On Thu, May 23, 2019 at 3:54 AM Nathan Chancellor
<natechancellor@xxxxxxxxx> wrote:
>
> On Thu, May 02, 2019 at 08:17:18PM -0700, Nathan Chancellor wrote:
> > On Thu, May 02, 2019 at 11:18:01AM -0700, Nick Desaulniers wrote:
> > > On Thu, May 2, 2019 at 8:16 AM Nathan Chancellor
> > > u8 data [4];
> >
> > data was __le32 in rsi_reset_chip() before commit f700546682a6 ("rsi:
> > fix nommu_map_sg overflow kernel panic").
> >
> > I wonder if this would be okay for this function:
> >
> > -------------------------------------------------
> >
> > diff --git a/drivers/net/wireless/rsi/rsi_91x_sdio.c b/drivers/net/wireless/rsi/rsi_91x_sdio.c
> > index f9c67ed473d1..0330c50ab99c 100644
> > --- a/drivers/net/wireless/rsi/rsi_91x_sdio.c
> > +++ b/drivers/net/wireless/rsi/rsi_91x_sdio.c
> > @@ -927,7 +927,7 @@ static int rsi_sdio_ta_reset(struct rsi_hw *adapter)
> > {
> > int status;
> > u32 addr;
> > - u8 *data;
> > + u8 data;
> >
> > status = rsi_sdio_master_access_msword(adapter, TA_BASE_ADDR);
> > if (status < 0) {
> > @@ -937,7 +937,7 @@ static int rsi_sdio_ta_reset(struct rsi_hw *adapter)
> > }
> >
> > rsi_dbg(INIT_ZONE, "%s: Bring TA out of reset\n", __func__);
> > - put_unaligned_le32(TA_HOLD_THREAD_VALUE, data);
> > + put_unaligned_le32(TA_HOLD_THREAD_VALUE, &data);
> > addr = TA_HOLD_THREAD_REG | RSI_SD_REQUEST_MASTER;
> > status = rsi_sdio_write_register_multiple(adapter, addr,
> > (u8 *)&data,
This is clearly not ok, as put_unaligned_le32() stores four bytes, and
the local variable is only one byte!
Also, sdio does use DMA for transfers, so the variable has to be
dynamically allocated. I think your original patch was correct.
The only change I'd possibly make would be to use
RSI_9116_REG_SIZE instead of sizeof(u32).
> Did any of the maintainers have any comments on what the correct
> solution is here to resolve this warning? It is one of the few left
> before we can turn on -Wuninitialized for the whole kernel.
I would argue that this should not stop us from turning it on, as the
warning is for a clear bug in the code that absolutely needs to be
fixed, rather than a false-positive.
Arnd
