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

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Digital Audio (PCM) abstract layer
* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
* Abramo Bagnara <abramo@alsa-project.org>
*/
#include <linux/slab.h>
#include <linux/sched/signal.h>
#include <linux/time.h>
#include <linux/math64.h>
#include <linux/export.h>
#include <sound/core.h>
#include <sound/control.h>
#include <sound/tlv.h>
#include <sound/info.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/timer.h>
#include "pcm_local.h"
ALSA: pcm: Replace PCM hwptr tracking with tracepoints ALSA PCM core has a mechanism tracking the PCM hwptr updates for analyzing XRUNs. But its log is limited (up to 10) and its log output is a kernel message, which is hard to handle. In this patch, the hwptr logging is moved to the tracing infrastructure instead of its own. Not only the hwptr updates but also XRUN and hwptr errors are recorded on the trace log, so that user can see such events at the exact timing. The new "snd_pcm" entry will appear in the tracing events: # ls -F /sys/kernel/debug/tracing/events/snd_pcm enable filter hw_ptr_error/ hwptr/ xrun/ The hwptr is for the regular hwptr update events. An event trace looks like: aplay-26187 [004] d..3 4012.834761: hwptr: pcmC0D0p/sub0: POS: pos=488, old=0, base=0, period=1024, buf=16384 "POS" shows the hwptr update by the explicit position update call and "IRQ" means the hwptr update by the interrupt, i.e. snd_pcm_period_elapsed() call. The "pos" is the passed ring-buffer offset by the caller, "old" is the previous hwptr, "base" is the hwptr base position, "period" and "buf" are period- and buffer-size of the target PCM substream. (Note that the hwptr position displayed here isn't the ring-buffer offset. It increments up to the PCM position boundary.) The XRUN event appears similarly, but without "pos" field. The hwptr error events appear with the PCM identifier and its reason string, such as "Lost interrupt?". The XRUN and hwptr error reports on kernel message are still left, can be turned on/off via xrun_debug proc like before. But the bit 3, 4, 5 and 6 bits of xrun_debug proc are dropped by this patch. Also, along with the change, the message strings have been reformatted to be a bit more consistent. Last but not least, the hwptr reporting is enabled only when CONFIG_SND_PCM_XRUN_DEBUG is set. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-11-04 14:45:59 +03:00
#ifdef CONFIG_SND_PCM_XRUN_DEBUG
#define CREATE_TRACE_POINTS
#include "pcm_trace.h"
#else
#define trace_hwptr(substream, pos, in_interrupt)
#define trace_xrun(substream)
#define trace_hw_ptr_error(substream, reason)
ALSA: pcm: add 'applptr' event of tracepoint In design of ALSA PCM core, status and control data for runtime of ALSA PCM substream are shared between kernel/user spaces by page frame mapping with read-only attribute. Both of hardware-side and application-side position on PCM buffer are maintained as a part of the status data. In a view of ALSA PCM application, these two positions can be updated by executing ioctl(2) with some commands. There's an event of tracepoint for hardware-side position; 'hwptr'. On the other hand, no events for application-side position. This commit adds a new event for this purpose; 'applptr'. When the application-side position is changed in kernel space, this event is probed with useful information for developers. I note that the event is not probed for all of ALSA PCM applications, When applications are written by read/write programming scenario, the event is surely probed. The applications execute ioctl(2) with SNDRV_PCM_IOCTL_[READ|WRITE][N/I]_FRAMES to read/write any PCM frame, then ALSA PCM core updates the application-side position in kernel land. However, when applications are written by mmap programming scenario, if maintaining the application side position in kernel space accurately, applications should voluntarily execute ioctl(2) with SNDRV_PCM_IOCTL_SYNC_PTR to commit the number of handled PCM frames. If not voluntarily, the application-side position is not changed, thus the added event is not probed. There's a loophole, using architectures to which ALSA PCM core judges non cache coherent. In this case, the status and control data is not mapped into processe's VMA for any applications. Userland library, alsa-lib, is programmed for this case. It executes ioctl(2) with SNDRV_PCM_IOCTL_SYNC_PTR command every time to requiring the status and control data. ARM is such an architecture. Below is an example with serial sound interface (ssi) on i.mx6 quad core SoC. I use v4.1 kernel released by fsl-community with patches from VIA Tech. Inc. for VAB820, and my backport patches for relevant features for this patchset. I use Ubuntu 17.04 from ports.ubuntu.com as user land for armhf architecture. $ aplay -v -M -D hw:imx6vab820sgtl5,0 /dev/urandom -f S16_LE -r 48000 --period-size=128 --buffer-size=256 Playing raw data '/dev/urandom' : Signed 16 bit Little Endian, Rate 48000 Hz, Mono Hardware PCM card 0 'imx6-vab820-sgtl5000' device 0 subdevice 0 Its setup is: stream : PLAYBACK access : MMAP_INTERLEAVED format : S16_LE subformat : STD channels : 1 rate : 48000 exact rate : 48000 (48000/1) msbits : 16 buffer_size : 256 period_size : 128 period_time : 2666 tstamp_mode : NONE tstamp_type : MONOTONIC period_step : 1 avail_min : 128 period_event : 0 start_threshold : 256 stop_threshold : 256 silence_threshold: 0 silence_size : 0 boundary : 1073741824 appl_ptr : 0 hw_ptr : 0 mmap_area[0] = 0x76f98000,0,16 (16) $ trace-cmd record -e snd_pcm:hwptr -e snd_pcm:applptr $ trace-cmd report ... 60.208495: applptr: pcmC0D0p/sub0: prev=1792, curr=1792, avail=0, period=128, buf=256 60.208633: applptr: pcmC0D0p/sub0: prev=1792, curr=1792, avail=0, period=128, buf=256 60.210022: hwptr: pcmC0D0p/sub0: IRQ: pos=128, old=1536, base=1536, period=128, buf=256 60.210202: applptr: pcmC0D0p/sub0: prev=1792, curr=1792, avail=128, period=128, buf=256 60.210344: hwptr: pcmC0D0p/sub0: POS: pos=128, old=1664, base=1536, period=128, buf=256 60.210348: applptr: pcmC0D0p/sub0: prev=1792, curr=1792, avail=128, period=128, buf=256 60.210486: applptr: pcmC0D0p/sub0: prev=1792, curr=1792, avail=128, period=128, buf=256 60.210626: applptr: pcmC0D0p/sub0: prev=1792, curr=1920, avail=0, period=128, buf=256 60.211002: applptr: pcmC0D0p/sub0: prev=1920, curr=1920, avail=0, period=128, buf=256 60.211142: hwptr: pcmC0D0p/sub0: POS: pos=128, old=1664, base=1536, period=128, buf=256 60.211146: applptr: pcmC0D0p/sub0: prev=1920, curr=1920, avail=0, period=128, buf=256 60.211287: applptr: pcmC0D0p/sub0: prev=1920, curr=1920, avail=0, period=128, buf=256 60.212690: hwptr: pcmC0D0p/sub0: IRQ: pos=0, old=1664, base=1536, period=128, buf=256 60.212866: applptr: pcmC0D0p/sub0: prev=1920, curr=1920, avail=128, period=128, buf=256 60.212999: hwptr: pcmC0D0p/sub0: POS: pos=0, old=1792, base=1792, period=128, buf=256 60.213003: applptr: pcmC0D0p/sub0: prev=1920, curr=1920, avail=128, period=128, buf=256 60.213135: applptr: pcmC0D0p/sub0: prev=1920, curr=1920, avail=128, period=128, buf=256 60.213276: applptr: pcmC0D0p/sub0: prev=1920, curr=2048, avail=0, period=128, buf=256 60.213654: applptr: pcmC0D0p/sub0: prev=2048, curr=2048, avail=0, period=128, buf=256 60.213796: hwptr: pcmC0D0p/sub0: POS: pos=0, old=1792, base=1792, period=128, buf=256 60.213800: applptr: pcmC0D0p/sub0: prev=2048, curr=2048, avail=0, period=128, buf=256 60.213937: applptr: pcmC0D0p/sub0: prev=2048, curr=2048, avail=0, period=128, buf=256 60.215356: hwptr: pcmC0D0p/sub0: IRQ: pos=128, old=1792, base=1792, period=128, buf=256 60.215542: applptr: pcmC0D0p/sub0: prev=2048, curr=2048, avail=128, period=128, buf=256 60.215679: hwptr: pcmC0D0p/sub0: POS: pos=128, old=1920, base=1792, period=128, buf=256 60.215683: applptr: pcmC0D0p/sub0: prev=2048, curr=2048, avail=128, period=128, buf=256 60.215813: applptr: pcmC0D0p/sub0: prev=2048, curr=2048, avail=128, period=128, buf=256 60.215947: applptr: pcmC0D0p/sub0: prev=2048, curr=2176, avail=0, period=128, buf=256 ... We can surely see 'applptr' event is probed even if the application run for mmap programming scenario ('-M' option and 'hw' plugin). Below is a result of strace: 02:44:15.886382 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.887203 poll([{fd=4, events=POLLOUT|POLLERR|POLLNVAL}], 1, -1) = 1 ([{fd=4, revents=POLLOUT}]) 02:44:15.887471 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.887637 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.887805 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.887969 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.888132 read(3, "..."..., 256) = 256 02:44:15.889040 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.889221 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.889431 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.889606 poll([{fd=4, events=POLLOUT|POLLERR|POLLNVAL}], 1, -1) = 1 ([{fd=4, revents=POLLOUT}]) 02:44:15.889833 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.889998 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.890164 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.891048 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.891228 read(3, "..."..., 256) = 256 02:44:15.891497 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.891661 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.891829 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.891991 poll([{fd=4, events=POLLOUT|POLLERR|POLLNVAL}], 1, -1) = 1 ([{fd=4, revents=POLLOUT}]) 02:44:15.893007 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 We can see 7 calls of ioctl(2) with SNDRV_PCM_IOCTL_SYNC_PTR per loop with call of poll(2). 128 PCM frames are transferred per loop of one poll(2), because the PCM substream is configured with S16_LE format and 1 channel (2 byte * 1 * 128 = 256 bytes). This equals to the size of period of PCM buffer. Comparing to the probed data, one of the 7 calls of ioctl(2) is actually used to commit the number of copied PCM frames to kernel space. The other calls are just used to check runtime status of PCM substream; e.g. XRUN. The tracepoint event is useful to investigate this case. I note that below modules are related to the above sample. * snd-soc-dummy.ko * snd-soc-imx-sgtl5000.ko * snd-soc-fsl-ssi.ko * snd-soc-imx-pcm-dma.ko * snd-soc-sgtl5000.ko My additional note is lock acquisition. The event is probed under acquiring PCM stream lock. This means that calculation in the event is free from any hardware events. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-06-12 03:41:45 +03:00
#define trace_applptr(substream, prev, curr)
ALSA: pcm: Replace PCM hwptr tracking with tracepoints ALSA PCM core has a mechanism tracking the PCM hwptr updates for analyzing XRUNs. But its log is limited (up to 10) and its log output is a kernel message, which is hard to handle. In this patch, the hwptr logging is moved to the tracing infrastructure instead of its own. Not only the hwptr updates but also XRUN and hwptr errors are recorded on the trace log, so that user can see such events at the exact timing. The new "snd_pcm" entry will appear in the tracing events: # ls -F /sys/kernel/debug/tracing/events/snd_pcm enable filter hw_ptr_error/ hwptr/ xrun/ The hwptr is for the regular hwptr update events. An event trace looks like: aplay-26187 [004] d..3 4012.834761: hwptr: pcmC0D0p/sub0: POS: pos=488, old=0, base=0, period=1024, buf=16384 "POS" shows the hwptr update by the explicit position update call and "IRQ" means the hwptr update by the interrupt, i.e. snd_pcm_period_elapsed() call. The "pos" is the passed ring-buffer offset by the caller, "old" is the previous hwptr, "base" is the hwptr base position, "period" and "buf" are period- and buffer-size of the target PCM substream. (Note that the hwptr position displayed here isn't the ring-buffer offset. It increments up to the PCM position boundary.) The XRUN event appears similarly, but without "pos" field. The hwptr error events appear with the PCM identifier and its reason string, such as "Lost interrupt?". The XRUN and hwptr error reports on kernel message are still left, can be turned on/off via xrun_debug proc like before. But the bit 3, 4, 5 and 6 bits of xrun_debug proc are dropped by this patch. Also, along with the change, the message strings have been reformatted to be a bit more consistent. Last but not least, the hwptr reporting is enabled only when CONFIG_SND_PCM_XRUN_DEBUG is set. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-11-04 14:45:59 +03:00
#endif
static int fill_silence_frames(struct snd_pcm_substream *substream,
snd_pcm_uframes_t off, snd_pcm_uframes_t frames);
static inline void update_silence_vars(struct snd_pcm_runtime *runtime,
snd_pcm_uframes_t ptr,
snd_pcm_uframes_t new_ptr)
{
snd_pcm_sframes_t delta;
delta = new_ptr - ptr;
if (delta == 0)
return;
if (delta < 0)
delta += runtime->boundary;
if ((snd_pcm_uframes_t)delta < runtime->silence_filled)
runtime->silence_filled -= delta;
else
runtime->silence_filled = 0;
runtime->silence_start = new_ptr;
}
/*
* fill ring buffer with silence
* runtime->silence_start: starting pointer to silence area
* runtime->silence_filled: size filled with silence
* runtime->silence_threshold: threshold from application
* runtime->silence_size: maximal size from application
*
* when runtime->silence_size >= runtime->boundary - fill processed area with silence immediately
*/
void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_uframes_t new_hw_ptr)
{
struct snd_pcm_runtime *runtime = substream->runtime;
snd_pcm_uframes_t frames, ofs, transfer;
int err;
if (runtime->silence_size < runtime->boundary) {
snd_pcm_sframes_t noise_dist;
snd_pcm_uframes_t appl_ptr = READ_ONCE(runtime->control->appl_ptr);
update_silence_vars(runtime, runtime->silence_start, appl_ptr);
/* initialization outside pointer updates */
if (new_hw_ptr == ULONG_MAX)
new_hw_ptr = runtime->status->hw_ptr;
/* get hw_avail with the boundary crossing */
noise_dist = appl_ptr - new_hw_ptr;
if (noise_dist < 0)
noise_dist += runtime->boundary;
/* total noise distance */
noise_dist += runtime->silence_filled;
if (noise_dist >= (snd_pcm_sframes_t) runtime->silence_threshold)
return;
frames = runtime->silence_threshold - noise_dist;
if (frames > runtime->silence_size)
frames = runtime->silence_size;
} else {
/*
* This filling mode aims at free-running mode (used for example by dmix),
* which doesn't update the application pointer.
*/
snd_pcm_uframes_t hw_ptr = runtime->status->hw_ptr;
if (new_hw_ptr == ULONG_MAX) {
/*
* Initialization, fill the whole unused buffer with silence.
*
* Usually, this is entered while stopped, before data is queued,
* so both pointers are expected to be zero.
*/
snd_pcm_sframes_t avail = runtime->control->appl_ptr - hw_ptr;
if (avail < 0)
avail += runtime->boundary;
/*
* In free-running mode, appl_ptr will be zero even while running,
* so we end up with a huge number. There is no useful way to
* handle this, so we just clear the whole buffer.
*/
runtime->silence_filled = avail > runtime->buffer_size ? 0 : avail;
runtime->silence_start = hw_ptr;
} else {
/* Silence the just played area immediately */
update_silence_vars(runtime, hw_ptr, new_hw_ptr);
}
/*
* In this mode, silence_filled actually includes the valid
* sample data from the user.
