[PATCH 23/28] Input: synaptics_usb - use seq_buf and snprintf() for name and phys

[Bill Wendling]

synusb_probe() constructs the device name and physical path using a mix of
strscpy(), strlcat(), and snprintf().

In preparation for removing the deprecated strlcat() API[1], use struct
seq_buf to incrementally build synusb->name, and format synusb->phys with
snprintf() after generating the USB path.

Link: https://github.com/KSPP/linux/issues/370 [1]
Cc: codemender-patching+linux@xxxxxxxxxx
Assisted-by: Gemini:1.5-Pro-002 [editor_update_file, make_kernel_build_single_file, test_runner_run_kunit_test]
Signed-off-by: Bill Wendling <morbo@xxxxxxxxxx>
---
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---
 drivers/input/mouse/synaptics_usb.c | 29 +++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/drivers/input/mouse/synaptics_usb.c b/drivers/input/mouse/synaptics_usb.c
index 880a0c79148c..d13d2d6202ee 100644
--- a/drivers/input/mouse/synaptics_usb.c
+++ b/drivers/input/mouse/synaptics_usb.c
@@ -41,6 +41,7 @@
 #include <linux/usb.h>
 #include <linux/input.h>
 #include <linux/usb/input.h>
+#include <linux/seq_buf.h>
 
 #define USB_VENDOR_ID_SYNAPTICS	0x06cb
 #define USB_DEVICE_ID_SYNAPTICS_TP	0x0001	/* Synaptics USB TouchPad */
@@ -278,6 +279,8 @@ static int synusb_probe(struct usb_interface *intf,
 	struct input_dev *input_dev;
 	unsigned int intf_num = intf->cur_altsetting->desc.bInterfaceNumber;
 	unsigned int altsetting = min(intf->num_altsetting, 1U);
+	struct seq_buf s;
+	char path[64];
 	int error;
 
 	error = usb_set_interface(udev, intf_num, altsetting);
@@ -334,27 +337,29 @@ static int synusb_probe(struct usb_interface *intf,
 			 ep->bInterval);
 	synusb->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 
+	seq_buf_init(&s, synusb->name, sizeof(synusb->name));
+
 	if (udev->manufacturer)
-		strscpy(synusb->name, udev->manufacturer,
-			sizeof(synusb->name));
+		seq_buf_puts(&s, udev->manufacturer);
 
 	if (udev->product) {
 		if (udev->manufacturer)
-			strlcat(synusb->name, " ", sizeof(synusb->name));
-		strlcat(synusb->name, udev->product, sizeof(synusb->name));
+			seq_buf_puts(&s, " ");
+		seq_buf_puts(&s, udev->product);
 	}
 
-	if (!strlen(synusb->name))
-		snprintf(synusb->name, sizeof(synusb->name),
-			 "USB Synaptics Device %04x:%04x",
-			 le16_to_cpu(udev->descriptor.idVendor),
-			 le16_to_cpu(udev->descriptor.idProduct));
+	if (!seq_buf_used(&s))
+		seq_buf_printf(&s, "USB Synaptics Device %04x:%04x",
+			       le16_to_cpu(udev->descriptor.idVendor),
+			       le16_to_cpu(udev->descriptor.idProduct));
 
 	if (synusb->flags & SYNUSB_STICK)
-		strlcat(synusb->name, " (Stick)", sizeof(synusb->name));
+		seq_buf_puts(&s, " (Stick)");
 
-	usb_make_path(udev, synusb->phys, sizeof(synusb->phys));
-	strlcat(synusb->phys, "/input0", sizeof(synusb->phys));
+	seq_buf_str(&s);
+
+	usb_make_path(udev, path, sizeof(path));
+	snprintf(synusb->phys, sizeof(synusb->phys), "%s/input0", path);
 
 	input_dev->name = synusb->name;
 	input_dev->phys = synusb->phys;
-- 
2.55.0.1032.g73a4cd73de-goog