Re: [PATCH] hid: logitech: don't use stack based dj_reportstructures

From: Jiri Kosina
Date: Sun Jun 03 2012 - 09:13:34 EST


On Fri, 1 Jun 2012, Marc Dionne wrote:

> On a system with a logitech wireless keyboard/mouse and DMA-API debugging
> enabled, this warning appears at boot:
>
> kernel: WARNING: at lib/dma-debug.c:929 check_for_stack.part.12+0x70/0xa7()
> kernel: Hardware name: MS-7593
> kernel: uhci_hcd 0000:00:1d.1: DMA-API: device driver maps memory fromstack [addr=ffff8801b0079c29]
>
> Make logi_dj_recv_query_paired_devices and logi_dj_recv_switch_to_dj_mode
> use a structure allocated with kzalloc rather than a stack based one.
>
> Signed-off-by: Marc Dionne <marc.c.dionne@xxxxxxxxx>

Applied, thanks Marc.

> ---
> drivers/hid/hid-logitech-dj.c | 38 ++++++++++++++++++++++++--------------
> 1 file changed, 24 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/hid/hid-logitech-dj.c b/drivers/hid/hid-logitech-dj.c
> index 5e8a7ed..0f9c146 100644
> --- a/drivers/hid/hid-logitech-dj.c
> +++ b/drivers/hid/hid-logitech-dj.c
> @@ -436,27 +436,37 @@ static int logi_dj_recv_send_report(struct dj_receiver_dev *djrcv_dev,
>
> static int logi_dj_recv_query_paired_devices(struct dj_receiver_dev *djrcv_dev)
> {
> - struct dj_report dj_report;
> + struct dj_report *dj_report;
> + int retval;
>
> - memset(&dj_report, 0, sizeof(dj_report));
> - dj_report.report_id = REPORT_ID_DJ_SHORT;
> - dj_report.device_index = 0xFF;
> - dj_report.report_type = REPORT_TYPE_CMD_GET_PAIRED_DEVICES;
> - return logi_dj_recv_send_report(djrcv_dev, &dj_report);
> + dj_report = kzalloc(sizeof(dj_report), GFP_KERNEL);
> + if (!dj_report)
> + return -ENOMEM;
> + dj_report->report_id = REPORT_ID_DJ_SHORT;
> + dj_report->device_index = 0xFF;
> + dj_report->report_type = REPORT_TYPE_CMD_GET_PAIRED_DEVICES;
> + retval = logi_dj_recv_send_report(djrcv_dev, dj_report);
> + kfree(dj_report);
> + return retval;
> }
>
> static int logi_dj_recv_switch_to_dj_mode(struct dj_receiver_dev *djrcv_dev,
> unsigned timeout)
> {
> - struct dj_report dj_report;
> + struct dj_report *dj_report;
> + int retval;
>
> - memset(&dj_report, 0, sizeof(dj_report));
> - dj_report.report_id = REPORT_ID_DJ_SHORT;
> - dj_report.device_index = 0xFF;
> - dj_report.report_type = REPORT_TYPE_CMD_SWITCH;
> - dj_report.report_params[CMD_SWITCH_PARAM_DEVBITFIELD] = 0x3F;
> - dj_report.report_params[CMD_SWITCH_PARAM_TIMEOUT_SECONDS] = (u8)timeout;
> - return logi_dj_recv_send_report(djrcv_dev, &dj_report);
> + dj_report = kzalloc(sizeof(dj_report), GFP_KERNEL);
> + if (!dj_report)
> + return -ENOMEM;
> + dj_report->report_id = REPORT_ID_DJ_SHORT;
> + dj_report->device_index = 0xFF;
> + dj_report->report_type = REPORT_TYPE_CMD_SWITCH;
> + dj_report->report_params[CMD_SWITCH_PARAM_DEVBITFIELD] = 0x3F;
> + dj_report->report_params[CMD_SWITCH_PARAM_TIMEOUT_SECONDS] = (u8)timeout;
> + retval = logi_dj_recv_send_report(djrcv_dev, dj_report);
> + kfree(dj_report);
> + return retval;
> }
>
>
> --
> 1.7.10.2
>

--
Jiri Kosina
SUSE Labs
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