objtool, ASoC: codecs: wcd934x: Remove potential undefined behavior in wcd934x_slim_i...
authorJosh Poimboeuf <jpoimboe@kernel.org>
Mon, 24 Mar 2025 21:56:09 +0000 (14:56 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 2 May 2025 05:59:19 +0000 (07:59 +0200)
commit777e6735fecc806982cf2ff91e156843e8dc9bfb
tree88f8137ed2bbc32cbbace349dd69ba99def39343
parent0485bdf88fb4a8cddb0ecd40506e063ad1b4f8fc
objtool, ASoC: codecs: wcd934x: Remove potential undefined behavior in wcd934x_slim_irq_handler()

[ 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