty(&timer->open_list_head)) {
ALSA: timer: Fix incorrectly assigned timer instance The clean up commit 41672c0c24a6 ("ALSA: timer: Simplify error path in snd_timer_open()") unified the error handling code paths with the standard goto, but it introduced a subtle bug: the timer instance is stored in snd_timer_open() incorrectly even if it returns an error. This may eventually lead to UAF, as spotted by fuzzer. The culprit is the snd_timer_open() code checks the SNDRV_TIMER_IFLG_EXCLUSIVE flag with the common variable timeri. This variable is supposed to be the newly created instance, but we (ab-)used it for a temporary check before the actual creation of a timer instance. After that point, there is another check for the max number of instances, and it bails out if over the threshold. Before the refactoring above, it worked fine because the code returned directly from that point. After the refactoring, however, it jumps to the unified error path that stores the timeri variable in return -- even if it returns an error. Unfortunately this stored value is kept in the caller side (snd_timer_user_tselect()) in tu->timeri. This causes inconsistency later, as if the timer was successfully assigned. In this patch, we fix it by not re-using timeri variable but a temporary variable for testing the exclusive connection, so timeri remains NULL at that point. Fixes: 41672c0c24a6 ("ALSA: timer: Simplify error path in snd_timer_open()") Reported-and-tested-by: Tristan Madani <tristmd@gmail.com> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20191106165547.23518-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2019-11-06 19:55:47 +03:00
struct snd_timer_instance *t =
list_entry(timer->open_list_head.next,
struct snd_timer_instance, open_list);
ALSA: timer: Fix incorrectly assigned timer instance The clean up commit 41672c0c24a6 ("ALSA: timer: Simplify error path in snd_timer_open()") unified the error handling code paths with the standard goto, but it introduced a subtle bug: the timer instance is stored in snd_timer_open() incorrectly even if it returns an error. This may eventually lead to UAF, as spotted by fuzzer. The culprit is the snd_timer_open() code checks the SNDRV_TIMER_IFLG_EXCLUSIVE flag with the common variable timeri. This variable is supposed to be the newly created instance, but we (ab-)used it for a temporary check before the actual creation of a timer instance. After that point, there is another check for the max number of instances, and it bails out if over the threshold. Before the refactoring above, it worked fine because the code returned directly from that point. After the refactoring, however, it jumps to the unified error path that stores the timeri variable in return -- even if it returns an error. Unfortunately this stored value is kept in the caller side (snd_timer_user_tselect()) in tu->timeri. This causes inconsistency later, as if the timer was successfully assigned. In this patch, we fix it by not re-using timeri variable but a temporary variable for testing the exclusive connection, so timeri remains NULL at that point. Fixes: 41672c0c24a6 ("ALSA: timer: Simplify error path in snd_timer_open()") Reported-and-tested-by: Tristan Madani <tristmd@gmail.com> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20191106165547.23518-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2019-11-06 19:55:47 +03:00
if (t->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
err = -EBUSY;
goto unlock;
}
}
if (timer->num_instances >= timer->max_instances) {
err = -EBUSY;
goto unlock;
}
if (!try_module_get(timer->module)) {
err = -EBUSY;
goto unlock;
}
/* take a card refcount for safe disconnection */
if (timer->card) {
get_device(&timer->card->card_dev);
card_dev_to_put = &timer->card->card_dev;
}
ALSA: timer: fix NULL pointer dereference on memory allocation failure I hit this with syzkaller: kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 1327 Comm: a.out Not tainted 4.8.0-rc2+ #190 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014 task: ffff88011278d600 task.stack: ffff8801120c0000 RIP: 0010:[<ffffffff82c8ba07>] [<ffffffff82c8ba07>] snd_hrtimer_start+0x77/0x100 RSP: 0018:ffff8801120c7a60 EFLAGS: 00010006 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000007 RDX: 0000000000000009 RSI: 1ffff10023483091 RDI: 0000000000000048 RBP: ffff8801120c7a78 R08: ffff88011a5cf768 R09: ffff88011a5ba790 R10: 0000000000000002 R11: ffffed00234b9ef1 R12: ffff880114843980 R13: ffffffff84213c00 R14: ffff880114843ab0 R15: 0000000000000286 FS: 00007f72958f3700(0000) GS:ffff88011aa00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000603001 CR3: 00000001126ab000 CR4: 00000000000006f0 Stack: ffff880114843980 ffff880111eb2dc0 ffff880114843a34 ffff8801120c7ad0 ffffffff82c81ab1 0000000000000000 ffffffff842138e0 0000000100000000 ffff880111eb2dd0 ffff880111eb2dc0 0000000000000001 ffff880111eb2dc0 Call Trace: [<ffffffff82c81ab1>] snd_timer_start1+0x331/0x670 [<ffffffff82c85bfd>] snd_timer_start+0x5d/0xa0 [<ffffffff82c8795e>] snd_timer_user_ioctl+0x88e/0x2830 [<ffffffff8159f3a0>] ? __follow_pte.isra.49+0x430/0x430 [<ffffffff82c870d0>] ? snd_timer_pause+0x80/0x80 [<ffffffff815a26fa>] ? do_wp_page+0x3aa/0x1c90 [<ffffffff8132762f>] ? put_prev_entity+0x108f/0x21a0 [<ffffffff82c870d0>] ? snd_timer_pause+0x80/0x80 [<ffffffff816b0733>] do_vfs_ioctl+0x193/0x1050 [<ffffffff813510af>] ? cpuacct_account_field+0x12f/0x1a0 [<ffffffff816b05a0>] ? ioctl_preallocate+0x200/0x200 [<ffffffff81002f2f>] ? syscall_trace_enter+0x3cf/0xdb0 [<ffffffff815045ba>] ? __context_tracking_exit.part.4+0x9a/0x1e0 [<ffffffff81002b60>] ? exit_to_usermode_loop+0x190/0x190 [<ffffffff82001a97>] ? check_preemption_disabled+0x37/0x1e0 [<ffffffff81d93889>] ? security_file_ioctl+0x89/0xb0 [<ffffffff816b167f>] SyS_ioctl+0x8f/0xc0 [<ffffffff816b15f0>] ? do_vfs_ioctl+0x1050/0x1050 [<ffffffff81005524>] do_syscall_64+0x1c4/0x4e0 [<ffffffff83c32b2a>] entry_SYSCALL64_slow_path+0x25/0x25 Code: c7 c7 c4 b9 c8 82 48 89 d9 4c 89 ee e8 63 88 7f fe e8 7e 46 7b fe 48 8d 7b 48 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 04 84 c0 7e 65 80 7b 48 00 74 0e e8 52 46 RIP [<ffffffff82c8ba07>] snd_hrtimer_start+0x77/0x100 RSP <ffff8801120c7a60> ---[ end trace 5955b08db7f2b029 ]--- This can happen if snd_hrtimer_open() fails to allocate memory and returns an error, which is currently not checked by snd_timer_open(): ioctl(SNDRV_TIMER_IOCTL_SELECT) - snd_timer_user_tselect() - snd_timer_close() - snd_hrtimer_close() - (struct snd_timer *) t->private_data = NULL - snd_timer_open() - snd_hrtimer_open() - kzalloc() fails; t->private_data is still NULL ioctl(SNDRV_TIMER_IOCTL_START) - snd_timer_user_start() - snd_timer_start() - snd_timer_start1() - snd_hrtimer_start() - t->private_data == NULL // boom Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-08-29 01:33:51 +03:00
if (list_empty(&timer->open_list_head) && timer->hw.open) {
err = timer->hw.open(timer);
ALSA: timer: fix NULL pointer dereference on memory allocation failure I hit this with syzkaller: kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 1327 Comm: a.out Not tainted 4.8.0-rc2+ #190 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014 task: ffff88011278d600 task.stack: ffff8801120c0000 RIP: 0010:[<ffffffff82c8ba07>] [<ffffffff82c8ba07>] snd_hrtimer_start+0x77/0x100 RSP: 0018:ffff8801120c7a60 EFLAGS: 00010006 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000007 RDX: 0000000000000009 RSI: 1ffff10023483091 RDI: 0000000000000048 RBP: ffff8801120c7a78 R08: ffff88011a5cf768 R09: ffff88011a5ba790 R10: 0000000000000002 R11: ffffed00234b9ef1 R12: ffff880114843980 R13: ffffffff84213c00 R14: ffff880114843ab0 R15: 0000000000000286 FS: 00007f72958f3700(0000) GS:ffff88011aa00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000603001 CR3: 00000001126ab000 CR4: 00000000000006f0 Stack: ffff880114843980 ffff880111eb2dc0 ffff880114843a34 ffff8801120c7ad0 ffffffff82c81ab1 0000000000000000 ffffffff842138e0 0000000100000000 ffff880111eb2dd0 ffff880111eb2dc0 0000000000000001 ffff880111eb2dc0 Call Trace: [<ffffffff82c81ab1>] snd_timer_start1+0x331/0x670 [<ffffffff82c85bfd>] snd_timer_start+0x5d/0xa0 [<ffffffff82c8795e>] snd_timer_user_ioctl+0x88e/0x2830 [<ffffffff8159f3a0>] ? __follow_pte.isra.49+0x430/0x430 [<ffffffff82c870d0>] ? snd_timer_pause+0x80/0x80 [<ffffffff815a26fa>] ? do_wp_page+0x3aa/0x1c90 [<ffffffff8132762f>] ? put_prev_entity+0x108f/0x21a0 [<ffffffff82c870d0>] ? snd_timer_pause+0x80/0x80 [<ffffffff816b0733>] do_vfs_ioctl+0x193/0x1050 [<ffffffff813510af>] ? cpuacct_account_field+0x12f/0x1a0 [<ffffffff816b05a0>] ? ioctl_preallocate+0x200/0x200 [<ffffffff81002f2f>] ? syscall_trace_enter+0x3cf/0xdb0 [<ffffffff815045ba>] ? __context_tracking_exit.part.4+0x9a/0x1e0 [<ffffffff81002b60>] ? exit_to_usermode_loop+0x190/0x190 [<ffffffff82001a97>] ? check_preemption_disabled+0x37/0x1e0 [<ffffffff81d93889>] ? security_file_ioctl+0x89/0xb0 [<ffffffff816b167f>] SyS_ioctl+0x8f/0xc0 [<ffffffff816b15f0>] ? do_vfs_ioctl+0x1050/0x1050 [<ffffffff81005524>] do_syscall_64+0x1c4/0x4e0 [<ffffffff83c32b2a>] entry_SYSCALL64_slow_path+0x25/0x25 Code: c7 c7 c4 b9 c8 82 48 89 d9 4c 89 ee e8 63 88 7f fe e8 7e 46 7b fe 48 8d 7b 48 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 04 84 c0 7e 65 80 7b 48 00 74 0e e8 52 46 RIP [<ffffffff82c8ba07>] snd_hrtimer_start+0x77/0x100 RSP <ffff8801120c7a60> ---[ end trace 5955b08db7f2b029 ]--- This can happen if snd_hrtimer_open() fails to allocate memory and returns an error, which is currently not checked by snd_timer_open(): ioctl(SNDRV_TIMER_IOCTL_SELECT) - snd_timer_user_tselect() - snd_timer_close() - snd_hrtimer_close() - (struct snd_timer *) t->private_data = NULL - snd_timer_open() - snd_hrtimer_open() - kzalloc() fails; t->private_data is still NULL ioctl(SNDRV_TIMER_IOCTL_START) - snd_timer_user_start() - snd_timer_start() - snd_timer_start1() - snd_hrtimer_start() - t->private_data == NULL // boom Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-08-29 01:33:51 +03:00
if (err) {
module_put(timer->module);
goto unlock;
ALSA: timer: fix NULL pointer dereference on memory allocation failure I hit this with syzkaller: kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 1327 Comm: a.out Not tainted 4.8.0-rc2+ #190 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014 task: ffff88011278d600 task.stack: ffff8801120c0000 RIP: 0010:[<ffffffff82c8ba07>] [<ffffffff82c8ba07>] snd_hrtimer_start+0x77/0x100 RSP: 0018:ffff8801120c7a60 EFLAGS: 00010006 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000007 RDX: 0000000000000009 RSI: 1ffff10023483091 RDI: 0000000000000048 RBP: ffff8801120c7a78 R08: ffff88011a5cf768 R09: ffff88011a5ba790 R10: 0000000000000002 R11: ffffed00234b9ef1 R12: ffff880114843980 R13: ffffffff84213c00 R14: ffff880114843ab0 R15: 0000000000000286 FS: 00007f72958f3700(0000) GS:ffff88011aa00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000603001 CR3: 00000001126ab000 CR4: 00000000000006f0 Stack: ffff880114843980 ffff880111eb2dc0 ffff880114843a34 ffff8801120c7ad0 ffffffff82c81ab1 0000000000000000 ffffffff842138e0 0000000100000000 ffff880111eb2dd0 ffff880111eb2dc0 0000000000000001 ffff880111eb2dc0 Call Trace: [<ffffffff82c81ab1>] snd_timer_start1+0x331/0x670 [<ffffffff82c85bfd>] snd_timer_start+0x5d/0xa0 [<ffffffff82c8795e>] snd_timer_user_ioctl+0x88e/0x2830 [<ffffffff8159f3a0>] ? __follow_pte.isra.49+0x430/0x430 [<ffffffff82c870d0>] ? snd_timer_pause+0x80/0x80 [<ffffffff815a26fa>] ? do_wp_page+0x3aa/0x1c90 [<ffffffff8132762f>] ? put_prev_entity+0x108f/0x21a0 [<ffffffff82c870d0>] ? snd_timer_pause+0x80/0x80 [<ffffffff816b0733>] do_vfs_ioctl+0x193/0x1050 [<ffffffff813510af>] ? cpuacct_account_field+0x12f/0x1a0 [<ffffffff816b05a0>] ? ioctl_preallocate+0x200/0x200 [<ffffffff81002f2f>] ? syscall_trace_enter+0x3cf/0xdb0 [<ffffffff815045ba>] ? __context_tracking_exit.part.4+0x9a/0x1e0 [<ffffffff81002b60>] ? exit_to_usermode_loop+0x190/0x190 [<ffffffff82001a97>] ? check_preemption_disabled+0x37/0x1e0 [<ffffffff81d93889>] ? security_file_ioctl+0x89/0xb0 [<ffffffff816b167f>] SyS_ioctl+0x8f/0xc0 [<ffffffff816b15f0>] ? do_vfs_ioctl+0x1050/0x1050 [<ffffffff81005524>] do_syscall_64+0x1c4/0x4e0 [<ffffffff83c32b2a>] entry_SYSCALL64_slow_path+0x25/0x25 Code: c7 c7 c4 b9 c8 82 48 89 d9 4c 89 ee e8 63 88 7f fe e8 7e 46 7b fe 48 8d 7b 48 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 04 84 c0 7e 65 80 7b 48 00 74 0e e8 52 46 RIP [<ffffffff82c8ba07>] snd_hrtimer_start+0x77/0x100 RSP <ffff8801120c7a60> ---[ end trace 5955b08db7f2b029 ]--- This can happen if snd_hrtimer_open() fails to allocate memory and returns an error, which is currently not checked by snd_timer_open(): ioctl(SNDRV_TIMER_IOCTL_SELECT) - snd_timer_user_tselect() - snd_timer_close() - snd_hrtimer_close() - (struct snd_timer *) t->private_data = NULL - snd_timer_open() - snd_hrtimer_open() - kzalloc() fails; t->private_data is still NULL ioctl(SNDRV_TIMER_IOCTL_START) - snd_timer_user_start() - snd_timer_start() - snd_timer_start1() - snd_hrtimer_start() - t->private_data == NULL // boom Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-08-29 01:33:51 +03:00
}
}
timeri->timer = timer;
timeri->slave_class = tid->dev_sclass;
timeri->slave_id = slave_id;
list_add_tail(&timeri->open_list, &timer->open_list_head);
timer->num_instances++;
err = snd_timer_check_master(timeri);
list_added:
if (err < 0)
snd_timer_close_locked(timeri, &card_dev_to_put);
unlock:
mutex_unlock(&register_mutex);
/* put_device() is called after unlock for avoiding deadlock */
if (err < 0 && card_dev_to_put)
put_device(card_dev_to_put);
return err;
}
EXPORT_SYMBOL(snd_timer_open);
/*
* close a timer instance
* call this with register_mutex down.
*/
static void snd_timer_close_locked(struct snd_timer_instance *timeri,
struct device **card_devp_to_put)
{
struct snd_timer *timer = timeri->timer;
struct snd_timer_instance *slave, *tmp;
if (timer) {
spin_lock_irq(&timer->lock);
timeri->flags |= SNDRV_TIMER_IFLG_DEAD;
spin_unlock_irq(&timer->lock);
}
if (!list_empty(&timeri->open_list)) {
list_del_init(&timeri->open_list);
if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
num_slaves--;
}
/* force to stop the timer */
snd_timer_stop(timeri);
if (timer) {
timer->num_instances--;
/* wait, until the active callback is finished */
spin_lock_irq(&timer->lock);
while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
spin_unlock_irq(&timer->lock);
udelay(10);
spin_lock_irq(&timer->lock);
}
spin_unlock_irq(&timer->lock);
/* remove slave links */
spin_lock_irq(&slave_active_lock);
spin_lock(&timer->lock);
timeri->timer = NULL;
list_for_each_entry_safe(slave, tmp, &timeri->slave_list_head,
open_list) {
list_move_tail(&slave->open_list, &snd_timer_slave_list);
timer->num_instances--;
slave->master = NULL;
slave->timer = NULL;
list_del_init(&slave->ack_list);
list_del_init(&slave->active_list);
}
spin_unlock(&timer->lock);
spin_unlock_irq(&slave_active_lock);
/* slave doesn't need to release timer resources below */
if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
timer = NULL;
}
if (timer) {
if (list_empty(&timer->open_list_head) && timer->hw.close)
timer->hw.close(timer);
/* release a card refcount for safe disconnection */
if (timer->card)
*card_devp_to_put = &timer->card->card_dev;
module_put(timer->module);
}
}
/*
* close a timer instance
*/
void snd_timer_close(struct snd_timer_instance *timeri)
{
struct device *card_dev_to_put = NULL;
if (snd_BUG_ON(!timeri))
return;
mutex_lock(&register_mutex);
snd_timer_close_locked(timeri, &card_dev_to_put);
mutex_unlock(&register_mutex);
/* put_device() is called after unlock for avoiding deadlock */
if (card_dev_to_put)
put_device(card_dev_to_put);
}
EXPORT_SYMBOL(snd_timer_close);
static unsigned long snd_timer_hw_resolution(struct snd_timer *timer)
{
if (timer->hw.c_resolution)
return timer->hw.c_resolution(timer);
else
return timer->hw.resolution;
}
unsigned long snd_timer_resolution(struct snd_timer_instance *timeri)
{
struct snd_timer * timer;
unsigned long ret = 0;
unsigned long flags;
if (timeri == NULL)
return 0;
timer = timeri->timer;
if (timer) {
spin_lock_irqsave(&timer->lock, flags);
ret = snd_timer_hw_resolution(timer);
spin_unlock_irqrestore(&timer->lock, flags);
}
return ret;
}
EXPORT_SYMBOL(snd_timer_resolution);
static void snd_timer_notify1(struct snd_timer_instance *ti, int event)
{
struct snd_timer *timer = ti->timer;
unsigned long resolution = 0;
struct snd_timer_instance *ts;
struct timespec64 tstamp;
if (timer_tstamp_monotonic)
ktime_get_ts64(&tstamp);
else
ktime_get_real_ts64(&tstamp);
if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_START ||
event > SNDRV_TIMER_EVENT_PAUSE))
return;
if (timer &&
(event == SNDRV_TIMER_EVENT_START ||
event == SNDRV_TIMER_EVENT_CONTINUE))
resolution = snd_timer_hw_resolution(timer);
if (ti->ccallback)
ti->ccallback(ti, event, &tstamp, resolution);
if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
return;
if (timer == NULL)
return;
if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
return;
list_for_each_entry(ts, &ti->slave_active_head, active_list)
if (ts->ccallback)
ts->ccallback(ts, event + 100, &tstamp, resolution);
}
/* start/continue a master timer */
static int snd_timer_start1(struct snd_timer_instance *timeri,
