summaryrefslogtreecommitdiff
path: root/sound/core
AgeCommit message (Collapse)Author
2017-04-14Merge branch 'for-linus' into for-nextTakashi Iwai
Back-merge to prepare for applying more FireWire updates.
2017-04-13ALSA: seq: Don't break snd_use_lock_sync() loop by timeoutTakashi Iwai
The snd_use_lock_sync() (thus its implementation snd_use_lock_sync_helper()) has the 5 seconds timeout to break out of the sync loop. It was introduced from the beginning, just to be "safer", in terms of avoiding the stupid bugs. However, as Ben Hutchings suggested, this timeout rather introduces a potential leak or use-after-free that was apparently fixed by the commit 2d7d54002e39 ("ALSA: seq: Fix race during FIFO resize"): for example, snd_seq_fifo_event_in() -> snd_seq_event_dup() -> copy_from_user() could block for a long time, and snd_use_lock_sync() goes timeout and still leaves the cell at releasing the pool. For fixing such a problem, we remove the break by the timeout while still keeping the warning. Suggested-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-04-12Merge branch 'for-linus' into for-nextTakashi Iwai
2017-03-31ALSA: timer: Info leak in snd_timer_user_tinterrupt()Dan Carpenter
The "r1" struct has memory holes. We clear it with memset on one path where it is used but not the other. Let's just memset it at the start of the function so it's always safe. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-03-31ALSA: timer: remove some dead codeDan Carpenter
We just checked "id.card < 0" on the lines before so we know it's not true here. We can delete that check. Also checkpatch.pl complains about some extra curly braces so we may as well fix that while we're at it. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-03-24ALSA: seq: Fix race during FIFO resizeTakashi Iwai
When a new event is queued while processing to resize the FIFO in snd_seq_fifo_clear(), it may lead to a use-after-free, as the old pool that is being queued gets removed. For avoiding this race, we need to close the pool to be deleted and sync its usage before actually deleting it. The issue was spotted by syzkaller. Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-03-21ALSA: seq: Fix racy cell insertions during snd_seq_pool_done()Takashi Iwai
When snd_seq_pool_done() is called, it marks the closing flag to refuse the further cell insertions. But snd_seq_pool_done() itself doesn't clear the cells but just waits until all cells are cleared by the caller side. That is, it's racy, and this leads to the endless stall as syzkaller spotted. This patch addresses the racy by splitting the setup of pool->closing flag out of snd_seq_pool_done(), and calling it properly before snd_seq_pool_done(). BugLink: http://lkml.kernel.org/r/CACT4Y+aqqy8bZA1fFieifNxR2fAfFQQABcBHj801+u5ePV0URw@mail.gmail.com Reported-and-tested-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-03-02sched/headers: Prepare to move signal wakeup & sigpending methods from ↵Ingo Molnar
<linux/sched.h> into <linux/sched/signal.h> Fix up affected files that include this signal functionality via sched.h. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-01Merge tag 'sound-fix-4.11-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound Pull sound fixes from Takashi Iwai: "A few last-minute fixes for rc1: - ALSA core timer and sequencer fixes for bugs spotted by syzkaller - a couple of trivial HD-audio fixups - additional PCI / codec IDs for Intel Geminilake - fixes for CT-XFi DMA mask bugs" * tag 'sound-fix-4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: ALSA: seq: Fix link corruption by event error handling ALSA: hda - Add subwoofer support for Dell Inspiron 17 7000 Gaming ALSA: ctxfi: Fallback DMA mask to 32bit ALSA: timer: Reject user params with too small ticks ALSA: hda: Add Geminilake HDMI codec ID ALSA: hda - Fix micmute hotkey problem for a lenovo AIO machine ALSA: hda - Add Geminilake PCI ID
2017-02-28ALSA: seq: Fix link corruption by event error handlingTakashi Iwai
