lkml.org 
[lkml]   [2016]   [Mar]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] HID: lenovo: Don't use stack variables for DMA buffers
Date
The lenovo_send_cmd_cptkbd function uses a stack variable to submit
commands via hid_hw_raw_request. Eventually this gets to the
usb_hcd_map_urb_for_dma function, which causes a warning to be thrown
if the CONFIG_DMA_API_DEBUG option is enabled.

Fix this by allocating a temporary buffer instead.

Reported-by: lejeczek <peljasz@yahoo.co.uk>
Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org>
---
drivers/hid/hid-lenovo.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/hid/hid-lenovo.c b/drivers/hid/hid-lenovo.c
index 0125e356bd8d..2ba5e8ea66a4 100644
--- a/drivers/hid/hid-lenovo.c
+++ b/drivers/hid/hid-lenovo.c
@@ -184,21 +184,31 @@ static int lenovo_send_cmd_cptkbd(struct hid_device *hdev,
unsigned char byte2, unsigned char byte3)
{
int ret;
- unsigned char buf[] = {0x18, byte2, byte3};
+ unsigned char *buf = NULL;
+
+ buf = kzalloc(3, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ buf[0] = 0x18;
+ buf[1] = byte2;
+ buf[2] = byte3;

switch (hdev->product) {
case USB_DEVICE_ID_LENOVO_CUSBKBD:
- ret = hid_hw_raw_request(hdev, 0x13, buf, sizeof(buf),
+ ret = hid_hw_raw_request(hdev, 0x13, buf, 3,
HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
break;
case USB_DEVICE_ID_LENOVO_CBTKBD:
- ret = hid_hw_output_report(hdev, buf, sizeof(buf));
+ ret = hid_hw_output_report(hdev, buf, 3);
break;
default:
ret = -EINVAL;
break;
}

+ kfree(buf);
+
return ret < 0 ? ret : 0; /* BT returns 0, USB returns sizeof(buf) */
}

--
2.5.5
\
 
 \ /
  Last update: 2016-03-28 15:41    [W:0.070 / U:0.780 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site