Subject: [PATCH -next v2] usb: usbtest: reduce stack usage in test_queue

From: Bixuan Cui <[email-masked]>
Date: Fri, 17 Jul 2020 08:22:53 +0800

Fix the warning: [-Werror=-Wframe-larger-than=]

drivers/usb/misc/usbtest.c: In function 'test_queue':
drivers/usb/misc/usbtest.c:2148:1:
warning: the frame size of 1232 bytes is larger than 1024 bytes

Reported-by: kbuild test robot <[email-masked]>
Acked-by: Alan Stern <[email-masked]>
Signed-off-by: Bixuan Cui <[email-masked]>
---
v2: Change MAX_SGLEN to param->sglen.

 drivers/usb/misc/usbtest.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/misc/usbtest.c b/drivers/usb/misc/usbtest.c
index 8b220d56647b..150090ee4ec1 100644
--- a/drivers/usb/misc/usbtest.c
+++ b/drivers/usb/misc/usbtest.c
@@ -2043,7 +2043,7 @@ test_queue(struct usbtest_dev *dev, struct usbtest_param_32 *param,
 	unsigned		i;
 	unsigned long		packets = 0;
 	int			status = 0;
-	struct urb		*urbs[MAX_SGLEN];
+	struct urb		**urbs;

 	if (!param->sglen || param->iterations > UINT_MAX / param->sglen)
 		return -EINVAL;
@@ -2051,6 +2051,10 @@ test_queue(struct usbtest_dev *dev, struct usbtest_param_32 *param,
 	if (param->sglen > MAX_SGLEN)
 		return -EINVAL;

+	urbs = kcalloc(param->sglen, sizeof(*urbs), GFP_KERNEL);
+	if (!urbs)
+		return -ENOMEM;
+
 	memset(&context, 0, sizeof(context));
 	context.count = param->iterations * param->sglen;
 	context.dev = dev;
@@ -2137,6 +2141,8 @@ test_queue(struct usbtest_dev *dev, struct usbtest_param_32 *param,
 	else if (context.errors >
 			(context.is_iso ? context.packet_count / 10 : 0))
 		status = -EIO;
+
+	kfree(urbs);
 	return status;

 fail:
@@ -2144,6 +2150,8 @@ test_queue(struct usbtest_dev *dev, struct usbtest_param_32 *param,
 		if (urbs[i])
 			simple_free_urb(urbs[i]);
 	}
+
+	kfree(urbs);
 	return status;
 }

--
2.17.1

.