The sequencer FIFO management has a bug that may lead to a corruption (shortage) of the cell linked list. When a sequencer client faces an error at the event delivery, it tries to put back the dequeued cell. When the first queue was put back, this forgot the tail pointer tracking, and the link will be screwed up. Although there is no memory corruption, the sequencer client may stall forever at exit while flushing the pending FIFO cells in snd_seq_pool_done(), as spotted by syzkaller. This patch addresses the missing tail pointer tracking at snd_seq_fifo_cell_putback(). Also the patch makes sure to clear the cell->enxt pointer at snd_seq_fifo_event_in() for avoiding a similar mess-up of the FIFO linked list. Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-02-28ALSA: timer: Reject user params with too small ticksTakashi Iwai
When a user sets a too small ticks with a fine-grained timer like hrtimer, the kernel tries to fire up the timer irq too frequently. This may lead to the condensed locks, eventually the kernel spinlock lockup with warnings. For avoiding such a situation, we define a lower limit of the resolution, namely 1ms. When the user passes a too small tick value that results in less than that, the kernel returns -EINVAL now. Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-02-24mm, fs: reduce fault, page_mkwrite, and pfn_mkwrite to take only vmfDave Jiang
->fault(), ->page_mkwrite(), and ->pfn_mkwrite() calls do not need to take a vma and vmf parameter when the vma already resides in vmf. Remove the vma parameter to simplify things. [arnd@arndb.de: fix ARM build] Link: http://lkml.kernel.org/r/20170125223558.1451224-1-arnd@arndb.de Link: http://lkml.kernel.org/r/148521301778.19116.10840599906674778980.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Jan Kara <jack@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-20Merge branch 'for-next' into for-linusTakashi Iwai
2017-02-08ALSA: seq: Fix race at creating a queueTakashi Iwai
When a sequencer queue is created in snd_seq_queue_alloc(),it adds the new queue element to the public list before referencing it. Thus the queue might be deleted before the call of snd_seq_queue_use(), and it results in the use-after-free error, as spotted by syzkaller. The fix is to reference the queue object at the right time. Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-02-07Merge branch 'for-linus' into for-nextTakashi Iwai
2017-02-06ALSA: seq: Don't handle loop timeout at snd_seq_pool_done()Takashi Iwai
snd_seq_pool_done() syncs with closing of all opened threads, but it aborts the wait loop with a timeout, and proceeds to the release resource even if not all threads have been closed. The timeout was 5 seconds, and if you run a crazy stuff, it can exceed easily, and may result in the access of the invalid memory address -- this is what syzkaller detected in a bug report. As a fix, let the code graduate from naiveness, simply remove the loop timeout. BugLink: http://lkml.kernel.org/r/CACT4Y+YdhDV2H5LLzDTJDVF-qiYHUHhtRaW4rbb4gUhTCQB81w@mail.gmail.com Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-01-12ALSA: seq: Constify snd_rawmidi_opsTakashi Iwai
Now snd_rawmidi_ops is maintained as a const pointer in snd_rawmidi, we can constify the definitions. Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-01-12ALSA: rawmidi: Add const to snd_rawmidi_opsTakashi Iwai
Make snd_rawmidi_substream.ops to be a const pointer to be safer and allow more optimization. The patches to constify each rawmidi ops will follow. Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-12-25ktime: Get rid of the unionThomas Gleixner
ktime is a union because the initial implementation stored the time in scalar nanoseconds on 64 bit machine and in a endianess optimized timespec variant for 32bit machines. The Y2038 cleanup removed the timespec variant and switched everything to scalar nanoseconds. The union remained, but become completely pointless. Get rid of the union and just keep ktime_t as simple typedef of type s64. The conversion was done with coccinelle and some manual mopping up. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org>
