[tip: objtool/urgent] objtool, ASoC: codecs: wcd934x: Remove potential undefined behavior in wcd934x_slim_irq_handler()

["tip-bot2 for Josh Poimboeuf" <tip-bot2@linutronix.de>]

The following commit has been merged into the objtool/urgent branch of tip:

Commit-ID:     46b70c569b774ea2c671bb3aff2a50d29760b7c3
Gitweb:        https://git.kernel.org/tip/46b70c569b774ea2c671bb3aff2a50d29760b7c3
Author:        Josh Poimboeuf <jpoimboe@kernel.org>
AuthorDate:    Mon, 24 Mar 2025 14:56:09 -07:00
Committer:     Ingo Molnar <mingo@kernel.org>
CommitterDate: Tue, 25 Mar 2025 09:20:29 +01:00

objtool, ASoC: codecs: wcd934x: Remove potential undefined behavior in wcd934x_slim_irq_handler()

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>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
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/
---
 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 910852e..c7f1b28 100644
--- a/sound/soc/codecs/wcd934x.c
+++ b/sound/soc/codecs/wcd934x.c
@@ -2273,7 +2273,7 @@ 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;