Re: [PATCH 1/2] tty: serial: samsung_tty: Fix a memory leak in s3c24xx_serial_getclk() in case of error

[Christophe JAILLET]

Le 10/06/2023 à 19:10, Andi Shyti a écrit :
> On Sat, Jun 10, 2023 at 06:23:58PM +0200, Krzysztof Kozlowski wrote:
> > On 10/06/2023 16:54, Andi Shyti wrote:
> > > On Sat, Jun 10, 2023 at 04:07:51PM +0200, Christophe JAILLET wrote:
> > > > Le 10/06/2023 à 12:26, Andi Shyti a écrit :
> > > > > > @@ -1459,8 +1459,10 @@ static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
> > > > > >    			continue;
> > > > > >    		rate = clk_get_rate(clk);
> > > > > > -		if (!rate)
> > > > > > +		if (!rate) {
> > > > > > +			clk_put(clk);
> > > > > >    			continue;
> > > > >
> > > > > could you also print an error here?
> > > >
> > > > Is:
> > > > 	dev_err(ourport->port.dev,
> > > > 		"Failed to get clock rate for %s.\n", clkname);
> >
> > Why do we need it? Most of other users of clk_get_rate() don't print.
>
> that's not a reason not to print it.
>
> > Probably because such condition is highly unlikely if not impossible.
>
> still... that's not a reason not to print it.
>
> All errors are unlikely and if it's unlikely, why there is no
> unlikely(!rate)? Which doesn't improve the reason not to print
> it.
>
> The more unlikely, the lauder you need to be:
>
> WARN_ON(!rate)... maybe too much!
> BUG_ON(!rate)... way too much!
>
> But these are inversely proportional to the likeliness of the
> error.
>
> > This makes simple function unnecessarily bigger...
>
> and... that's not a reason not to print it :)
>
> If it's needed, it's needed. If we are considering the error,
> then we need to treat it as an error.
>
> In any case, I'm not strong with it, indeed, I r-b it anyway. I
> personally prefer and suggested printing the error. Up to
> Christophe.

git grep -A5 clk_get_rate | grep dev_err | wc -l
173
git grep clk_get_rate | wc -l
1464

(+ Krzysztof's argumentation)

So lets go for v1.

Can v1 be taken as is?
(knowing that I don't really care about the new 3/3 related to abs())

Or should I send a v3 to ease the process?

CJ


> Thanks,
> Andi