[PATCH] ASoC: SDCA: Shrink detected_mode_handler() stack frame

[PATCH] ASoC: SDCA: Shrink detected_mode_handler() stack frame

[Charles Keepax]

The stack frame for detected_mode_handler() is a bit large. Dynamically
allocate the control value struct, which is most of the size, to avoid
this.

Fixes: b9ab3b618241 ("ASoC: SDCA: Add some initial IRQ handlers")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202507182222.OLgOy9fX-lkp@intel.com/
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
---
 sound/soc/sdca/sdca_interrupts.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/sound/soc/sdca/sdca_interrupts.c b/sound/soc/sdca/sdca_interrupts.c
index b76512732af8..a5b2adaac312 100644
--- a/sound/soc/sdca/sdca_interrupts.c
+++ b/sound/soc/sdca/sdca_interrupts.c
@@ -144,7 +144,7 @@ static irqreturn_t detected_mode_handler(int irq, void *data)
 	struct snd_soc_card *card = component->card;
 	struct rw_semaphore *rwsem = &card->snd_card->controls_rwsem;
 	struct snd_kcontrol *kctl = interrupt->priv;
-	struct snd_ctl_elem_value ucontrol;
+	struct snd_ctl_elem_value *ucontrol __free(kfree) = NULL;
 	struct soc_enum *soc_enum;
 	unsigned int reg, val;
 	int ret;
@@ -204,10 +204,14 @@ static irqreturn_t detected_mode_handler(int irq, void *data)
 
 	dev_dbg(dev, "%s: %#x\n", interrupt->name, val);
 
-	ucontrol.value.enumerated.item[0] = snd_soc_enum_val_to_item(soc_enum, val);
+	ucontrol = kzalloc(sizeof(*ucontrol), GFP_KERNEL);
+	if (!ucontrol)
+		return IRQ_NONE;
+
+	ucontrol->value.enumerated.item[0] = snd_soc_enum_val_to_item(soc_enum, val);
 
 	down_write(rwsem);
-	ret = kctl->put(kctl, &ucontrol);
+	ret = kctl->put(kctl, ucontrol);
 	up_write(rwsem);
 	if (ret < 0) {
 		dev_err(dev, "failed to update selected mode: %d\n", ret);
-- 
2.39.5

Re: [PATCH] ASoC: SDCA: Shrink detected_mode_handler() stack frame

[Arnd Bergmann]

On Tue, Jul 22, 2025, at 12:23, Charles Keepax wrote:
> The stack frame for detected_mode_handler() is a bit large. Dynamically
> allocate the control value struct, which is most of the size, to avoid
> this.
>
> Fixes: b9ab3b618241 ("ASoC: SDCA: Add some initial IRQ handlers")
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: 
> https://lore.kernel.org/oe-kbuild-all/202507182222.OLgOy9fX-lkp@intel.com/
> Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>

Reviewed-by: Arnd Bergmann <arnd@arndb.de>

Re: [PATCH] ASoC: SDCA: Shrink detected_mode_handler() stack frame

[Mark Brown]

On Tue, 22 Jul 2025 11:23:05 +0100, Charles Keepax wrote:
> The stack frame for detected_mode_handler() is a bit large. Dynamically
> allocate the control value struct, which is most of the size, to avoid
> this.
> 
> 

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next

Thanks!

[1/1] ASoC: SDCA: Shrink detected_mode_handler() stack frame
      commit: 59c5dbd585a0bee70e51fcdf36185f7602b9c285

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark