The put() operation is expected to return:
1) 0 on success if no changes were made
2) 1 on success if changes were made
3) error code otherwise
Currently 2) is usually ignored when writing control-operations. While
forcing compliance is not an option right now, make it easier for
developers to adhere to the expectations and notice problems by logging
them when CONFIG_SND_CTL_DEBUG is enabled.
Due to large size of struct snd_ctl_elem_value, 'value_buf' is provided
as a reusable buffer for kctl->put() verification. This prevents
exhausting the stack when verifying the operation.
>From user perspective, patch introduces a new trace/events category
'snd_ctl' containing a single 'snd_ctl_put' event type. Log sample:
amixer-1086 [003] ..... 8.035939: snd_ctl_put: success: expected=0, actual=0 for ctl numid=1, iface=MIXER, name='Master Playback Volume', index=0, device=0, subdevice=0, card=0
amixer-1087 [003] ..... 8.938721: snd_ctl_put: success: expected=1, actual=1 for ctl numid=1, iface=MIXER, name='Master Playback Volume', index=0, device=0, subdevice=0, card=0
amixer-1088 [003] ..... 9.631470: snd_ctl_put: success: expected=1, actual=1 for ctl numid=1, iface=MIXER, name='Master Playback Volume', index=0, device=0, subdevice=0, card=0
amixer-1089 [000] ..... 9.636786: snd_ctl_put: fail: expected=1, actual=0 for ctl numid=5, iface=MIXER, name='Loopback Mute', index=0, device=0, subdevice=0, card=0
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260224205619.584795-1-cezary.rojewski@intel.com
This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
Replace the remaining strcpy() and sprintf() usages in the ALSA core
code with the safer versions.
The first strcpy() points actually to card->id, hence just use
strscpy() with card->id instead.
The append of suffix string is slightly rewritten so that we can use
scnprintf() and strscpy().
Only for safety, no actual behavior change.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20250710100727.22653-104-tiwai@suse.de
We'll re-use the existing rwlock for the protection of control list
lookup, too, and now rename it to a more generic name.
This is a preliminary change, only the rename of the struct field
here, no functional changes.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20240809104234.8488-2-tiwai@suse.de
The card-specific debugfs entries are removed at the last stage of
card free phase, and it's performed after synchronization of the
closes of all opened fds. This works fine for most cases, but it can
be potentially problematic for a hotplug device like USB-audio. Due
to the nature of snd_card_free_when_closed(), the card free isn't
called immediately after the driver removal for a hotplug device, but
it's left until the last fd is closed. It implies that the card
debugfs entries also remain. Meanwhile, when a new device is inserted
before the last close and the very same card slot is assigned, the
driver tries to create the card debugfs root again on the very same
path. This conflicts with the remaining entry, and results in the
kernel warning such as:
debugfs: Directory 'card0' with parent 'sound' already present!
with the missing debugfs entry afterwards.
For avoiding such conflicts, remove debugfs entries at the device
disconnection phase instead. The jack kctl debugfs entries get
removed in snd_jack_dev_disconnect() instead of each kctl
private_free.
Fixes: 2d670ea2bd ("ALSA: jack: implement software jack injection via debugfs")
Link: https://lore.kernel.org/r/20240524151256.32521-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
We used '#ifdef MODULE' for judging whether the system supports the
sound module or not, and /proc/asound/modules is created only when
'#ifdef MODULE' is true. The check is not really appropriate, though,
because the flag means only for the sound core and the drivers are
still allowed to be built as modules even if 'MODULE' is not set in
sound/core/init.c.
For fixing the inconsistency, replace those ifdefs with 'ifdef
CONFIG_MODULES'. One place for a NULL module check is rewritten with
IS_MODULE(CONFIG_SND) to be more intuitive. It can't be changed to
CONFIG_MODULES; otherwise it would hit a WARN_ON() incorrectly.
This is a slight behavior change; the modules proc entry appears now
no matter whether the sound core is built-in or not as long as modules
are enabled on the kernel in general. This can't be avoided due to
the nature of kernel builds.
