On Saturday, August 28, 2021 11:24:52 PM CEST Phillip Potter wrote:
> Simplify c2h_evt_hdl function by removing majority of its code. The
> function always returns _FAIL anyway, due to the wrapper function it
> calls always returning _FAIL. For this reason, it is better to just
> return _FAIL directly.
>
> Leave the call to c2h_evt_read in place, as without it, event handling
> semantics of the driver would be changed, despite nothing actually being
> done with the event.
>
> Signed-off-by: Phillip Potter <phil@xxxxxxxxxxxxxxxx>
> ---
> drivers/staging/r8188eu/core/rtw_cmd.c | 21 +++------------------
> 1 file changed, 3 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/staging/r8188eu/core/rtw_cmd.c b/drivers/staging/r8188eu/core/rtw_cmd.c
> index ce73ac7cf973..b520c6b43c03 100644
> --- a/drivers/staging/r8188eu/core/rtw_cmd.c
> +++ b/drivers/staging/r8188eu/core/rtw_cmd.c
> @@ -1854,27 +1854,12 @@ u8 rtw_c2h_wk_cmd(struct adapter *padapter, u8 *c2h_evt)
>
> static s32 c2h_evt_hdl(struct adapter *adapter, struct c2h_evt_hdr *c2h_evt, c2h_id_filter filter)
> {
> - s32 ret = _FAIL;
> u8 buf[16];
>
> - if (!c2h_evt) {
> - /* No c2h event in cmd_obj, read c2h event before handling*/
> - if (c2h_evt_read(adapter, buf) == _SUCCESS) {
> - c2h_evt = (struct c2h_evt_hdr *)buf;
Dear Philip,
Not related to your patch, but what kind of odd assignment is it? c2h_evt takes
the address of a local variable and therefore it crashes the kernel whenever
someone decides to dereference it after this function returns and unwinds
the stack...
> + if (!c2h_evt)
> + c2h_evt_read(adapter, buf);
Having said that, I strongly doubt that this path is ever taken. I didn't check the call
chain, but it may be that the function in never called or, if it is called, it always
has a valid c2h_evt argument.
Actually I don't mean to suggest something specific. It simply looks odd, so I'd check
and if this happens to be the case, I'd remove the whole c2h_evt_hdl().
Regards,
Fabio
>
> - if (filter && !filter(c2h_evt->id))
> - goto exit;
> -
> - ret = rtw_hal_c2h_handler(adapter, c2h_evt);
> - }
> - } else {
> - if (filter && !filter(c2h_evt->id))
> - goto exit;
> -
> - ret = rtw_hal_c2h_handler(adapter, c2h_evt);
> - }
> -exit:
> - return ret;
> + return _FAIL;
> }
>
> static void c2h_wk_callback(struct work_struct *work)
> --
> 2.31.1
>
>