2016-12-14Merge tag 'sound-4.10-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound Pull sound updates from Takashi Iwai: "No dramatic changes are found in this development cycle, but as usual, many commits are applied in a wide range of drivers. Most of big changes are in ASoC, where a few bits of framework work and quite a lot of cleanups and improvements to existing code have been done. The rest are usual stuff, a few HD-audio and USB-audio quirks and fixes, as well as the drop of kthread usages in the whole subsystem. Below are some highlights: ASoC: - support for stereo DAPM controls - some initial work on the of-graph sound card - regmap conversions of the remaining AC'97 drivers - a new version of the topology ABI; this should be backward compatible - updates / cleanups of rsnd, sunxi, sti, nau8825, samsung, arizona, Intel skylake, atom-sst - new drivers for Cirrus Logic CS42L42, Qualcomm MSM8916-WCD, and Realtek RT5665 USB-audio: - yet another race fix at disconnection - tolerated packet size calculation for some Android devices - quirks for Axe-Fx II, QuickCam, TEAC 501/503 HD-audio: - improvement of Dell pin fixup mapping - quirks for HP Z1 Gen3, Alienware 15 R2 2016 and ALC622 headset mic Misc: - replace all kthread usages with simple works" * tag 'sound-4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (296 commits) ALSA: hiface: Fix M2Tech hiFace driver sampling rate change ALSA: usb-audio: Eliminate noise at the start of DSD playback. ALSA: usb-audio: Add native DSD support for TEAC 501/503 DAC ASoC: wm_adsp: wm_adsp_buf_alloc should use kfree in error path ASoC: topology: avoid uninitialized kcontrol_type ALSA: usb-audio: Add QuickCam Communicate Deluxe/S7500 to volume_control_quirks ALSA: usb-audio: add implicit fb quirk for Axe-Fx II ASoC: zte: spdif: correct ZX_SPDIF_CLK_RAT define ASoC: zte: spdif and i2s drivers are not zx296702 specific ASoC: rsnd: setup BRGCKR/BRRA/BRRB when starting ASoC: rsnd: enable/disable ADG when suspend/resume timing ASoC: rsnd: tidyup ssi->usrcnt counter check in hw_params ALSA: cs46xx: add a new line ASoC: Intel: update bxt_da7219_max98357a to support quad ch dmic capture ASoC: nau8825: disable sinc filter for high THD of ADC ALSA: usb-audio: more tolerant packetsize ALSA: usb-audio: avoid setting of sample rate multiple times on bus ASoC: cs35l34: Simplify the logic to set CS35L34_MCLK_CTL setting ALSA: hda - Gate the mic jack on HP Z1 Gen3 AiO ALSA: hda: when comparing pin configurations, ignore assoc in addition to seq ...
2016-12-12printk/sound: handle more message headersPetr Mladek
Commit 4bcc595ccd80 ("printk: reinstate KERN_CONT for printing continuation lines") allows to define more message headers for a single message. The motivation is that continuous lines might get mixed. Therefore it make sense to define the right log level for every piece of a cont line. This patch allows to copy only the real message level. We should ignore KERN_CONT because <filename:line> is added for each message. By other words, we want to know where each piece of the line comes from. [pmladek@suse.com: fix a check of the valid message level] Link: http://lkml.kernel.org/r/20161111183444.GE2145@dhcp128.suse.cz Link: http://lkml.kernel.org/r/1478695291-12169-5-git-send-email-pmladek@suse.com Signed-off-by: Petr Mladek <pmladek@suse.com> Cc: Joe Perches <joe@perches.com> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Takashi Iwai <tiwai@suse.com> Cc: Chris Mason <clm@fb.com> Cc: Josef Bacik <jbacik@fb.com> Cc: David Sterba <dsterba@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-11-12ALSA: oss: don't opencode IS_REACHABLE()Fabian Frederick
Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-11-12ALSA: rawmidi: don't opencode IS_REACHABLE()Fabian Frederick
Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-11-08ALSA: info: Return error for invalid read/writeTakashi Iwai
Currently the ALSA proc handler allows read or write even if the proc file were write-only or read-only. It's mostly harmless, does thing but allocating memory and ignores the input/output. But it doesn't tell user about the invalid use, and it's confusing and inconsistent in comparison with other proc files. This patch adds some sanity checks and let the proc handler returning an -EIO error when the invalid read/write is performed. Cc: <stable@vger.kernel.org> # v4.2+ Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-11-08ALSA: info: Limit the proc text input sizeTakashi Iwai
The ALSA proc handler allows currently the write in the unlimited size until kmalloc() fails. But basically the write is supposed to be only for small inputs, mostly for one line inputs, and we don't have to handle too large sizes at all. Since the kmalloc error results in the kernel warning, it's better to limit the size beforehand. This patch adds the limit of 16kB, which must be large enough for the currently existing code. Cc: stable@vger.kernel.org # v4.2+ Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-10-25ALSA: seq: Fix time account regressionTakashi Iwai
The recent rewrite of the sequencer time accounting using timespec64 in the commit [3915bf294652: ALSA: seq_timer: use monotonic times internally] introduced a bad regression. Namely, the time reported back doesn't increase but goes back and forth. The culprit was obvious: the delta is stored to the result (cur_time = delta), instead of adding the delta (cur_time += delta)! Let's fix it. Fixes: 3915bf294652 ('ALSA: seq_timer: use monotonic times internally') Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=177571 Reported-by: Yves Guillemot <yc.guillemot@wanadoo.fr> Cc: <stable@vger.kernel.org> # v4.8+ Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-10-12ALSA: seq: fix passing wrong pointer in function call of compatibility layerTakashi Sakamoto
This commit is a fix for Linux 4.9-rc1. In former commit, a function call of compatibility layer for ALSA sequencer core was obsoleted by an alternative. Although, the alternative gets a pointer to kernel stack due to mis-programming. As a result, ALSA sequencer core unexpectedly refers over kernel stack. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Fixes: 8ce8eb601c71 ("ALSA: seq: add an alternative way to handle ioctl requests") Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-09-16ALSA: compress: fix some missing and misplaced \n in messagesColin Ian King
Fix a missing \n in a pr_debug message and move the \n to the end of a pr_err message. Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-09-13ALSA: seq: fix to copy from/to user spaceTakashi Sakamoto
When checking value of request for copy operation, current implementation compares shifted value to macros, while these macros are already shifted. As a result, it never performs to copy from/to user space. This commit fixes the bug. Fixes: 8ce8eb601c71('ALSA: seq: add an alternative way to handle ioctl requests' Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-09-11Merge branch 'for-linus' into for-nextTakashi Iwai
Back-merge from for-linus just to make the further development easier.
2016-09-08ALSA: rawmidi: Fix possible deadlock with virmidi registrationTakashi Iwai
