[PATCH AUTOSEL 5.10 4/4] objtool, ASoC: codecs: wcd934x: Remove potential undefined behavior in wcd934x_slim_irq_handler()

[PATCH AUTOSEL 5.10 4/4] objtool, ASoC: codecs: wcd934x: Remove potential undefined behavior in wcd934x_slim_irq_handler()

[Sasha Levin]

From: Josh Poimboeuf <jpoimboe@kernel.org>

[ Upstream commit 060aed9c0093b341480770457093449771cf1496 ]

If 'port_id' is negative, the shift counts in wcd934x_slim_irq_handler()
also become negative, resulting in undefined behavior due to shift out
of bounds.

If I'm reading the code correctly, that appears to be not possible, but
with KCOV enabled, Clang's range analysis isn't always able to determine
that and generates undefined behavior.

As a result the code generation isn't optimal, and undefined behavior
should be avoided regardless.  Improve code generation and remove the
undefined behavior by converting the signed variables to unsigned.

Fixes the following warning with UBSAN:

  sound/soc/codecs/snd-soc-wcd934x.o: warning: objtool: .text.wcd934x_slim_irq_handler: unexpected end of section

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Mark Brown <broonie@kernel.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/7e863839ec7301bf9c0f429a03873d44e484c31c.1742852847.git.jpoimboe@kernel.org
Closes: https://lore.kernel.org/oe-kbuild-all/202503180044.oH9gyPeg-lkp@intel.com/
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 sound/soc/codecs/wcd934x.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/soc/codecs/wcd934x.c b/sound/soc/codecs/wcd934x.c
index 104751ac6cd14..8580f5e95ccf6 100644
--- a/sound/soc/codecs/wcd934x.c
+++ b/sound/soc/codecs/wcd934x.c
@@ -2188,7 +2188,7 @@ static irqreturn_t wcd934x_slim_irq_handler(int irq, void *data)
 {
 	struct wcd934x_codec *wcd = data;
 	unsigned long status = 0;
-	int i, j, port_id;
+	unsigned int i, j, port_id;
 	unsigned int val, int_val = 0;
 	irqreturn_t ret = IRQ_NONE;
 	bool tx;
-- 
2.39.5