Re: Re: [PATCH v2] clk: boston: fix possible memory leak in clk_boston_setup()

[<wang.yi59@zte.com.cn>]

[-- Attachment #1.1: Type: text/plain, Size: 3301 bytes --]

> Quoting wang.yi59@zte.com.cn (2018-10-29 23:13:24)
> > > Quoting Yi Wang (2018-10-29 01:31:47)
> > > > 'onecell' is malloced in clk_boston_setup(), but is not freed
> > > > before leaving from the error handling cases.
> > >
> > > How did you find this? Visual inspection? Some coccinelle script?
> >
> > Smatch report this:
> > drivers/clk/imgtec/clk-boston.c:76 clk_boston_setup() warn: possible memory leak of 'onecell'
> > drivers/clk/imgtec/clk-boston.c:83 clk_boston_setup() warn: possible memory leak of 'onecell'
> > drivers/clk/imgtec/clk-boston.c:90 clk_boston_setup() warn: possible memory leak of 'onecell'
>
> Ok. Please include those details in the commit text.

Ok :)

>
> >
> > >
> > > >
> > > > Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
> > > > ---
> > > > v2: fix syntax issue in comment, thanks to  Sergei.
> > > >
> > > >  drivers/clk/imgtec/clk-boston.c | 11 ++++++++---
> > > >  1 file changed, 8 insertions(+), 3 deletions(-)
> > > >
> > > > diff --git a/drivers/clk/imgtec/clk-boston.c b/drivers/clk/imgtec/clk-boston.c
> > > > index 15af423..f5d54a6 100644
> > > > --- a/drivers/clk/imgtec/clk-boston.c
> > > > +++ b/drivers/clk/imgtec/clk-boston.c
> > > > @@ -73,27 +73,32 @@ static void __init clk_boston_setup(struct device_node *np)
> > > >         hw = clk_hw_register_fixed_rate(NULL, "input", NULL, 0, in_freq);
> > > >         if (IS_ERR(hw)) {
> > > >                 pr_err("failed to register input clock: %ld\n", PTR_ERR(hw));
> > > > -               return;
> > > > +               goto error;
> > > >         }
> > > >         onecell->hws[BOSTON_CLK_INPUT] = hw;
> > > >
> > > >         hw = clk_hw_register_fixed_rate(NULL, "sys", "input", 0, sys_freq);
> > > >         if (IS_ERR(hw)) {
> > > >                 pr_err("failed to register sys clock: %ld\n", PTR_ERR(hw));
> > > > -               return;
> > > > +               goto error;
> > > >         }
> > > >         onecell->hws[BOSTON_CLK_SYS] = hw;
> > > >
> > > >         hw = clk_hw_register_fixed_rate(NULL, "cpu", "input", 0, cpu_freq);
> > > >         if (IS_ERR(hw)) {
> > > >                 pr_err("failed to register cpu clock: %ld\n", PTR_ERR(hw));
> > > > -               return;
> > > > +               goto error;
> > > >         }
> > > >         onecell->hws[BOSTON_CLK_CPU] = hw;
> > > >
> > > >         err = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, onecell);
> > > >         if (err)
> > > >                 pr_err("failed to add DT provider: %d\n", err);
> > > > +
> > > > +       return;
> > > > +
> > > > +error:
> > > > +       kfree(onecell);
> > >
> > > Ok, sure. But then clks are still left registered on failure?
> >
> > Yeah, but this patch does not change the original flow of the function, so I suppose
> > if you deem this is not proper, it's better to improve that in another patch, what do
> > you think?
> >
>
> I think we should attempt to fix all the theoretical problems with the
> driver instead of just fixing some things to make static checkers happy.
> It looks like this driver was written with the assumption that if things
> go bad we give up all hope. It would be better to clean everything up
> properly if things go bad and have better code.

Agreed. I will send another patch to fix this. Thanks for your advice.

---
Best wishes
Yi Wang