Re: [PATCH 05/14] staging: r8188eu: use a local buffer for efuse data

[Larry Finger]

On 7/12/22 07:25, Dan Carpenter wrote:
> On Sat, Jul 09, 2022 at 07:09:51PM +0200, Martin Kaiser wrote:
> > The efuse_eeprom_data array in struct eeprom_priv is used only by
> > ReadAdapterInfo8188EU. We can remove efuse_eeprom_data and use a local
> > buffer instead.
> >
> > Use EFUSE_MAP_LEN_88E as buffer size. Its value is the same as
> > HWSET_MAX_SIZE_512. The functions that access the buffer use
> > EFUSE_MAP_LEN_88E for its size.
> >
> > Signed-off-by: Martin Kaiser <martin@xxxxxxxxx>
> > ---
> >   drivers/staging/r8188eu/hal/usb_halinit.c    | 23 ++++++++++----------
> >   drivers/staging/r8188eu/include/rtw_eeprom.h |  3 ---
> >   2 files changed, 12 insertions(+), 14 deletions(-)
> >
> > diff --git a/drivers/staging/r8188eu/hal/usb_halinit.c b/drivers/staging/r8188eu/hal/usb_halinit.c
> > index 18c2817bf1e3..807d8ce8cbfc 100644
> > --- a/drivers/staging/r8188eu/hal/usb_halinit.c
> > +++ b/drivers/staging/r8188eu/hal/usb_halinit.c
> > @@ -929,6 +929,7 @@ void ReadAdapterInfo8188EU(struct adapter *Adapter)
> >   {
> >   	struct eeprom_priv *eeprom = &Adapter->eeprompriv;
> >   	struct led_priv *ledpriv = &Adapter->ledpriv;
> > +	u8 efuse_buf[EFUSE_MAP_LEN_88E] __aligned(4);
>
> This is 512 bytes.  We used to be slightly worried about declaring 512
> bytes on the stack, but I'm not sure the situation now.

I think we should still avoid using an on-stack buffer of that size. It is 
better to use a local pointer, and kmalloc() the buffer and free it before exit.

Larry