On 2.6.32-rc6 from wireless-testing, the following warning is emitted:
------------[ cut here ]------------
WARNING: at lib/dma-debug.c:860 check_for_stack+0xaa/0xe0()
Hardware name: HP Pavilion dv2700 Notebook PC
ehci_hcd 0000:00:02.1: DMA-API: device driver maps memory fromstack
[addr=ffff8800b6e2bca8]
Modules linked in: <Removed>
Pid: 16378, comm: modprobe Not tainted 2.6.32-rc6-wl #244
Call Trace:
[<ffffffff81049698>] warn_slowpath_common+0x78/0xb0
[<ffffffff8104972c>] warn_slowpath_fmt+0x3c/0x40
[<ffffffff811ae52a>] check_for_stack+0xaa/0xe0
[<ffffffff811afc8d>] debug_dma_map_page+0xfd/0x170
[<ffffffffa006297a>] usb_hcd_submit_urb+0x3da/0x9c0 [usbcore]
[<ffffffff81076e6f>] ? lockdep_init_map+0x5f/0x5d0
[<ffffffffa0063365>] usb_submit_urb+0xe5/0x260 [usbcore]
[<ffffffffa0064b7e>] usb_start_wait_urb+0x5e/0xf0 [usbcore]
[<ffffffffa0063943>] ? usb_init_urb+0x23/0x40 [usbcore]
[<ffffffffa0064cd4>] usb_bulk_msg+0xc4/0x150 [usbcore]
[<ffffffffa0441a91>] T.719+0x31/0x40 [p54usb]
[<ffffffffa0441acf>] p54u_upload_firmware_3887+0x2f/0x490 [p54usb]
[<ffffffffa049c667>] ? p54_parse_firmware+0x427/0x450 [p54common]
<Rest of traceback removed>
---[ end trace f77df0316ddad3de ]---
Signed-off-by: Larry Finger <[email protected]>
Cc: Stable <[email protected]>
---
John,
This is 2.6.32 material. Sorry to find it so late in the rc cycle. I hop
DaveM doesn't give you too much trouble.
V2 - Fix line wraps in trace back.
Larry
---
Index: wireless-testing/drivers/net/wireless/p54/p54usb.c
===================================================================
--- wireless-testing.orig/drivers/net/wireless/p54/p54usb.c
+++ wireless-testing/drivers/net/wireless/p54/p54usb.c
@@ -426,12 +426,16 @@ static const char p54u_romboot_3887[] =
static int p54u_firmware_reset_3887(struct ieee80211_hw *dev)
{
struct p54u_priv *priv = dev->priv;
- u8 buf[4];
+ u8 *buf;
int ret;
- memcpy(&buf, p54u_romboot_3887, sizeof(buf));
+ buf = kmalloc(4, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+ memcpy(buf, p54u_romboot_3887, 4);
ret = p54u_bulk_msg(priv, P54U_PIPE_DATA,
- buf, sizeof(buf));
+ buf, 4);
+ kfree(buf);
if (ret)
dev_err(&priv->udev->dev, "(p54usb) unable to jump to "
"boot ROM (%d)!\n", ret);
On Thursday 12 November 2009 01:02:29 Larry Finger wrote:
> On 2.6.32-rc6 from wireless-testing, the following warning is emitted:
>
> ------------[ cut here ]------------
> WARNING: at lib/dma-debug.c:860 check_for_stack+0xaa/0xe0()
> Hardware name: HP Pavilion dv2700 Notebook PC
> ehci_hcd 0000:00:02.1: DMA-API: device driver maps memory fromstack
> [addr=ffff8800b6e2bca8]
> Modules linked in: <Removed>
> Pid: 16378, comm: modprobe Not tainted 2.6.32-rc6-wl #244
> Call Trace:
> [<ffffffff81049698>] warn_slowpath_common+0x78/0xb0
> [<ffffffff8104972c>] warn_slowpath_fmt+0x3c/0x40
> [<ffffffff811ae52a>] check_for_stack+0xaa/0xe0