Link: https://lore.kernel.org/r/20240520170349.2417900-1-xu.yang_2@nxp.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Xu Yang <xu.yang_2@nxp.com>
Link: https://lore.kernel.org/r/20240522070442.17786-2-tiwai@suse.de
The commit 81033c6b58 ("ALSA: core: Warn on empty module")
introduced a WARN_ON() for a NULL module pointer passed at snd_card
object creation, and it also wraps the code around it with '#ifdef
MODULE'. This works in most cases, but the devils are always in
details. "MODULE" is defined when the target code (i.e. the sound
core) is built as a module; but this doesn't mean that the caller is
also built-in or not. Namely, when only the sound core is built-in
(CONFIG_SND=y) while the driver is a module (CONFIG_SND_USB_AUDIO=m),
the passed module pointer is ignored even if it's non-NULL, and
card->module remains as NULL. This would result in the missing module
reference up/down at the device open/close, leading to a race with the
code execution after the module removal.
For addressing the bug, move the assignment of card->module again out
of ifdef. The WARN_ON() is still wrapped with ifdef because the
module can be really NULL when all sound drivers are built-in.
Note that we keep 'ifdef MODULE' for WARN_ON(), otherwise it would
lead to a false-positive NULL module check. Admittedly it won't catch
perfectly, i.e. no check is performed when CONFIG_SND=y. But, it's no
real problem as it's only for debugging, and the condition is pretty
rare.
Fixes: 81033c6b58 ("ALSA: core: Warn on empty module")
Reported-by: Xu Yang <xu.yang_2@nxp.com>
Closes: https://lore.kernel.org/r/20240520170349.2417900-1-xu.yang_2@nxp.com
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Xu Yang <xu.yang_2@nxp.com>
Link: https://lore.kernel.org/r/20240522070442.17786-1-tiwai@suse.de
Since the recent code change, the conditional build with CONFIG_PM is
calling only snd_power_sync_ref(). As a dummy function is provided
for this function, we can get rid of CONFIG_PM gracefully now.
Link: https://lore.kernel.org/r/20240510125128.6058-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
In snd_card_disconnect(), we set card->shutdown flag at the beginning,
call callbacks and do sync for card->power_ref_sleep waiters at the
end. The callback may delete a kctl element, and this can lead to a
deadlock when the device was in the suspended state. Namely:
* A process waits for the power up at snd_power_ref_and_wait() in
snd_ctl_info() or read/write() inside card->controls_rwsem.
* The system gets disconnected meanwhile, and the driver tries to
delete a kctl via snd_ctl_remove*(); it tries to take
card->controls_rwsem again, but this is already locked by the
above. Since the sleeper isn't woken up, this deadlocks.
An easy fix is to wake up sleepers before processing the driver
disconnect callbacks but right after setting the card->shutdown flag.
Then all sleepers will abort immediately, and the code flows again.
So, basically this patch moves the wait_event() call at the right
timing. While we're at it, just to be sure, call wait_event_all()
instead of wait_event(), although we don't use exclusive events on
this queue for now.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=218816
Cc: <stable@vger.kernel.org>
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20240510101424.6279-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
There is no need to use temporary string for the debugfs directory name as
we can use the device name of the card.
This change will also fixes the following compiler warning/error (W=1):
sound/core/init.c: In function ‘snd_card_init’:
sound/core/init.c:367:28: error: ‘%d’ directive writing between 1 and 10 bytes into a region of size 4 [-Werror=format-overflow=]
367 | sprintf(name, "card%d", idx);
| ^~
sound/core/init.c:367:23: note: directive argument in the range [0, 2147483646]
367 | sprintf(name, "card%d", idx);
| ^~~~~~~~
sound/core/init.c:367:9: note: ‘sprintf’ output between 6 and 15 bytes into a destination of size 8
367 | sprintf(name, "card%d", idx);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
The idx is guarantied to be less than SNDRV_CARDS (max 256 or 8) by the
code in snd_card_init(), however the compiler does not see that.