*/
frames = runtime->buffer_size - runtime->silence_filled;
}
if (snd_BUG_ON(frames > runtime->buffer_size))
return;
if (frames == 0)
return;
ofs = (runtime->silence_start + runtime->silence_filled) % runtime->buffer_size;
do {
transfer = ofs + frames > runtime->buffer_size ? runtime->buffer_size - ofs : frames;
err = fill_silence_frames(substream, ofs, transfer);
snd_BUG_ON(err < 0);
runtime->silence_filled += transfer;
frames -= transfer;
ofs = 0;
} while (frames > 0);
ALSA: memalloc: Support for non-contiguous page allocation This patch adds the support for allocation of non-contiguous DMA pages in the common memalloc helper. It's another SG-buffer type, but unlike the existing one, this is directional and requires the explicit sync / invalidation of dirty pages on non-coherent architectures. For this enhancement, the following points are changed: - snd_dma_device stores the DMA direction. - snd_dma_device stores need_sync flag indicating whether the explicit sync is required or not. - A new variant of helper functions, snd_dma_alloc_dir_pages() and *_all() are introduced; the old snd_dma_alloc_pages() and *_all() kept as just wrappers with DMA_BIDIRECTIONAL. - A new helper snd_dma_buffer_sync() is introduced; this gets called in the appropriate places. - A new allocation type, SNDRV_DMA_TYPE_NONCONTIG, is introduced. When the driver allocates pages with this new type, and it may require the SNDRV_PCM_INFO_EXPLICIT_SYNC flag set to the PCM hardware.info for taking the full control of PCM applptr and hwptr changes (that implies disabling the mmap of control/status data). When the buffer allocation is managed by snd_pcm_set_managed_buffer(), this flag is automatically set depending on the result of dma_need_sync() internally. Otherwise, if the buffer is managed manually, the driver has to set the flag explicitly, too. The explicit sync between CPU and device for non-coherent memory is performed at the points before and after read/write transfer as well as the applptr/hwptr syncptr ioctl. In the case of mmap mode, user-space is supposed to call the syncptr ioctl with the hwptr flag to update and fetch the status at first; this corresponds to CPU-sync. Then user-space advances the applptr via syncptr ioctl again with applptr flag, and this corresponds to the device sync with flushing. Other than the DMA direction and the explicit sync, the usage of this new buffer type is almost equivalent with the existing SNDRV_DMA_TYPE_DEV_SG; you can get the page and the address via snd_sgbuf_get_page() and snd_sgbuf_get_addr(), also calculate the continuous pages via snd_sgbuf_get_chunk_size(). For those SG-page handling, the non-contig type shares the same ops with the vmalloc handler. As we do always vmap the SG pages at first, the actual address can be deduced from the vmapped address easily without iterating the SG-list. Link: https://lore.kernel.org/r/20211017074859.24112-2-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-10-17 10:48:57 +03:00
snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_DEVICE);
}
#ifdef CONFIG_SND_DEBUG
void snd_pcm_debug_name(struct snd_pcm_substream *substream,
char *name, size_t len)
{
snprintf(name, len, "pcmC%dD%d%c:%d",
substream->pcm->card->number,
substream->pcm->device,
substream->stream ? 'c' : 'p',
substream->number);
}
EXPORT_SYMBOL(snd_pcm_debug_name);
#endif
#define XRUN_DEBUG_BASIC (1<<0)
#define XRUN_DEBUG_STACK (1<<1) /* dump also stack */
#define XRUN_DEBUG_JIFFIESCHECK (1<<2) /* do jiffies check */
#ifdef CONFIG_SND_PCM_XRUN_DEBUG
#define xrun_debug(substream, mask) \
((substream)->pstr->xrun_debug & (mask))
#else
#define xrun_debug(substream, mask) 0
#endif
#define dump_stack_on_xrun(substream) do { \
if (xrun_debug(substream, XRUN_DEBUG_STACK)) \
dump_stack(); \
} while (0)
/* call with stream lock held */
void __snd_pcm_xrun(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
ALSA: pcm: Replace PCM hwptr tracking with tracepoints ALSA PCM core has a mechanism tracking the PCM hwptr updates for analyzing XRUNs. But its log is limited (up to 10) and its log output is a kernel message, which is hard to handle. In this patch, the hwptr logging is moved to the tracing infrastructure instead of its own. Not only the hwptr updates but also XRUN and hwptr errors are recorded on the trace log, so that user can see such events at the exact timing. The new "snd_pcm" entry will appear in the tracing events: # ls -F /sys/kernel/debug/tracing/events/snd_pcm enable filter hw_ptr_error/ hwptr/ xrun/ The hwptr is for the regular hwptr update events. An event trace looks like: aplay-26187 [004] d..3 4012.834761: hwptr: pcmC0D0p/sub0: POS: pos=488, old=0, base=0, period=1024, buf=16384 "POS" shows the hwptr update by the explicit position update call and "IRQ" means the hwptr update by the interrupt, i.e. snd_pcm_period_elapsed() call. The "pos" is the passed ring-buffer offset by the caller, "old" is the previous hwptr, "base" is the hwptr base position, "period" and "buf" are period- and buffer-size of the target PCM substream. (Note that the hwptr position displayed here isn't the ring-buffer offset. It increments up to the PCM position boundary.) The XRUN event appears similarly, but without "pos" field. The hwptr error events appear with the PCM identifier and its reason string, such as "Lost interrupt?". The XRUN and hwptr error reports on kernel message are still left, can be turned on/off via xrun_debug proc like before. But the bit 3, 4, 5 and 6 bits of xrun_debug proc are dropped by this patch. Also, along with the change, the message strings have been reformatted to be a bit more consistent. Last but not least, the hwptr reporting is enabled only when CONFIG_SND_PCM_XRUN_DEBUG is set. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-11-04 14:45:59 +03:00
trace_xrun(substream);
if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) {
struct timespec64 tstamp;
snd_pcm_gettime(runtime, &tstamp);
ALSA: add new 32-bit layout for snd_pcm_mmap_status/control The snd_pcm_mmap_status and snd_pcm_mmap_control interfaces are one of the trickiest areas to get right when moving to 64-bit time_t in user space. The snd_pcm_mmap_status structure layout is incompatible with user space that uses a 64-bit time_t, so we need a new layout for it. Since the SNDRV_PCM_IOCTL_SYNC_PTR ioctl combines it with snd_pcm_mmap_control into snd_pcm_sync_ptr, we need to change those two as well. Both structures are also exported via an mmap() operation on certain architectures, and this suffers from incompatibility between 32-bit and 64-bit user space. As we have to change both structures anyway, this is a good opportunity to fix the mmap() problem as well, so let's standardize on the existing 64-bit layout of the structure where possible. The downside is that we lose mmap() support for existing 32-bit x86 and powerpc applications, adding that would introduce very noticeable runtime overhead and complexity. My assumption here is that not too many people will miss the removed feature, given that: - Almost all x86 and powerpc users these days are on 64-bit kernels, the majority of today's 32-bit users are on architectures that never supported mmap (ARM, MIPS, ...). - It never worked in compat mode (it was intentionally disabled there) - The application already needs to work with a fallback to SNDRV_PCM_IOCTL_SYNC_PTR, which will keep working with both the old and new structure layout. Both the ioctl() and mmap() based interfaces are changed at the same time, as they are based on the same structures. Unlike other interfaces, we change the uapi header to export both the traditional structure and a version that is portable between 32-bit and 64-bit user space code and that corresponds to the existing 64-bit layout. We further check the __USE_TIME_BITS64 macro that will be defined by future C library versions whenever we use the new time_t definition, so any existing user space source code will not see any changes until it gets rebuilt against a new C library. However, the new structures are all visible in addition to the old ones, allowing applications to explicitly request the new structures. In order to detect the difference between the old snd_pcm_mmap_status and the new __snd_pcm_mmap_status64 structure from the ioctl command number, we rely on one quirk in the structure definition: snd_pcm_mmap_status must be aligned to alignof(time_t), which leads the compiler to insert four bytes of padding in struct snd_pcm_sync_ptr after 'flags' and a corresponding change in the size of snd_pcm_sync_ptr itself. On x86-32 (and only there), the compiler doesn't use 64-bit alignment in structure, so I'm adding an explicit pad in the structure that has no effect on the existing 64-bit architectures but ensures that the layout matches for x86. The snd_pcm_uframes_t type compatibility requires another hack: we can't easily make that 64 bit wide, so I leave the type as 'unsigned long', but add padding before and after it, to ensure that the data is properly aligned to the respective 64-bit field in the in-kernel structure. For the SNDRV_PCM_MMAP_OFFSET_STATUS/CONTROL constants that are used as the virtual file offset in the mmap() function, we also have to introduce new constants that depend on hte __USE_TIME_BITS64 macro: The existing macros are renamed to SNDRV_PCM_MMAP_OFFSET_STATUS_OLD and SNDRV_PCM_MMAP_OFFSET_CONTROL_OLD, they continue to work fine on 64-bit architectures, but stop working on native 32-bit user space. The replacement _NEW constants are now used by default for user space built with __USE_TIME_BITS64, those now work on all new kernels for x86, ppc and alpha (32 and 64 bit, native and compat). It might be a good idea for a future alsa-lib to support both the _OLD and _NEW macros and use the corresponding structures directly. Unmodified alsa-lib source code will retain the current behavior, so it will no longer be able to use mmap() for the status/control structures on 32-bit systems, until either the C library gets updated to 64-bit time_t or alsa-lib gets updated to support both mmap() layouts. Co-developed-with: Baolin Wang <baolin.wang@linaro.org> Signed-off-by: Baolin Wang <baolin.wang@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-04-24 15:06:15 +03:00
runtime->status->tstamp.tv_sec = tstamp.tv_sec;
runtime->status->tstamp.tv_nsec = tstamp.tv_nsec;
}
snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {
char name[16];
snd_pcm_debug_name(substream, name, sizeof(name));
pcm_warn(substream->pcm, "XRUN: %s\n", name);
dump_stack_on_xrun(substream);
}
}
#ifdef CONFIG_SND_PCM_XRUN_DEBUG
ALSA: pcm: Replace PCM hwptr tracking with tracepoints ALSA PCM core has a mechanism tracking the PCM hwptr updates for analyzing XRUNs. But its log is limited (up to 10) and its log output is a kernel message, which is hard to handle. In this patch, the hwptr logging is moved to the tracing infrastructure instead of its own. Not only the hwptr updates but also XRUN and hwptr errors are recorded on the trace log, so that user can see such events at the exact timing. The new "snd_pcm" entry will appear in the tracing events: # ls -F /sys/kernel/debug/tracing/events/snd_pcm enable filter hw_ptr_error/ hwptr/ xrun/ The hwptr is for the regular hwptr update events. An event trace looks like: aplay-26187 [004] d..3 4012.834761: hwptr: pcmC0D0p/sub0: POS: pos=488, old=0, base=0, period=1024, buf=16384 "POS" shows the hwptr update by the explicit position update call and "IRQ" means the hwptr update by the interrupt, i.e. snd_pcm_period_elapsed() call. The "pos" is the passed ring-buffer offset by the caller, "old" is the previous hwptr, "base" is the hwptr base position, "period" and "buf" are period- and buffer-size of the target PCM substream. (Note that the hwptr position displayed here isn't the ring-buffer offset. It increments up to the PCM position boundary.) The XRUN event appears similarly, but without "pos" field. The hwptr error events appear with the PCM identifier and its reason string, such as "Lost interrupt?". The XRUN and hwptr error reports on kernel message are still left, can be turned on/off via xrun_debug proc like before. But the bit 3, 4, 5 and 6 bits of xrun_debug proc are dropped by this patch. Also, along with the change, the message strings have been reformatted to be a bit more consistent. Last but not least, the hwptr reporting is enabled only when CONFIG_SND_PCM_XRUN_DEBUG is set. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-11-04 14:45:59 +03:00
#define hw_ptr_error(substream, in_interrupt, reason, fmt, args...) \
do { \
ALSA: pcm: Replace PCM hwptr tracking with tracepoints ALSA PCM core has a mechanism tracking the PCM hwptr updates for analyzing XRUNs. But its log is limited (up to 10) and its log output is a kernel message, which is hard to handle. In this patch, the hwptr logging is moved to the tracing infrastructure instead of its own. Not only the hwptr updates but also XRUN and hwptr errors are recorded on the trace log, so that user can see such events at the exact timing. The new "snd_pcm" entry will appear in the tracing events: # ls -F /sys/kernel/debug/tracing/events/snd_pcm enable filter hw_ptr_error/ hwptr/ xrun/ The hwptr is for the regular hwptr update events. An event trace looks like: aplay-26187 [004] d..3 4012.834761: hwptr: pcmC0D0p/sub0: POS: pos=488, old=0, base=0, period=1024, buf=16384 "POS" shows the hwptr update by the explicit position update call and "IRQ" means the hwptr update by the interrupt, i.e. snd_pcm_period_elapsed() call. The "pos" is the passed ring-buffer offset by the caller, "old" is the previous hwptr, "base" is the hwptr base position, "period" and "buf" are period- and buffer-size of the target PCM substream. (Note that the hwptr position displayed here isn't the ring-buffer offset. It increments up to the PCM position boundary.) The XRUN event appears similarly, but without "pos" field. The hwptr error events appear with the PCM identifier and its reason string, such as "Lost interrupt?". The XRUN and hwptr error reports on kernel message are still left, can be turned on/off via xrun_debug proc like before. But the bit 3, 4, 5 and 6 bits of xrun_debug proc are dropped by this patch. Also, along with the change, the message strings have been reformatted to be a bit more consistent. Last but not least, the hwptr reporting is enabled only when CONFIG_SND_PCM_XRUN_DEBUG is set. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-11-04 14:45:59 +03:00
trace_hw_ptr_error(substream, reason); \
if (xrun_debug(substream, XRUN_DEBUG_BASIC)) { \
ALSA: pcm: Replace PCM hwptr tracking with tracepoints ALSA PCM core has a mechanism tracking the PCM hwptr updates for analyzing XRUNs. But its log is limited (up to 10) and its log output is a kernel message, which is hard to handle. In this patch, the hwptr logging is moved to the tracing infrastructure instead of its own. Not only the hwptr updates but also XRUN and hwptr errors are recorded on the trace log, so that user can see such events at the exact timing. The new "snd_pcm" entry will appear in the tracing events: # ls -F /sys/kernel/debug/tracing/events/snd_pcm enable filter hw_ptr_error/ hwptr/ xrun/ The hwptr is for the regular hwptr update events. An event trace looks like: aplay-26187 [004] d..3 4012.834761: hwptr: pcmC0D0p/sub0: POS: pos=488, old=0, base=0, period=1024, buf=16384 "POS" shows the hwptr update by the explicit position update call and "IRQ" means the hwptr update by the interrupt, i.e. snd_pcm_period_elapsed() call. The "pos" is the passed ring-buffer offset by the caller, "old" is the previous hwptr, "base" is the hwptr base position, "period" and "buf" are period- and buffer-size of the target PCM substream. (Note that the hwptr position displayed here isn't the ring-buffer offset. It increments up to the PCM position boundary.) The XRUN event appears similarly, but without "pos" field. The hwptr error events appear with the PCM identifier and its reason string, such as "Lost interrupt?". The XRUN and hwptr error reports on kernel message are still left, can be turned on/off via xrun_debug proc like before. But the bit 3, 4, 5 and 6 bits of xrun_debug proc are dropped by this patch. Also, along with the change, the message strings have been reformatted to be a bit more consistent. Last but not least, the hwptr reporting is enabled only when CONFIG_SND_PCM_XRUN_DEBUG is set. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-11-04 14:45:59 +03:00
pr_err_ratelimited("ALSA: PCM: [%c] " reason ": " fmt, \
(in_interrupt) ? 'Q' : 'P', ##args); \
dump_stack_on_xrun(substream); \
} \
} while (0)
#else /* ! CONFIG_SND_PCM_XRUN_DEBUG */
#define hw_ptr_error(substream, fmt, args...) do { } while (0)
#endif
int snd_pcm_update_state(struct snd_pcm_substream *substream,
struct snd_pcm_runtime *runtime)
{
snd_pcm_uframes_t avail;
avail = snd_pcm_avail(substream);
if (avail > runtime->avail_max)
runtime->avail_max = avail;
if (runtime->state == SNDRV_PCM_STATE_DRAINING) {
if (avail >= runtime->buffer_size) {
snd_pcm_drain_done(substream);
return -EPIPE;
}
} else {
if (avail >= runtime->stop_threshold) {
__snd_pcm_xrun(substream);
return -EPIPE;
}
}
if (runtime->twake) {
if (avail >= runtime->twake)
wake_up(&runtime->tsleep);
} else if (avail >= runtime->control->avail_min)
wake_up(&runtime->sleep);
return 0;
}
static void update_audio_tstamp(struct snd_pcm_substream *substream,
struct timespec64 *curr_tstamp,
struct timespec64 *audio_tstamp)
{
struct snd_pcm_runtime *runtime = substream->runtime;
u64 audio_frames, audio_nsecs;
struct timespec64 driver_tstamp;
if (runtime->tstamp_mode != SNDRV_PCM_TSTAMP_ENABLE)
return;
if (!(substream->ops->get_time_info) ||
(runtime->audio_tstamp_report.actual_type ==
SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {
/*
* provide audio timestamp derived from pointer position
* add delay only if requested
*/
audio_frames = runtime->hw_ptr_wrap + runtime->status->hw_ptr;
if (runtime->audio_tstamp_config.report_delay) {
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
audio_frames -= runtime->delay;
else
audio_frames += runtime->delay;
}
audio_nsecs = div_u64(audio_frames * 1000000000LL,
runtime->rate);
*audio_tstamp = ns_to_timespec64(audio_nsecs);
}
if (runtime->status->audio_tstamp.tv_sec != audio_tstamp->tv_sec ||
runtime->status->audio_tstamp.tv_nsec != audio_tstamp->tv_nsec) {
ALSA: add new 32-bit layout for snd_pcm_mmap_status/control The snd_pcm_mmap_status and snd_pcm_mmap_control interfaces are one of the trickiest areas to get right when moving to 64-bit time_t in user space. The snd_pcm_mmap_status structure layout is incompatible with user space that uses a 64-bit time_t, so we need a new layout for it. Since the SNDRV_PCM_IOCTL_SYNC_PTR ioctl combines it with snd_pcm_mmap_control into snd_pcm_sync_ptr, we need to change those two as well. Both structures are also exported via an mmap() operation on certain architectures, and this suffers from incompatibility between 32-bit and 64-bit user space. As we have to change both structures anyway, this is a good opportunity to fix the mmap() problem as well, so let's standardize on the existing 64-bit layout of the structure where possible. The downside is that we lose mmap() support for existing 32-bit x86 and powerpc applications, adding that would introduce very noticeable runtime overhead and complexity. My assumption here is that not too many people will miss the removed feature, given that: - Almost all x86 and powerpc users these days are on 64-bit kernels, the majority of today's 32-bit users are on architectures that never supported mmap (ARM, MIPS, ...). - It never worked in compat mode (it was intentionally disabled there) - The application already needs to work with a fallback to SNDRV_PCM_IOCTL_SYNC_PTR, which will keep working with both the old and new structure layout. Both the ioctl() and mmap() based interfaces are changed at the same time, as they are based on the same structures. Unlike other interfaces, we change the uapi header to export both the traditional structure and a version that is portable between 32-bit and 64-bit user space code and that corresponds to the existing 64-bit layout. We further check the __USE_TIME_BITS64 macro that will be defined by future C library versions whenever we use the new time_t definition, so any existing user space source code will not see any changes until it gets rebuilt against a new C library. However, the new structures are all visible in addition to the old ones, allowing applications to explicitly request the new structures. In order to detect the difference between the old snd_pcm_mmap_status and the new __snd_pcm_mmap_status64 structure from the ioctl command number, we rely on one quirk in the structure definition: snd_pcm_mmap_status must be aligned to alignof(time_t), which leads the compiler to insert four bytes of padding in struct snd_pcm_sync_ptr after 'flags' and a corresponding change in the size of snd_pcm_sync_ptr itself. On x86-32 (and only there), the compiler doesn't use 64-bit alignment in structure, so I'm adding an explicit pad in the structure that has no effect on the existing 64-bit architectures but ensures that the layout matches for x86. The snd_pcm_uframes_t type compatibility requires another hack: we can't easily make that 64 bit wide, so I leave the type as 'unsigned long', but add padding before and after it, to ensure that the data is properly aligned to the respective 64-bit field in the in-kernel structure. For the SNDRV_PCM_MMAP_OFFSET_STATUS/CONTROL constants that are used as the virtual file offset in the mmap() function, we also have to introduce new constants that depend on hte __USE_TIME_BITS64 macro: The existing macros are renamed to SNDRV_PCM_MMAP_OFFSET_STATUS_OLD and SNDRV_PCM_MMAP_OFFSET_CONTROL_OLD, they continue to work fine on 64-bit architectures, but stop working on native 32-bit user space. The replacement _NEW constants are now used by default for user space built with __USE_TIME_BITS64, those now work on all new kernels for x86, ppc and alpha (32 and 64 bit, native and compat). It might be a good idea for a future alsa-lib to support both the _OLD and _NEW macros and use the corresponding structures directly. Unmodified alsa-lib source code will retain the current behavior, so it will no longer be able to use mmap() for the status/control structures on 32-bit systems, until either the C library gets updated to 64-bit time_t or alsa-lib gets updated to support both mmap() layouts. Co-developed-with: Baolin Wang <baolin.wang@linaro.org> Signed-off-by: Baolin Wang <baolin.wang@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-04-24 15:06:15 +03:00
runtime->status->audio_tstamp.tv_sec = audio_tstamp->tv_sec;
runtime->status->audio_tstamp.tv_nsec = audio_tstamp->tv_nsec;
runtime->status->tstamp.tv_sec = curr_tstamp->tv_sec;
runtime->status->tstamp.tv_nsec = curr_tstamp->tv_nsec;
ALSA: pcm: update tstamp only if audio_tstamp changed commit 3179f6200188 ("ALSA: core: add .get_time_info") had a side effect of changing the behaviour of the PCM runtime tstamp. Prior to this change tstamp was not updated by snd_pcm_update_hw_ptr0() unless the hw_ptr had moved, after this change tstamp was always updated. For an application using alsa-lib, doing snd_pcm_readi() followed by snd_pcm_status() to estimate the age of the read samples by subtracting status->avail * [sample rate] from status->tstamp this change degraded the accuracy of the estimate on devices where the pcm hw does not provide a granular hw_ptr, e.g., devices using soc-generic-dmaengine-pcm.c and a dma-engine with residue_granularity DMA_RESIDUE_GRANULARITY_DESCRIPTOR. The accuracy of the estimate depended on the latency between the PCM hw completing a period and the driver called snd_pcm_period_elapsed() to notify ALSA core, typically determined by interrupt handling latency. After the change the accuracy of the estimate depended on the latency between the PCM hw completing a period and the application calling snd_pcm_status(), determined by the scheduling of the application process. The maximum error of the estimate is one period length in both cases, but the error average and variance is smaller when it depends on interrupt latency. Instead of always updating tstamp, update it only if audio_tstamp changed. Fixes: 3179f6200188 ("ALSA: core: add .get_time_info") Suggested-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Henrik Eriksson <henrik.eriksson@axis.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-11-21 11:29:28 +03:00
}
/*
* re-take a driver timestamp to let apps detect if the reference tstamp
* read by low-level hardware was provided with a delay
*/
snd_pcm_gettime(substream->runtime, &driver_tstamp);
runtime->driver_tstamp = driver_tstamp;
}
static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
unsigned int in_interrupt)
{
struct snd_pcm_runtime *runtime = substream->runtime;
snd_pcm_uframes_t pos;
snd_pcm_uframes_t old_hw_ptr, new_hw_ptr, hw_base;
snd_pcm_sframes_t hdelta, delta;
unsigned long jdelta;
unsigned long curr_jiffies;
struct timespec64 curr_tstamp;
struct timespec64 audio_tstamp;
int crossed_boundary = 0;
old_hw_ptr = runtime->status->hw_ptr;
/*
* group pointer, time and jiffies reads to allow for more
* accurate correlations/corrections.