bool start, unsigned long ticks)
{
struct snd_timer *timer;
int result;
unsigned long flags;
timer = timeri->timer;
if (!timer)
return -EINVAL;
spin_lock_irqsave(&timer->lock, flags);
if (timeri->flags & SNDRV_TIMER_IFLG_DEAD) {
result = -EINVAL;
goto unlock;
}
if (timer->card && timer->card->shutdown) {
result = -ENODEV;
goto unlock;
}
if (timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
SNDRV_TIMER_IFLG_START)) {
result = -EBUSY;
goto unlock;
}
if (start)
timeri->ticks = timeri->cticks = ticks;
else if (!timeri->cticks)
timeri->cticks = 1;
timeri->pticks = 0;
list_move_tail(&timeri->active_list, &timer->active_list_head);
if (timer->running) {
if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
goto __start_now;
timer->flags |= SNDRV_TIMER_FLG_RESCHED;
timeri->flags |= SNDRV_TIMER_IFLG_START;
result = 1; /* delayed start */
} else {
if (start)
timer->sticks = ticks;
timer->hw.start(timer);
__start_now:
timer->running++;
timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
result = 0;
}
snd_timer_notify1(timeri, start ? SNDRV_TIMER_EVENT_START :
SNDRV_TIMER_EVENT_CONTINUE);
unlock:
spin_unlock_irqrestore(&timer->lock, flags);
return result;
}
/* start/continue a slave timer */
static int snd_timer_start_slave(struct snd_timer_instance *timeri,
bool start)
{
unsigned long flags;
int err;
spin_lock_irqsave(&slave_active_lock, flags);
if (timeri->flags & SNDRV_TIMER_IFLG_DEAD) {
err = -EINVAL;
goto unlock;
}
if (timeri->flags & SNDRV_TIMER_IFLG_RUNNING) {
err = -EBUSY;
goto unlock;
}
timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
if (timeri->master && timeri->timer) {
spin_lock(&timeri->timer->lock);
list_add_tail(&timeri->active_list,
&timeri->master->slave_active_head);
snd_timer_notify1(timeri, start ? SNDRV_TIMER_EVENT_START :
SNDRV_TIMER_EVENT_CONTINUE);
spin_unlock(&timeri->timer->lock);
}
err = 1; /* delayed start */
unlock:
spin_unlock_irqrestore(&slave_active_lock, flags);
return err;
}
/* stop/pause a master timer */
static int snd_timer_stop1(struct snd_timer_instance *timeri, bool stop)
{
struct snd_timer *timer;
int result = 0;
unsigned long flags;
timer = timeri->timer;
if (!timer)
return -EINVAL;
spin_lock_irqsave(&timer->lock, flags);
if (!(timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
SNDRV_TIMER_IFLG_START))) {
result = -EBUSY;
goto unlock;
}
list_del_init(&timeri->ack_list);
list_del_init(&timeri->active_list);
if (timer->card && timer->card->shutdown)
goto unlock;
if (stop) {
timeri->cticks = timeri->ticks;
timeri->pticks = 0;
}
if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
!(--timer->running)) {
timer->hw.stop(timer);
if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
snd_timer_reschedule(timer, 0);
if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
timer->hw.start(timer);
}
}
}
timeri->flags &= ~(SNDRV_TIMER_IFLG_RUNNING | SNDRV_TIMER_IFLG_START);
ALSA: timer: Fix zero-division by continue of uninitialized instance When a user timer instance is continued without the explicit start beforehand, the system gets eventually zero-division error like: divide error: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN CPU: 1 PID: 27320 Comm: syz-executor Not tainted 4.8.0-rc3-next-20160825+ #8 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff88003c9b2280 task.stack: ffff880027280000 RIP: 0010:[<ffffffff858e1a6c>] [< inline >] ktime_divns include/linux/ktime.h:195 RIP: 0010:[<ffffffff858e1a6c>] [<ffffffff858e1a6c>] snd_hrtimer_callback+0x1bc/0x3c0 sound/core/hrtimer.c:62 Call Trace: <IRQ> [< inline >] __run_hrtimer kernel/time/hrtimer.c:1238 [<ffffffff81504335>] __hrtimer_run_queues+0x325/0xe70 kernel/time/hrtimer.c:1302 [<ffffffff81506ceb>] hrtimer_interrupt+0x18b/0x420 kernel/time/hrtimer.c:1336 [<ffffffff8126d8df>] local_apic_timer_interrupt+0x6f/0xe0 arch/x86/kernel/apic/apic.c:933 [<ffffffff86e13056>] smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:957 [<ffffffff86e1210c>] apic_timer_interrupt+0x8c/0xa0 arch/x86/entry/entry_64.S:487 <EOI> ..... Although a similar issue was spotted and a fix patch was merged in commit [6b760bb2c63a: ALSA: timer: fix division by zero after SNDRV_TIMER_IOCTL_CONTINUE], it seems covering only a part of iceberg. In this patch, we fix the issue a bit more drastically. Basically the continue of an uninitialized timer is supposed to be a fresh start, so we do it for user timers. For the direct snd_timer_continue() call, there is no way to pass the initial tick value, so we kick out for the uninitialized case. Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-09-07 16:45:31 +03:00
if (stop)
timeri->flags &= ~SNDRV_TIMER_IFLG_PAUSED;
else
timeri->flags |= SNDRV_TIMER_IFLG_PAUSED;
snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP :
SNDRV_TIMER_EVENT_PAUSE);
unlock:
spin_unlock_irqrestore(&timer->lock, flags);
return result;
}
/* stop/pause a slave timer */
static int snd_timer_stop_slave(struct snd_timer_instance *timeri, bool stop)
{
unsigned long flags;
spin_lock_irqsave(&slave_active_lock, flags);
if (!(timeri->flags & SNDRV_TIMER_IFLG_RUNNING)) {
spin_unlock_irqrestore(&slave_active_lock, flags);
return -EBUSY;
}
timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
if (timeri->timer) {
spin_lock(&timeri->timer->lock);
list_del_init(&timeri->ack_list);
list_del_init(&timeri->active_list);
snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP :
SNDRV_TIMER_EVENT_PAUSE);
spin_unlock(&timeri->timer->lock);
}
spin_unlock_irqrestore(&slave_active_lock, flags);
return 0;
}
/*
* start the timer instance
*/
int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
{
if (timeri == NULL || ticks < 1)
return -EINVAL;
if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
return snd_timer_start_slave(timeri, true);
else
return snd_timer_start1(timeri, true, ticks);
}
EXPORT_SYMBOL(snd_timer_start);
/*
* stop the timer instance.
*
* do not call this from the timer callback!
*/
int snd_timer_stop(struct snd_timer_instance *timeri)
{
if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
return snd_timer_stop_slave(timeri, true);
else
return snd_timer_stop1(timeri, true);
}
EXPORT_SYMBOL(snd_timer_stop);
/*
* start again.. the tick is kept.
*/
int snd_timer_continue(struct snd_timer_instance *timeri)
{
ALSA: timer: Fix zero-division by continue of uninitialized instance When a user timer instance is continued without the explicit start beforehand, the system gets eventually zero-division error like: divide error: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN CPU: 1 PID: 27320 Comm: syz-executor Not tainted 4.8.0-rc3-next-20160825+ #8 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff88003c9b2280 task.stack: ffff880027280000 RIP: 0010:[<ffffffff858e1a6c>] [< inline >] ktime_divns include/linux/ktime.h:195 RIP: 0010:[<ffffffff858e1a6c>] [<ffffffff858e1a6c>] snd_hrtimer_callback+0x1bc/0x3c0 sound/core/hrtimer.c:62 Call Trace: <IRQ> [< inline >] __run_hrtimer kernel/time/hrtimer.c:1238 [<ffffffff81504335>] __hrtimer_run_queues+0x325/0xe70 kernel/time/hrtimer.c:1302 [<ffffffff81506ceb>] hrtimer_interrupt+0x18b/0x420 kernel/time/hrtimer.c:1336 [<ffffffff8126d8df>] local_apic_timer_interrupt+0x6f/0xe0 arch/x86/kernel/apic/apic.c:933 [<ffffffff86e13056>] smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:957 [<ffffffff86e1210c>] apic_timer_interrupt+0x8c/0xa0 arch/x86/entry/entry_64.S:487 <EOI> ..... Although a similar issue was spotted and a fix patch was merged in commit [6b760bb2c63a: ALSA: timer: fix division by zero after SNDRV_TIMER_IOCTL_CONTINUE], it seems covering only a part of iceberg. In this patch, we fix the issue a bit more drastically. Basically the continue of an uninitialized timer is supposed to be a fresh start, so we do it for user timers. For the direct snd_timer_continue() call, there is no way to pass the initial tick value, so we kick out for the uninitialized case. Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-09-07 16:45:31 +03:00
/* timer can continue only after pause */
if (!(timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
return -EINVAL;
if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
return snd_timer_start_slave(timeri, false);
else
return snd_timer_start1(timeri, false, 0);
}
EXPORT_SYMBOL(snd_timer_continue);
/*
* pause.. remember the ticks left
*/
int snd_timer_pause(struct snd_timer_instance * timeri)
{
if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
return snd_timer_stop_slave(timeri, false);
else
return snd_timer_stop1(timeri, false);
}
EXPORT_SYMBOL(snd_timer_pause);
/*
* reschedule the timer
*
* start pending instances and check the scheduling ticks.