The warnings got brought to light by a recent patch upstream:
commit 6d4ab2e97d ("extrawarn: enable format and stringop overflow warnings in W=1")
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Suggested-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Link: https://lore.kernel.org/r/20230912110113.3166-1-peter.ujfalusi@linux.intel.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
All callers from other files ignore the return value of this function.
And it can only ever return a non-zero value if the parameter card is NULL.
Move the check for card being NULL into snd_card_free_when_closed() to keep
the previous behaviour. Note this isn't necessary for
snd_card_disconnect_sync() because if card was NULL in there the dereference
of card for dev_err() would oops the kernel. Replace this by an oops
triggered by the dereference of card for spin_lock_irq().
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Acked-by: Geoff Levand <geoff@infradead.org>
Acked-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20230207191907.467756-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
During the code change to add the support for devres-managed card
instance, we put an explicit kfree(card) call at the error path in
snd_card_new(). This is needed for the early error path before the
card is initialized with the device, but is rather superfluous and
causes a double-free at the error path after the card instance is
initialized, as the destructor of the card object already contains a
kfree() call.
This patch fixes the double-free situation by removing the superfluous
kfree(). Meanwhile we need to call kfree() explicitly for the early
error path, so it's added there instead.
Fixes: e8ad415b7a ("ALSA: core: Add managed card creation")
Reported-by: Rondreis <linhaoguo86@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/CAB7eexL1zBnB636hwS27d-LdPYZ_R1-5fJS_h=ZbCWYU=UPWJg@mail.gmail.com
Link: https://lore.kernel.org/r/20220919123516.28222-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The control elements are managed in a single linked list and we
traverse the whole list for matching each numid or ctl id per every
inquiry of a control element. This is OK-ish for a small number of
elements but obviously it doesn't scale. Especially the matching with
the ctl id takes time because it checks each field of the snd_ctl_id
element, e.g. the name string is matched with strcmp().
This patch adds the hash tables with Xarray for improving the lookup
speed of a control element. There are two xarray tables added to the
card; one for numid and another for ctl id. For the numid, we use the
numid as the index, while for the ctl id, we calculate a hash key.
The lookup is done via a single xa_load() execution. As long as the
given control element is found on the Xarray table, that's fine, we
can give back a quick lookup result. The problem is when no entry
hits on the table, and for this case, we have a slight optimization.
Namely, the driver checks whether we had a collision on Xarray table,
and do a fallback search (linear lookup of the full entries) only if a
hash key collision happened beforehand.
So, in theory, the inquiry for a non-existing element might take still
time even with this patch in a worst case, but this must be pretty
rare.
The feature is enabled via CONFIG_SND_CTL_FAST_LOOKUP, which is turned
on as default. For simplicity, the option can be turned off only when
CONFIG_EXPERT is set ("You are expert? Then you manage 1000 knobs").
Link: https://lore.kernel.org/r/20211028130027.18764-1-tiwai@suse.de
Link: https://lore.kernel.org/r/20220609180504.775-1-tiwai@suse.de
Link: https://lore.kernel.org/all/cover.1653813866.git.quic_rbankapu@quicinc.com/
Link: https://lore.kernel.org/r/20220610064537.18660-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This is a small helper function to handle the error path more easily
when an error happens during the probe for the device with the
device-managed card. Since devres releases in the reverser order of
the creations, usually snd_card_free() gets called at the last in the
probe error path unless it already reached snd_card_register() calls.
Due to this nature, when a driver expects the resource releases in
card->private_free, this might be called too lately.
As a workaround, one should call the probe like:
static int __some_probe(...) { // do real probe.... }
static int some_probe(...)
{
return snd_card_free_on_error(dev, __some_probe(dev, ...));
}
so that the snd_card_free() is called explicitly at the beginning of
the error path from the probe.
This function will be used in the upcoming fixes to address the
regressions by devres usages.
Fixes: e8ad415b7a ("ALSA: core: Add managed card creation")
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220412093141.8008-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Cezary RojewskiandTakashi Iwai
Linus Torvalds
Kees Cook
Jaroslav KyselaandTakashi Iwai
Peter UjfalusiandTakashi Iwai
Ivan OrlovandTakashi Iwai
Uwe Kleine-KönigandTakashi Iwai