* The values are stored at the end of this routine after
* corrections for hw_ptr position
*/
pos = substream->ops->pointer(substream);
curr_jiffies = jiffies;
if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) {
if ((substream->ops->get_time_info) &&
(runtime->audio_tstamp_config.type_requested != SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {
substream->ops->get_time_info(substream, &curr_tstamp,
&audio_tstamp,
&runtime->audio_tstamp_config,
&runtime->audio_tstamp_report);
/* re-test in case tstamp type is not supported in hardware and was demoted to DEFAULT */
if (runtime->audio_tstamp_report.actual_type == SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)
snd_pcm_gettime(runtime, &curr_tstamp);
} else
snd_pcm_gettime(runtime, &curr_tstamp);
}
if (pos == SNDRV_PCM_POS_XRUN) {
__snd_pcm_xrun(substream);
return -EPIPE;
}
if (pos >= runtime->buffer_size) {
if (printk_ratelimit()) {
char name[16];
snd_pcm_debug_name(substream, name, sizeof(name));
pcm_err(substream->pcm,
"invalid position: %s, pos = %ld, buffer size = %ld, period size = %ld\n",
name, pos, runtime->buffer_size,
runtime->period_size);
}
pos = 0;
}
pos -= pos % runtime->min_align;
ALSA: pcm: Replace PCM hwptr tracking with tracepoints ALSA PCM core has a mechanism tracking the PCM hwptr updates for analyzing XRUNs. But its log is limited (up to 10) and its log output is a kernel message, which is hard to handle. In this patch, the hwptr logging is moved to the tracing infrastructure instead of its own. Not only the hwptr updates but also XRUN and hwptr errors are recorded on the trace log, so that user can see such events at the exact timing. The new "snd_pcm" entry will appear in the tracing events: # ls -F /sys/kernel/debug/tracing/events/snd_pcm enable filter hw_ptr_error/ hwptr/ xrun/ The hwptr is for the regular hwptr update events. An event trace looks like: aplay-26187 [004] d..3 4012.834761: hwptr: pcmC0D0p/sub0: POS: pos=488, old=0, base=0, period=1024, buf=16384 "POS" shows the hwptr update by the explicit position update call and "IRQ" means the hwptr update by the interrupt, i.e. snd_pcm_period_elapsed() call. The "pos" is the passed ring-buffer offset by the caller, "old" is the previous hwptr, "base" is the hwptr base position, "period" and "buf" are period- and buffer-size of the target PCM substream. (Note that the hwptr position displayed here isn't the ring-buffer offset. It increments up to the PCM position boundary.) The XRUN event appears similarly, but without "pos" field. The hwptr error events appear with the PCM identifier and its reason string, such as "Lost interrupt?". The XRUN and hwptr error reports on kernel message are still left, can be turned on/off via xrun_debug proc like before. But the bit 3, 4, 5 and 6 bits of xrun_debug proc are dropped by this patch. Also, along with the change, the message strings have been reformatted to be a bit more consistent. Last but not least, the hwptr reporting is enabled only when CONFIG_SND_PCM_XRUN_DEBUG is set. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-11-04 14:45:59 +03:00
trace_hwptr(substream, pos, in_interrupt);
hw_base = runtime->hw_ptr_base;
new_hw_ptr = hw_base + pos;
if (in_interrupt) {
/* we know that one period was processed */
/* delta = "expected next hw_ptr" for in_interrupt != 0 */
delta = runtime->hw_ptr_interrupt + runtime->period_size;
if (delta > new_hw_ptr) {
/* check for double acknowledged interrupts */
hdelta = curr_jiffies - runtime->hw_ptr_jiffies;
if (hdelta > runtime->hw_ptr_buffer_jiffies/2 + 1) {
hw_base += runtime->buffer_size;
if (hw_base >= runtime->boundary) {
hw_base = 0;
crossed_boundary++;
}
new_hw_ptr = hw_base + pos;
goto __delta;
}
}
}
/* new_hw_ptr might be lower than old_hw_ptr in case when */
/* pointer crosses the end of the ring buffer */
if (new_hw_ptr < old_hw_ptr) {
hw_base += runtime->buffer_size;
if (hw_base >= runtime->boundary) {
hw_base = 0;
crossed_boundary++;
}
new_hw_ptr = hw_base + pos;
}
__delta:
delta = new_hw_ptr - old_hw_ptr;
if (delta < 0)
delta += runtime->boundary;
if (runtime->no_period_wakeup) {
snd_pcm_sframes_t xrun_threshold;
/*
* Without regular period interrupts, we have to check
* the elapsed time to detect xruns.
*/
jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
if (jdelta < runtime->hw_ptr_buffer_jiffies / 2)
goto no_delta_check;
hdelta = jdelta - delta * HZ / runtime->rate;
xrun_threshold = runtime->hw_ptr_buffer_jiffies / 2 + 1;
while (hdelta > xrun_threshold) {
delta += runtime->buffer_size;
hw_base += runtime->buffer_size;
if (hw_base >= runtime->boundary) {
hw_base = 0;
crossed_boundary++;
}
new_hw_ptr = hw_base + pos;
hdelta -= runtime->hw_ptr_buffer_jiffies;
}
goto no_delta_check;
}
/* something must be really wrong */
if (delta >= runtime->buffer_size + runtime->period_size) {
ALSA: pcm: Replace PCM hwptr tracking with tracepoints ALSA PCM core has a mechanism tracking the PCM hwptr updates for analyzing XRUNs. But its log is limited (up to 10) and its log output is a kernel message, which is hard to handle. In this patch, the hwptr logging is moved to the tracing infrastructure instead of its own. Not only the hwptr updates but also XRUN and hwptr errors are recorded on the trace log, so that user can see such events at the exact timing. The new "snd_pcm" entry will appear in the tracing events: # ls -F /sys/kernel/debug/tracing/events/snd_pcm enable filter hw_ptr_error/ hwptr/ xrun/ The hwptr is for the regular hwptr update events. An event trace looks like: aplay-26187 [004] d..3 4012.834761: hwptr: pcmC0D0p/sub0: POS: pos=488, old=0, base=0, period=1024, buf=16384 "POS" shows the hwptr update by the explicit position update call and "IRQ" means the hwptr update by the interrupt, i.e. snd_pcm_period_elapsed() call. The "pos" is the passed ring-buffer offset by the caller, "old" is the previous hwptr, "base" is the hwptr base position, "period" and "buf" are period- and buffer-size of the target PCM substream. (Note that the hwptr position displayed here isn't the ring-buffer offset. It increments up to the PCM position boundary.) The XRUN event appears similarly, but without "pos" field. The hwptr error events appear with the PCM identifier and its reason string, such as "Lost interrupt?". The XRUN and hwptr error reports on kernel message are still left, can be turned on/off via xrun_debug proc like before. But the bit 3, 4, 5 and 6 bits of xrun_debug proc are dropped by this patch. Also, along with the change, the message strings have been reformatted to be a bit more consistent. Last but not least, the hwptr reporting is enabled only when CONFIG_SND_PCM_XRUN_DEBUG is set. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-11-04 14:45:59 +03:00
hw_ptr_error(substream, in_interrupt, "Unexpected hw_ptr",
"(stream=%i, pos=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
substream->stream, (long)pos,
(long)new_hw_ptr, (long)old_hw_ptr);
return 0;
}
/* Do jiffies check only in xrun_debug mode */
if (!xrun_debug(substream, XRUN_DEBUG_JIFFIESCHECK))
goto no_jiffies_check;
/* Skip the jiffies check for hardwares with BATCH flag.
* Such hardware usually just increases the position at each IRQ,
* thus it can't give any strange position.
*/
if (runtime->hw.info & SNDRV_PCM_INFO_BATCH)
goto no_jiffies_check;
hdelta = delta;
if (hdelta < runtime->delay)
goto no_jiffies_check;
hdelta -= runtime->delay;
jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
if (((hdelta * HZ) / runtime->rate) > jdelta + HZ/100) {
delta = jdelta /
(((runtime->period_size * HZ) / runtime->rate)
+ HZ/100);
/* move new_hw_ptr according jiffies not pos variable */
new_hw_ptr = old_hw_ptr;
hw_base = delta;
/* use loop to avoid checks for delta overflows */
/* the delta value is small or zero in most cases */
while (delta > 0) {
new_hw_ptr += runtime->period_size;
if (new_hw_ptr >= runtime->boundary) {
new_hw_ptr -= runtime->boundary;
crossed_boundary--;
}
delta--;
}
/* align hw_base to buffer_size */
ALSA: pcm: Replace PCM hwptr tracking with tracepoints ALSA PCM core has a mechanism tracking the PCM hwptr updates for analyzing XRUNs. But its log is limited (up to 10) and its log output is a kernel message, which is hard to handle. In this patch, the hwptr logging is moved to the tracing infrastructure instead of its own. Not only the hwptr updates but also XRUN and hwptr errors are recorded on the trace log, so that user can see such events at the exact timing. The new "snd_pcm" entry will appear in the tracing events: # ls -F /sys/kernel/debug/tracing/events/snd_pcm enable filter hw_ptr_error/ hwptr/ xrun/ The hwptr is for the regular hwptr update events. An event trace looks like: aplay-26187 [004] d..3 4012.834761: hwptr: pcmC0D0p/sub0: POS: pos=488, old=0, base=0, period=1024, buf=16384 "POS" shows the hwptr update by the explicit position update call and "IRQ" means the hwptr update by the interrupt, i.e. snd_pcm_period_elapsed() call. The "pos" is the passed ring-buffer offset by the caller, "old" is the previous hwptr, "base" is the hwptr base position, "period" and "buf" are period- and buffer-size of the target PCM substream. (Note that the hwptr position displayed here isn't the ring-buffer offset. It increments up to the PCM position boundary.) The XRUN event appears similarly, but without "pos" field. The hwptr error events appear with the PCM identifier and its reason string, such as "Lost interrupt?". The XRUN and hwptr error reports on kernel message are still left, can be turned on/off via xrun_debug proc like before. But the bit 3, 4, 5 and 6 bits of xrun_debug proc are dropped by this patch. Also, along with the change, the message strings have been reformatted to be a bit more consistent. Last but not least, the hwptr reporting is enabled only when CONFIG_SND_PCM_XRUN_DEBUG is set. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-11-04 14:45:59 +03:00
hw_ptr_error(substream, in_interrupt, "hw_ptr skipping",
"(pos=%ld, delta=%ld, period=%ld, jdelta=%lu/%lu/%lu, hw_ptr=%ld/%ld)\n",
(long)pos, (long)hdelta,
(long)runtime->period_size, jdelta,
((hdelta * HZ) / runtime->rate), hw_base,
(unsigned long)old_hw_ptr,
(unsigned long)new_hw_ptr);
/* reset values to proper state */
delta = 0;
hw_base = new_hw_ptr - (new_hw_ptr % runtime->buffer_size);
}
no_jiffies_check:
if (delta > runtime->period_size + runtime->period_size / 2) {
ALSA: pcm: Replace PCM hwptr tracking with tracepoints ALSA PCM core has a mechanism tracking the PCM hwptr updates for analyzing XRUNs. But its log is limited (up to 10) and its log output is a kernel message, which is hard to handle. In this patch, the hwptr logging is moved to the tracing infrastructure instead of its own. Not only the hwptr updates but also XRUN and hwptr errors are recorded on the trace log, so that user can see such events at the exact timing. The new "snd_pcm" entry will appear in the tracing events: # ls -F /sys/kernel/debug/tracing/events/snd_pcm enable filter hw_ptr_error/ hwptr/ xrun/ The hwptr is for the regular hwptr update events. An event trace looks like: aplay-26187 [004] d..3 4012.834761: hwptr: pcmC0D0p/sub0: POS: pos=488, old=0, base=0, period=1024, buf=16384 "POS" shows the hwptr update by the explicit position update call and "IRQ" means the hwptr update by the interrupt, i.e. snd_pcm_period_elapsed() call. The "pos" is the passed ring-buffer offset by the caller, "old" is the previous hwptr, "base" is the hwptr base position, "period" and "buf" are period- and buffer-size of the target PCM substream. (Note that the hwptr position displayed here isn't the ring-buffer offset. It increments up to the PCM position boundary.) The XRUN event appears similarly, but without "pos" field. The hwptr error events appear with the PCM identifier and its reason string, such as "Lost interrupt?". The XRUN and hwptr error reports on kernel message are still left, can be turned on/off via xrun_debug proc like before. But the bit 3, 4, 5 and 6 bits of xrun_debug proc are dropped by this patch. Also, along with the change, the message strings have been reformatted to be a bit more consistent. Last but not least, the hwptr reporting is enabled only when CONFIG_SND_PCM_XRUN_DEBUG is set. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-11-04 14:45:59 +03:00
hw_ptr_error(substream, in_interrupt,
"Lost interrupts?",
"(stream=%i, delta=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
substream->stream, (long)delta,
(long)new_hw_ptr,
(long)old_hw_ptr);
}
no_delta_check:
if (runtime->status->hw_ptr == new_hw_ptr) {
ALSA: pcm: fix incorrect hw_base increase There is a corner case that ALSA keeps increasing the hw_ptr but DMA already stop working/updating the position for a long time. In following log we can see the position returned from DMA driver does not move at all but the hw_ptr got increased at some point of time so snd_pcm_avail() will return a large number which seems to be a buffer underrun event from user space program point of view. The program thinks there is space in the buffer and fill more data. [ 418.510086] sound pcmC0D5p: pos 96 hw_ptr 96 appl_ptr 4096 avail 12368 [ 418.510149] sound pcmC0D5p: pos 96 hw_ptr 96 appl_ptr 6910 avail 9554 ... [ 418.681052] sound pcmC0D5p: pos 96 hw_ptr 96 appl_ptr 15102 avail 1362 [ 418.681130] sound pcmC0D5p: pos 96 hw_ptr 96 appl_ptr 16464 avail 0 [ 418.726515] sound pcmC0D5p: pos 96 hw_ptr 16464 appl_ptr 16464 avail 16368 This is because the hw_base will be increased by runtime->buffer_size frames unconditionally if the hw_ptr is not updated for over half of buffer time. As the hw_base increases, so does the hw_ptr increased by the same number. The avail value returned from snd_pcm_avail() could exceed the limit (buffer_size) easily becase the hw_ptr itself got increased by same buffer_size samples when the corner case happens. In following log, the buffer_size is 16368 samples but the avail is 21810 samples so CRAS server complains about it. [ 418.851755] sound pcmC0D5p: pos 96 hw_ptr 16464 appl_ptr 27390 avail 5442 [ 418.926491] sound pcmC0D5p: pos 96 hw_ptr 32832 appl_ptr 27390 avail 21810 cras_server[1907]: pcm_avail returned frames larger than buf_size: sof-glkda7219max: :0,5: 21810 > 16368 By updating runtime->hw_ptr_jiffies each time the HWSYNC is called, the hw_base will keep the same when buffer stall happens at long as the interval between each HWSYNC call is shorter than half of buffer time. Following is a log captured by a patched kernel. The hw_base/hw_ptr value is fixed in this corner case and user space program should be aware of the buffer stall and handle it. [ 293.525543] sound pcmC0D5p: pos 96 hw_ptr 96 appl_ptr 4096 avail 12368 [ 293.525606] sound pcmC0D5p: pos 96 hw_ptr 96 appl_ptr 6880 avail 9584 [ 293.525975] sound pcmC0D5p: pos 96 hw_ptr 96 appl_ptr 10976 avail 5488 [ 293.611178] sound pcmC0D5p: pos 96 hw_ptr 96 appl_ptr 15072 avail 1392 [ 293.696429] sound pcmC0D5p: pos 96 hw_ptr 96 appl_ptr 16464 avail 0 ... [ 381.139517] sound pcmC0D5p: pos 96 hw_ptr 96 appl_ptr 16464 avail 0 Signed-off-by: Brent Lu <brent.lu@intel.com> Reviewed-by: Jaroslav Kysela <perex@perex.cz> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/1589776238-23877-1-git-send-email-brent.lu@intel.com Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-05-18 07:30:38 +03:00
runtime->hw_ptr_jiffies = curr_jiffies;
update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);
return 0;
}
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
runtime->silence_size > 0)
snd_pcm_playback_silence(substream, new_hw_ptr);
if (in_interrupt) {
delta = new_hw_ptr - runtime->hw_ptr_interrupt;
if (delta < 0)
delta += runtime->boundary;
delta -= (snd_pcm_uframes_t)delta % runtime->period_size;
runtime->hw_ptr_interrupt += delta;
if (runtime->hw_ptr_interrupt >= runtime->boundary)
runtime->hw_ptr_interrupt -= runtime->boundary;
}
runtime->hw_ptr_base = hw_base;
runtime->status->hw_ptr = new_hw_ptr;
runtime->hw_ptr_jiffies = curr_jiffies;
if (crossed_boundary) {
snd_BUG_ON(crossed_boundary != 1);
runtime->hw_ptr_wrap += runtime->boundary;
}
update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);
return snd_pcm_update_state(substream, runtime);
}
/* CAUTION: call it with irq disabled */
int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
{
return snd_pcm_update_hw_ptr0(substream, 0);
}
/**
* snd_pcm_set_ops - set the PCM operators
* @pcm: the pcm instance
* @direction: stream direction, SNDRV_PCM_STREAM_XXX
* @ops: the operator table
*
* Sets the given PCM operators to the pcm instance.