* when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
*/
static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left)
{
struct snd_timer_instance *ti;
unsigned long ticks = ~0UL;
list_for_each_entry(ti, &timer->active_list_head, active_list) {
if (ti->flags & SNDRV_TIMER_IFLG_START) {
ti->flags &= ~SNDRV_TIMER_IFLG_START;
ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
timer->running++;
}
if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
if (ticks > ti->cticks)
ticks = ti->cticks;
}
}
if (ticks == ~0UL) {
timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
return;
}
if (ticks > timer->hw.ticks)
ticks = timer->hw.ticks;
if (ticks_left != ticks)
timer->flags |= SNDRV_TIMER_FLG_CHANGE;
timer->sticks = ticks;
}
/* call callbacks in timer ack list */
static void snd_timer_process_callbacks(struct snd_timer *timer,
struct list_head *head)
{
struct snd_timer_instance *ti;
unsigned long resolution, ticks;
while (!list_empty(head)) {
ti = list_first_entry(head, struct snd_timer_instance,
ack_list);
/* remove from ack_list and make empty */
list_del_init(&ti->ack_list);
if (!(ti->flags & SNDRV_TIMER_IFLG_DEAD)) {
ticks = ti->pticks;
ti->pticks = 0;
resolution = ti->resolution;
ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
spin_unlock(&timer->lock);
if (ti->callback)
ti->callback(ti, resolution, ticks);
spin_lock(&timer->lock);
ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
}
}
}
/* clear pending instances from ack list */
static void snd_timer_clear_callbacks(struct snd_timer *timer,
struct list_head *head)
{
unsigned long flags;
spin_lock_irqsave(&timer->lock, flags);
while (!list_empty(head))
list_del_init(head->next);
spin_unlock_irqrestore(&timer->lock, flags);
}
/*
* timer tasklet
*
*/
static void snd_timer_tasklet(unsigned long arg)
{
struct snd_timer *timer = (struct snd_timer *) arg;
unsigned long flags;
if (timer->card && timer->card->shutdown) {
snd_timer_clear_callbacks(timer, &timer->sack_list_head);
return;
}
spin_lock_irqsave(&timer->lock, flags);
snd_timer_process_callbacks(timer, &timer->sack_list_head);
spin_unlock_irqrestore(&timer->lock, flags);
}
/*
* timer interrupt
*
* ticks_left is usually equal to timer->sticks.
*
*/
void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
{
struct snd_timer_instance *ti, *ts, *tmp;
unsigned long resolution;
struct list_head *ack_list_head;
unsigned long flags;
int use_tasklet = 0;
if (timer == NULL)
return;
if (timer->card && timer->card->shutdown) {
snd_timer_clear_callbacks(timer, &timer->ack_list_head);
return;
}
spin_lock_irqsave(&timer->lock, flags);
/* remember the current resolution */
resolution = snd_timer_hw_resolution(timer);
/* loop for all active instances
* Here we cannot use list_for_each_entry because the active_list of a
* processed instance is relinked to done_list_head before the callback
* is called.
*/
list_for_each_entry_safe(ti, tmp, &timer->active_list_head,
active_list) {
if (ti->flags & SNDRV_TIMER_IFLG_DEAD)
continue;
if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
continue;
ti->pticks += ticks_left;
ti->resolution = resolution;
if (ti->cticks < ticks_left)
ti->cticks = 0;
else
ti->cticks -= ticks_left;
if (ti->cticks) /* not expired */
continue;
if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
ti->cticks = ti->ticks;
} else {
ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
--timer->running;
list_del_init(&ti->active_list);
}
if ((timer->hw.flags & SNDRV_TIMER_HW_TASKLET) ||
(ti->flags & SNDRV_TIMER_IFLG_FAST))
ack_list_head = &timer->ack_list_head;
else
ack_list_head = &timer->sack_list_head;
if (list_empty(&ti->ack_list))
list_add_tail(&ti->ack_list, ack_list_head);
list_for_each_entry(ts, &ti->slave_active_head, active_list) {
ts->pticks = ti->pticks;
ts->resolution = resolution;
if (list_empty(&ts->ack_list))
list_add_tail(&ts->ack_list, ack_list_head);
}
}
if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
snd_timer_reschedule(timer, timer->sticks);
if (timer->running) {
if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
timer->hw.stop(timer);
timer->flags |= SNDRV_TIMER_FLG_CHANGE;
}
if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
(timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
/* restart timer */
timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
timer->hw.start(timer);
}
} else {
timer->hw.stop(timer);
}
/* now process all fast callbacks */
snd_timer_process_callbacks(timer, &timer->ack_list_head);
/* do we have any slow callbacks? */
use_tasklet = !list_empty(&timer->sack_list_head);
spin_unlock_irqrestore(&timer->lock, flags);
if (use_tasklet)
tasklet_schedule(&timer->task_queue);
}
EXPORT_SYMBOL(snd_timer_interrupt);
/*
*/
int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
struct snd_timer **rtimer)
{
struct snd_timer *timer;
int err;
static struct snd_device_ops ops = {
.dev_free = snd_timer_dev_free,
.dev_register = snd_timer_dev_register,
.dev_disconnect = snd_timer_dev_disconnect,
};
if (snd_BUG_ON(!tid))
return -EINVAL;
if (tid->dev_class == SNDRV_TIMER_CLASS_CARD ||
tid->dev_class == SNDRV_TIMER_CLASS_PCM) {
if (WARN_ON(!card))
return -EINVAL;
}
if (rtimer)
*rtimer = NULL;
timer = kzalloc(sizeof(*timer), GFP_KERNEL);
if (!timer)
return -ENOMEM;
timer->tmr_class = tid->dev_class;
timer->card = card;
timer->tmr_device = tid->device;
timer->tmr_subdevice = tid->subdevice;
if (id)
strlcpy(timer->id, id, sizeof(timer->id));
ALSA: timer: fix division by zero after SNDRV_TIMER_IOCTL_CONTINUE I got this: divide error: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 1327 Comm: a.out Not tainted 4.8.0-rc2+ #189 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014 task: ffff8801120a9580 task.stack: ffff8801120b0000 RIP: 0010:[<ffffffff82c8bd9a>] [<ffffffff82c8bd9a>] snd_hrtimer_callback+0x1da/0x3f0 RSP: 0018:ffff88011aa87da8 EFLAGS: 00010006 RAX: 0000000000004f76 RBX: ffff880112655e88 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff880112655ea0 RDI: 0000000000000001 RBP: ffff88011aa87e00 R08: ffff88013fff905c R09: ffff88013fff9048 R10: ffff88013fff9050 R11: 00000001050a7b8c R12: ffff880114778a00 R13: ffff880114778ab4 R14: ffff880114778b30 R15: 0000000000000000 FS: 00007f071647c700(0000) GS:ffff88011aa80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000603001 CR3: 0000000112021000 CR4: 00000000000006e0 Stack: 0000000000000000 ffff880114778ab8 ffff880112655ea0 0000000000004f76 ffff880112655ec8 ffff880112655e80 ffff880112655e88 ffff88011aa98fc0 00000000b97ccf2b dffffc0000000000 ffff88011aa98fc0 ffff88011aa87ef0 Call Trace: <IRQ> [<ffffffff813abce7>] __hrtimer_run_queues+0x347/0xa00 [<ffffffff82c8bbc0>] ? snd_hrtimer_close+0x130/0x130 [<ffffffff813ab9a0>] ? retrigger_next_event+0x1b0/0x1b0 [<ffffffff813ae1a6>] ? hrtimer_interrupt+0x136/0x4b0 [<ffffffff813ae220>] hrtimer_interrupt+0x1b0/0x4b0 [<ffffffff8120f91e>] local_apic_timer_interrupt+0x6e/0xf0 [<ffffffff81227ad3>] ? kvm_guest_apic_eoi_write+0x13/0xc0 [<ffffffff83c35086>] smp_apic_timer_interrupt+0x76/0xa0 [<ffffffff83c3416c>] apic_timer_interrupt+0x8c/0xa0 <EOI> [<ffffffff83c3239c>] ? _raw_spin_unlock_irqrestore+0x2c/0x60 [<ffffffff82c8185d>] snd_timer_start1+0xdd/0x670 [<ffffffff82c87015>] snd_timer_continue+0x45/0x80 [<ffffffff82c88100>] snd_timer_user_ioctl+0x1030/0x2830 [<ffffffff8159f3a0>] ? __follow_pte.isra.49+0x430/0x430 [<ffffffff82c870d0>] ? snd_timer_pause+0x80/0x80 [<ffffffff815a26fa>] ? do_wp_page+0x3aa/0x1c90 [<ffffffff815aa4f8>] ? handle_mm_fault+0xbc8/0x27f0 [<ffffffff815a9930>] ? __pmd_alloc+0x370/0x370 [<ffffffff82c870d0>] ? snd_timer_pause+0x80/0x80 [<ffffffff816b0733>] do_vfs_ioctl+0x193/0x1050 [<ffffffff816b05a0>] ? ioctl_preallocate+0x200/0x200 [<ffffffff81002f2f>] ? syscall_trace_enter+0x3cf/0xdb0 [<ffffffff815045ba>] ? __context_tracking_exit.part.4+0x9a/0x1e0 [<ffffffff81002b60>] ? exit_to_usermode_loop+0x190/0x190 [<ffffffff82001a97>] ? check_preemption_disabled+0x37/0x1e0 [<ffffffff81d93889>] ? security_file_ioctl+0x89/0xb0 [<ffffffff816b167f>] SyS_ioctl+0x8f/0xc0 [<ffffffff816b15f0>] ? do_vfs_ioctl+0x1050/0x1050 [<ffffffff81005524>] do_syscall_64+0x1c4/0x4e0 [<ffffffff83c32b2a>] entry_SYSCALL64_slow_path+0x25/0x25 Code: e8 fc 42 7b fe 8b 0d 06 8a 50 03 49 0f af cf 48 85 c9 0f 88 7c 01 00 00 48 89 4d a8 e8 e0 42 7b fe 48 8b 45 c0 48 8b 4d a8 48 99 <48> f7 f9 49 01 c7 e8 cb 42 7b fe 48 8b 55 d0 48 b8 00 00 00 00 RIP [<ffffffff82c8bd9a>] snd_hrtimer_callback+0x1da/0x3f0 RSP <ffff88011aa87da8> ---[ end trace 6aa380f756a21074 ]--- The problem happens when you call ioctl(SNDRV_TIMER_IOCTL_CONTINUE) on a completely new/unused timer -- it will have ->sticks == 0, which causes a divide by 0 in snd_hrtimer_callback(). Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-08-29 01:33:50 +03:00