> [<ffffffff811afc8d>] debug_dma_map_page+0xfd/0x170
> [<ffffffffa006297a>] usb_hcd_submit_urb+0x3da/0x9c0 [usbcore]
> [<ffffffff81076e6f>] ? lockdep_init_map+0x5f/0x5d0
> [<ffffffffa0063365>] usb_submit_urb+0xe5/0x260 [usbcore]
> [<ffffffffa0064b7e>] usb_start_wait_urb+0x5e/0xf0 [usbcore]
> [<ffffffffa0063943>] ? usb_init_urb+0x23/0x40 [usbcore]
> [<ffffffffa0064cd4>] usb_bulk_msg+0xc4/0x150 [usbcore]
> [<ffffffffa0441a91>] T.719+0x31/0x40 [p54usb]
> [<ffffffffa0441acf>] p54u_upload_firmware_3887+0x2f/0x490 [p54usb]
> [<ffffffffa049c667>] ? p54_parse_firmware+0x427/0x450 [p54common]
> <Rest of traceback removed>
> ---[ end trace f77df0316ddad3de ]---
>
> Signed-off-by: Larry Finger <[email protected]>
> Cc: Stable <[email protected]>
> ---
>
> John,
>
> This is 2.6.32 material. Sorry to find it so late in the rc cycle. I hop
> DaveM doesn't give you too much trouble.
>
> V2 - Fix line wraps in trace back.
>
> Larry
> ---
>
> Index: wireless-testing/drivers/net/wireless/p54/p54usb.c
> ===================================================================
> --- wireless-testing.orig/drivers/net/wireless/p54/p54usb.c
> +++ wireless-testing/drivers/net/wireless/p54/p54usb.c
> @@ -426,12 +426,16 @@ static const char p54u_romboot_3887[] =
> static int p54u_firmware_reset_3887(struct ieee80211_hw *dev)
> {
> struct p54u_priv *priv = dev->priv;
> - u8 buf[4];
> + u8 *buf;
> int ret;
>
> - memcpy(&buf, p54u_romboot_3887, sizeof(buf));
> + buf = kmalloc(4, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
> + memcpy(buf, p54u_romboot_3887, 4);
> ret = p54u_bulk_msg(priv, P54U_PIPE_DATA,
> - buf, sizeof(buf));
> + buf, 4);
> + kfree(buf);
> if (ret)
> dev_err(&priv->udev->dev, "(p54usb) unable to jump to "
> "boot ROM (%d)!\n", ret);
>
Acked-by: Christian Lamparter <[email protected]>
FYI, p54u_upload_firmware_net2280 will likely produce the same
same WARN, since "__le32 reg;" is held on the stack as well.
Regards,
Chr
On 11/12/2009 03:51 AM, Christian Lamparter wrote:
> On Thursday 12 November 2009 01:02:29 Larry Finger wrote:
>> On 2.6.32-rc6 from wireless-testing, the following warning is emitted:
>>
>> ------------[ cut here ]------------
>> WARNING: at lib/dma-debug.c:860 check_for_stack+0xaa/0xe0()
>> Hardware name: HP Pavilion dv2700 Notebook PC
>> ehci_hcd 0000:00:02.1: DMA-API: device driver maps memory fromstack
>> [addr=ffff8800b6e2bca8]
-- snip --
>
> Acked-by: Christian Lamparter <[email protected]>
>
> FYI, p54u_upload_firmware_net2280 will likely produce the same
> same WARN, since "__le32 reg;" is held on the stack as well.
I was pretty certain that the WARN is only for DMA buffers on the stack. After
reviewing the code lib/dma-debug.c, nothing changed my mind. In
p54u_upload_firmware_net2280, the buffer is kmalloc'ed already. It should be OK.
Larry