*/
void snd_pcm_set_ops(struct snd_pcm *pcm, int direction,
const struct snd_pcm_ops *ops)
{
struct snd_pcm_str *stream = &pcm->streams[direction];
struct snd_pcm_substream *substream;
for (substream = stream->substream; substream != NULL; substream = substream->next)
substream->ops = ops;
}
EXPORT_SYMBOL(snd_pcm_set_ops);
/**
* snd_pcm_set_sync - set the PCM sync id
* @substream: the pcm substream
*
* Sets the PCM sync identifier for the card.
*/
void snd_pcm_set_sync(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
runtime->sync.id32[0] = substream->pcm->card->number;
runtime->sync.id32[1] = -1;
runtime->sync.id32[2] = -1;
runtime->sync.id32[3] = -1;
}
EXPORT_SYMBOL(snd_pcm_set_sync);
/*
* Standard ioctl routine
*/
static inline unsigned int div32(unsigned int a, unsigned int b,
unsigned int *r)
{
if (b == 0) {
*r = 0;
return UINT_MAX;
}
*r = a % b;
return a / b;
}
static inline unsigned int div_down(unsigned int a, unsigned int b)
{
if (b == 0)
return UINT_MAX;
return a / b;
}
static inline unsigned int div_up(unsigned int a, unsigned int b)
{
unsigned int r;
unsigned int q;
if (b == 0)
return UINT_MAX;
q = div32(a, b, &r);
if (r)
++q;
return q;
}
static inline unsigned int mul(unsigned int a, unsigned int b)
{
if (a == 0)
return 0;
if (div_down(UINT_MAX, a) < b)
return UINT_MAX;
return a * b;
}
static inline unsigned int muldiv32(unsigned int a, unsigned int b,
unsigned int c, unsigned int *r)
{
u_int64_t n = (u_int64_t) a * b;
if (c == 0) {
*r = 0;
return UINT_MAX;
}
n = div_u64_rem(n, c, r);
if (n >= UINT_MAX) {
*r = 0;
return UINT_MAX;
}
return n;
}
/**
* snd_interval_refine - refine the interval value of configurator
* @i: the interval value to refine
* @v: the interval value to refer to
*
* Refines the interval value with the reference value.
* The interval is changed to the range satisfying both intervals.
* The interval status (min, max, integer, etc.) are evaluated.
*
* Return: Positive if the value is changed, zero if it's not changed, or a
* negative error code.
*/
int snd_interval_refine(struct snd_interval *i, const struct snd_interval *v)
{
int changed = 0;
if (snd_BUG_ON(snd_interval_empty(i)))
return -EINVAL;
if (i->min < v->min) {
i->min = v->min;
i->openmin = v->openmin;
changed = 1;
} else if (i->min == v->min && !i->openmin && v->openmin) {
i->openmin = 1;
changed = 1;
}
if (i->max > v->max) {
i->max = v->max;
i->openmax = v->openmax;
changed = 1;
} else if (i->max == v->max && !i->openmax && v->openmax) {
i->openmax = 1;
changed = 1;
}
if (!i->integer && v->integer) {
i->integer = 1;
changed = 1;
}
if (i->integer) {
if (i->openmin) {
i->min++;
i->openmin = 0;
}
if (i->openmax) {
i->max--;
i->openmax = 0;
}
} else if (!i->openmin && !i->openmax && i->min == i->max)
i->integer = 1;
if (snd_interval_checkempty(i)) {
snd_interval_none(i);
return -EINVAL;
}
return changed;
}
EXPORT_SYMBOL(snd_interval_refine);
static int snd_interval_refine_first(struct snd_interval *i)
{
const unsigned int last_max = i->max;
if (snd_BUG_ON(snd_interval_empty(i)))
return -EINVAL;
if (snd_interval_single(i))
return 0;
i->max = i->min;
if (i->openmin)
i->max++;
/* only exclude max value if also excluded before refine */
i->openmax = (i->openmax && i->max >= last_max);
return 1;
}
static int snd_interval_refine_last(struct snd_interval *i)
{
const unsigned int last_min = i->min;
if (snd_BUG_ON(snd_interval_empty(i)))
return -EINVAL;
if (snd_interval_single(i))
return 0;
i->min = i->max;
if (i->openmax)
i->min--;
/* only exclude min value if also excluded before refine */
i->openmin = (i->openmin && i->min <= last_min);
return 1;
}
void snd_interval_mul(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
{
if (a->empty || b->empty) {
snd_interval_none(c);
return;
}
c->empty = 0;
c->min = mul(a->min, b->min);
c->openmin = (a->openmin || b->openmin);
c->max = mul(a->max, b->max);
c->openmax = (a->openmax || b->openmax);
c->integer = (a->integer && b->integer);
}
/**
* snd_interval_div - refine the interval value with division
* @a: dividend
* @b: divisor
* @c: quotient
*
* c = a / b
*
* Returns non-zero if the value is changed, zero if not changed.
*/
void snd_interval_div(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
{
unsigned int r;
if (a->empty || b->empty) {
snd_interval_none(c);
return;
}
c->empty = 0;
c->min = div32(a->min, b->max, &r);
c->openmin = (r || a->openmin || b->openmax);
if (b->min > 0) {
c->max = div32(a->max, b->min, &r);
if (r) {
c->max++;
c->openmax = 1;
} else
c->openmax = (a->openmax || b->openmin);
} else {
c->max = UINT_MAX;
c->openmax = 0;
}
c->integer = 0;
}
/**
* snd_interval_muldivk - refine the interval value
* @a: dividend 1
* @b: dividend 2
* @k: divisor (as integer)
* @c: result
*
* c = a * b / k
*
* Returns non-zero if the value is changed, zero if not changed.
*/
void snd_interval_muldivk(const struct snd_interval *a, const struct snd_interval *b,
unsigned int k, struct snd_interval *c)
{
unsigned int r;
if (a->empty || b->empty) {
snd_interval_none(c);
return;
}
c->empty = 0;
c->min = muldiv32(a->min, b->min, k, &r);
c->openmin = (r || a->openmin || b->openmin);
c->max = muldiv32(a->max, b->max, k, &r);
if (r) {
c->max++;
c->openmax = 1;
} else
c->openmax = (a->openmax || b->openmax);
c->integer = 0;
}
/**
* snd_interval_mulkdiv - refine the interval value
* @a: dividend 1
* @k: dividend 2 (as integer)
* @b: divisor
* @c: result
*
* c = a * k / b
*
* Returns non-zero if the value is changed, zero if not changed.
*/
void snd_interval_mulkdiv(const struct snd_interval *a, unsigned int k,
const struct snd_interval *b, struct snd_interval *c)
{
unsigned int r;
if (a->empty || b->empty) {
snd_interval_none(c);
return;
}
c->empty = 0;
c->min = muldiv32(a->min, k, b->max, &r);
c->openmin = (r || a->openmin || b->openmax);
if (b->min > 0) {
c->max = muldiv32(a->max, k, b->min, &r);
if (r) {
c->max++;
c->openmax = 1;
} else
c->openmax = (a->openmax || b->openmin);
} else {
c->max = UINT_MAX;
c->openmax = 0;
}
c->integer = 0;
}
/* ---- */
/**
* snd_interval_ratnum - refine the interval value
* @i: interval to refine
* @rats_count: number of ratnum_t
* @rats: ratnum_t array
* @nump: pointer to store the resultant numerator
* @denp: pointer to store the resultant denominator
*
* Return: Positive if the value is changed, zero if it's not changed, or a
* negative error code.
*/
int snd_interval_ratnum(struct snd_interval *i,
unsigned int rats_count, const struct snd_ratnum *rats,
unsigned int *nump, unsigned int *denp)
{
unsigned int best_num, best_den;
int best_diff;
unsigned int k;
struct snd_interval t;
int err;
unsigned int result_num, result_den;
int result_diff;
best_num = best_den = best_diff = 0;
for (k = 0; k < rats_count; ++k) {
unsigned int num = rats[k].num;
unsigned int den;
unsigned int q = i->min;
int diff;
if (q == 0)
q = 1;
den = div_up(num, q);
if (den < rats[k].den_min)
continue;
if (den > rats[k].den_max)
den = rats[k].den_max;
else {
unsigned int r;
r = (den - rats[k].den_min) % rats[k].den_step;
if (r != 0)
den -= r;
}
diff = num - q * den;
if (diff < 0)
diff = -diff;
if (best_num == 0 ||
diff * best_den < best_diff * den) {
best_diff = diff;
best_den = den;
best_num = num;
}
}
if (best_den == 0) {
i->empty = 1;
return -EINVAL;
}
t.min = div_down(best_num, best_den);
t.openmin = !!(best_num % best_den);
result_num = best_num;
result_diff = best_diff;
result_den = best_den;
best_num = best_den = best_diff = 0;
for (k = 0; k < rats_count; ++k) {
unsigned int num = rats[k].num;
unsigned int den;
unsigned int q = i->max;
int diff;
if (q == 0) {
i->empty = 1;
return -EINVAL;
}
den = div_down(num, q);
if (den > rats[k].den_max)
continue;
if (den < rats[k].den_min)
den = rats[k].den_min;
else {
unsigned int r;
r = (den - rats[k].den_min) % rats[k].den_step;
if (r != 0)
den += rats[k].den_step - r;
}
diff = q * den - num;
if (diff < 0)
diff = -diff;
if (best_num == 0 ||
diff * best_den < best_diff * den) {
best_diff = diff;
best_den = den;
best_num = num;
}
}
if (best_den == 0) {
i->empty = 1;
return -EINVAL;
}
t.max = div_up(best_num, best_den);
t.openmax = !!(best_num % best_den);
t.integer = 0;
err = snd_interval_refine(i, &t);
if (err < 0)
return err;
if (snd_interval_single(i)) {
if (best_diff * result_den < result_diff * best_den) {
result_num = best_num;
result_den = best_den;
}
if (nump)
*nump = result_num;
if (denp)
*denp = result_den;
}
return err;
}
EXPORT_SYMBOL(snd_interval_ratnum);
/**
* snd_interval_ratden - refine the interval value
* @i: interval to refine
* @rats_count: number of struct ratden
* @rats: struct ratden array
* @nump: pointer to store the resultant numerator
* @denp: pointer to store the resultant denominator
*
* Return: Positive if the value is changed, zero if it's not changed, or a
* negative error code.
*/
static int snd_interval_ratden(struct snd_interval *i,
unsigned int rats_count,
const struct snd_ratden *rats,
unsigned int *nump, unsigned int *denp)
{
unsigned int best_num, best_diff, best_den;
unsigned int k;
struct snd_interval t;
int err;
best_num = best_den = best_diff = 0;
for (k = 0; k < rats_count; ++k) {
unsigned int num;
unsigned int den = rats[k].den;
unsigned int q = i->min;
int diff;
num = mul(q, den);
if (num > rats[k].num_max)
continue;
if (num < rats[k].num_min)
num = rats[k].num_max;
else {
unsigned int r;
r = (num - rats[k].num_min) % rats[k].num_step;
if (r != 0)
num += rats[k].num_step - r;
}
diff = num - q * den;
if (best_num == 0 ||
diff * best_den < best_diff * den) {
best_diff = diff;
best_den = den;
best_num = num;
}
}
if (best_den == 0) {
i->empty = 1;
return -EINVAL;
}
t.min = div_down(best_num, best_den);
t.openmin = !!(best_num % best_den);
best_num = best_den = best_diff = 0;
for (k = 0; k < rats_count; ++k) {
unsigned int num;
unsigned int den = rats[k].den;
unsigned int q = i->max;
int diff;
num = mul(q, den);
if (num < rats[k].num_min)
continue;
if (num > rats[k].num_max)
num = rats[k].num_max;
else {
unsigned int r;
r = (num - rats[k].num_min) % rats[k].num_step;
if (r != 0)
num -= r;
}
diff = q * den - num;
if (best_num == 0 ||
diff * best_den < best_diff * den) {
best_diff = diff;
best_den = den;
best_num = num;
}
}
if (best_den == 0) {
i->empty = 1;
return -EINVAL;
}
t.max = div_up(best_num, best_den);
t.openmax = !!(best_num % best_den);
t.integer = 0;
err = snd_interval_refine(i, &t);
if (err < 0)
return err;
if (snd_interval_single(i)) {
if (nump)
*nump = best_num;
if (denp)
*denp = best_den;
}
return err;
}
/**
* snd_interval_list - refine the interval value from the list
* @i: the interval value to refine
* @count: the number of elements in the list
* @list: the value list
* @mask: the bit-mask to evaluate
*
* Refines the interval value from the list.
* When mask is non-zero, only the elements corresponding to bit 1 are
* evaluated.
*
* Return: Positive if the value is changed, zero if it's not changed, or a
* negative error code.
*/
int snd_interval_list(struct snd_interval *i, unsigned int count,
const unsigned int *list, unsigned int mask)
{
unsigned int k;
struct snd_interval list_range;
if (!count) {
i->empty = 1;
return -EINVAL;
}
snd_interval_any(&list_range);
list_range.min = UINT_MAX;
list_range.max = 0;
for (k = 0; k < count; k++) {
if (mask && !(mask & (1 << k)))
continue;
if (!snd_interval_test(i, list[k]))
continue;
list_range.min = min(list_range.min, list[k]);
list_range.max = max(list_range.max, list[k]);
}
return snd_interval_refine(i, &list_range);
}
EXPORT_SYMBOL(snd_interval_list);
/**
* snd_interval_ranges - refine the interval value from the list of ranges
* @i: the interval value to refine
* @count: the number of elements in the list of ranges
* @ranges: the ranges list
* @mask: the bit-mask to evaluate
*
* Refines the interval value from the list of ranges.
* When mask is non-zero, only the elements corresponding to bit 1 are
* evaluated.
*
* Return: Positive if the value is changed, zero if it's not changed, or a
* negative error code.
*/
int snd_interval_ranges(struct snd_interval *i, unsigned int count,
const struct snd_interval *ranges, unsigned int mask)
{
unsigned int k;
struct snd_interval range_union;
struct snd_interval range;
if (!count) {
snd_interval_none(i);
return -EINVAL;
}
snd_interval_any(&range_union);
range_union.min = UINT_MAX;
range_union.max = 0;
for (k = 0; k < count; k++) {
if (mask && !(mask & (1 << k)))
continue;
snd_interval_copy(&range, &ranges[k]);
if (snd_interval_refine(&range, i) < 0)
continue;
if (snd_interval_empty(&range))
continue;
if (range.min < range_union.min) {
range_union.min = range.min;
range_union.openmin = 1;
}
if (range.min == range_union.min && !range.openmin)
range_union.openmin = 0;
if (range.max > range_union.max) {
range_union.max = range.max;
range_union.openmax = 1;
}
if (range.max == range_union.max && !range.openmax)
range_union.openmax = 0;
}
return snd_interval_refine(i, &range_union);
}
EXPORT_SYMBOL(snd_interval_ranges);
static int snd_interval_step(struct snd_interval *i, unsigned int step)
{
unsigned int n;
int changed = 0;
n = i->min % step;
if (n != 0 || i->openmin) {
i->min += step - n;
i->openmin = 0;
changed = 1;
}
n = i->max % step;
if (n != 0 || i->openmax) {
i->max -= n;
i->openmax = 0;
changed = 1;
}
if (snd_interval_checkempty(i)) {
i->empty = 1;
return -EINVAL;
}
return changed;
}
/* Info constraints helpers */
/**
* snd_pcm_hw_rule_add - add the hw-constraint rule
* @runtime: the pcm runtime instance
* @cond: condition bits
* @var: the variable to evaluate
* @func: the evaluation function
* @private: the private data pointer passed to function
* @dep: the dependent variables
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_pcm_hw_rule_add(struct snd_pcm_runtime *runtime, unsigned int cond,
int var,
snd_pcm_hw_rule_func_t func, void *private,
int dep, ...)