timer->sticks = 1;
INIT_LIST_HEAD(&timer->device_list);
INIT_LIST_HEAD(&timer->open_list_head);
INIT_LIST_HEAD(&timer->active_list_head);
INIT_LIST_HEAD(&timer->ack_list_head);
INIT_LIST_HEAD(&timer->sack_list_head);
spin_lock_init(&timer->lock);
tasklet_init(&timer->task_queue, snd_timer_tasklet,
(unsigned long)timer);
timer->max_instances = 1000; /* default limit per timer */
if (card != NULL) {
timer->module = card->module;
err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops);
if (err < 0) {
snd_timer_free(timer);
return err;
}
}
if (rtimer)
*rtimer = timer;
return 0;
}
EXPORT_SYMBOL(snd_timer_new);
static int snd_timer_free(struct snd_timer *timer)
{
if (!timer)
return 0;
mutex_lock(&register_mutex);
if (! list_empty(&timer->open_list_head)) {
struct list_head *p, *n;
struct snd_timer_instance *ti;
pr_warn("ALSA: timer %p is busy?\n", timer);
list_for_each_safe(p, n, &timer->open_list_head) {
list_del_init(p);
ti = list_entry(p, struct snd_timer_instance, open_list);
ti->timer = NULL;
}
}
list_del(&timer->device_list);
mutex_unlock(&register_mutex);
if (timer->private_free)
timer->private_free(timer);
kfree(timer);
return 0;
}
static int snd_timer_dev_free(struct snd_device *device)
{
struct snd_timer *timer = device->device_data;
return snd_timer_free(timer);
}
static int snd_timer_dev_register(struct snd_device *dev)
{
struct snd_timer *timer = dev->device_data;
struct snd_timer *timer1;
if (snd_BUG_ON(!timer || !timer->hw.start || !timer->hw.stop))
return -ENXIO;
if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
!timer->hw.resolution && timer->hw.c_resolution == NULL)
return -EINVAL;
mutex_lock(&register_mutex);
list_for_each_entry(timer1, &snd_timer_list, device_list) {
if (timer1->tmr_class > timer->tmr_class)
break;
if (timer1->tmr_class < timer->tmr_class)
continue;
if (timer1->card && timer->card) {
if (timer1->card->number > timer->card->number)
break;
if (timer1->card->number < timer->card->number)
continue;
}
if (timer1->tmr_device > timer->tmr_device)
break;
if (timer1->tmr_device < timer->tmr_device)
continue;
if (timer1->tmr_subdevice > timer->tmr_subdevice)
break;
if (timer1->tmr_subdevice < timer->tmr_subdevice)
continue;
/* conflicts.. */
mutex_unlock(&register_mutex);
return -EBUSY;
}
list_add_tail(&timer->device_list, &timer1->device_list);
mutex_unlock(&register_mutex);
return 0;
}
static int snd_timer_dev_disconnect(struct snd_device *device)
{
struct snd_timer *timer = device->device_data;
struct snd_timer_instance *ti;
mutex_lock(&register_mutex);
list_del_init(&timer->device_list);
/* wake up pending sleepers */
list_for_each_entry(ti, &timer->open_list_head, open_list) {
if (ti->disconnect)
ti->disconnect(ti);
}
mutex_unlock(&register_mutex);
return 0;
}
void snd_timer_notify(struct snd_timer *timer, int event, struct timespec64 *tstamp)
{
unsigned long flags;
unsigned long resolution = 0;
struct snd_timer_instance *ti, *ts;
if (timer->card && timer->card->shutdown)
return;
if (! (timer->hw.flags & SNDRV_TIMER_HW_SLAVE))
return;
if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_MSTART ||
event > SNDRV_TIMER_EVENT_MRESUME))
return;
spin_lock_irqsave(&timer->lock, flags);
if (event == SNDRV_TIMER_EVENT_MSTART ||
event == SNDRV_TIMER_EVENT_MCONTINUE ||
event == SNDRV_TIMER_EVENT_MRESUME)
resolution = snd_timer_hw_resolution(timer);
list_for_each_entry(ti, &timer->active_list_head, active_list) {
if (ti->ccallback)
ti->ccallback(ti, event, tstamp, resolution);
list_for_each_entry(ts, &ti->slave_active_head, active_list)
if (ts->ccallback)
ts->ccallback(ts, event, tstamp, resolution);
}
spin_unlock_irqrestore(&timer->lock, flags);
}
EXPORT_SYMBOL(snd_timer_notify);
/*
* exported functions for global timers
*/
int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer)
{
struct snd_timer_id tid;
tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
tid.card = -1;
tid.device = device;
tid.subdevice = 0;
return snd_timer_new(NULL, id, &tid, rtimer);
}
EXPORT_SYMBOL(snd_timer_global_new);
int snd_timer_global_free(struct snd_timer *timer)
{
return snd_timer_free(timer);
}
EXPORT_SYMBOL(snd_timer_global_free);
int snd_timer_global_register(struct snd_timer *timer)
{
struct snd_device dev;
memset(&dev, 0, sizeof(dev));
dev.device_data = timer;
return snd_timer_dev_register(&dev);
}
EXPORT_SYMBOL(snd_timer_global_register);
/*
* System timer
*/
struct snd_timer_system_private {
struct timer_list tlist;
struct snd_timer *snd_timer;
unsigned long last_expires;
unsigned long last_jiffies;
unsigned long correction;
};
static void snd_timer_s_function(struct timer_list *t)
{
struct snd_timer_system_private *priv = from_timer(priv, t,
tlist);
struct snd_timer *timer = priv->snd_timer;
unsigned long jiff = jiffies;
if (time_after(jiff, priv->last_expires))
priv->correction += (long)jiff - (long)priv->last_expires;
snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
}
static int snd_timer_s_start(struct snd_timer * timer)
{
struct snd_timer_system_private *priv;
unsigned long njiff;
priv = (struct snd_timer_system_private *) timer->private_data;
njiff = (priv->last_jiffies = jiffies);
if (priv->correction > timer->sticks - 1) {
priv->correction -= timer->sticks - 1;
njiff++;
} else {
njiff += timer->sticks - priv->correction;
priv->correction = 0;
}
priv->last_expires = njiff;
mod_timer(&priv->tlist, njiff);
return 0;
}
static int snd_timer_s_stop(struct snd_timer * timer)
{
struct snd_timer_system_private *priv;
unsigned long jiff;
priv = (struct snd_timer_system_private *) timer->private_data;
del_timer(&priv->tlist);
jiff = jiffies;
if (time_before(jiff, priv->last_expires))
timer->sticks = priv->last_expires - jiff;
else
timer->sticks = 1;
priv->correction = 0;
return 0;
}
static int snd_timer_s_close(struct snd_timer *timer)
{
struct snd_timer_system_private *priv;
priv = (struct snd_timer_system_private *)timer->private_data;
del_timer_sync(&priv->tlist);
return 0;
}
static struct snd_timer_hardware snd_timer_system =
{
.flags = SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_TASKLET,
.resolution = 1000000000L / HZ,
.ticks = 10000000L,
.close = snd_timer_s_close,
.start = snd_timer_s_start,
.stop = snd_timer_s_stop
};
static void snd_timer_free_system(struct snd_timer *timer)
{
kfree(timer->private_data);
}
static int snd_timer_register_system(void)
{
struct snd_timer *timer;
struct snd_timer_system_private *priv;
int err;
err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer);
if (err < 0)
return err;
strcpy(timer->name, "system timer");
timer->hw = snd_timer_system;
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
if (priv == NULL) {
snd_timer_free(timer);
return -ENOMEM;
}
priv->snd_timer = timer;
timer_setup(&priv->tlist, snd_timer_s_function, 0);
timer->private_data = priv;
timer->private_free = snd_timer_free_system;
return snd_timer_global_register(timer);
}
#ifdef CONFIG_SND_PROC_FS
/*
* Info interface
*/
static void snd_timer_proc_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
struct snd_timer *timer;
struct snd_timer_instance *ti;
mutex_lock(&register_mutex);
list_for_each_entry(timer, &snd_timer_list, device_list) {
if (timer->card && timer->card->shutdown)
continue;
switch (timer->tmr_class) {
case SNDRV_TIMER_CLASS_GLOBAL:
snd_iprintf(buffer, "G%i: ", timer->tmr_device);
break;
case SNDRV_TIMER_CLASS_CARD:
snd_iprintf(buffer, "C%i-%i: ",
timer->card->number, timer->tmr_device);
break;
