kernel/linux.git/sound/core/control_compat.c, branch linux-6.9.y

ALSA: control: Use guard() for locking

2024-02-28T14:01:21+00:00

We can simplify the code gracefully with new guard() macro and co for automatic cleanup of locks. The lops calls under multiple rwsems are factored out as a simple macro, so that it can be called easily from snd_ctl_dev_register() and snd_ctl_dev_disconnect(). There are a few remaining explicit rwsem and spinlock calls, and those are the places where the lock downgrade happens or where the temporary unlock/relocking happens -- which guard() doens't cover well yet. Only the code refactoring, and no functional changes. Signed-off-by: Takashi Iwai Link: https://lore.kernel.org/r/20240227085306.9764-9-tiwai@suse.de

ALSA: control: Use automatic cleanup of kfree()

2024-02-23T09:57:30+00:00

There are common patterns where a temporary buffer is allocated and freed at the exit, and those can be simplified with the recent cleanup mechanism via __free(kfree). A caveat is that some allocations are memdup_user() and they return an error pointer instead of NULL. Those need special cares and the value has to be cleared with no_free_ptr() at the allocation error path. Other than that, the conversions are straightforward. No functional changes, only code refactoring. Signed-off-by: Takashi Iwai Link: https://lore.kernel.org/r/20240222111509.28390-3-tiwai@suse.de

ALSA: control: Replace with __packed attribute

2023-10-26T07:42:43+00:00

Replace the old __attribute__((packed)) with the new __packed. Only cleanup, no functional changes. Link: https://lore.kernel.org/r/20231025132314.5878-2-tiwai@suse.de Signed-off-by: Takashi Iwai

ALSA: control: Introduce unlocked version for snd_ctl_find_*() helpers

2023-07-20T08:03:00+00:00

For reducing the unnecessary use of controls_rwsem in the drivers, this patch adds a new variant for snd_ctl_find_*() helpers: snd_ctl_find_id_locked() and snd_ctl_find_numid_locked() look for a kctl element inside the card->controls_rwsem -- that is, doing the very same as what snd_ctl_find_id() and snd_ctl_find_numid() did until now. snd_ctl_find_id() and snd_ctl_find_numid() remain same, i.e. still unlocked version, but they will be switched to locked version once after all callers are replaced. The patch also replaces the calls of snd_ctl_find_id() and snd_ctl_find_numid() in a few places; all of those are places where we know that the functions are called properly with controls_rwsem held. All others are without rwsem (although they should have been). After this patch, we'll turn on the locking in snd_ctl_find_id() and snd_ctl_find_numid() to be more race-free. Link: https://lore.kernel.org/r/20230718141304.1032-10-tiwai@suse.de Signed-off-by: Takashi Iwai

ALSA: compat_ioctl: use correct snd_ctl_elem_type_t type

2023-05-17T15:01:51+00:00

SNDRV_CTL_ELEM_TYPE_* are type of snd_ctl_elem_type_t, we have to __force cast them to int when comparing them with int to fix the following sparse warnings. sound/core/control_compat.c:203:14: sparse: warning: restricted snd_ctl_elem_type_t degrades to integer sound/core/control_compat.c:205:14: sparse: warning: restricted snd_ctl_elem_type_t degrades to integer sound/core/control_compat.c:207:14: sparse: warning: restricted snd_ctl_elem_type_t degrades to integer sound/core/control_compat.c:209:14: sparse: warning: restricted snd_ctl_elem_type_t degrades to integer sound/core/control_compat.c:237:21: sparse: warning: restricted snd_ctl_elem_type_t degrades to integer sound/core/control_compat.c:238:21: sparse: warning: restricted snd_ctl_elem_type_t degrades to integer sound/core/control_compat.c:270:21: sparse: warning: restricted snd_ctl_elem_type_t degrades to integer sound/core/control_compat.c:271:21: sparse: warning: restricted snd_ctl_elem_type_t degrades to integer Signed-off-by: Min-Hua Chen Link: https://lore.kernel.org/r/20230516223806.185683-1-minhuadotchen@gmail.com Signed-off-by: Takashi Iwai

x86: Remove toolchain check for X32 ABI capability

2022-03-15T09:32:48+00:00

Commit 0bf6276392e9 ("x32: Warn and disable rather than error if binutils too old") added a small test in arch/x86/Makefile because binutils 2.22 or newer is needed to properly support elf32-x86-64. This check is no longer necessary, as the minimum supported version of binutils is 2.23, which is enforced at configuration time with scripts/min-tool-version.sh. Remove this check and replace all uses of CONFIG_X86_X32 with CONFIG_X86_X32_ABI, as two symbols are no longer necessary. [nathan: Rebase, fix up a few places where CONFIG_X86_X32 was still used, and simplify commit message to satisfy -tip requirements] Signed-off-by: Masahiro Yamada Signed-off-by: Nathan Chancellor Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20220314194842.3452-2-nathan@kernel.org