{
struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
struct snd_pcm_hw_rule *c;
unsigned int k;
va_list args;
va_start(args, dep);
if (constrs->rules_num >= constrs->rules_all) {
struct snd_pcm_hw_rule *new;
unsigned int new_rules = constrs->rules_all + 16;
ALSA: pcm: use krealloc_array() Use the helper that checks for overflows internally instead of manually calculating the size of the new array. Link: https://lkml.kernel.org/r/20201109110654.12547-4-brgl@bgdev.pl Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Reviewed-by: Takashi Iwai <tiwai@suse.de> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Christian Knig <christian.koenig@amd.com> Cc: Christoph Lameter <cl@linux.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: David Airlie <airlied@linux.ie> Cc: David Rientjes <rientjes@google.com> Cc: Gustavo Padovan <gustavo@padovan.org> Cc: James Morse <james.morse@arm.com> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Jason Wang <jasowang@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Maxime Ripard <mripard@kernel.org> Cc: "Michael S . Tsirkin" <mst@redhat.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Robert Richter <rric@kernel.org> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Takashi Iwai <tiwai@suse.com> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 06:03:59 +03:00
new = krealloc_array(constrs->rules, new_rules,
sizeof(*c), GFP_KERNEL);
if (!new) {
va_end(args);
return -ENOMEM;
}
constrs->rules = new;
constrs->rules_all = new_rules;
}
c = &constrs->rules[constrs->rules_num];
c->cond = cond;
c->func = func;
c->var = var;
c->private = private;
k = 0;
while (1) {
if (snd_BUG_ON(k >= ARRAY_SIZE(c->deps))) {
va_end(args);
return -EINVAL;
}
c->deps[k++] = dep;
if (dep < 0)
break;
dep = va_arg(args, int);
}
constrs->rules_num++;
va_end(args);
return 0;
}
EXPORT_SYMBOL(snd_pcm_hw_rule_add);
/**
* snd_pcm_hw_constraint_mask - apply the given bitmap mask constraint
* @runtime: PCM runtime instance
* @var: hw_params variable to apply the mask
* @mask: the bitmap mask
*
* Apply the constraint of the given bitmap mask to a 32-bit mask parameter.
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
u_int32_t mask)
{
struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
struct snd_mask *maskp = constrs_mask(constrs, var);
*maskp->bits &= mask;
memset(maskp->bits + 1, 0, (SNDRV_MASK_MAX-32) / 8); /* clear rest */
if (*maskp->bits == 0)
return -EINVAL;
return 0;
}
/**
* snd_pcm_hw_constraint_mask64 - apply the given bitmap mask constraint
* @runtime: PCM runtime instance
* @var: hw_params variable to apply the mask
* @mask: the 64bit bitmap mask
*
* Apply the constraint of the given bitmap mask to a 64-bit mask parameter.
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
u_int64_t mask)
{
struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
struct snd_mask *maskp = constrs_mask(constrs, var);
maskp->bits[0] &= (u_int32_t)mask;
maskp->bits[1] &= (u_int32_t)(mask >> 32);
memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
if (! maskp->bits[0] && ! maskp->bits[1])
return -EINVAL;
return 0;
}
EXPORT_SYMBOL(snd_pcm_hw_constraint_mask64);
/**
* snd_pcm_hw_constraint_integer - apply an integer constraint to an interval
* @runtime: PCM runtime instance
* @var: hw_params variable to apply the integer constraint
*
* Apply the constraint of integer to an interval parameter.
*
* Return: Positive if the value is changed, zero if it's not changed, or a
* negative error code.
*/
int snd_pcm_hw_constraint_integer(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var)
{
struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
return snd_interval_setinteger(constrs_interval(constrs, var));
}
EXPORT_SYMBOL(snd_pcm_hw_constraint_integer);
/**
* snd_pcm_hw_constraint_minmax - apply a min/max range constraint to an interval
* @runtime: PCM runtime instance
* @var: hw_params variable to apply the range
* @min: the minimal value
* @max: the maximal value
*
* Apply the min/max range constraint to an interval parameter.
*
* Return: Positive if the value is changed, zero if it's not changed, or a
* negative error code.
*/
int snd_pcm_hw_constraint_minmax(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
unsigned int min, unsigned int max)
{
struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
struct snd_interval t;
t.min = min;
t.max = max;
t.openmin = t.openmax = 0;
t.integer = 0;
return snd_interval_refine(constrs_interval(constrs, var), &t);
}
EXPORT_SYMBOL(snd_pcm_hw_constraint_minmax);
static int snd_pcm_hw_rule_list(struct snd_pcm_hw_params *params,
struct snd_pcm_hw_rule *rule)
{
struct snd_pcm_hw_constraint_list *list = rule->private;
return snd_interval_list(hw_param_interval(params, rule->var), list->count, list->list, list->mask);
}
/**
* snd_pcm_hw_constraint_list - apply a list of constraints to a parameter
* @runtime: PCM runtime instance
* @cond: condition bits
* @var: hw_params variable to apply the list constraint
* @l: list
*
* Apply the list of constraints to an interval parameter.
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_pcm_hw_constraint_list(struct snd_pcm_runtime *runtime,
unsigned int cond,
snd_pcm_hw_param_t var,
const struct snd_pcm_hw_constraint_list *l)
{
return snd_pcm_hw_rule_add(runtime, cond, var,
snd_pcm_hw_rule_list, (void *)l,
var, -1);
}
EXPORT_SYMBOL(snd_pcm_hw_constraint_list);
static int snd_pcm_hw_rule_ranges(struct snd_pcm_hw_params *params,
struct snd_pcm_hw_rule *rule)
{
struct snd_pcm_hw_constraint_ranges *r = rule->private;
return snd_interval_ranges(hw_param_interval(params, rule->var),
r->count, r->ranges, r->mask);
}
/**
* snd_pcm_hw_constraint_ranges - apply list of range constraints to a parameter
* @runtime: PCM runtime instance
* @cond: condition bits
* @var: hw_params variable to apply the list of range constraints
* @r: ranges
*
* Apply the list of range constraints to an interval parameter.
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_pcm_hw_constraint_ranges(struct snd_pcm_runtime *runtime,
unsigned int cond,
snd_pcm_hw_param_t var,
const struct snd_pcm_hw_constraint_ranges *r)
{
return snd_pcm_hw_rule_add(runtime, cond, var,
snd_pcm_hw_rule_ranges, (void *)r,
var, -1);
}
EXPORT_SYMBOL(snd_pcm_hw_constraint_ranges);
static int snd_pcm_hw_rule_ratnums(struct snd_pcm_hw_params *params,
struct snd_pcm_hw_rule *rule)
{
const struct snd_pcm_hw_constraint_ratnums *r = rule->private;
unsigned int num = 0, den = 0;
int err;
err = snd_interval_ratnum(hw_param_interval(params, rule->var),
r->nrats, r->rats, &num, &den);
if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
params->rate_num = num;
params->rate_den = den;
}
return err;
}
/**
* snd_pcm_hw_constraint_ratnums - apply ratnums constraint to a parameter
* @runtime: PCM runtime instance
* @cond: condition bits
* @var: hw_params variable to apply the ratnums constraint
* @r: struct snd_ratnums constriants
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime,
unsigned int cond,
snd_pcm_hw_param_t var,
const struct snd_pcm_hw_constraint_ratnums *r)
{
return snd_pcm_hw_rule_add(runtime, cond, var,
snd_pcm_hw_rule_ratnums, (void *)r,
var, -1);
}
EXPORT_SYMBOL(snd_pcm_hw_constraint_ratnums);
static int snd_pcm_hw_rule_ratdens(struct snd_pcm_hw_params *params,
struct snd_pcm_hw_rule *rule)
{
const struct snd_pcm_hw_constraint_ratdens *r = rule->private;
unsigned int num = 0, den = 0;
int err = snd_interval_ratden(hw_param_interval(params, rule->var),
r->nrats, r->rats, &num, &den);
if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
params->rate_num = num;
params->rate_den = den;
}
return err;
}
/**
* snd_pcm_hw_constraint_ratdens - apply ratdens constraint to a parameter
* @runtime: PCM runtime instance
* @cond: condition bits
* @var: hw_params variable to apply the ratdens constraint
* @r: struct snd_ratdens constriants
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime,
unsigned int cond,
snd_pcm_hw_param_t var,
const struct snd_pcm_hw_constraint_ratdens *r)
{
return snd_pcm_hw_rule_add(runtime, cond, var,
snd_pcm_hw_rule_ratdens, (void *)r,
var, -1);
}
EXPORT_SYMBOL(snd_pcm_hw_constraint_ratdens);
static int snd_pcm_hw_rule_msbits(struct snd_pcm_hw_params *params,
struct snd_pcm_hw_rule *rule)
{
unsigned int l = (unsigned long) rule->private;
int width = l & 0xffff;
unsigned int msbits = l >> 16;
const struct snd_interval *i =
hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
if (!snd_interval_single(i))
return 0;
if ((snd_interval_value(i) == width) ||
(width == 0 && snd_interval_value(i) > msbits))
params->msbits = min_not_zero(params->msbits, msbits);
return 0;
}
/**
* snd_pcm_hw_constraint_msbits - add a hw constraint msbits rule
* @runtime: PCM runtime instance
* @cond: condition bits
* @width: sample bits width
* @msbits: msbits width
*
* This constraint will set the number of most significant bits (msbits) if a
* sample format with the specified width has been select. If width is set to 0
* the msbits will be set for any sample format with a width larger than the
* specified msbits.
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime,
unsigned int cond,
unsigned int width,
unsigned int msbits)
{
unsigned long l = (msbits << 16) | width;
return snd_pcm_hw_rule_add(runtime, cond, -1,
snd_pcm_hw_rule_msbits,
(void*) l,
SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
}
EXPORT_SYMBOL(snd_pcm_hw_constraint_msbits);
static int snd_pcm_hw_rule_step(struct snd_pcm_hw_params *params,
struct snd_pcm_hw_rule *rule)
{
unsigned long step = (unsigned long) rule->private;
return snd_interval_step(hw_param_interval(params, rule->var), step);
}
/**
* snd_pcm_hw_constraint_step - add a hw constraint step rule
* @runtime: PCM runtime instance
* @cond: condition bits
* @var: hw_params variable to apply the step constraint
* @step: step size
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_pcm_hw_constraint_step(struct snd_pcm_runtime *runtime,
unsigned int cond,
snd_pcm_hw_param_t var,
unsigned long step)
{
return snd_pcm_hw_rule_add(runtime, cond, var,
snd_pcm_hw_rule_step, (void *) step,
var, -1);
}
EXPORT_SYMBOL(snd_pcm_hw_constraint_step);
static int snd_pcm_hw_rule_pow2(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
{
static const unsigned int pow2_sizes[] = {
1<<0, 1<<1, 1<<2, 1<<3, 1<<4, 1<<5, 1<<6, 1<<7,
1<<8, 1<<9, 1<<10, 1<<11, 1<<12, 1<<13, 1<<14, 1<<15,
1<<16, 1<<17, 1<<18, 1<<19, 1<<20, 1<<21, 1<<22, 1<<23,
1<<24, 1<<25, 1<<26, 1<<27, 1<<28, 1<<29, 1<<30
};
return snd_interval_list(hw_param_interval(params, rule->var),
ARRAY_SIZE(pow2_sizes), pow2_sizes, 0);
}
/**
* snd_pcm_hw_constraint_pow2 - add a hw constraint power-of-2 rule
* @runtime: PCM runtime instance
* @cond: condition bits
* @var: hw_params variable to apply the power-of-2 constraint
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime,
unsigned int cond,
snd_pcm_hw_param_t var)
{
return snd_pcm_hw_rule_add(runtime, cond, var,
snd_pcm_hw_rule_pow2, NULL,
var, -1);
}
EXPORT_SYMBOL(snd_pcm_hw_constraint_pow2);
static int snd_pcm_hw_rule_noresample_func(struct snd_pcm_hw_params *params,
struct snd_pcm_hw_rule *rule)
{
unsigned int base_rate = (unsigned int)(uintptr_t)rule->private;
struct snd_interval *rate;
rate = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
return snd_interval_list(rate, 1, &base_rate, 0);
}
/**
* snd_pcm_hw_rule_noresample - add a rule to allow disabling hw resampling
* @runtime: PCM runtime instance
* @base_rate: the rate at which the hardware does not resample
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_pcm_hw_rule_noresample(struct snd_pcm_runtime *runtime,
unsigned int base_rate)
{
return snd_pcm_hw_rule_add(runtime, SNDRV_PCM_HW_PARAMS_NORESAMPLE,
SNDRV_PCM_HW_PARAM_RATE,
snd_pcm_hw_rule_noresample_func,
(void *)(uintptr_t)base_rate,
SNDRV_PCM_HW_PARAM_RATE, -1);
}
EXPORT_SYMBOL(snd_pcm_hw_rule_noresample);
static void _snd_pcm_hw_param_any(struct snd_pcm_hw_params *params,
snd_pcm_hw_param_t var)
{
if (hw_is_mask(var)) {
snd_mask_any(hw_param_mask(params, var));
params->cmask |= 1 << var;
params->rmask |= 1 << var;
return;
}
if (hw_is_interval(var)) {
snd_interval_any(hw_param_interval(params, var));
params->cmask |= 1 << var;
params->rmask |= 1 << var;
return;
}
snd_BUG();
}
void _snd_pcm_hw_params_any(struct snd_pcm_hw_params *params)
{
unsigned int k;
memset(params, 0, sizeof(*params));
for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++)
_snd_pcm_hw_param_any(params, k);
for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++)
_snd_pcm_hw_param_any(params, k);
params->info = ~0U;
}
EXPORT_SYMBOL(_snd_pcm_hw_params_any);
/**
* snd_pcm_hw_param_value - return @params field @var value
* @params: the hw_params instance
* @var: parameter to retrieve
* @dir: pointer to the direction (-1,0,1) or %NULL
*
* Return: The value for field @var if it's fixed in configuration space
* defined by @params. -%EINVAL otherwise.
*/
int snd_pcm_hw_param_value(const struct snd_pcm_hw_params *params,
snd_pcm_hw_param_t var, int *dir)
{
if (hw_is_mask(var)) {
const struct snd_mask *mask = hw_param_mask_c(params, var);
if (!snd_mask_single(mask))
return -EINVAL;
if (dir)
*dir = 0;
return snd_mask_value(mask);
}
if (hw_is_interval(var)) {
const struct snd_interval *i = hw_param_interval_c(params, var);
if (!snd_interval_single(i))
return -EINVAL;
if (dir)
*dir = i->openmin;
return snd_interval_value(i);
}
return -EINVAL;
}
EXPORT_SYMBOL(snd_pcm_hw_param_value);
void _snd_pcm_hw_param_setempty(struct snd_pcm_hw_params *params,
snd_pcm_hw_param_t var)
{
if (hw_is_mask(var)) {
snd_mask_none(hw_param_mask(params, var));
params->cmask |= 1 << var;
params->rmask |= 1 << var;
} else if (hw_is_interval(var)) {
snd_interval_none(hw_param_interval(params, var));
params->cmask |= 1 << var;
params->rmask |= 1 << var;
} else {
snd_BUG();
}
}
EXPORT_SYMBOL(_snd_pcm_hw_param_setempty);
static int _snd_pcm_hw_param_first(struct snd_pcm_hw_params *params,
snd_pcm_hw_param_t var)
{
int changed;
if (hw_is_mask(var))
changed = snd_mask_refine_first(hw_param_mask(params, var));
else if (hw_is_interval(var))
changed = snd_interval_refine_first(hw_param_interval(params, var));
else
return -EINVAL;
if (changed > 0) {
params->cmask |= 1 << var;
params->rmask |= 1 << var;
}
return changed;
}
/**
* snd_pcm_hw_param_first - refine config space and return minimum value
* @pcm: PCM instance
* @params: the hw_params instance
* @var: parameter to retrieve
* @dir: pointer to the direction (-1,0,1) or %NULL
*
* Inside configuration space defined by @params remove from @var all
* values > minimum. Reduce configuration space accordingly.
*
* Return: The minimum, or a negative error code on failure.
*/
int snd_pcm_hw_param_first(struct snd_pcm_substream *pcm,
struct snd_pcm_hw_params *params,
snd_pcm_hw_param_t var, int *dir)
{
int changed = _snd_pcm_hw_param_first(params, var);
if (changed < 0)
return changed;
if (params->rmask) {
int err = snd_pcm_hw_refine(pcm, params);
ALSA: pcm: Remove incorrect snd_BUG_ON() usages syzkaller triggered kernel warnings through PCM OSS emulation at closing a stream: WARNING: CPU: 0 PID: 3502 at sound/core/pcm_lib.c:1635 snd_pcm_hw_param_first+0x289/0x690 sound/core/pcm_lib.c:1635 Call Trace: .... snd_pcm_hw_param_near.constprop.27+0x78d/0x9a0 sound/core/oss/pcm_oss.c:457 snd_pcm_oss_change_params+0x17d3/0x3720 sound/core/oss/pcm_oss.c:969 snd_pcm_oss_make_ready+0xaa/0x130 sound/core/oss/pcm_oss.c:1128 snd_pcm_oss_sync+0x257/0x830 sound/core/oss/pcm_oss.c:1638 snd_pcm_oss_release+0x20b/0x280 sound/core/oss/pcm_oss.c:2431 __fput+0x327/0x7e0 fs/file_table.c:210 .... This happens while it tries to open and set up the aloop device concurrently. The warning above (invoked from snd_BUG_ON() macro) is to detect the unexpected logical error where snd_pcm_hw_refine() call shouldn't fail. The theory is true for the case where the hw_params config rules are static. But for an aloop device, the hw_params rule condition does vary dynamically depending on the connected target; when another device is opened and changes the parameters, the device connected in another side is also affected, and it caused the error from snd_pcm_hw_refine(). That is, the simplest "solution" for this is to remove the incorrect assumption of static rules, and treat such an error as a normal error path. As there are a couple of other places using snd_BUG_ON() incorrectly, this patch removes these spurious snd_BUG_ON() calls. Reported-by: syzbot+6f11c7e2a1b91d466432@syzkaller.appspotmail.com Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-01-01 11:50:50 +03:00
if (err < 0)
return err;
}
return snd_pcm_hw_param_value(params, var, dir);
}
EXPORT_SYMBOL(snd_pcm_hw_param_first);
static int _snd_pcm_hw_param_last(struct snd_pcm_hw_params *params,
snd_pcm_hw_param_t var)
{
int changed;
if (hw_is_mask(var))
changed = snd_mask_refine_last(hw_param_mask(params, var));
else if (hw_is_interval(var))
changed = snd_interval_refine_last(hw_param_interval(params, var));
else
return -EINVAL;
if (changed > 0) {
params->cmask |= 1 << var;
params->rmask |= 1 << var;
}
return changed;
}
/**
* snd_pcm_hw_param_last - refine config space and return maximum value
* @pcm: PCM instance
* @params: the hw_params instance
* @var: parameter to retrieve
* @dir: pointer to the direction (-1,0,1) or %NULL
*
* Inside configuration space defined by @params remove from @var all
* values < maximum. Reduce configuration space accordingly.
