From: Sascha Hauer <s.hauer@pengutronix.de>
To: Ahmad Fatoum <a.fatoum@pengutronix.de>
Cc: barebox@lists.infradead.org
Subject: Re: [RFC PATCH] ddr: fsl: fix null pointer dereference handling DDR4 memories
Date: Wed, 29 Apr 2020 09:25:48 +0200 [thread overview]
Message-ID: <20200429072548.GD5877@pengutronix.de> (raw)
In-Reply-To: <20200429064014.26584-1-a.fatoum@pengutronix.de>
On Wed, Apr 29, 2020 at 08:40:14AM +0200, Ahmad Fatoum wrote:
> cppcheck reports:
>
> drivers/ddr/fsl/util.c:42:27: error: Null pointer dereference:
> c [ctunullpointer]
> unsigned int data_rate = c->ddr_freq;
> ^
> drivers/ddr/fsl/ctrl_regs.c:1114:55: note: Calling function
> get_memory_clk_period_ps, 1st argument is null
> const unsigned int mclk_ps = get_memory_clk_period_ps(0);
>
> Because get_memory_clk_period_ps expects a valid pointer, but is instead
> passed NULL. Fix this by passing along the DDR controller handle like all
> other calls to the function do. This is untested.
This is obviously correct, so applied.
>
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> ---
> drivers/ddr/fsl/ctrl_regs.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/ddr/fsl/ctrl_regs.c b/drivers/ddr/fsl/ctrl_regs.c
> index 4957320d600c..eb99e0ea21e7 100644
> --- a/drivers/ddr/fsl/ctrl_regs.c
> +++ b/drivers/ddr/fsl/ctrl_regs.c
> @@ -1111,7 +1111,7 @@ static void set_ddr_sdram_mode_9(struct fsl_ddr_controller *c,
> unsigned short esdmode5; /* Extended SDRAM mode 5 */
> int rtt_park = 0;
> bool four_cs = false;
> - const unsigned int mclk_ps = get_memory_clk_period_ps(0);
> + const unsigned int mclk_ps = get_memory_clk_period_ps(c);
mclk_ps is only used under certain circumstances. It seems on my
layersape board it is unused. This NULL pointer deref doesn't trigger
there.
Sascha
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prev parent reply other threads:[~2020-04-29 7:25 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-29 6:40 Ahmad Fatoum
2020-04-29 7:25 ` Sascha Hauer [this message]
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