kernel/sound/core/control_compat.c, branch linux-rolling-stable

ALSA: control: Relax __free() variable declarations

2026-02-26T23:00:56Z

[ Upstream commit 7b4721ca3159bce6338dbdf9188b785083571ed4 ] We used to have a variable declaration with __free() initialized with NULL. This was to keep the old coding style rule, but recently it's relaxed and rather recommends to follow the new rule to declare in place of use for __free() -- which avoids potential deadlocks or UAFs with nested cleanups. Although the current code has no bug, per se, let's follow the new standard and move the declaration to the place of assignment (or directly assign the allocated result) instead of NULL initializations. Fixes: 7dba48a474e6 ("ALSA: control_led: Use guard() for locking") Fixes: 1052d9882269 ("ALSA: control: Use automatic cleanup of kfree()") Signed-off-by: Takashi Iwai Link: https://patch.msgid.link/20251216140634.171890-3-tiwai@suse.de Signed-off-by: Sasha Levin

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

2024-08-09T12:25:24Z

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

ALSA: control: Optimize locking for look-up

2024-08-09T12:24:55Z

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

2024-08-08T16:31:54Z

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

2024-02-28T14:01:21Z

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()

2024-02-23T09:57:30Z

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

2023-10-26T07:42:43Z

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

2023-07-20T08:03:00Z

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

2023-05-17T15:01:51Z

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

2022-03-15T09:32:48Z

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