case SNDRV_TIMER_CLASS_PCM:
snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
timer->tmr_device, timer->tmr_subdevice);
break;
default:
snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class,
timer->card ? timer->card->number : -1,
timer->tmr_device, timer->tmr_subdevice);
}
snd_iprintf(buffer, "%s :", timer->name);
if (timer->hw.resolution)
snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
timer->hw.resolution / 1000,
timer->hw.resolution % 1000,
timer->hw.ticks);
if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
snd_iprintf(buffer, " SLAVE");
snd_iprintf(buffer, "\n");
list_for_each_entry(ti, &timer->open_list_head, open_list)
snd_iprintf(buffer, " Client %s : %s\n",
ti->owner ? ti->owner : "unknown",
ti->flags & (SNDRV_TIMER_IFLG_START |
SNDRV_TIMER_IFLG_RUNNING)
? "running" : "stopped");
}
mutex_unlock(&register_mutex);
}
static struct snd_info_entry *snd_timer_proc_entry;
static void __init snd_timer_proc_init(void)
{
struct snd_info_entry *entry;
entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL);
if (entry != NULL) {
entry->c.text.read = snd_timer_proc_read;
if (snd_info_register(entry) < 0) {
snd_info_free_entry(entry);
entry = NULL;
}
}
snd_timer_proc_entry = entry;
}
static void __exit snd_timer_proc_done(void)
{
snd_info_free_entry(snd_timer_proc_entry);
}
#else /* !CONFIG_SND_PROC_FS */
#define snd_timer_proc_init()
#define snd_timer_proc_done()
#endif
/*
* USER SPACE interface
*/
static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
unsigned long resolution,
unsigned long ticks)
{
struct snd_timer_user *tu = timeri->callback_data;
struct snd_timer_read *r;
int prev;
spin_lock(&tu->qlock);
if (tu->qused > 0) {
prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
r = &tu->queue[prev];
if (r->resolution == resolution) {
r->ticks += ticks;
goto __wake;
}
}
if (tu->qused >= tu->queue_size) {
tu->overrun++;
} else {
r = &tu->queue[tu->qtail++];
tu->qtail %= tu->queue_size;
r->resolution = resolution;
r->ticks = ticks;
tu->qused++;
}
__wake:
spin_unlock(&tu->qlock);
kill_fasync(&tu->fasync, SIGIO, POLL_IN);
wake_up(&tu->qchange_sleep);
}
static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
struct snd_timer_tread *tread)
{
if (tu->qused >= tu->queue_size) {
tu->overrun++;
} else {
memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
tu->qtail %= tu->queue_size;
tu->qused++;
}
}
static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
int event,
struct timespec64 *tstamp,
unsigned long resolution)
{
struct snd_timer_user *tu = timeri->callback_data;
struct snd_timer_tread r1;
unsigned long flags;
if (event >= SNDRV_TIMER_EVENT_START &&
event <= SNDRV_TIMER_EVENT_PAUSE)
tu->tstamp = *tstamp;
if ((tu->filter & (1 << event)) == 0 || !tu->tread)
return;
memset(&r1, 0, sizeof(r1));
r1.event = event;
r1.tstamp = timespec64_to_timespec(*tstamp);
r1.val = resolution;
spin_lock_irqsave(&tu->qlock, flags);
snd_timer_user_append_to_tqueue(tu, &r1);
spin_unlock_irqrestore(&tu->qlock, flags);
kill_fasync(&tu->fasync, SIGIO, POLL_IN);
wake_up(&tu->qchange_sleep);
}
static void snd_timer_user_disconnect(struct snd_timer_instance *timeri)
{
struct snd_timer_user *tu = timeri->callback_data;
tu->disconnected = true;
wake_up(&tu->qchange_sleep);
}
static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
unsigned long resolution,
unsigned long ticks)
{
struct snd_timer_user *tu = timeri->callback_data;
struct snd_timer_tread *r, r1;
struct timespec64 tstamp;
int prev, append = 0;
memset(&r1, 0, sizeof(r1));
memset(&tstamp, 0, sizeof(tstamp));
spin_lock(&tu->qlock);
if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
(1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
spin_unlock(&tu->qlock);
return;
}
if (tu->last_resolution != resolution || ticks > 0) {
if (timer_tstamp_monotonic)
ktime_get_ts64(&tstamp);
else
ktime_get_real_ts64(&tstamp);
}
if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
tu->last_resolution != resolution) {
r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
r1.tstamp = timespec64_to_timespec(tstamp);
r1.val = resolution;
snd_timer_user_append_to_tqueue(tu, &r1);
tu->last_resolution = resolution;
append++;
}
if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
goto __wake;
if (ticks == 0)
goto __wake;
if (tu->qused > 0) {
prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
r = &tu->tqueue[prev];
if (r->event == SNDRV_TIMER_EVENT_TICK) {
r->tstamp = timespec64_to_timespec(tstamp);
r->val += ticks;
append++;
goto __wake;
}
}
r1.event = SNDRV_TIMER_EVENT_TICK;
r1.tstamp = timespec64_to_timespec(tstamp);
r1.val = ticks;
snd_timer_user_append_to_tqueue(tu, &r1);
append++;
__wake:
spin_unlock(&tu->qlock);
if (append == 0)
return;
kill_fasync(&tu->fasync, SIGIO, POLL_IN);
wake_up(&tu->qchange_sleep);
}
static int realloc_user_queue(struct snd_timer_user *tu, int size)
{
struct snd_timer_read *queue = NULL;
struct snd_timer_tread *tqueue = NULL;
if (tu->tread) {
tqueue = kcalloc(size, sizeof(*tqueue), GFP_KERNEL);
if (!tqueue)
return -ENOMEM;
} else {
queue = kcalloc(size, sizeof(*queue), GFP_KERNEL);
if (!queue)
return -ENOMEM;
}
spin_lock_irq(&tu->qlock);
kfree(tu->queue);
kfree(tu->tqueue);
tu->queue_size = size;
tu->queue = queue;
tu->tqueue = tqueue;
tu->qhead = tu->qtail = tu->qused = 0;
spin_unlock_irq(&tu->qlock);
return 0;
}
static int snd_timer_user_open(struct inode *inode, struct file *file)
{
struct snd_timer_user *tu;
int err;
*: 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;
tu = kzalloc(sizeof(*tu), GFP_KERNEL);
if (tu == NULL)
return -ENOMEM;
spin_lock_init(&tu->qlock);
init_waitqueue_head(&tu->qchange_sleep);
mutex_init(&tu->ioctl_lock);
tu->ticks = 1;
if (realloc_user_queue(tu, 128) < 0) {
kfree(tu);
return -ENOMEM;
}
file->private_data = tu;
return 0;
}
static int snd_timer_user_release(struct inode *inode, struct file *file)
{
struct snd_timer_user *tu;
if (file->private_data) {
tu = file->private_data;
file->private_data = NULL;
mutex_lock(&tu->ioctl_lock);
if (tu->timeri) {
snd_timer_close(tu->timeri);
snd_timer_instance_free(tu->timeri);
}
mutex_unlock(&tu->ioctl_lock);
kfree(tu->queue);
kfree(tu->tqueue);
kfree(tu);
}
return 0;
}
static void snd_timer_user_zero_id(struct snd_timer_id *id)
{
id->dev_class = SNDRV_TIMER_CLASS_NONE;
id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
id->card = -1;
id->device = -1;
id->subdevice = -1;
}
static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *timer)
{
id->dev_class = timer->tmr_class;
id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
id->card = timer->card ? timer->card->number : -1;
id->device = timer->tmr_device;
id->subdevice = timer->tmr_subdevice;
}
static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
{
struct snd_timer_id id;
struct snd_timer *timer;
struct list_head *p;
if (copy_from_user(&id, _tid, sizeof(id)))
return -EFAULT;
mutex_lock(&register_mutex);
if (id.dev_class < 0) { /* first item */
if (list_empty(&snd_timer_list))
snd_timer_user_zero_id(&id);
else {
timer = list_entry(snd_timer_list.next,
struct snd_timer, device_list);
snd_timer_user_copy_id(&id, timer);
}
} else {
switch (id.dev_class) {
case SNDRV_TIMER_CLASS_GLOBAL:
id.device = id.device < 0 ? 0 : id.device + 1;
list_for_each(p, &snd_timer_list) {
timer = list_entry(p, struct snd_timer, device_list);
if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
snd_timer_user_copy_id(&id, timer);
break;
}
if (timer->tmr_device >= id.device) {
snd_timer_user_copy_id(&id, timer);
break;
}
}
if (p == &snd_timer_list)
snd_timer_user_zero_id(&id);
break;
case SNDRV_TIMER_CLASS_CARD:
case SNDRV_TIMER_CLASS_PCM:
if (id.card < 0) {
id.card = 0;
} else {
if (id.device < 0) {
id.device = 0;
} else {
if (id.subdevice < 0)
id.subdevice = 0;
else if (id.subdevice < INT_MAX)
id.subdevice++;
}
}
list_for_each(p, &snd_timer_list) {
timer = list_entry(p, struct snd_timer, device_list);
if (timer->tmr_class > id.dev_class) {
snd_timer_user_copy_id(&id, timer);
break;
}
if (timer->tmr_class < id.dev_class)
continue;
if (timer->card->number > id.card) {
snd_timer_user_copy_id(&id, timer);
