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From:   Fuqian Huang <huangfq.daxian@gmail.com>
Cc:     Mauro Carvalho Chehab <mchehab@kernel.org>,
        Antoine Jacquet <royale@zerezo.com>,
        linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-usb@vger.kernel.org, Fuqian Huang <huangfq.daxian@gmail.com>
Subject: [PATCH v2 13/35] media/usb: Use kmemdup rather than duplicating its implementation
Date:   Thu,  4 Jul 2019 00:28:57 +0800
Message-Id: <20190703162857.32461-1-huangfq.daxian@gmail.com>
To:     unlisted-recipients:; (no To-header on input)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

kmemdup is introduced to duplicate a region of memory in a neat way.
Rather than kmalloc/kzalloc + memcpy, which the programmer needs to
write the size twice (sometimes lead to mistakes), kmemdup improves
readability, leads to smaller code and also reduce the chances of mistakes.
Suggestion to use kmemdup rather than using kmalloc/kzalloc + memcpy.

Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
---
Changes in v2:
  - Fix a typo in commit message (memset -> memcpy)

 drivers/media/usb/em28xx/em28xx-cards.c | 3 +--
 drivers/media/usb/zr364xx/zr364xx.c     | 4 +---
 2 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/media/usb/em28xx/em28xx-cards.c b/drivers/media/usb/em28xx/em28xx-cards.c
index 1283c7ca9ad5..6e33782c3ca6 100644
--- a/drivers/media/usb/em28xx/em28xx-cards.c
+++ b/drivers/media/usb/em28xx/em28xx-cards.c
@@ -3566,13 +3566,12 @@ static int em28xx_init_dev(struct em28xx *dev, struct usb_device *udev,
 static int em28xx_duplicate_dev(struct em28xx *dev)
 {
 	int nr;
-	struct em28xx *sec_dev = kzalloc(sizeof(*sec_dev), GFP_KERNEL);
+	struct em28xx *sec_dev = kmemdup(dev, sizeof(*sec_dev), GFP_KERNEL);
 
 	if (!sec_dev) {
 		dev->dev_next = NULL;
 		return -ENOMEM;
 	}
-	memcpy(sec_dev, dev, sizeof(*sec_dev));
 	/* Check to see next free device and mark as used */
 	do {
 		nr = find_first_zero_bit(em28xx_devused, EM28XX_MAXBOARDS);
diff --git a/drivers/media/usb/zr364xx/zr364xx.c b/drivers/media/usb/zr364xx/zr364xx.c
index 37a7992585df..39df6bfece2c 100644
--- a/drivers/media/usb/zr364xx/zr364xx.c
+++ b/drivers/media/usb/zr364xx/zr364xx.c
@@ -199,12 +199,10 @@ static int send_control_msg(struct usb_device *udev, u8 request, u16 value,
 {
 	int status;
 
-	unsigned char *transfer_buffer = kmalloc(size, GFP_KERNEL);
+	unsigned char *transfer_buffer = kmemdup(cp, size, GFP_KERNEL);
 	if (!transfer_buffer)
 		return -ENOMEM;
 
-	memcpy(transfer_buffer, cp, size);
-
 	status = usb_control_msg(udev,
 				 usb_sndctrlpipe(udev, 0),
 				 request,
-- 
2.11.0