From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B45E1264F8C; Mon, 7 Apr 2025 18:14:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744049653; cv=none; b=E+Pva6bZUiHBfh02VVewSfWesr6QqdTc5BLsU9bXwSPK+6047BTBCrjjEViwCHy3KVb2Pw3/r2zfHc27G8HYqT+dpm0428uxFFeAj2r2u4ACiNAdghVFt9eqWNpZWuV/kB6y7qBtMYwwqAZwkALLSMOws0dMXxkYn1XzvV6TxLw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744049653; c=relaxed/simple; bh=Yk5EVY6E2bB8THsuHW5DZrTErkIlJ64imF/RTteQeBk=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=nIVZwKwboA9tiGIaADj9zliOJdOfvxFhMU+jNvcPXtc2NAm0SGh4aQzDimWHBTUHz8xEfWBq0BXdjCNO1hsRF1nSgFZydXV9rPVexRobr4loQm2+g9xH3FUPta9E+9lZs23BpysXeE9tgU2woL6+wqq2orytgdx3Xrk7KuheNcU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=BPDP/btP; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="BPDP/btP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 97B09C4CEDD; Mon, 7 Apr 2025 18:14:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1744049653; bh=Yk5EVY6E2bB8THsuHW5DZrTErkIlJ64imF/RTteQeBk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BPDP/btPGm16FTbfo37nbN17O1JT/86bdWzIvqeoEnWhzElBmG/biFz3mxnHi7T8/ g8JULbU9ZxCMTXdLAoXY3dM0LT8OINZgA6Nx8Jh1/OK0l5J4PveXRpMyUaEtqoSa9+ 0kZeSwlkilys5OMQMab581vDwe3qfdX51K+fWT2D7uGZBWNidu754skVe0My/4CHHb n36w0t8MUUJN9l9TMcyQ5HQH3SMa8kXcwffhR/59FSmBQhZ1H5EbxZKC2x2IyebI6D J7nnAh92xbPjrpRSufOuxuyQB9Ld8hwPHg3kjruUxB9wPfXg/kQvua8+EEMTwPf9Ax m8GAXNG5saCCg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Josh Poimboeuf , kernel test robot , Ingo Molnar , Mark Brown , Liam Girdwood , Linus Torvalds , Sasha Levin Subject: [PATCH AUTOSEL 6.12 21/22] objtool, regulator: rk808: Remove potential undefined behavior in rk806_set_mode_dcdc() Date: Mon, 7 Apr 2025 14:13:31 -0400 Message-Id: <20250407181333.3182622-21-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250407181333.3182622-1-sashal@kernel.org> References: <20250407181333.3182622-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.12.22 Content-Transfer-Encoding: 8bit From: Josh Poimboeuf [ Upstream commit 29c578c848402a34e8c8e115bf66cb6008b77062 ] If 'ctr_bit' is negative, the shift counts become negative, causing a shift of bounds and undefined behavior. Presumably that's not possible in normal operation, but 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 an UBSAN kernel: vmlinux.o: warning: objtool: rk806_set_mode_dcdc() falls through to next function rk806_get_mode_dcdc() vmlinux.o: warning: objtool: .text.rk806_set_mode_dcdc: unexpected end of section Reported-by: kernel test robot Signed-off-by: Josh Poimboeuf Signed-off-by: Ingo Molnar Acked-by: Mark Brown Cc: Liam Girdwood Cc: Linus Torvalds Link: https://lore.kernel.org/r/2023abcddf3f524ba478d64339996f25dc4097d2.1742852847.git.jpoimboe@kernel.org Closes: https://lore.kernel.org/oe-kbuild-all/202503182350.52KeHGD4-lkp@intel.com/ Signed-off-by: Sasha Levin --- drivers/regulator/rk808-regulator.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/regulator/rk808-regulator.c b/drivers/regulator/rk808-regulator.c index 37476d2558fda..72df554b6375b 100644 --- a/drivers/regulator/rk808-regulator.c +++ b/drivers/regulator/rk808-regulator.c @@ -270,8 +270,8 @@ static const unsigned int rk817_buck1_4_ramp_table[] = { static int rk806_set_mode_dcdc(struct regulator_dev *rdev, unsigned int mode) { - int rid = rdev_get_id(rdev); - int ctr_bit, reg; + unsigned int rid = rdev_get_id(rdev); + unsigned int ctr_bit, reg; reg = RK806_POWER_FPWM_EN0 + rid / 8; ctr_bit = rid % 8; -- 2.39.5