When a seq-virmidi driver is initialized, it registers a rawmidi instance with its callback to create an associated seq kernel client. Currently it's done throughly in rawmidi's register_mutex context. Recently it was found that this may lead to a deadlock another rawmidi device that is being attached with the sequencer is accessed, as both open with the same register_mutex. This was actually triggered by syzkaller, as Dmitry Vyukov reported: ====================================================== [ INFO: possible circular locking dependency detected ] 4.8.0-rc1+ #11 Not tainted ------------------------------------------------------- syz-executor/7154 is trying to acquire lock: (register_mutex#5){+.+.+.}, at: [<ffffffff84fd6d4b>] snd_rawmidi_kernel_open+0x4b/0x260 sound/core/rawmidi.c:341 but task is already holding lock: (&grp->list_mutex){++++.+}, at: [<ffffffff850138bb>] check_and_subscribe_port+0x5b/0x5c0 sound/core/seq/seq_ports.c:495 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&grp->list_mutex){++++.+}: [<ffffffff8147a3a8>] lock_acquire+0x208/0x430 kernel/locking/lockdep.c:3746 [<ffffffff863f6199>] down_read+0x49/0xc0 kernel/locking/rwsem.c:22 [< inline >] deliver_to_subscribers sound/core/seq/seq_clientmgr.c:681 [<ffffffff85005c5e>] snd_seq_deliver_event+0x35e/0x890 sound/core/seq/seq_clientmgr.c:822 [<ffffffff85006e96>] > snd_seq_kernel_client_dispatch+0x126/0x170 sound/core/seq/seq_clientmgr.c:2418 [<ffffffff85012c52>] snd_seq_system_broadcast+0xb2/0xf0 sound/core/seq/seq_system.c:101 [<ffffffff84fff70a>] snd_seq_create_kernel_client+0x24a/0x330 sound/core/seq/seq_clientmgr.c:2297 [< inline >] snd_virmidi_dev_attach_seq sound/core/seq/seq_virmidi.c:383 [<ffffffff8502d29f>] snd_virmidi_dev_register+0x29f/0x750 sound/core/seq/seq_virmidi.c:450 [<ffffffff84fd208c>] snd_rawmidi_dev_register+0x30c/0xd40 sound/core/rawmidi.c:1645 [<ffffffff84f816d3>] __snd_device_register.part.0+0x63/0xc0 sound/core/device.c:164 [< inline >] __snd_device_register sound/core/device.c:162 [<ffffffff84f8235d>] snd_device_register_all+0xad/0x110 sound/core/device.c:212 [<ffffffff84f7546f>] snd_card_register+0xef/0x6c0 sound/core/init.c:749 [<ffffffff85040b7f>] snd_virmidi_probe+0x3ef/0x590 sound/drivers/virmidi.c:123 [<ffffffff833ebf7b>] platform_drv_probe+0x8b/0x170 drivers/base/platform.c:564 ...... -> #0 (register_mutex#5){+.+.+.}: [< inline >] check_prev_add kernel/locking/lockdep.c:1829 [< inline >] check_prevs_add kernel/locking/lockdep.c:1939 [< inline >] validate_chain kernel/locking/lockdep.c:2266 [<ffffffff814791f4>] __lock_acquire+0x4d44/0x4d80 kernel/locking/lockdep.c:3335 [<ffffffff8147a3a8>] lock_acquire+0x208/0x430 kernel/locking/lockdep.c:3746 [< inline >] __mutex_lock_common kernel/locking/mutex.c:521 [<ffffffff863f0ef1>] mutex_lock_nested+0xb1/0xa20 kernel/locking/mutex.c:621 [<ffffffff84fd6d4b>] snd_rawmidi_kernel_open+0x4b/0x260 sound/core/rawmidi.c:341 [<ffffffff8502e7c7>] midisynth_subscribe+0xf7/0x350 sound/core/seq/seq_midi.c:188 [< inline >] subscribe_port sound/core/seq/seq_ports.c:427 [<ffffffff85013cc7>] check_and_subscribe_port+0x467/0x5c0 sound/core/seq/seq_ports.c:510 [<ffffffff85015da9>] snd_seq_port_connect+0x2c9/0x500 sound/core/seq/seq_ports.c:579 [<ffffffff850079b8>] snd_seq_ioctl_subscribe_port+0x1d8/0x2b0 sound/core/seq/seq_clientmgr.c:1480 [<ffffffff84ffe9e4>] snd_seq_do_ioctl+0x184/0x1e0 sound/core/seq/seq_clientmgr.c:2225 [<ffffffff84ffeae8>] snd_seq_kernel_client_ctl+0xa8/0x110 sound/core/seq/seq_clientmgr.c:2440 [<ffffffff85027664>] snd_seq_oss_midi_open+0x3b4/0x610 sound/core/seq/oss/seq_oss_midi.c:375 [<ffffffff85023d67>] snd_seq_oss_synth_setup_midi+0x107/0x4c0 sound/core/seq/oss/seq_oss_synth.c:281 [<ffffffff8501b0a8>] snd_seq_oss_open+0x748/0x8d0 sound/core/seq/oss/seq_oss_init.c:274 [<ffffffff85019d8a>] odev_open+0x6a/0x90 sound/core/seq/oss/seq_oss.c:138 [<ffffffff84f7040f>] soundcore_open+0x30f/0x640 sound/sound_core.c:639 ...... other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&grp->list_mutex); lock(register_mutex#5); lock(&grp->list_mutex); lock(register_mutex#5); *** DEADLOCK *** ====================================================== The fix is to simply move the registration parts in snd_rawmidi_dev_register() to the outside of the register_mutex lock. The lock is needed only to manage the linked list, and it's not necessarily to cover the whole initialization process. Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-09-08ALSA: timer: Fix zero-division by continue of uninitialized instanceTakashi Iwai