break;
}
if (timer->card->number < id.card)
continue;
if (timer->tmr_device > id.device) {
snd_timer_user_copy_id(&id, timer);
break;
}
if (timer->tmr_device < id.device)
continue;
if (timer->tmr_subdevice > id.subdevice) {
snd_timer_user_copy_id(&id, timer);
break;
}
if (timer->tmr_subdevice < id.subdevice)
continue;
snd_timer_user_copy_id(&id, timer);
break;
}
if (p == &snd_timer_list)
snd_timer_user_zero_id(&id);
break;
default:
snd_timer_user_zero_id(&id);
}
}
mutex_unlock(&register_mutex);
if (copy_to_user(_tid, &id, sizeof(*_tid)))
return -EFAULT;
return 0;
}
static int snd_timer_user_ginfo(struct file *file,
struct snd_timer_ginfo __user *_ginfo)
{
struct snd_timer_ginfo *ginfo;
struct snd_timer_id tid;
struct snd_timer *t;
struct list_head *p;
int err = 0;
ginfo = memdup_user(_ginfo, sizeof(*ginfo));
if (IS_ERR(ginfo))
return PTR_ERR(ginfo);
tid = ginfo->tid;
memset(ginfo, 0, sizeof(*ginfo));
ginfo->tid = tid;
mutex_lock(&register_mutex);
t = snd_timer_find(&tid);
if (t != NULL) {
ginfo->card = t->card ? t->card->number : -1;
if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
strlcpy(ginfo->id, t->id, sizeof(ginfo->id));
strlcpy(ginfo->name, t->name, sizeof(ginfo->name));
ginfo->resolution = t->hw.resolution;
if (t->hw.resolution_min > 0) {
ginfo->resolution_min = t->hw.resolution_min;
ginfo->resolution_max = t->hw.resolution_max;
}
list_for_each(p, &t->open_list_head) {
ginfo->clients++;
}
} else {
err = -ENODEV;
}
mutex_unlock(&register_mutex);
if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
err = -EFAULT;
kfree(ginfo);
return err;
}
static int timer_set_gparams(struct snd_timer_gparams *gparams)
{
struct snd_timer *t;
int err;
mutex_lock(&register_mutex);
t = snd_timer_find(&gparams->tid);
if (!t) {
err = -ENODEV;
goto _error;
}
if (!list_empty(&t->open_list_head)) {
err = -EBUSY;
goto _error;
}
if (!t->hw.set_period) {
err = -ENOSYS;
goto _error;
}
err = t->hw.set_period(t, gparams->period_num, gparams->period_den);
_error:
mutex_unlock(&register_mutex);
return err;
}
static int snd_timer_user_gparams(struct file *file,
struct snd_timer_gparams __user *_gparams)
{
struct snd_timer_gparams gparams;
if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
return -EFAULT;
return timer_set_gparams(&gparams);
}
static int snd_timer_user_gstatus(struct file *file,
struct snd_timer_gstatus __user *_gstatus)
{
struct snd_timer_gstatus gstatus;
struct snd_timer_id tid;
struct snd_timer *t;
int err = 0;
if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
return -EFAULT;
tid = gstatus.tid;
memset(&gstatus, 0, sizeof(gstatus));
gstatus.tid = tid;
mutex_lock(&register_mutex);
t = snd_timer_find(&tid);
if (t != NULL) {
spin_lock_irq(&t->lock);
gstatus.resolution = snd_timer_hw_resolution(t);
if (t->hw.precise_resolution) {
t->hw.precise_resolution(t, &gstatus.resolution_num,
&gstatus.resolution_den);
} else {
gstatus.resolution_num = gstatus.resolution;
gstatus.resolution_den = 1000000000uL;
}
spin_unlock_irq(&t->lock);
} else {
err = -ENODEV;
}
mutex_unlock(&register_mutex);
if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
err = -EFAULT;
return err;
}
static int snd_timer_user_tselect(struct file *file,
struct snd_timer_select __user *_tselect)
{
struct snd_timer_user *tu;
struct snd_timer_select tselect;
char str[32];
int err = 0;
tu = file->private_data;
if (tu->timeri) {
snd_timer_close(tu->timeri);
snd_timer_instance_free(tu->timeri);
tu->timeri = NULL;
}
if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
err = -EFAULT;
goto __err;
}
sprintf(str, "application %i", current->pid);
if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
tu->timeri = snd_timer_instance_new(str);
if (!tu->timeri) {
err = -ENOMEM;
goto __err;
}
tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
tu->timeri->callback = tu->tread
? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
tu->timeri->ccallback = snd_timer_user_ccallback;
tu->timeri->callback_data = (void *)tu;
tu->timeri->disconnect = snd_timer_user_disconnect;
err = snd_timer_open(tu->timeri, &tselect.id, current->pid);
if (err < 0) {
snd_timer_instance_free(tu->timeri);
tu->timeri = NULL;
}
__err:
return err;
}
static int snd_timer_user_info(struct file *file,
struct snd_timer_info __user *_info)
{
struct snd_timer_user *tu;
struct snd_timer_info *info;
struct snd_timer *t;
int err = 0;
tu = file->private_data;
if (!tu->timeri)
return -EBADFD;
t = tu->timeri->timer;
if (!t)
return -EBADFD;
info = kzalloc(sizeof(*info), GFP_KERNEL);
if (! info)
return -ENOMEM;
info->card = t->card ? t->card->number : -1;
if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
info->flags |= SNDRV_TIMER_FLG_SLAVE;
strlcpy(info->id, t->id, sizeof(info->id));
strlcpy(info->name, t->name, sizeof(info->name));
info->resolution = t->hw.resolution;
if (copy_to_user(_info, info, sizeof(*_info)))
err = -EFAULT;
kfree(info);
return err;
}
static int snd_timer_user_params(struct file *file,
struct snd_timer_params __user *_params)
{
struct snd_timer_user *tu;
struct snd_timer_params params;
struct snd_timer *t;
int err;
tu = file->private_data;
if (!tu->timeri)
return -EBADFD;
t = tu->timeri->timer;
if (!t)
return -EBADFD;
if (copy_from_user(&params, _params, sizeof(params)))
return -EFAULT;
if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
u64 resolution;
if (params.ticks < 1) {
err = -EINVAL;
goto _end;
}
/* Don't allow resolution less than 1ms */
resolution = snd_timer_resolution(tu->timeri);
resolution *= params.ticks;
if (resolution < 1000000) {
err = -EINVAL;
goto _end;
}
}
if (params.queue_size > 0 &&
(params.queue_size < 32 || params.queue_size > 1024)) {
err = -EINVAL;
goto _end;
}
if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
(1<<SNDRV_TIMER_EVENT_TICK)|
(1<<SNDRV_TIMER_EVENT_START)|
(1<<SNDRV_TIMER_EVENT_STOP)|
(1<<SNDRV_TIMER_EVENT_CONTINUE)|
(1<<SNDRV_TIMER_EVENT_PAUSE)|
(1<<SNDRV_TIMER_EVENT_SUSPEND)|
(1<<SNDRV_TIMER_EVENT_RESUME)|
(1<<SNDRV_TIMER_EVENT_MSTART)|
(1<<SNDRV_TIMER_EVENT_MSTOP)|
(1<<SNDRV_TIMER_EVENT_MCONTINUE)|
(1<<SNDRV_TIMER_EVENT_MPAUSE)|
(1<<SNDRV_TIMER_EVENT_MSUSPEND)|
(1<<SNDRV_TIMER_EVENT_MRESUME))) {
err = -EINVAL;
goto _end;
}
snd_timer_stop(tu->timeri);
spin_lock_irq(&t->lock);
tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
SNDRV_TIMER_IFLG_EXCLUSIVE|
SNDRV_TIMER_IFLG_EARLY_EVENT);
if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
spin_unlock_irq(&t->lock);
if (params.queue_size > 0 &&
(unsigned int)tu->queue_size != params.queue_size) {
err = realloc_user_queue(tu, params.queue_size);
if (err < 0)
goto _end;
}
spin_lock_irq(&tu->qlock);
tu->qhead = tu->qtail = tu->qused = 0;
if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
if (tu->tread) {
struct snd_timer_tread tread;
memset(&tread, 0, sizeof(tread));
tread.event = SNDRV_TIMER_EVENT_EARLY;
tread.tstamp.tv_sec = 0;
tread.tstamp.tv_nsec = 0;
tread.val = 0;
snd_timer_user_append_to_tqueue(tu, &tread);
} else {
struct snd_timer_read *r = &tu->queue[0];
r->resolution = 0;
r->ticks = 0;
tu->qused++;
tu->qtail++;
}
}
tu->filter = params.filter;
tu->ticks = params.ticks;
spin_unlock_irq(&tu->qlock);
err = 0;
_end:
if (copy_to_user(_params, &params, sizeof(params)))
return -EFAULT;
return err;
}
static int snd_timer_user_status(struct file *file,
struct snd_timer_status __user *_status)
{
struct snd_timer_user *tu;
struct snd_timer_status status;
tu = file->private_data;
if (!tu->timeri)
return -EBADFD;
memset(&status, 0, sizeof(status));
status.tstamp = timespec64_to_timespec(tu->tstamp);
status.resolution = snd_timer_resolution(tu->timeri);
status.lost = tu->timeri->lost;
status.overrun = tu->overrun;
spin_lock_irq(&tu->qlock);
status.queue = tu->qused;
spin_unlock_irq(&tu->qlock);
if (copy_to_user(_status, &status, sizeof(status)))
return -EFAULT;
return 0;
}
static int snd_timer_user_start(struct file *file)
{
int err;
struct snd_timer_user *tu;
tu = file->private_data;
if (!tu->timeri)
return -EBADFD;
snd_timer_stop(tu->timeri);
tu->timeri->lost = 0;
tu->last_resolution = 0;
err = snd_timer_start(tu->timeri, tu->ticks);
if (err < 0)
return err;
