kernel/linux.git/sound/core/control_compat.c, branch v6.18.22

Merge branch 'topic/control-lookup-rwlock' into for-next

2024-08-09T12:25:24+00:00

Pull control lookup optimization changes. Signed-off-by: Takashi Iwai

ALSA: control: Optimize locking for look-up

2024-08-09T12:24:55+00:00

For a fast look-up of a control element via either numid or name matching (enabled via CONFIG_SND_CTL_FAST_LOOKUP), a locking isn't needed at all thanks to Xarray. OTOH, the locking is still needed for a slow linked-list traversal, and that's rather a rare case. In this patch, we reduce the use of locking at snd_ctl_find_*() API functions, and switch from controls_rwsem to controls_rwlock for avoiding unnecessary lock inversions. This also resulted in a nice cleanup, as *_unlocked() version of snd_ctl_find_*() APIs can be dropped. snd_ctl_find_id_mixer_unlocked() is still left just as an alias of snd_ctl_find_id_mixer(), since soc-card.c has a wrapper and there are several users. Once after converting there, we can remove it later. Signed-off-by: Takashi Iwai Link: https://patch.msgid.link/20240809104234.8488-3-tiwai@suse.de

ALSA: control: Fix power_ref lock order for compat code, too

2024-08-08T16:31:54+00:00

In the previous change for swapping the power_ref and controls_rwsem lock order, the code path for the compat layer was forgotten. This patch covers the remaining code. Fixes: fcc62b19104a ("ALSA: control: Take power_ref lock primarily") Link: https://patch.msgid.link/20240808163128.20383-1-tiwai@suse.de Signed-off-by: Takashi Iwai

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