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>
2016-09-06ALSA: pcm: Fix avail to return error if stream is suspendedJeeja KP
When the stream is in suspended state some applications wait on "Stream Pipe Error" in response to snd_pcm_avail call to resume the stream. In the current implementation snd_pcm_avail() returns zero when the stream is in suspended state. This causes application to enter in infinite loop for frames to be available. "Stream pipe Error" code is getting returned for read/write call when the stream is in suspended state. Similarly update snd_pcm_avail to return -ESTRPIPE. Signed-off-by: Jeeja KP <jeeja.kp@intel.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-09-02ALSA: timer: fix NULL pointer dereference in read()/ioctl() raceVegard Nossum
I got this with syzkaller: ================================================================== BUG: KASAN: null-ptr-deref on address 0000000000000020 Read of size 32 by task syz-executor/22519 CPU: 1 PID: 22519 Comm: syz-executor Not tainted 4.8.0-rc2+ #169 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2 014 0000000000000001 ffff880111a17a00 ffffffff81f9f141 ffff880111a17a90 ffff880111a17c50 ffff880114584a58 ffff880114584a10 ffff880111a17a80 ffffffff8161fe3f ffff880100000000 ffff880118d74a48 ffff880118d74a68 Call Trace: [<ffffffff81f9f141>] dump_stack+0x83/0xb2 [<ffffffff8161fe3f>] kasan_report_error+0x41f/0x4c0 [<ffffffff8161ff74>] kasan_report+0x34/0x40 [<ffffffff82c84b54>] ? snd_timer_user_read+0x554/0x790 [<ffffffff8161e79e>] check_memory_region+0x13e/0x1a0 [<ffffffff8161e9c1>] kasan_check_read+0x11/0x20 [<ffffffff82c84b54>] snd_timer_user_read+0x554/0x790 [<ffffffff82c84600>] ? snd_timer_user_info_compat.isra.5+0x2b0/0x2b0 [<ffffffff817d0831>] ? proc_fault_inject_write+0x1c1/0x250 [<ffffffff817d0670>] ? next_tgid+0x2a0/0x2a0 [<ffffffff8127c278>] ? do_group_exit+0x108/0x330 [<ffffffff8174653a>] ? fsnotify+0x72a/0xca0 [<ffffffff81674dfe>] __vfs_read+0x10e/0x550 [<ffffffff82c84600>] ? snd_timer_user_info_compat.isra.5+0x2b0/0x2b0 [<ffffffff81674cf0>] ? do_sendfile+0xc50/0xc50 [<ffffffff81745e10>] ? __fsnotify_update_child_dentry_flags+0x60/0x60 [<ffffffff8143fec6>] ? kcov_ioctl+0x56/0x190 [<ffffffff81e5ada2>] ? common_file_perm+0x2e2/0x380 [<ffffffff81746b0e>] ? __fsnotify_parent+0x5e/0x2b0 [<ffffffff81d93536>] ? security_file_permission+0x86/0x1e0 [<ffffffff816728f5>] ? rw_verify_area+0xe5/0x2b0 [<ffffffff81675355>] vfs_read+0x115/0x330 [<ffffffff81676371>] SyS_read+0xd1/0x1a0 [<ffffffff816762a0>] ? vfs_write+0x4b0/0x4b0 [<ffffffff82001c2c>] ? __this_cpu_preempt_check+0x1c/0x20 [<ffffffff8150455a>] ? __context_tracking_exit.part.4+0x3a/0x1e0 [<ffffffff816762a0>] ? vfs_write+0x4b0/0x4b0 [<ffffffff81005524>] do_syscall_64+0x1c4/0x4e0 [<ffffffff810052fc>] ? syscall_return_slowpath+0x16c/0x1d0 [<ffffffff83c3276a>] entry_SYSCALL64_slow_path+0x25/0x25 ================================================================== There are a couple of problems that I can see: - ioctl(SNDRV_TIMER_IOCTL_SELECT), which potentially sets tu->queue/tu->tqueue to NULL on memory allocation failure, so read() would get a NULL pointer dereference like the above splat - the same ioctl() can free tu->queue/to->tqueue which means read() could potentially see (and dereference) the freed pointer We can fix both by taking the ioctl_lock mutex when dereferencing ->queue/->tqueue, since that's always held over all the ioctl() code. Just looking at the code I find it likely that there are more problems here such as tu->qhead pointing outside the buffer if the size is changed concurrently using SNDRV_TIMER_IOCTL_PARAMS. Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-08-31ALSA: seq: initialize whole fields of automatic variable with union typeTakashi Sakamoto
