Re: [PATCH 1/5] hid: Correctly sign-extend all values in HidP_GetScaledUsageValue().

[Aric Stewart]

Signed-off-by: Aric Stewart

On 2/12/19 12:06 AM, Zebediah Figura wrote:
> Signed-off-by: Zebediah Figura
>
> dlls/hid/hidp.c | 15 ++++++++++++++-
>   1 file changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/dlls/hid/hidp.c b/dlls/hid/hidp.c
> index 15d827edf1..ac5f22203d 100644
> --- a/dlls/hid/hidp.c
> +++ b/dlls/hid/hidp.c
> @@ -259,6 +259,19 @@ static NTSTATUS find_value(HIDP_REPORT_TYPE ReportType, USAGE UsagePage, USHORT
>       return HIDP_STATUS_USAGE_NOT_FOUND;
>   }
>
> +static LONG sign_extend(ULONG value, const WINE_HID_ELEMENT *element)
> +{
> - UINT bit_count = element->bitCount;
> -
> - if ((value & (1 << (bit_count - 1)))
> -
>        && element->ElementType == ValueElement
> -
>        && element->caps.value.LogicalMin < 0)
> - {
> -
>    value -= (1 << bit_count);
> - }
> - return value;
>
> +}
> - NTSTATUS WINAPI HidP_GetScaledUsageValue(HIDP_REPORT_TYPE ReportType, USAGE UsagePage,
>                                          USHORT LinkCollection, USAGE Usage, PLONG UsageValue,
>                                          PHIDP_PREPARSED_DATA PreparsedData, PCHAR Report, ULONG ReportLength)
>
> @@ -277,7 +290,7 @@ NTSTATUS WINAPI HidP_GetScaledUsageValue(HIDP_REPORT_TYPE ReportType, USAGE Usag
>                                element->valueStartBit, element->bitCount, &rawValue);
>           if (rc != HIDP_STATUS_SUCCESS)
>               return rc;
> -
>    *UsageValue = rawValue;
> -
>    *UsageValue = sign_extend(rawValue, element);
> }
>
> return rc;