return 0;
}
static int snd_timer_user_stop(struct file *file)
{
int err;
struct snd_timer_user *tu;
tu = file->private_data;
if (!tu->timeri)
return -EBADFD;
err = snd_timer_stop(tu->timeri);
if (err < 0)
return err;
return 0;
}
static int snd_timer_user_continue(struct file *file)
{
int err;
struct snd_timer_user *tu;
tu = file->private_data;
if (!tu->timeri)
return -EBADFD;
ALSA: timer: Fix zero-division by continue of uninitialized instance When a user timer instance is continued without the explicit start beforehand, the system gets eventually zero-division error like: divide error: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN CPU: 1 PID: 27320 Comm: syz-executor Not tainted 4.8.0-rc3-next-20160825+ #8 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff88003c9b2280 task.stack: ffff880027280000 RIP: 0010:[<ffffffff858e1a6c>] [< inline >] ktime_divns include/linux/ktime.h:195 RIP: 0010:[<ffffffff858e1a6c>] [<ffffffff858e1a6c>] snd_hrtimer_callback+0x1bc/0x3c0 sound/core/hrtimer.c:62 Call Trace: <IRQ> [< inline >] __run_hrtimer kernel/time/hrtimer.c:1238 [<ffffffff81504335>] __hrtimer_run_queues+0x325/0xe70 kernel/time/hrtimer.c:1302 [<ffffffff81506ceb>] hrtimer_interrupt+0x18b/0x420 kernel/time/hrtimer.c:1336 [<ffffffff8126d8df>] local_apic_timer_interrupt+0x6f/0xe0 arch/x86/kernel/apic/apic.c:933 [<ffffffff86e13056>] smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:957 [<ffffffff86e1210c>] apic_timer_interrupt+0x8c/0xa0 arch/x86/entry/entry_64.S:487 <EOI> ..... Although a similar issue was spotted and a fix patch was merged in commit [6b760bb2c63a: ALSA: timer: fix division by zero after SNDRV_TIMER_IOCTL_CONTINUE], it seems covering only a part of iceberg. In this patch, we fix the issue a bit more drastically. Basically the continue of an uninitialized timer is supposed to be a fresh start, so we do it for user timers. For the direct snd_timer_continue() call, there is no way to pass the initial tick value, so we kick out for the uninitialized case. Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-09-07 16:45:31 +03:00
/* start timer instead of continue if it's not used before */
if (!(tu->timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
return snd_timer_user_start(file);
tu->timeri->lost = 0;
err = snd_timer_continue(tu->timeri);
if (err < 0)
return err;
return 0;
}
static int snd_timer_user_pause(struct file *file)
{
int err;
struct snd_timer_user *tu;
tu = file->private_data;
if (!tu->timeri)
return -EBADFD;
err = snd_timer_pause(tu->timeri);
if (err < 0)
return err;
return 0;
}
enum {
SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
};
static long __snd_timer_user_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct snd_timer_user *tu;
void __user *argp = (void __user *)arg;
int __user *p = argp;
tu = file->private_data;
switch (cmd) {
case SNDRV_TIMER_IOCTL_PVERSION:
return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
return snd_timer_user_next_device(argp);
case SNDRV_TIMER_IOCTL_TREAD:
{
int xarg, old_tread;
if (tu->timeri) /* too late */
return -EBUSY;
if (get_user(xarg, p))
return -EFAULT;
old_tread = tu->tread;
tu->tread = xarg ? 1 : 0;
if (tu->tread != old_tread &&
realloc_user_queue(tu, tu->queue_size) < 0) {
tu->tread = old_tread;
return -ENOMEM;
}
return 0;
}
case SNDRV_TIMER_IOCTL_GINFO:
return snd_timer_user_ginfo(file, argp);
case SNDRV_TIMER_IOCTL_GPARAMS:
return snd_timer_user_gparams(file, argp);
case SNDRV_TIMER_IOCTL_GSTATUS:
return snd_timer_user_gstatus(file, argp);
case SNDRV_TIMER_IOCTL_SELECT:
return snd_timer_user_tselect(file, argp);
case SNDRV_TIMER_IOCTL_INFO:
return snd_timer_user_info(file, argp);
case SNDRV_TIMER_IOCTL_PARAMS:
return snd_timer_user_params(file, argp);
case SNDRV_TIMER_IOCTL_STATUS:
return snd_timer_user_status(file, argp);
case SNDRV_TIMER_IOCTL_START:
case SNDRV_TIMER_IOCTL_START_OLD:
return snd_timer_user_start(file);
case SNDRV_TIMER_IOCTL_STOP:
case SNDRV_TIMER_IOCTL_STOP_OLD:
return snd_timer_user_stop(file);
case SNDRV_TIMER_IOCTL_CONTINUE:
case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
return snd_timer_user_continue(file);
case SNDRV_TIMER_IOCTL_PAUSE:
case SNDRV_TIMER_IOCTL_PAUSE_OLD:
return snd_timer_user_pause(file);
}
return -ENOTTY;
}
static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct snd_timer_user *tu = file->private_data;
long ret;
mutex_lock(&tu->ioctl_lock);
ret = __snd_timer_user_ioctl(file, cmd, arg);
mutex_unlock(&tu->ioctl_lock);
return ret;
}
static int snd_timer_user_fasync(int fd, struct file * file, int on)
{
struct snd_timer_user *tu;
tu = file->private_data;
return fasync_helper(fd, file, on, &tu->fasync);
}
static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
size_t count, loff_t *offset)
{
struct snd_timer_user *tu;
long result = 0, unit;
int qhead;
int err = 0;
tu = file->private_data;
unit = tu->tread ? sizeof(struct snd_timer_tread) : sizeof(struct snd_timer_read);
mutex_lock(&tu->ioctl_lock);
spin_lock_irq(&tu->qlock);
while ((long)count - result >= unit) {
while (!tu->qused) {
wait_queue_entry_t wait;
if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
err = -EAGAIN;
goto _error;
}
set_current_state(TASK_INTERRUPTIBLE);
init_waitqueue_entry(&wait, current);
add_wait_queue(&tu->qchange_sleep, &wait);
spin_unlock_irq(&tu->qlock);
mutex_unlock(&tu->ioctl_lock);
schedule();
mutex_lock(&tu->ioctl_lock);
spin_lock_irq(&tu->qlock);
remove_wait_queue(&tu->qchange_sleep, &wait);
if (tu->disconnected) {
err = -ENODEV;
goto _error;
}
if (signal_pending(current)) {
err = -ERESTARTSYS;
goto _error;
}
}
qhead = tu->qhead++;
tu->qhead %= tu->queue_size;
tu->qused--;
spin_unlock_irq(&tu->qlock);
if (tu->tread) {
if (copy_to_user(buffer, &tu->tqueue[qhead],
sizeof(struct snd_timer_tread)))
err = -EFAULT;
} else {
if (copy_to_user(buffer, &tu->queue[qhead],
sizeof(struct snd_timer_read)))
err = -EFAULT;
}
spin_lock_irq(&tu->qlock);
if (err < 0)
goto _error;
result += unit;
buffer += unit;
}
_error:
spin_unlock_irq(&tu->qlock);
mutex_unlock(&tu->ioctl_lock);
return result > 0 ? result : err;
}
static __poll_t snd_timer_user_poll(struct file *file, poll_table * wait)
{
__poll_t mask;
struct snd_timer_user *tu;
tu = file->private_data;
poll_wait(file, &tu->qchange_sleep, wait);
mask = 0;
spin_lock_irq(&tu->qlock);
if (tu->qused)
mask |= EPOLLIN | EPOLLRDNORM;
if (tu->disconnected)
mask |= EPOLLERR;
spin_unlock_irq(&tu->qlock);
return mask;
}
#ifdef CONFIG_COMPAT
#include "timer_compat.c"
#else
#define snd_timer_user_ioctl_compat NULL
#endif
static const struct file_operations snd_timer_f_ops =
{
.owner = THIS_MODULE,
.read = snd_timer_user_read,
.open = snd_timer_user_open,
.release = snd_timer_user_release,
.llseek = no_llseek,
.poll = snd_timer_user_poll,
.unlocked_ioctl = snd_timer_user_ioctl,
.compat_ioctl = snd_timer_user_ioctl_compat,
.fasync = snd_timer_user_fasync,
};
/* unregister the system timer */
static void snd_timer_free_all(void)
{
struct snd_timer *timer, *n;
list_for_each_entry_safe(timer, n, &snd_timer_list, device_list)
snd_timer_free(timer);
}
static struct device timer_dev;
/*
* ENTRY functions
*/
static int __init alsa_timer_init(void)
{
int err;
snd_device_initialize(&timer_dev, NULL);
dev_set_name(&timer_dev, "timer");
#ifdef SNDRV_OSS_INFO_DEV_TIMERS
snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
"system timer");
#endif
err = snd_timer_register_system();
if (err < 0) {
pr_err("ALSA: unable to register system timer (%i)\n", err);
goto put_timer;
}
err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
&snd_timer_f_ops, NULL, &timer_dev);
if (err < 0) {
pr_err("ALSA: unable to register timer device (%i)\n", err);
snd_timer_free_all();
goto put_timer;
}
snd_timer_proc_init();
return 0;
put_timer:
put_device(&timer_dev);
return err;
}
static void __exit alsa_timer_exit(void)
{
snd_unregister_device(&timer_dev);
snd_timer_free_all();
put_device(&timer_dev);
snd_timer_proc_done();
#ifdef SNDRV_OSS_INFO_DEV_TIMERS
snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
#endif
}
module_init(alsa_timer_init)
module_exit(alsa_timer_exit)