ALSA: ctl: Fix copy of updated id with element read/write

2021-12-02T15:41:07+00:00

When control_compat.c:copy_ctl_value_to_user() is used, by ctl_elem_read_user() & ctl_elem_write_user(), it must also copy back the snd_ctl_elem_id value that may have been updated (filled in) by the call to snd_ctl_elem_read/snd_ctl_elem_write(). This matches the functionality provided by snd_ctl_elem_read_user() and snd_ctl_elem_write_user(), via snd_ctl_build_ioff(). Without this, and without making additional calls to snd_ctl_info() which are unnecessary when using the non-compat calls, a userspace application will not know the numid value for the element and consequently will not be able to use the poll/read interface on the control file to determine which elements have updates. Signed-off-by: Alan Young Cc: Link: https://lore.kernel.org/r/20211202150607.543389-1-consult.awy@gmail.com Signed-off-by: Takashi Iwai

ALSA: control: Drop superfluous snd_power_wait() calls

2021-05-25T06:48:49+00:00

Now we have more fine-grained power controls in each kcontrol ops, the coarse checks of snd_power_wait() in a few control ioctls became superfluous. Let's drop them. Reviewed-by: Jaroslav Kysela Link: https://lore.kernel.org/r/20210523090920.15345-4-tiwai@suse.de Signed-off-by: Takashi Iwai

ALSA: control: Track in-flight control read/write/tlv accesses

2021-05-25T06:48:28+00:00

Although the power state check is performed in various places (e.g. at the entrance of quite a few ioctls), there can be still some pending tasks that already went into the ioctl handler or other ops, and those may access the hardware even after the power state check. For example, kcontrol access ioctl paths that call info/get/put callbacks may update the hardware registers. If a system wants to assure the free from such hw access (like the case of PCI rescan feature we're going to implement in future), this situation must be avoided, and we have to sync such in-flight tasks finishing beforehand. For that purpose, this patch introduces a few new things in core code: - A refcount, power_ref, and a wait queue, power_ref_sleep, to the card object - A few new helpers, snd_power_ref(), snd_power_unref(), snd_power_ref_and_wait(), and snd_power_sync_ref() In the code paths that call kctl info/read/write/tlv ops, we check the power state with the newly introduced snd_power_ref_and_wait(). This function also takes the card.power_ref refcount for tracking this in-flight task. Once after the access finishes, snd_power_unref() is called to released the refcount in return. So the driver can sync via snd_power_sync_ref() assuring that all in-flight tasks have been finished. As of this patch, snd_power_sync_ref() is called only at snd_card_disconnect(), but it'll be used in other places in future. Note that atomic_t is used for power_ref intentionally instead of refcount_t. It's because of the design of refcount_t type; refcount_t cannot be zero-based, and it cannot do dec_and_test() call for multiple times, hence it's not suitable for our purpose. Also, this patch changes snd_power_wait() to accept only SNDRV_CTL_POWER_D0, which is the only value that makes sense. In later patch, the snd_power_wait() calls will be cleaned up. Reviewed-by: Jaroslav Kysela Link: https://lore.kernel.org/r/20210523090920.15345-3-tiwai@suse.de Signed-off-by: Takashi Iwai

ALSA: compat_ioctl: avoid compat_alloc_user_space

2020-09-21T08:37:07+00:00

Using compat_alloc_user_space() tends to add complexity to the ioctl handling, so I am trying to remove it everywhere. The two callers in sound/core can rewritten to just call the same code that operates on a kernel pointer as the native handler. Signed-off-by: Arnd Bergmann Link: https://lore.kernel.org/r/20200918095642.1446243-1-arnd@arndb.de Signed-off-by: Takashi Iwai