*
* Return: The maximum, or a negative error code on failure.
*/
int snd_pcm_hw_param_last(struct snd_pcm_substream *pcm,
struct snd_pcm_hw_params *params,
snd_pcm_hw_param_t var, int *dir)
{
int changed = _snd_pcm_hw_param_last(params, var);
if (changed < 0)
return changed;
if (params->rmask) {
int err = snd_pcm_hw_refine(pcm, params);
ALSA: pcm: Remove incorrect snd_BUG_ON() usages syzkaller triggered kernel warnings through PCM OSS emulation at closing a stream: WARNING: CPU: 0 PID: 3502 at sound/core/pcm_lib.c:1635 snd_pcm_hw_param_first+0x289/0x690 sound/core/pcm_lib.c:1635 Call Trace: .... snd_pcm_hw_param_near.constprop.27+0x78d/0x9a0 sound/core/oss/pcm_oss.c:457 snd_pcm_oss_change_params+0x17d3/0x3720 sound/core/oss/pcm_oss.c:969 snd_pcm_oss_make_ready+0xaa/0x130 sound/core/oss/pcm_oss.c:1128 snd_pcm_oss_sync+0x257/0x830 sound/core/oss/pcm_oss.c:1638 snd_pcm_oss_release+0x20b/0x280 sound/core/oss/pcm_oss.c:2431 __fput+0x327/0x7e0 fs/file_table.c:210 .... This happens while it tries to open and set up the aloop device concurrently. The warning above (invoked from snd_BUG_ON() macro) is to detect the unexpected logical error where snd_pcm_hw_refine() call shouldn't fail. The theory is true for the case where the hw_params config rules are static. But for an aloop device, the hw_params rule condition does vary dynamically depending on the connected target; when another device is opened and changes the parameters, the device connected in another side is also affected, and it caused the error from snd_pcm_hw_refine(). That is, the simplest "solution" for this is to remove the incorrect assumption of static rules, and treat such an error as a normal error path. As there are a couple of other places using snd_BUG_ON() incorrectly, this patch removes these spurious snd_BUG_ON() calls. Reported-by: syzbot+6f11c7e2a1b91d466432@syzkaller.appspotmail.com Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-01-01 11:50:50 +03:00
if (err < 0)
return err;
}
return snd_pcm_hw_param_value(params, var, dir);
}
EXPORT_SYMBOL(snd_pcm_hw_param_last);
static int snd_pcm_lib_ioctl_reset(struct snd_pcm_substream *substream,
void *arg)
{
struct snd_pcm_runtime *runtime = substream->runtime;
unsigned long flags;
snd_pcm_stream_lock_irqsave(substream, flags);
if (snd_pcm_running(substream) &&
snd_pcm_update_hw_ptr(substream) >= 0)
runtime->status->hw_ptr %= runtime->buffer_size;
else {
runtime->status->hw_ptr = 0;
runtime->hw_ptr_wrap = 0;
}
snd_pcm_stream_unlock_irqrestore(substream, flags);
return 0;
}
static int snd_pcm_lib_ioctl_channel_info(struct snd_pcm_substream *substream,
void *arg)
{
struct snd_pcm_channel_info *info = arg;
struct snd_pcm_runtime *runtime = substream->runtime;
int width;
if (!(runtime->info & SNDRV_PCM_INFO_MMAP)) {
info->offset = -1;
return 0;
}
width = snd_pcm_format_physical_width(runtime->format);
if (width < 0)
return width;
info->offset = 0;
switch (runtime->access) {
case SNDRV_PCM_ACCESS_MMAP_INTERLEAVED:
case SNDRV_PCM_ACCESS_RW_INTERLEAVED:
info->first = info->channel * width;
info->step = runtime->channels * width;
break;
case SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED:
case SNDRV_PCM_ACCESS_RW_NONINTERLEAVED:
{
size_t size = runtime->dma_bytes / runtime->channels;
info->first = info->channel * size * 8;
info->step = width;
break;
}
default:
snd_BUG();
break;
}
return 0;
}
static int snd_pcm_lib_ioctl_fifo_size(struct snd_pcm_substream *substream,
void *arg)
{
struct snd_pcm_hw_params *params = arg;
snd_pcm_format_t format;
int channels;
ssize_t frame_size;
params->fifo_size = substream->runtime->hw.fifo_size;
if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_FIFO_IN_FRAMES)) {
format = params_format(params);
channels = params_channels(params);
frame_size = snd_pcm_format_size(format, channels);
if (frame_size > 0)
params->fifo_size /= frame_size;
}
return 0;
}
/**
* snd_pcm_lib_ioctl - a generic PCM ioctl callback
* @substream: the pcm substream instance
* @cmd: ioctl command
* @arg: ioctl argument
*
* Processes the generic ioctl commands for PCM.
* Can be passed as the ioctl callback for PCM ops.
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
unsigned int cmd, void *arg)
{
switch (cmd) {
case SNDRV_PCM_IOCTL1_RESET:
return snd_pcm_lib_ioctl_reset(substream, arg);
case SNDRV_PCM_IOCTL1_CHANNEL_INFO:
return snd_pcm_lib_ioctl_channel_info(substream, arg);
case SNDRV_PCM_IOCTL1_FIFO_SIZE:
return snd_pcm_lib_ioctl_fifo_size(substream, arg);
}
return -ENXIO;
}
EXPORT_SYMBOL(snd_pcm_lib_ioctl);
/**
* snd_pcm_period_elapsed_under_stream_lock() - update the status of runtime for the next period
* under acquired lock of PCM substream.
* @substream: the instance of pcm substream.
*
* This function is called when the batch of audio data frames as the same size as the period of
* buffer is already processed in audio data transmission.
*
* The call of function updates the status of runtime with the latest position of audio data
* transmission, checks overrun and underrun over buffer, awaken user processes from waiting for
* available audio data frames, sampling audio timestamp, and performs stop or drain the PCM
* substream according to configured threshold.
*
* The function is intended to use for the case that PCM driver operates audio data frames under
* acquired lock of PCM substream; e.g. in callback of any operation of &snd_pcm_ops in process
* context. In any interrupt context, it's preferrable to use ``snd_pcm_period_elapsed()`` instead
* since lock of PCM substream should be acquired in advance.
*
* Developer should pay enough attention that some callbacks in &snd_pcm_ops are done by the call of
* function:
*
* - .pointer - to retrieve current position of audio data transmission by frame count or XRUN state.
* - .trigger - with SNDRV_PCM_TRIGGER_STOP at XRUN or DRAINING state.
* - .get_time_info - to retrieve audio time stamp if needed.
*
* Even if more than one periods have elapsed since the last call, you have to call this only once.
*/
void snd_pcm_period_elapsed_under_stream_lock(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime;
if (PCM_RUNTIME_CHECK(substream))
return;
runtime = substream->runtime;
if (!snd_pcm_running(substream) ||
snd_pcm_update_hw_ptr0(substream, 1) < 0)
goto _end;
#ifdef CONFIG_SND_PCM_TIMER
if (substream->timer_running)
snd_timer_interrupt(substream->timer, 1);
#endif
_end:
snd_kill_fasync(runtime->fasync, SIGIO, POLL_IN);
}
EXPORT_SYMBOL(snd_pcm_period_elapsed_under_stream_lock);
/**
* snd_pcm_period_elapsed() - update the status of runtime for the next period by acquiring lock of
* PCM substream.
* @substream: the instance of PCM substream.
*
* This function is mostly similar to ``snd_pcm_period_elapsed_under_stream_lock()`` except for
* acquiring lock of PCM substream voluntarily.
*
* It's typically called by any type of IRQ handler when hardware IRQ occurs to notify event that
* the batch of audio data frames as the same size as the period of buffer is already processed in
* audio data transmission.
*/
void snd_pcm_period_elapsed(struct snd_pcm_substream *substream)
{
unsigned long flags;
if (snd_BUG_ON(!substream))
return;
snd_pcm_stream_lock_irqsave(substream, flags);
snd_pcm_period_elapsed_under_stream_lock(substream);
snd_pcm_stream_unlock_irqrestore(substream, flags);
}
EXPORT_SYMBOL(snd_pcm_period_elapsed);
/*
* Wait until avail_min data becomes available
* Returns a negative error code if any error occurs during operation.
* The available space is stored on availp. When err = 0 and avail = 0
* on the capture stream, it indicates the stream is in DRAINING state.
*/
static int wait_for_avail(struct snd_pcm_substream *substream,
snd_pcm_uframes_t *availp)
{
struct snd_pcm_runtime *runtime = substream->runtime;
int is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
wait_queue_entry_t wait;
int err = 0;
snd_pcm_uframes_t avail = 0;
long wait_time, tout;
ALSA: pcm - fix race condition in wait_for_avail() wait_for_avail() in pcm_lib.c has a race in it (observed in practice by an Intel validation group). The function is supposed to return once space in the buffer has become available, or if some timeout happens. The entity that creates space (irq handler of sound driver and some such) will do a wake up on a waitqueue that this function registers for. However there are two races in the existing code 1) If space became available between the caller noticing there was no space and this function actually sleeping, the wakeup is missed and the timeout condition will happen instead 2) If a wakeup happened but not sufficient space became available, the code will loop again and wait for more space. However, if the second wake comes in prior to hitting the schedule_timeout_interruptible(), it will be missed, and potentially you'll wait out until the timeout happens. The fix consists of using more careful setting of the current state (so that if a wakeup happens in the main loop window, the schedule_timeout() falls through) and by checking for available space prior to going into the schedule_timeout() loop, but after being on the waitqueue and having the state set to interruptible. [tiwai: the following changes have been added to Arjan's original patch: - merged akpm's fix for waitqueue adding order into a single patch - reduction of duplicated code of avail check ] Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: <stable@kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2011-09-15 10:49:25 +04:00
init_waitqueue_entry(&wait, current);
set_current_state(TASK_INTERRUPTIBLE);
add_wait_queue(&runtime->tsleep, &wait);
if (runtime->no_period_wakeup)
wait_time = MAX_SCHEDULE_TIMEOUT;
else {
/* use wait time from substream if available */
if (substream->wait_time) {
wait_time = substream->wait_time;
} else {
wait_time = 100;
if (runtime->rate) {
long t = runtime->buffer_size * 1100 / runtime->rate;
wait_time = max(t, wait_time);
}
}
wait_time = msecs_to_jiffies(wait_time);
}
ALSA: pcm - fix race condition in wait_for_avail() wait_for_avail() in pcm_lib.c has a race in it (observed in practice by an Intel validation group). The function is supposed to return once space in the buffer has become available, or if some timeout happens. The entity that creates space (irq handler of sound driver and some such) will do a wake up on a waitqueue that this function registers for. However there are two races in the existing code 1) If space became available between the caller noticing there was no space and this function actually sleeping, the wakeup is missed and the timeout condition will happen instead 2) If a wakeup happened but not sufficient space became available, the code will loop again and wait for more space. However, if the second wake comes in prior to hitting the schedule_timeout_interruptible(), it will be missed, and potentially you'll wait out until the timeout happens. The fix consists of using more careful setting of the current state (so that if a wakeup happens in the main loop window, the schedule_timeout() falls through) and by checking for available space prior to going into the schedule_timeout() loop, but after being on the waitqueue and having the state set to interruptible. [tiwai: the following changes have been added to Arjan's original patch: - merged akpm's fix for waitqueue adding order into a single patch - reduction of duplicated code of avail check ] Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: <stable@kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2011-09-15 10:49:25 +04:00
for (;;) {
if (signal_pending(current)) {
err = -ERESTARTSYS;
break;
}
ALSA: pcm - fix race condition in wait_for_avail() wait_for_avail() in pcm_lib.c has a race in it (observed in practice by an Intel validation group). The function is supposed to return once space in the buffer has become available, or if some timeout happens. The entity that creates space (irq handler of sound driver and some such) will do a wake up on a waitqueue that this function registers for. However there are two races in the existing code 1) If space became available between the caller noticing there was no space and this function actually sleeping, the wakeup is missed and the timeout condition will happen instead 2) If a wakeup happened but not sufficient space became available, the code will loop again and wait for more space. However, if the second wake comes in prior to hitting the schedule_timeout_interruptible(), it will be missed, and potentially you'll wait out until the timeout happens. The fix consists of using more careful setting of the current state (so that if a wakeup happens in the main loop window, the schedule_timeout() falls through) and by checking for available space prior to going into the schedule_timeout() loop, but after being on the waitqueue and having the state set to interruptible. [tiwai: the following changes have been added to Arjan's original patch: - merged akpm's fix for waitqueue adding order into a single patch - reduction of duplicated code of avail check ] Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: <stable@kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2011-09-15 10:49:25 +04:00
/*
* We need to check if space became available already
* (and thus the wakeup happened already) first to close
* the race of space already having become available.
* This check must happen after been added to the waitqueue
* and having current state be INTERRUPTIBLE.
