Hi Demitry:
Thanks for your quick response, following your advice, a careful way
is changing the return type of "hideep_nvm_unlock()" from void to
int, and its caller "hideep_program_nvm()" also needs to add the
return check.
If this sounds ok, I would go ahead to modify the patch accordingly.
On Tue, Jun 15, 2021 at 11:15 AM Dmitry Torokhov
<dmitry.torokhov@xxxxxxxxx> wrote:
>
> Hi Yizhuo,
>
> On Tue, Jun 15, 2021 at 10:26:09AM -0700, Yizhuo Zhai wrote:
> > Inside function hideep_nvm_unlock(), variable "unmask_code" could
> > be uninitialized if hideep_pgm_r_reg() returns error, however, it
> > is used in the later if statement after an "and" operation, which
> > is potentially unsafe.
>
> I do not think that simply initializing the variable makes the code
> behave any better. If we want to fix this properly we need to check for
> errors returned by hideep_pgm_r_reg() and hideep_pgm_w_reg() and exit
> this function early, signalling the caller about errors.
>
> >
> > Signed-off-by: Yizhuo <yzhai003@xxxxxxx>
> > ---
> > drivers/input/touchscreen/hideep.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/input/touchscreen/hideep.c
> > b/drivers/input/touchscreen/hideep.c
> > index ddad4a82a5e5..49b713ad4384 100644
> > --- a/drivers/input/touchscreen/hideep.c
> > +++ b/drivers/input/touchscreen/hideep.c
> > @@ -363,7 +363,7 @@ static int hideep_enter_pgm(struct hideep_ts *ts)
> >
> > static void hideep_nvm_unlock(struct hideep_ts *ts)
> > {
> > - u32 unmask_code;
> > + u32 unmask_code = 0;
> >
> > hideep_pgm_w_reg(ts, HIDEEP_FLASH_CFG, HIDEEP_NVM_SFR_RPAGE);
> > hideep_pgm_r_reg(ts, 0x0000000C, &unmask_code);
> > --
> > 2.17.1
>
> Thanks.
>
> --
> Dmitry
--
Kind Regards,
Yizhuo Zhai
Computer Science, Graduate Student
University of California, Riverside
