[PATCH] clk: ti: clkctrl: Fix returning uninitialized data

[PATCH] clk: ti: clkctrl: Fix returning uninitialized data

[Tony Lindgren]

If we do a clk_get() for a clock that does not exists, we have
_ti_omap4_clkctrl_xlate() return uninitialized data if no match
is found. This can be seen in some cases with SLAB_DEBUG enabled:

Unable to handle kernel paging request at virtual address 5a5a5a5a
...
clk_hw_create_clk.part.33
sysc_notifier_call
notifier_call_chain
blocking_notifier_call_chain
device_add

Let's fix this by setting a found flag only when we find a match.

Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reported-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Fixes: 88a172526c32 ("clk: ti: add support for clkctrl clocks")
Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 drivers/clk/ti/clkctrl.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/ti/clkctrl.c b/drivers/clk/ti/clkctrl.c
--- a/drivers/clk/ti/clkctrl.c
+++ b/drivers/clk/ti/clkctrl.c
@@ -229,6 +229,7 @@ static struct clk_hw *_ti_omap4_clkctrl_xlate(struct of_phandle_args *clkspec,
 {
 	struct omap_clkctrl_provider *provider = data;
 	struct omap_clkctrl_clk *entry;
+	bool found = false;
 
 	if (clkspec->args_count != 2)
 		return ERR_PTR(-EINVAL);
@@ -238,11 +239,13 @@ static struct clk_hw *_ti_omap4_clkctrl_xlate(struct of_phandle_args *clkspec,
 
 	list_for_each_entry(entry, &provider->clocks, node) {
 		if (entry->reg_offset == clkspec->args[0] &&
-		    entry->bit_offset == clkspec->args[1])
+		    entry->bit_offset == clkspec->args[1]) {
+			found = true;
 			break;
+		}
 	}
 
-	if (!entry)
+	if (!found)
 		return ERR_PTR(-EINVAL);
 
 	return entry->clk;
-- 
2.21.0

Re: [PATCH] clk: ti: clkctrl: Fix returning uninitialized data

[Tomi Valkeinen]

On 30/05/2019 09:55, Tony Lindgren wrote:
> If we do a clk_get() for a clock that does not exists, we have
> _ti_omap4_clkctrl_xlate() return uninitialized data if no match
> is found. This can be seen in some cases with SLAB_DEBUG enabled:
> 
> Unable to handle kernel paging request at virtual address 5a5a5a5a
> ...
> clk_hw_create_clk.part.33
> sysc_notifier_call
> notifier_call_chain
> blocking_notifier_call_chain
> device_add
> 
> Let's fix this by setting a found flag only when we find a match.
> 
> Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
> Reported-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
> Fixes: 88a172526c32 ("clk: ti: add support for clkctrl clocks")
> Signed-off-by: Tony Lindgren <tony@atomide.com>
> ---
>   drivers/clk/ti/clkctrl.c | 7 +++++--
>   1 file changed, 5 insertions(+), 2 deletions(-)

I can boot again with this fix, thanks!

Tested-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

-- 
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

Re: [PATCH] clk: ti: clkctrl: Fix returning uninitialized data

[Peter Ujfalusi]

On 30/05/2019 9.55, Tony Lindgren wrote:
> If we do a clk_get() for a clock that does not exists, we have
> _ti_omap4_clkctrl_xlate() return uninitialized data if no match
> is found. This can be seen in some cases with SLAB_DEBUG enabled:
> 
> Unable to handle kernel paging request at virtual address 5a5a5a5a
> ...
> clk_hw_create_clk.part.33
> sysc_notifier_call
> notifier_call_chain
> blocking_notifier_call_chain
> device_add
> 
> Let's fix this by setting a found flag only when we find a match.

Tested-by: Peter Ujfalusi <peter.ujfalusi@ti.com>

> 
> Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
> Reported-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
> Fixes: 88a172526c32 ("clk: ti: add support for clkctrl clocks")
> Signed-off-by: Tony Lindgren <tony@atomide.com>
> ---
>  drivers/clk/ti/clkctrl.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/clk/ti/clkctrl.c b/drivers/clk/ti/clkctrl.c
> --- a/drivers/clk/ti/clkctrl.c
> +++ b/drivers/clk/ti/clkctrl.c
> @@ -229,6 +229,7 @@ static struct clk_hw *_ti_omap4_clkctrl_xlate(struct of_phandle_args *clkspec,
>  {
>  	struct omap_clkctrl_provider *provider = data;
>  	struct omap_clkctrl_clk *entry;
> +	bool found = false;
>  
>  	if (clkspec->args_count != 2)
>  		return ERR_PTR(-EINVAL);
> @@ -238,11 +239,13 @@ static struct clk_hw *_ti_omap4_clkctrl_xlate(struct of_phandle_args *clkspec,
>  
>  	list_for_each_entry(entry, &provider->clocks, node) {
>  		if (entry->reg_offset == clkspec->args[0] &&
> -		    entry->bit_offset == clkspec->args[1])
> +		    entry->bit_offset == clkspec->args[1]) {
> +			found = true;
>  			break;
> +		}
>  	}
>  
> -	if (!entry)
> +	if (!found)
>  		return ERR_PTR(-EINVAL);
>  
>  	return entry->clk;
> 

- Péter

Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

Re: [PATCH] clk: ti: clkctrl: Fix returning uninitialized data

[Stephen Boyd]

Quoting Tony Lindgren (2019-05-29 23:55:57)
> If we do a clk_get() for a clock that does not exists, we have
> _ti_omap4_clkctrl_xlate() return uninitialized data if no match
> is found. This can be seen in some cases with SLAB_DEBUG enabled:
> 
> Unable to handle kernel paging request at virtual address 5a5a5a5a
> ...
> clk_hw_create_clk.part.33
> sysc_notifier_call
> notifier_call_chain
> blocking_notifier_call_chain
> device_add
> 
> Let's fix this by setting a found flag only when we find a match.
> 
> Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
> Reported-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
> Fixes: 88a172526c32 ("clk: ti: add support for clkctrl clocks")
> Signed-off-by: Tony Lindgren <tony@atomide.com>
> ---

Applied to clk-fixes