*/
avail = snd_pcm_avail(substream);
ALSA: pcm - fix race condition in wait_for_avail() wait_for_avail() in pcm_lib.c has a race in it (observed in practice by an Intel validation group). The function is supposed to return once space in the buffer has become available, or if some timeout happens. The entity that creates space (irq handler of sound driver and some such) will do a wake up on a waitqueue that this function registers for. However there are two races in the existing code 1) If space became available between the caller noticing there was no space and this function actually sleeping, the wakeup is missed and the timeout condition will happen instead 2) If a wakeup happened but not sufficient space became available, the code will loop again and wait for more space. However, if the second wake comes in prior to hitting the schedule_timeout_interruptible(), it will be missed, and potentially you'll wait out until the timeout happens. The fix consists of using more careful setting of the current state (so that if a wakeup happens in the main loop window, the schedule_timeout() falls through) and by checking for available space prior to going into the schedule_timeout() loop, but after being on the waitqueue and having the state set to interruptible. [tiwai: the following changes have been added to Arjan's original patch: - merged akpm's fix for waitqueue adding order into a single patch - reduction of duplicated code of avail check ] Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: <stable@kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2011-09-15 10:49:25 +04:00
if (avail >= runtime->twake)
break;
snd_pcm_stream_unlock_irq(substream);
ALSA: pcm - fix race condition in wait_for_avail() wait_for_avail() in pcm_lib.c has a race in it (observed in practice by an Intel validation group). The function is supposed to return once space in the buffer has become available, or if some timeout happens. The entity that creates space (irq handler of sound driver and some such) will do a wake up on a waitqueue that this function registers for. However there are two races in the existing code 1) If space became available between the caller noticing there was no space and this function actually sleeping, the wakeup is missed and the timeout condition will happen instead 2) If a wakeup happened but not sufficient space became available, the code will loop again and wait for more space. However, if the second wake comes in prior to hitting the schedule_timeout_interruptible(), it will be missed, and potentially you'll wait out until the timeout happens. The fix consists of using more careful setting of the current state (so that if a wakeup happens in the main loop window, the schedule_timeout() falls through) and by checking for available space prior to going into the schedule_timeout() loop, but after being on the waitqueue and having the state set to interruptible. [tiwai: the following changes have been added to Arjan's original patch: - merged akpm's fix for waitqueue adding order into a single patch - reduction of duplicated code of avail check ] Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: <stable@kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2011-09-15 10:49:25 +04:00
tout = schedule_timeout(wait_time);
snd_pcm_stream_lock_irq(substream);
ALSA: pcm - fix race condition in wait_for_avail() wait_for_avail() in pcm_lib.c has a race in it (observed in practice by an Intel validation group). The function is supposed to return once space in the buffer has become available, or if some timeout happens. The entity that creates space (irq handler of sound driver and some such) will do a wake up on a waitqueue that this function registers for. However there are two races in the existing code 1) If space became available between the caller noticing there was no space and this function actually sleeping, the wakeup is missed and the timeout condition will happen instead 2) If a wakeup happened but not sufficient space became available, the code will loop again and wait for more space. However, if the second wake comes in prior to hitting the schedule_timeout_interruptible(), it will be missed, and potentially you'll wait out until the timeout happens. The fix consists of using more careful setting of the current state (so that if a wakeup happens in the main loop window, the schedule_timeout() falls through) and by checking for available space prior to going into the schedule_timeout() loop, but after being on the waitqueue and having the state set to interruptible. [tiwai: the following changes have been added to Arjan's original patch: - merged akpm's fix for waitqueue adding order into a single patch - reduction of duplicated code of avail check ] Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: <stable@kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2011-09-15 10:49:25 +04:00
set_current_state(TASK_INTERRUPTIBLE);
switch (runtime->state) {
case SNDRV_PCM_STATE_SUSPENDED:
err = -ESTRPIPE;
goto _endloop;
case SNDRV_PCM_STATE_XRUN:
err = -EPIPE;
goto _endloop;
case SNDRV_PCM_STATE_DRAINING:
if (is_playback)
err = -EPIPE;
else
avail = 0; /* indicate draining */
goto _endloop;
case SNDRV_PCM_STATE_OPEN:
case SNDRV_PCM_STATE_SETUP:
case SNDRV_PCM_STATE_DISCONNECTED:
err = -EBADFD;
goto _endloop;
case SNDRV_PCM_STATE_PAUSED:
continue;
}
if (!tout) {
pcm_dbg(substream->pcm,
"%s timeout (DMA or IRQ trouble?)\n",
is_playback ? "playback write" : "capture read");
err = -EIO;
break;
}
}
_endloop:
ALSA: pcm - fix race condition in wait_for_avail() wait_for_avail() in pcm_lib.c has a race in it (observed in practice by an Intel validation group). The function is supposed to return once space in the buffer has become available, or if some timeout happens. The entity that creates space (irq handler of sound driver and some such) will do a wake up on a waitqueue that this function registers for. However there are two races in the existing code 1) If space became available between the caller noticing there was no space and this function actually sleeping, the wakeup is missed and the timeout condition will happen instead 2) If a wakeup happened but not sufficient space became available, the code will loop again and wait for more space. However, if the second wake comes in prior to hitting the schedule_timeout_interruptible(), it will be missed, and potentially you'll wait out until the timeout happens. The fix consists of using more careful setting of the current state (so that if a wakeup happens in the main loop window, the schedule_timeout() falls through) and by checking for available space prior to going into the schedule_timeout() loop, but after being on the waitqueue and having the state set to interruptible. [tiwai: the following changes have been added to Arjan's original patch: - merged akpm's fix for waitqueue adding order into a single patch - reduction of duplicated code of avail check ] Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: <stable@kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2011-09-15 10:49:25 +04:00
set_current_state(TASK_RUNNING);
remove_wait_queue(&runtime->tsleep, &wait);
*availp = avail;
return err;
}
typedef int (*pcm_transfer_f)(struct snd_pcm_substream *substream,
int channel, unsigned long hwoff,
void *buf, unsigned long bytes);
typedef int (*pcm_copy_f)(struct snd_pcm_substream *, snd_pcm_uframes_t, void *,
snd_pcm_uframes_t, snd_pcm_uframes_t, pcm_transfer_f);
/* calculate the target DMA-buffer position to be written/read */
static void *get_dma_ptr(struct snd_pcm_runtime *runtime,
int channel, unsigned long hwoff)
{
return runtime->dma_area + hwoff +
channel * (runtime->dma_bytes / runtime->channels);
}
/* default copy_user ops for write; used for both interleaved and non- modes */
static int default_write_copy(struct snd_pcm_substream *substream,
int channel, unsigned long hwoff,
void *buf, unsigned long bytes)
{
if (copy_from_user(get_dma_ptr(substream->runtime, channel, hwoff),
(void __user *)buf, bytes))
return -EFAULT;
return 0;
}
/* default copy_kernel ops for write */
static int default_write_copy_kernel(struct snd_pcm_substream *substream,
int channel, unsigned long hwoff,
void *buf, unsigned long bytes)
{
memcpy(get_dma_ptr(substream->runtime, channel, hwoff), buf, bytes);
return 0;
}
/* fill silence instead of copy data; called as a transfer helper
* from __snd_pcm_lib_write() or directly from noninterleaved_copy() when
* a NULL buffer is passed
*/
static int fill_silence(struct snd_pcm_substream *substream, int channel,
unsigned long hwoff, void *buf, unsigned long bytes)
{
struct snd_pcm_runtime *runtime = substream->runtime;
if (substream->stream != SNDRV_PCM_STREAM_PLAYBACK)
return 0;
if (substream->ops->fill_silence)
return substream->ops->fill_silence(substream, channel,
hwoff, bytes);
snd_pcm_format_set_silence(runtime->format,
get_dma_ptr(runtime, channel, hwoff),
bytes_to_samples(runtime, bytes));
return 0;
}
/* default copy_user ops for read; used for both interleaved and non- modes */
static int default_read_copy(struct snd_pcm_substream *substream,
int channel, unsigned long hwoff,
void *buf, unsigned long bytes)
{
if (copy_to_user((void __user *)buf,
get_dma_ptr(substream->runtime, channel, hwoff),
bytes))
return -EFAULT;
return 0;
}
/* default copy_kernel ops for read */
static int default_read_copy_kernel(struct snd_pcm_substream *substream,
int channel, unsigned long hwoff,
void *buf, unsigned long bytes)
{
memcpy(buf, get_dma_ptr(substream->runtime, channel, hwoff), bytes);
return 0;
}
/* call transfer function with the converted pointers and sizes;
* for interleaved mode, it's one shot for all samples
*/
static int interleaved_copy(struct snd_pcm_substream *substream,
snd_pcm_uframes_t hwoff, void *data,
snd_pcm_uframes_t off,
snd_pcm_uframes_t frames,
pcm_transfer_f transfer)
{
struct snd_pcm_runtime *runtime = substream->runtime;
/* convert to bytes */
hwoff = frames_to_bytes(runtime, hwoff);
off = frames_to_bytes(runtime, off);
frames = frames_to_bytes(runtime, frames);
return transfer(substream, 0, hwoff, data + off, frames);
}
/* call transfer function with the converted pointers and sizes for each
* non-interleaved channel; when buffer is NULL, silencing instead of copying
*/
static int noninterleaved_copy(struct snd_pcm_substream *substream,
snd_pcm_uframes_t hwoff, void *data,
snd_pcm_uframes_t off,
snd_pcm_uframes_t frames,
pcm_transfer_f transfer)
{
struct snd_pcm_runtime *runtime = substream->runtime;
int channels = runtime->channels;
void **bufs = data;
int c, err;
/* convert to bytes; note that it's not frames_to_bytes() here.
* in non-interleaved mode, we copy for each channel, thus
* each copy is n_samples bytes x channels = whole frames.
*/
off = samples_to_bytes(runtime, off);
frames = samples_to_bytes(runtime, frames);
hwoff = samples_to_bytes(runtime, hwoff);
for (c = 0; c < channels; ++c, ++bufs) {
if (!data || !*bufs)
err = fill_silence(substream, c, hwoff, NULL, frames);
else
err = transfer(substream, c, hwoff, *bufs + off,
frames);
if (err < 0)
return err;
}
return 0;
}
/* fill silence on the given buffer position;
* called from snd_pcm_playback_silence()
*/
static int fill_silence_frames(struct snd_pcm_substream *substream,
snd_pcm_uframes_t off, snd_pcm_uframes_t frames)
{
if (substream->runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
substream->runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED)
return interleaved_copy(substream, off, NULL, 0, frames,
fill_silence);
else
return noninterleaved_copy(substream, off, NULL, 0, frames,
fill_silence);
}
/* sanity-check for read/write methods */
static int pcm_sanity_check(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime;
if (PCM_RUNTIME_CHECK(substream))
return -ENXIO;
runtime = substream->runtime;
if (snd_BUG_ON(!substream->ops->copy_user && !runtime->dma_area))
return -EINVAL;
if (runtime->state == SNDRV_PCM_STATE_OPEN)
return -EBADFD;
return 0;
}
static int pcm_accessible_state(struct snd_pcm_runtime *runtime)
{
switch (runtime->state) {
case SNDRV_PCM_STATE_PREPARED:
case SNDRV_PCM_STATE_RUNNING:
case SNDRV_PCM_STATE_PAUSED:
return 0;
case SNDRV_PCM_STATE_XRUN:
return -EPIPE;
case SNDRV_PCM_STATE_SUSPENDED:
return -ESTRPIPE;
default:
return -EBADFD;
}
}
/* update to the given appl_ptr and call ack callback if needed;
* when an error is returned, take back to the original value
*/
int pcm_lib_apply_appl_ptr(struct snd_pcm_substream *substream,
snd_pcm_uframes_t appl_ptr)
{
struct snd_pcm_runtime *runtime = substream->runtime;
snd_pcm_uframes_t old_appl_ptr = runtime->control->appl_ptr;
snd_pcm_sframes_t diff;
int ret;
if (old_appl_ptr == appl_ptr)
return 0;
if (appl_ptr >= runtime->boundary)
return -EINVAL;
/*
* check if a rewind is requested by the application
*/
if (substream->runtime->info & SNDRV_PCM_INFO_NO_REWINDS) {
diff = appl_ptr - old_appl_ptr;
if (diff >= 0) {
if (diff > runtime->buffer_size)
return -EINVAL;
} else {
if (runtime->boundary + diff > runtime->buffer_size)
return -EINVAL;
}
}
runtime->control->appl_ptr = appl_ptr;
if (substream->ops->ack) {
ret = substream->ops->ack(substream);
if (ret < 0) {
runtime->control->appl_ptr = old_appl_ptr;
if (ret == -EPIPE)
__snd_pcm_xrun(substream);
return ret;
}
}
ALSA: pcm: add 'applptr' event of tracepoint In design of ALSA PCM core, status and control data for runtime of ALSA PCM substream are shared between kernel/user spaces by page frame mapping with read-only attribute. Both of hardware-side and application-side position on PCM buffer are maintained as a part of the status data. In a view of ALSA PCM application, these two positions can be updated by executing ioctl(2) with some commands. There's an event of tracepoint for hardware-side position; 'hwptr'. On the other hand, no events for application-side position. This commit adds a new event for this purpose; 'applptr'. When the application-side position is changed in kernel space, this event is probed with useful information for developers. I note that the event is not probed for all of ALSA PCM applications, When applications are written by read/write programming scenario, the event is surely probed. The applications execute ioctl(2) with SNDRV_PCM_IOCTL_[READ|WRITE][N/I]_FRAMES to read/write any PCM frame, then ALSA PCM core updates the application-side position in kernel land. However, when applications are written by mmap programming scenario, if maintaining the application side position in kernel space accurately, applications should voluntarily execute ioctl(2) with SNDRV_PCM_IOCTL_SYNC_PTR to commit the number of handled PCM frames. If not voluntarily, the application-side position is not changed, thus the added event is not probed. There's a loophole, using architectures to which ALSA PCM core judges non cache coherent. In this case, the status and control data is not mapped into processe's VMA for any applications. Userland library, alsa-lib, is programmed for this case. It executes ioctl(2) with SNDRV_PCM_IOCTL_SYNC_PTR command every time to requiring the status and control data. ARM is such an architecture. Below is an example with serial sound interface (ssi) on i.mx6 quad core SoC. I use v4.1 kernel released by fsl-community with patches from VIA Tech. Inc. for VAB820, and my backport patches for relevant features for this patchset. I use Ubuntu 17.04 from ports.ubuntu.com as user land for armhf architecture. $ aplay -v -M -D hw:imx6vab820sgtl5,0 /dev/urandom -f S16_LE -r 48000 --period-size=128 --buffer-size=256 Playing raw data '/dev/urandom' : Signed 16 bit Little Endian, Rate 48000 Hz, Mono Hardware PCM card 0 'imx6-vab820-sgtl5000' device 0 subdevice 0 Its setup is: stream : PLAYBACK access : MMAP_INTERLEAVED format : S16_LE subformat : STD channels : 1 rate : 48000 exact rate : 48000 (48000/1) msbits : 16 buffer_size : 256 period_size : 128 period_time : 2666 tstamp_mode : NONE tstamp_type : MONOTONIC period_step : 1 avail_min : 128 period_event : 0 start_threshold : 256 stop_threshold : 256 silence_threshold: 0 silence_size : 0 boundary : 1073741824 appl_ptr : 0 hw_ptr : 0 mmap_area[0] = 0x76f98000,0,16 (16) $ trace-cmd record -e snd_pcm:hwptr -e snd_pcm:applptr $ trace-cmd report ... 60.208495: applptr: pcmC0D0p/sub0: prev=1792, curr=1792, avail=0, period=128, buf=256 60.208633: applptr: pcmC0D0p/sub0: prev=1792, curr=1792, avail=0, period=128, buf=256 60.210022: hwptr: pcmC0D0p/sub0: IRQ: pos=128, old=1536, base=1536, period=128, buf=256 60.210202: applptr: pcmC0D0p/sub0: prev=1792, curr=1792, avail=128, period=128, buf=256 60.210344: hwptr: pcmC0D0p/sub0: POS: pos=128, old=1664, base=1536, period=128, buf=256 60.210348: applptr: pcmC0D0p/sub0: prev=1792, curr=1792, avail=128, period=128, buf=256 60.210486: applptr: pcmC0D0p/sub0: prev=1792, curr=1792, avail=128, period=128, buf=256 60.210626: applptr: pcmC0D0p/sub0: prev=1792, curr=1920, avail=0, period=128, buf=256 60.211002: applptr: pcmC0D0p/sub0: prev=1920, curr=1920, avail=0, period=128, buf=256 60.211142: hwptr: pcmC0D0p/sub0: POS: pos=128, old=1664, base=1536, period=128, buf=256 60.211146: applptr: pcmC0D0p/sub0: prev=1920, curr=1920, avail=0, period=128, buf=256 60.211287: applptr: pcmC0D0p/sub0: prev=1920, curr=1920, avail=0, period=128, buf=256 60.212690: hwptr: pcmC0D0p/sub0: IRQ: pos=0, old=1664, base=1536, period=128, buf=256 60.212866: applptr: pcmC0D0p/sub0: prev=1920, curr=1920, avail=128, period=128, buf=256 60.212999: hwptr: pcmC0D0p/sub0: POS: pos=0, old=1792, base=1792, period=128, buf=256 60.213003: applptr: pcmC0D0p/sub0: prev=1920, curr=1920, avail=128, period=128, buf=256 60.213135: applptr: pcmC0D0p/sub0: prev=1920, curr=1920, avail=128, period=128, buf=256 60.213276: applptr: pcmC0D0p/sub0: prev=1920, curr=2048, avail=0, period=128, buf=256 60.213654: applptr: pcmC0D0p/sub0: prev=2048, curr=2048, avail=0, period=128, buf=256 60.213796: hwptr: pcmC0D0p/sub0: POS: pos=0, old=1792, base=1792, period=128, buf=256 60.213800: applptr: pcmC0D0p/sub0: prev=2048, curr=2048, avail=0, period=128, buf=256 60.213937: applptr: pcmC0D0p/sub0: prev=2048, curr=2048, avail=0, period=128, buf=256 60.215356: hwptr: pcmC0D0p/sub0: IRQ: pos=128, old=1792, base=1792, period=128, buf=256 60.215542: applptr: pcmC0D0p/sub0: prev=2048, curr=2048, avail=128, period=128, buf=256 60.215679: hwptr: pcmC0D0p/sub0: POS: pos=128, old=1920, base=1792, period=128, buf=256 60.215683: applptr: pcmC0D0p/sub0: prev=2048, curr=2048, avail=128, period=128, buf=256 60.215813: applptr: pcmC0D0p/sub0: prev=2048, curr=2048, avail=128, period=128, buf=256 60.215947: applptr: pcmC0D0p/sub0: prev=2048, curr=2176, avail=0, period=128, buf=256 ... We can surely see 'applptr' event is probed even if the application run for mmap programming scenario ('-M' option and 'hw' plugin). Below is a result of strace: 02:44:15.886382 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.887203 poll([{fd=4, events=POLLOUT|POLLERR|POLLNVAL}], 1, -1) = 1 ([{fd=4, revents=POLLOUT}]) 02:44:15.887471 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.887637 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.887805 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.887969 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.888132 read(3, "..."..., 256) = 256 02:44:15.889040 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.889221 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.889431 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.889606 poll([{fd=4, events=POLLOUT|POLLERR|POLLNVAL}], 1, -1) = 1 ([{fd=4, revents=POLLOUT}]) 02:44:15.889833 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.889998 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.890164 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.891048 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.891228 read(3, "..."..., 256) = 256 02:44:15.891497 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.891661 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.891829 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 02:44:15.891991 poll([{fd=4, events=POLLOUT|POLLERR|POLLNVAL}], 1, -1) = 1 ([{fd=4, revents=POLLOUT}]) 02:44:15.893007 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0 We can see 7 calls of ioctl(2) with SNDRV_PCM_IOCTL_SYNC_PTR per loop with call of poll(2). 128 PCM frames are transferred per loop of one poll(2), because the PCM substream is configured with S16_LE format and 1 channel (2 byte * 1 * 128 = 256 bytes). This equals to the size of period of PCM buffer. Comparing to the probed data, one of the 7 calls of ioctl(2) is actually used to commit the number of copied PCM frames to kernel space. The other calls are just used to check runtime status of PCM substream; e.g. XRUN. The tracepoint event is useful to investigate this case. I note that below modules are related to the above sample. * snd-soc-dummy.ko * snd-soc-imx-sgtl5000.ko * snd-soc-fsl-ssi.ko * snd-soc-imx-pcm-dma.ko * snd-soc-sgtl5000.ko My additional note is lock acquisition. The event is probed under acquiring PCM stream lock. This means that calculation in the event is free from any hardware events. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-06-12 03:41:45 +03:00
trace_applptr(substream, old_appl_ptr, appl_ptr);
return 0;
}
/* the common loop for read/write data */
snd_pcm_sframes_t __snd_pcm_lib_xfer(struct snd_pcm_substream *substream,
void *data, bool interleaved,
snd_pcm_uframes_t size, bool in_kernel)
{
struct snd_pcm_runtime *runtime = substream->runtime;
snd_pcm_uframes_t xfer = 0;
snd_pcm_uframes_t offset = 0;
snd_pcm_uframes_t avail;
pcm_copy_f writer;
pcm_transfer_f transfer;
bool nonblock;
bool is_playback;
int err;
err = pcm_sanity_check(substream);
if (err < 0)
return err;
is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
if (interleaved) {
if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
runtime->channels > 1)
return -EINVAL;
writer = interleaved_copy;
} else {
if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
return -EINVAL;
writer = noninterleaved_copy;
}
if (!data) {
if (is_playback)
transfer = fill_silence;
else
return -EINVAL;
} else if (in_kernel) {
if (substream->ops->copy_kernel)
transfer = substream->ops->copy_kernel;
else
transfer = is_playback ?
default_write_copy_kernel : default_read_copy_kernel;
} else {
if (substream->ops->copy_user)
transfer = (pcm_transfer_f)substream->ops->copy_user;
else
transfer = is_playback ?
