Received-SPF: pass (google.com: domain of linux-kernel+bounces-41605-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223;
From: Erick Archer <erick.archer@gmx.com>
To: Vinod Koul <vkoul@kernel.org>,
	"Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: Erick Archer <erick.archer@gmx.com>,
	dmaengine@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	linux-hardening@vger.kernel.org
Subject: [PATCH] dmaengine: pl08x: Use kcalloc() instead of kzalloc()
Date: Sun, 28 Jan 2024 12:52:36 +0100
Message-Id: <20240128115236.4791-1-erick.archer@gmx.com>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
UI-OutboundReport: notjunk:1;M01:P0:NqWDpYotzqo=;YRCXAJOFtmujiztYMgzyJerwsJ2
 /VNB6fVwkBl5evt3pnh9L91ilk14Ne7edFPWUOJ4RX73VcxLPD9AjKqEG5usCnfLyykIMfZah
 L4qdB4Op1PvYUWK1Ro+lt/Qu2+uS6q1i3uJ6M+4pOjZRQ5/TltA5H6pDkjFYM2Or0yw3k/i3F
 bEpNSfCOabKffmwE13OCnNuQaV3MARhfwCPV7LNSqvR3aeyzuzSW7Y/ibLZEIzMUieVqA/nZ7
 BksZZnmMOAmiqDJxCKum3WKpGHC48dzh5hm6txYIUbhdZ3JK1a8PuSN/yG1GaFgIWjYMd7X8u
 ljVqvPrcIUzs8G2Io1oulc/XzRdx5j9pXIZCgphpHN7iHmYM0QWZ5PeRyJFpv5Iln9rTILm+H
 K1ZyNjAUyAM/WilEgE3sqLjZmTPo3tRijA+1pITz8Pk3HW7BivG47IfXu87/JOFZD/PQwaJEl
 KlvO7/UvFuxz4xAHOVX4JTkNRz2AmyVrdN97z4gUX3hV9SPj3wcVq8O4O84XBnOcvfgHckJQi
 SuGP8ez8oLMfHnewSQfpqSe1ss1D0lAIJSAcHjVEQ3x+dUTra36/6mb0WNKzJo5OuImr6gd2U
 gS5enXim+kJMv8FQAt4aMgFO3yBucLEuAdplCpIOB6l4RCxgDOWpBC1wguykKVCrmI5l8RCcf
 SR5tO8dAQfyrR435pJrKdKGIsb0TtMhEtVIKek7w3/6tV+R4S/uge0cp46lUfpxDwhkWhssot
 FLjR8VxSgNYk9Ctxk/lYJyhWaQY8SCXeowqf3cV/M0pmKboqJf0VmijKmHQx+38GFbJhI5n86
 epx6wOTa5eRHN5dc/Z3Hi1+F42rW+5W5tuXPaSvZ5FPU40PFcNic7XxQgTU1iNoQ2tiFJYjjO
 8KisukA11HOlrSnOz6C/svPsobWntEUOePplcuzq8jqgfEUtSId3DBoYqWcLM9W89w+9CNSG+
 1Xww/wifeRY2UF0NVIqEIOzLDyg=

This is an effort to get rid of all multiplications from allocation
functions in order to prevent integer overflows [1].

Here the multiplication is obviously safe because the "channels"
member can only be 8 or 2. This value is set when the "vendor_data"
structs are initialized.

static struct vendor_data vendor_pl080 =3D {
	[...]
	.channels =3D 8,
	[...]
};

static struct vendor_data vendor_nomadik =3D {
	[...]
	.channels =3D 8,
	[...]
};

static struct vendor_data vendor_pl080s =3D {
	[...]
	.channels =3D 8,
	[...]
};

static struct vendor_data vendor_pl081 =3D {
	[...]
	.channels =3D 2,
	[...]
};

However, using kcalloc() is more appropriate [1] and improves
readability. This patch has no effect on runtime behavior.

Link: https://github.com/KSPP/linux/issues/162 [1]
Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-co=
ded-arithmetic-in-allocator-arguments [1]
Signed-off-by: Erick Archer <erick.archer@gmx.com>
=2D--
 drivers/dma/amba-pl08x.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
index eea8bd33b4b7..e40766108787 100644
=2D-- a/drivers/dma/amba-pl08x.c
+++ b/drivers/dma/amba-pl08x.c
@@ -2855,8 +2855,8 @@ static int pl08x_probe(struct amba_device *adev, con=
st struct amba_id *id)
 	}

 	/* Initialize physical channels */
-	pl08x->phy_chans =3D kzalloc((vd->channels * sizeof(*pl08x->phy_chans)),
-			GFP_KERNEL);
+	pl08x->phy_chans =3D kcalloc(vd->channels, sizeof(*pl08x->phy_chans),
+				   GFP_KERNEL);
 	if (!pl08x->phy_chans) {
 		ret =3D -ENOMEM;
 		goto out_no_phychans;
=2D-
2.25.1