Currently, automatic variable of 'union ioctl_arg' type is initialized by designated initialization. Although, the actual effect is interpretation of early element of int type and initialization of 'int pversion'. Therefore the first field corresponding to int type is initialized to zero. This is against my expectation to initialize whole fields. This commit uses memset() to initialize the variable, instead of designated initialization. Fixes: 04a56dd8ed0d ('ALSA: seq: change ioctl command operation to get data in kernel space') Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-08-29ALSA: timer: fix NULL pointer dereference on memory allocation failureVegard Nossum
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>
2016-08-29ALSA: timer: fix division by zero after SNDRV_TIMER_IOCTL_CONTINUEVegard Nossum
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>
2016-08-22ALSA: compress: Use memdup_user() rather than duplicating its implementationMarkus Elfring
Reuse existing functionality from memdup_user() instead of keeping duplicate source code. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Acked-by: Vinod Koul <vinod.koul@intel.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-08-22ALSA: seq: obsolete change of address limitTakashi Sakamoto
Former commits change existent functions so that they don't handle data in kernel space. Copying from/to userspace is done outside of the functions, thus no need to change address limit of running task. This commit obsoletes get_fs()/set_fs() and applies corresponding changes. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-08-22ALSA: seq: change ioctl command operation to get data in kernel spaceTakashi Sakamoto
In previous commit, a new table for functions with data in kernel space is added to replace current table. This commit changes existent functions to fit the table. These functions are added to the new table and removed from the old table. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-08-22ALSA: seq: add an alternative way to handle ioctl requestsTakashi Sakamoto
ALSA sequencer is designed with two types of clients; application and kernel. Operations for each ioctl command should handle data in both of user space and kernel space, while current implementation just allows them to handle data in user space. Data in kernel space is handled with change of address limit of running tasks. This commit adds a new table to map ioctl commands to corresponding functions. The functions get data in kernel space. Helper functions to operate kernel and application clients seek entries from the table. Especially, the helper function for application is responsible for coping from user space to kernel space or vise versa. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-08-22ALSA: seq: add documentation for snd_seq_kernel_client_ctlTakashi Sakamoto
This kernel API is used by kernel implementation. Currently, it's used for kernel clients of ALSA sequencer, while it can be used for application clients. The difference is just on address spaces of argument. In short, this kernel API can be available for application client with data in kernel space. This commit adds a document about this. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-07-26Merge tag 'asoc-v4.8' of ↵Takashi Iwai
git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus ASoC: Updates for v4.8 Not really any framework work this time around (though we have seen one of the Analog Devices drivers move more to the clock API which is good to see) but rather a lot of new drivers: - Lots of updates for the Intel drivers, mostly board support and bug fixing, and to the NAU8825 driver. - Work on generalizing bits of simple-card to allow more code sharing with the Renesas rsrc-card (which can't use simple-card due to DPCM). - Removal of the Odroid X2 driver due to replacement with simple-card. - Support for several new Mediatek platforms and associated boards. - New drivers for Allwinner A10, Analog Devices ADAU7002, Broadcom Cygnus, Cirrus Logic CS35L33 and CS53L30, Maxim MAX8960 and MAX98504, Realtek RT5514 and Wolfson WM8758
2016-07-25Merge branch 'for-next' into for-linusTakashi Iwai
Merged 4.8 changes.