default_write_copy : default_read_copy;
}
if (size == 0)
return 0;
nonblock = !!(substream->f_flags & O_NONBLOCK);
snd_pcm_stream_lock_irq(substream);
err = pcm_accessible_state(runtime);
if (err < 0)
goto _end_unlock;
runtime->twake = runtime->control->avail_min ? : 1;
if (runtime->state == SNDRV_PCM_STATE_RUNNING)
snd_pcm_update_hw_ptr(substream);
/*
* If size < start_threshold, wait indefinitely. Another
* thread may start capture
*/
if (!is_playback &&
runtime->state == SNDRV_PCM_STATE_PREPARED &&
size >= runtime->start_threshold) {
err = snd_pcm_start(substream);
if (err < 0)
goto _end_unlock;
}
avail = snd_pcm_avail(substream);
while (size > 0) {
snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
snd_pcm_uframes_t cont;
if (!avail) {
if (!is_playback &&
runtime->state == SNDRV_PCM_STATE_DRAINING) {
snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
goto _end_unlock;
}
if (nonblock) {
err = -EAGAIN;
goto _end_unlock;
}
runtime->twake = min_t(snd_pcm_uframes_t, size,
runtime->control->avail_min ? : 1);
err = wait_for_avail(substream, &avail);
if (err < 0)
goto _end_unlock;
if (!avail)
continue; /* draining */
}
frames = size > avail ? avail : size;
appl_ptr = READ_ONCE(runtime->control->appl_ptr);
appl_ofs = appl_ptr % runtime->buffer_size;
cont = runtime->buffer_size - appl_ofs;
if (frames > cont)
frames = cont;
if (snd_BUG_ON(!frames)) {
err = -EINVAL;
goto _end_unlock;
}
ALSA: pcm: Fix potential AB/BA lock with buffer_mutex and mmap_lock syzbot caught a potential deadlock between the PCM runtime->buffer_mutex and the mm->mmap_lock. It was brought by the recent fix to cover the racy read/write and other ioctls, and in that commit, I overlooked a (hopefully only) corner case that may take the revert lock, namely, the OSS mmap. The OSS mmap operation exceptionally allows to re-configure the parameters inside the OSS mmap syscall, where mm->mmap_mutex is already held. Meanwhile, the copy_from/to_user calls at read/write operations also take the mm->mmap_lock internally, hence it may lead to a AB/BA deadlock. A similar problem was already seen in the past and we fixed it with a refcount (in commit b248371628aa). The former fix covered only the call paths with OSS read/write and OSS ioctls, while we need to cover the concurrent access via both ALSA and OSS APIs now. This patch addresses the problem above by replacing the buffer_mutex lock in the read/write operations with a refcount similar as we've used for OSS. The new field, runtime->buffer_accessing, keeps the number of concurrent read/write operations. Unlike the former buffer_mutex protection, this protects only around the copy_from/to_user() calls; the other codes are basically protected by the PCM stream lock. The refcount can be a negative, meaning blocked by the ioctls. If a negative value is seen, the read/write aborts with -EBUSY. In the ioctl side, OTOH, they check this refcount, too, and set to a negative value for blocking unless it's already being accessed. Reported-by: syzbot+6e5c88838328e99c7e1c@syzkaller.appspotmail.com Fixes: dca947d4d26d ("ALSA: pcm: Fix races among concurrent read/write and buffer changes") Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/000000000000381a0d05db622a81@google.com Link: https://lore.kernel.org/r/20220330120903.4738-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-03-30 15:09:03 +03:00
if (!atomic_inc_unless_negative(&runtime->buffer_accessing)) {
err = -EBUSY;
goto _end_unlock;
}
snd_pcm_stream_unlock_irq(substream);
ALSA: memalloc: Support for non-contiguous page allocation This patch adds the support for allocation of non-contiguous DMA pages in the common memalloc helper. It's another SG-buffer type, but unlike the existing one, this is directional and requires the explicit sync / invalidation of dirty pages on non-coherent architectures. For this enhancement, the following points are changed: - snd_dma_device stores the DMA direction. - snd_dma_device stores need_sync flag indicating whether the explicit sync is required or not. - A new variant of helper functions, snd_dma_alloc_dir_pages() and *_all() are introduced; the old snd_dma_alloc_pages() and *_all() kept as just wrappers with DMA_BIDIRECTIONAL. - A new helper snd_dma_buffer_sync() is introduced; this gets called in the appropriate places. - A new allocation type, SNDRV_DMA_TYPE_NONCONTIG, is introduced. When the driver allocates pages with this new type, and it may require the SNDRV_PCM_INFO_EXPLICIT_SYNC flag set to the PCM hardware.info for taking the full control of PCM applptr and hwptr changes (that implies disabling the mmap of control/status data). When the buffer allocation is managed by snd_pcm_set_managed_buffer(), this flag is automatically set depending on the result of dma_need_sync() internally. Otherwise, if the buffer is managed manually, the driver has to set the flag explicitly, too. The explicit sync between CPU and device for non-coherent memory is performed at the points before and after read/write transfer as well as the applptr/hwptr syncptr ioctl. In the case of mmap mode, user-space is supposed to call the syncptr ioctl with the hwptr flag to update and fetch the status at first; this corresponds to CPU-sync. Then user-space advances the applptr via syncptr ioctl again with applptr flag, and this corresponds to the device sync with flushing. Other than the DMA direction and the explicit sync, the usage of this new buffer type is almost equivalent with the existing SNDRV_DMA_TYPE_DEV_SG; you can get the page and the address via snd_sgbuf_get_page() and snd_sgbuf_get_addr(), also calculate the continuous pages via snd_sgbuf_get_chunk_size(). For those SG-page handling, the non-contig type shares the same ops with the vmalloc handler. As we do always vmap the SG pages at first, the actual address can be deduced from the vmapped address easily without iterating the SG-list. Link: https://lore.kernel.org/r/20211017074859.24112-2-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-10-17 10:48:57 +03:00
if (!is_playback)
snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_CPU);
err = writer(substream, appl_ofs, data, offset, frames,
transfer);
ALSA: memalloc: Support for non-contiguous page allocation This patch adds the support for allocation of non-contiguous DMA pages in the common memalloc helper. It's another SG-buffer type, but unlike the existing one, this is directional and requires the explicit sync / invalidation of dirty pages on non-coherent architectures. For this enhancement, the following points are changed: - snd_dma_device stores the DMA direction. - snd_dma_device stores need_sync flag indicating whether the explicit sync is required or not. - A new variant of helper functions, snd_dma_alloc_dir_pages() and *_all() are introduced; the old snd_dma_alloc_pages() and *_all() kept as just wrappers with DMA_BIDIRECTIONAL. - A new helper snd_dma_buffer_sync() is introduced; this gets called in the appropriate places. - A new allocation type, SNDRV_DMA_TYPE_NONCONTIG, is introduced. When the driver allocates pages with this new type, and it may require the SNDRV_PCM_INFO_EXPLICIT_SYNC flag set to the PCM hardware.info for taking the full control of PCM applptr and hwptr changes (that implies disabling the mmap of control/status data). When the buffer allocation is managed by snd_pcm_set_managed_buffer(), this flag is automatically set depending on the result of dma_need_sync() internally. Otherwise, if the buffer is managed manually, the driver has to set the flag explicitly, too. The explicit sync between CPU and device for non-coherent memory is performed at the points before and after read/write transfer as well as the applptr/hwptr syncptr ioctl. In the case of mmap mode, user-space is supposed to call the syncptr ioctl with the hwptr flag to update and fetch the status at first; this corresponds to CPU-sync. Then user-space advances the applptr via syncptr ioctl again with applptr flag, and this corresponds to the device sync with flushing. Other than the DMA direction and the explicit sync, the usage of this new buffer type is almost equivalent with the existing SNDRV_DMA_TYPE_DEV_SG; you can get the page and the address via snd_sgbuf_get_page() and snd_sgbuf_get_addr(), also calculate the continuous pages via snd_sgbuf_get_chunk_size(). For those SG-page handling, the non-contig type shares the same ops with the vmalloc handler. As we do always vmap the SG pages at first, the actual address can be deduced from the vmapped address easily without iterating the SG-list. Link: https://lore.kernel.org/r/20211017074859.24112-2-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-10-17 10:48:57 +03:00
if (is_playback)
snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_DEVICE);
snd_pcm_stream_lock_irq(substream);
ALSA: pcm: Fix potential AB/BA lock with buffer_mutex and mmap_lock syzbot caught a potential deadlock between the PCM runtime->buffer_mutex and the mm->mmap_lock. It was brought by the recent fix to cover the racy read/write and other ioctls, and in that commit, I overlooked a (hopefully only) corner case that may take the revert lock, namely, the OSS mmap. The OSS mmap operation exceptionally allows to re-configure the parameters inside the OSS mmap syscall, where mm->mmap_mutex is already held. Meanwhile, the copy_from/to_user calls at read/write operations also take the mm->mmap_lock internally, hence it may lead to a AB/BA deadlock. A similar problem was already seen in the past and we fixed it with a refcount (in commit b248371628aa). The former fix covered only the call paths with OSS read/write and OSS ioctls, while we need to cover the concurrent access via both ALSA and OSS APIs now. This patch addresses the problem above by replacing the buffer_mutex lock in the read/write operations with a refcount similar as we've used for OSS. The new field, runtime->buffer_accessing, keeps the number of concurrent read/write operations. Unlike the former buffer_mutex protection, this protects only around the copy_from/to_user() calls; the other codes are basically protected by the PCM stream lock. The refcount can be a negative, meaning blocked by the ioctls. If a negative value is seen, the read/write aborts with -EBUSY. In the ioctl side, OTOH, they check this refcount, too, and set to a negative value for blocking unless it's already being accessed. Reported-by: syzbot+6e5c88838328e99c7e1c@syzkaller.appspotmail.com Fixes: dca947d4d26d ("ALSA: pcm: Fix races among concurrent read/write and buffer changes") Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/000000000000381a0d05db622a81@google.com Link: https://lore.kernel.org/r/20220330120903.4738-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-03-30 15:09:03 +03:00
atomic_dec(&runtime->buffer_accessing);
if (err < 0)
goto _end_unlock;
err = pcm_accessible_state(runtime);
if (err < 0)
goto _end_unlock;
appl_ptr += frames;
if (appl_ptr >= runtime->boundary)
appl_ptr -= runtime->boundary;
err = pcm_lib_apply_appl_ptr(substream, appl_ptr);
if (err < 0)
goto _end_unlock;
offset += frames;
size -= frames;
xfer += frames;
avail -= frames;
if (is_playback &&
runtime->state == SNDRV_PCM_STATE_PREPARED &&
snd_pcm_playback_hw_avail(runtime) >= (snd_pcm_sframes_t)runtime->start_threshold) {
err = snd_pcm_start(substream);
if (err < 0)
goto _end_unlock;
}
}
_end_unlock:
runtime->twake = 0;
if (xfer > 0 && err >= 0)
snd_pcm_update_state(substream, runtime);
snd_pcm_stream_unlock_irq(substream);
return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
}
EXPORT_SYMBOL(__snd_pcm_lib_xfer);
/*
* standard channel mapping helpers
*/
/* default channel maps for multi-channel playbacks, up to 8 channels */
const struct snd_pcm_chmap_elem snd_pcm_std_chmaps[] = {
{ .channels = 1,
.map = { SNDRV_CHMAP_MONO } },
{ .channels = 2,
.map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
{ .channels = 4,
.map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
{ .channels = 6,
.map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE } },
{ .channels = 8,
.map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
{ }
};
EXPORT_SYMBOL_GPL(snd_pcm_std_chmaps);
/* alternative channel maps with CLFE <-> surround swapped for 6/8 channels */
const struct snd_pcm_chmap_elem snd_pcm_alt_chmaps[] = {
{ .channels = 1,
.map = { SNDRV_CHMAP_MONO } },
{ .channels = 2,
.map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
{ .channels = 4,
.map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
{ .channels = 6,
.map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
{ .channels = 8,
.map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
{ }
};
EXPORT_SYMBOL_GPL(snd_pcm_alt_chmaps);
static bool valid_chmap_channels(const struct snd_pcm_chmap *info, int ch)
{
if (ch > info->max_channels)
return false;
return !info->channel_mask || (info->channel_mask & (1U << ch));
}
static int pcm_chmap_ctl_info(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_info *uinfo)
{
struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
uinfo->count = info->max_channels;
uinfo->value.integer.min = 0;
uinfo->value.integer.max = SNDRV_CHMAP_LAST;
return 0;
}
/* get callback for channel map ctl element
* stores the channel position firstly matching with the current channels
*/
static int pcm_chmap_ctl_get(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *ucontrol)
{
struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
struct snd_pcm_substream *substream;
const struct snd_pcm_chmap_elem *map;
if (!info->chmap)
return -EINVAL;
substream = snd_pcm_chmap_substream(info, idx);
if (!substream)
return -ENODEV;
memset(ucontrol->value.integer.value, 0,
ALSA: control: Add verification for kctl accesses The current implementation of ALSA control API fully relies on the callbacks of each driver, and there is no verification of the values passed via API. This patch is an attempt to improve the situation slightly by adding the validation code for the values stored via info and get callbacks. The patch adds a new kconfig, CONFIG_SND_CTL_VALIDATION. It depends on CONFIG_SND_DEBUG and off as default since the validation would require a slight overhead including the additional call of info callback at each get callback invocation. When this config is enabled, the values stored by each info callback invocation are verified, namely: - Whether the info type is valid - Whether the number of enum items is non-zero - Whether the given info count is within the allowed boundary Similarly, the values stored at each get callback are verified as well: - Whether the values are within the given range - Whether the values are aligned with the given step - Whether any further changes are seen in the data array over the given info count The last point helps identifying a possibly invalid data type access, typically a case where the info callback declares the type being SNDRV_CTL_ELEM_TYPE_ENUMERATED while the get/put callbacks store the values in value.integer.value[] array. When a validation fails, the ALSA core logs an error message including the device and the control ID, and the API call also returns an error. So, with the new validation turned on, the driver behavior difference may be visible on user-space, too -- it's intentional, though, so that we can catch an error more clearly. The patch also introduces a new ctl access type, SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK. A driver may pass this flag with other access bits to indicate that the ctl element won't be verified. It's useful when a driver code is specially written to access the data greater than info->count size by some reason. For example, this flag is actually set now in HD-audio HDMI codec driver which needs to clear the data array in the case of the disconnected monitor. Also, the PCM channel-map helper code is slightly modified to avoid the false-positive hit by this validation code, too. Link: https://lore.kernel.org/r/20200104083556.27789-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-01-04 11:35:56 +03:00
sizeof(long) * info->max_channels);
if (!substream->runtime)
return 0; /* no channels set */
for (map = info->chmap; map->channels; map++) {
int i;
if (map->channels == substream->runtime->channels &&
valid_chmap_channels(info, map->channels)) {
for (i = 0; i < map->channels; i++)
ucontrol->value.integer.value[i] = map->map[i];
return 0;
}
}
return -EINVAL;
}
/* tlv callback for channel map ctl element
* expands the pre-defined channel maps in a form of TLV
*/
static int pcm_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
unsigned int size, unsigned int __user *tlv)
{
struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
const struct snd_pcm_chmap_elem *map;
unsigned int __user *dst;
int c, count = 0;
if (!info->chmap)
return -EINVAL;
if (size < 8)
return -ENOMEM;
if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
return -EFAULT;
size -= 8;
dst = tlv + 2;
for (map = info->chmap; map->channels; map++) {
int chs_bytes = map->channels * 4;
if (!valid_chmap_channels(info, map->channels))
continue;
if (size < 8)
return -ENOMEM;
if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
put_user(chs_bytes, dst + 1))
return -EFAULT;
dst += 2;
size -= 8;
count += 8;
if (size < chs_bytes)
return -ENOMEM;
size -= chs_bytes;
count += chs_bytes;
for (c = 0; c < map->channels; c++) {
if (put_user(map->map[c], dst))
return -EFAULT;
dst++;
}
}
if (put_user(count, tlv + 1))
return -EFAULT;
return 0;
}
static void pcm_chmap_ctl_private_free(struct snd_kcontrol *kcontrol)
{
struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
info->pcm->streams[info->stream].chmap_kctl = NULL;
kfree(info);
}
/**
* snd_pcm_add_chmap_ctls - create channel-mapping control elements
* @pcm: the assigned PCM instance
* @stream: stream direction
* @chmap: channel map elements (for query)
* @max_channels: the max number of channels for the stream
* @private_value: the value passed to each kcontrol's private_value field
* @info_ret: store struct snd_pcm_chmap instance if non-NULL
*
* Create channel-mapping control elements assigned to the given PCM stream(s).
* Return: Zero if successful, or a negative error value.
*/
int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream,
const struct snd_pcm_chmap_elem *chmap,
int max_channels,
unsigned long private_value,
struct snd_pcm_chmap **info_ret)
{
struct snd_pcm_chmap *info;
struct snd_kcontrol_new knew = {
.iface = SNDRV_CTL_ELEM_IFACE_PCM,
.access = SNDRV_CTL_ELEM_ACCESS_READ |
SNDRV_CTL_ELEM_ACCESS_TLV_READ |
SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK,
.info = pcm_chmap_ctl_info,
.get = pcm_chmap_ctl_get,
.tlv.c = pcm_chmap_ctl_tlv,
};
int err;
if (WARN_ON(pcm->streams[stream].chmap_kctl))
return -EBUSY;
info = kzalloc(sizeof(*info), GFP_KERNEL);
if (!info)
return -ENOMEM;
info->pcm = pcm;
info->stream = stream;
info->chmap = chmap;
info->max_channels = max_channels;
if (stream == SNDRV_PCM_STREAM_PLAYBACK)
knew.name = "Playback Channel Map";
else
knew.name = "Capture Channel Map";
knew.device = pcm->device;
knew.count = pcm->streams[stream].substream_count;
knew.private_value = private_value;
info->kctl = snd_ctl_new1(&knew, info);
if (!info->kctl) {
kfree(info);
return -ENOMEM;
}
info->kctl->private_free = pcm_chmap_ctl_private_free;
err = snd_ctl_add(pcm->card, info->kctl);
if (err < 0)
return err;
pcm->streams[stream].chmap_kctl = info->kctl;
if (info_ret)
*info_ret = info;
return 0;
}
EXPORT_SYMBOL_GPL(snd_pcm_add_chmap_ctls);