From: maxime.coquelin@st•com (Maxime Coquelin)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] clk: divider: Fix overflow in clk_divider_bestdiv
Date: Wed, 7 May 2014 18:50:35 +0200 [thread overview]
Message-ID: <536A645B.9000709@st.com> (raw)
In-Reply-To: <1399479850-25292-1-git-send-email-t.figa@samsung.com>
Hi Tomasz,
On 05/07/2014 06:24 PM, Tomasz Figa wrote:
> Commit c686078 ("clk: divider: Add round to closest divider") introduced
> a helper function to check whether given divisor is the best one instead
> of direct check. However due to int type used instead of unsigned long
> for passing calculated rates to this function in certain cases an
> overflow could occur, for example when trying to obtain maximum possible
> clock rate by calling clk_round_rate(..., UINT_MAX).
>
> This patch fixes this issue by changing the type of rate, now and best
> arguments of the function to unsigned long, which is the type that
> should be used for clock rates.
Good catch.
Acked-by: Maxime Coquelin <maxime.coquelin@st•com>
Thanks,
Maxime
>
> Signed-off-by: Tomasz Figa <t.figa@samsung•com>
> ---
> drivers/clk/clk-divider.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c
> index c572945..e0b360a 100644
> --- a/drivers/clk/clk-divider.c
> +++ b/drivers/clk/clk-divider.c
> @@ -232,7 +232,7 @@ static int _div_round(struct clk_divider *divider, unsigned long parent_rate,
> }
>
> static bool _is_best_div(struct clk_divider *divider,
> - int rate, int now, int best)
> + unsigned long rate, unsigned long now, unsigned long best)
> {
> if (divider->flags & CLK_DIVIDER_ROUND_CLOSEST)
> return abs(rate - now) < abs(rate - best);
>
next prev parent reply other threads:[~2014-05-07 16:50 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-07 16:24 [PATCH] clk: divider: Fix overflow in clk_divider_bestdiv Tomasz Figa
2014-05-07 16:50 ` Maxime Coquelin [this message]
2014-05-15 16:51 ` Tomasz Figa
2014-05-24 23:33 ` [FIX] [CRITICAL] " Tomasz Figa
2014-05-28 2:16 ` Mike Turquette
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