2016-07-24Merge remote-tracking branches 'asoc/topic/adau', 'asoc/topic/adau7002', ↵Mark Brown
'asoc/topic/adsp', 'asoc/topic/ak4613' and 'asoc/topic/ak4642' into asoc-next
2016-07-08ALSA: pcm: Free chmap at PCM free callback, tooTakashi Iwai
The chmap ctls assigned to PCM streams are freed in the PCM disconnect callback. However, since the disconnect callback isn't called when the card gets freed before registering, the chmap ctls may still be left assigned. They are eventually freed together with other ctls, but it may cause an Oops at pcm_chmap_ctl_private_free(), as the function refers to the assigned PCM stream, while the PCM objects have been already freed beforehand. The fix is to free the chmap ctls also at PCM free callback, not only at PCM disconnect. Reported-by: Laxminath Kasam <b_lkasam@codeaurora.org> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-07-08ALSA: ctl: Stop notification after disconnectionTakashi Iwai
snd_ctl_remove() has a notification for the removal event. It's superfluous when done during the device got disconnected. Although the notification itself is mostly harmless, it may potentially be harmful, and should be suppressed. Actually some components PCM may free ctl elements during the disconnect or free callbacks, thus it's no theoretical issue. This patch adds the check of card->shutdown flag for avoiding unnecessary notifications after (or during) the disconnect. Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-07-07ALSA: control: add dimension validator for userspace elementsTakashi Sakamoto
The 'dimen' field in struct snd_ctl_elem_info is used to compose all of members in the element as multi-dimensional matrix. The field has four members. Each member represents the width in each dimension level by element member unit. For example, if the members consist of typical two dimensional matrix, the dimen[0] represents the number of rows and dimen[1] represents the number of columns (or vise-versa). The total members in the matrix should be exactly the same as the number of members in the element, while current implementation has no validator of this information. In a view of userspace applications, the information must be valid so that it cannot cause any bugs such as buffer-over-run. This commit adds a validator of dimension information for userspace applications which add new element sets. When they add the element sets with wrong dimension information, they receive -EINVAL. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-07-04ALSA: timer: Fix negative queue usage by racy accessesTakashi Iwai
The user timer tu->qused counter may go to a negative value when multiple concurrent reads are performed since both the check and the decrement of tu->qused are done in two individual locked contexts. This results in bogus read outs, and the endless loop in the user-space side. The fix is to move the decrement of the tu->qused counter into the same spinlock context as the zero-check of the counter. Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-06-17ALSA: seq_timer: use monotonic times internallyArnd Bergmann
The sequencer client manager reports timestamps in units of unsigned 32-bit seconds/nanoseconds, but that does not suffer from the y2038 overflow because it stores only the delta since the 'last_update' time was recorded. However, the use of the do_gettimeofday() function is problematic and we have to replace it to avoid the overflow on on 32-bit architectures. This uses 'struct timespec64' to record 'last_update', and changes the code to use monotonic timestamps that do not suffer from leap seconds and settimeofday updates. As a side-effect, the code can now use the timespec64_sub() helper and become more readable and also avoid a multiplication to convert from microseconds to nanoseconds. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-17 20:32:39 +0000