[PATCH] mtd: nand: atmel: fix of_irq_get() error check

[PATCH] mtd: nand: atmel: fix of_irq_get() error check

[Sergei Shtylyov]

[-- Attachment #1: mtd-nand-atmel-fix-of_irq_get-error-check.patch --]
[-- Type: text/plain, Size: 1693 bytes --]

of_irq_get() may return 0 as well as negative error number on failure,
while the driver only checks for the negative values.  The driver would
then call devm_request_irq() for IRQ0  in its probe method and never get
a valid interrupt.

Check for 'nc->irq <= 0' instead and return -ENXIO from the driver's probe
iff of_irq_get() returned 0.

Fixes: f88fc122cc34 ("mtd: nand: Cleanup/rework the atmel_nand driver")
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>

---
The patch is against the 'master' branch of the 'linux-mtd.git' repo --
the 'nand/fixes'  branch seems too old...

 drivers/mtd/nand/atmel/nand-controller.c |   12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

Index: linux-mtd/drivers/mtd/nand/atmel/nand-controller.c
===================================================================
--- linux-mtd.orig/drivers/mtd/nand/atmel/nand-controller.c
+++ linux-mtd/drivers/mtd/nand/atmel/nand-controller.c
@@ -2078,11 +2078,11 @@ atmel_hsmc_nand_controller_legacy_init(s
 	}
 
 	nc->irq = of_irq_get(nand_np, 0);
-	if (nc->irq < 0) {
-		ret = nc->irq;
-		if (ret != -EPROBE_DEFER)
+	if (nc->irq <= 0) {
+		if (nc->irq != -EPROBE_DEFER)
 			dev_err(dev, "Failed to get IRQ number (err = %d)\n",
-				ret);
+				nc->irq);
+		ret = nc->irq ?: -ENXIO;
 		goto out;
 	}
 
@@ -2168,11 +2168,11 @@ atmel_hsmc_nand_controller_init(struct a
 
 	nc->irq = of_irq_get(np, 0);
 	of_node_put(np);
-	if (nc->irq < 0) {
+	if (nc->irq <= 0) {
 		if (nc->irq != -EPROBE_DEFER)
 			dev_err(dev, "Failed to get IRQ number (err = %d)\n",
 				nc->irq);
-		return nc->irq;
+		return nc->irq ?: -ENXIO;
 	}
 
 	np = of_parse_phandle(dev->of_node, "atmel,nfc-io", 0);

Re: [PATCH] mtd: nand: atmel: fix of_irq_get() error check

[Yang, Wenyou]

tested


On 2017/8/6 5:14, Sergei Shtylyov wrote:

RE: [PATCH] mtd: nand: atmel: fix of_irq_get() error check

[Wenyou.Yang]

Sorry, noise, please ignore.


> -----Original Message-----
> From: Wenyou Yang - A41535
> Sent: 2017年8月7日 11:39
> To: Wenyou Yang - A41535 <Wenyou.Yang@microchip.com>; Boris Brezillon
> <boris.brezillon@free-electrons.com>; Richard Weinberger <richard@nod.at>;
> David Woodhouse <dwmw2@infradead.org>; Brian Norris
> <computersforpeace@gmail.com>; Marek Vasut <marek.vasut@gmail.com>;
> Cyrille Pitchen <cyrille.pitchen@wedev4u.fr>; linux-mtd@lists.infradead.org
> Subject: Re: [PATCH] mtd: nand: atmel: fix of_irq_get() error check
> 
> tested
> 
> 
> On 2017/8/6 5:14, Sergei Shtylyov wrote:

Best Regards,
Wenyou Yang

RE: [PATCH] mtd: nand: atmel: fix of_irq_get() error check

[Wenyou.Yang]

> -----Original Message-----
> From: Sergei Shtylyov [mailto:sergei.shtylyov@cogentembedded.com]
> Sent: 2017年8月6日 5:14
> To: Wenyou Yang - A41535 <Wenyou.Yang@microchip.com>; Josh Wu
> <rainyfeeling@outlook.com>; Boris Brezillon <boris.brezillon@free-
> electrons.com>; Richard Weinberger <richard@nod.at>; David Woodhouse
> <dwmw2@infradead.org>; Brian Norris <computersforpeace@gmail.com>; Marek
> Vasut <marek.vasut@gmail.com>; Cyrille Pitchen <cyrille.pitchen@wedev4u.fr>;
> linux-mtd@lists.infradead.org
> Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
> Subject: [PATCH] mtd: nand: atmel: fix of_irq_get() error check
> 
> of_irq_get() may return 0 as well as negative error number on failure, while the
> driver only checks for the negative values.  The driver would then call
> devm_request_irq() for IRQ0  in its probe method and never get a valid interrupt.
> 
> Check for 'nc->irq <= 0' instead and return -ENXIO from the driver's probe iff
> of_irq_get() returned 0.
> 
> Fixes: f88fc122cc34 ("mtd: nand: Cleanup/rework the atmel_nand driver")
> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
> 

Indeed.

Acked-by: Wenyou Yang <Wenyou.yang@microchip.com>


Best Regards,
Wenyou Yang

Re: [PATCH] mtd: nand: atmel: fix of_irq_get() error check

[Boris Brezillon]

Le Sun, 06 Aug 2017 00:14:28 +0300,
Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> a écrit :

> of_irq_get() may return 0 as well as negative error number on failure,
> while the driver only checks for the negative values.  The driver would
> then call devm_request_irq() for IRQ0  in its probe method and never get
> a valid interrupt.
> 
> Check for 'nc->irq <= 0' instead and return -ENXIO from the driver's probe
> iff of_irq_get() returned 0.
> 
> Fixes: f88fc122cc34 ("mtd: nand: Cleanup/rework the atmel_nand driver")
> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
> 
> ---
> The patch is against the 'master' branch of the 'linux-mtd.git' repo --
> the 'nand/fixes'  branch seems too old...
> 
>  drivers/mtd/nand/atmel/nand-controller.c |   12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> Index: linux-mtd/drivers/mtd/nand/atmel/nand-controller.c
> ===================================================================
> --- linux-mtd.orig/drivers/mtd/nand/atmel/nand-controller.c
> +++ linux-mtd/drivers/mtd/nand/atmel/nand-controller.c
> @@ -2078,11 +2078,11 @@ atmel_hsmc_nand_controller_legacy_init(s
>  	}
>  
>  	nc->irq = of_irq_get(nand_np, 0);
> -	if (nc->irq < 0) {
> -		ret = nc->irq;
> -		if (ret != -EPROBE_DEFER)
> +	if (nc->irq <= 0) {
> +		if (nc->irq != -EPROBE_DEFER)
>  			dev_err(dev, "Failed to get IRQ number (err = %d)\n",
> -				ret);
> +				nc->irq);

nc->irq can be 0 here which doesn't make any sense for an error return
code, so I'd suggest to still use ret and move the 'ret = nc->irq ?:
-ENXIO' line before doing the != -EPROBE_DEFER test.

> +		ret = nc->irq ?: -ENXIO;

Why ENXIO and not EINVAL?

>  		goto out;
>  	}
>  
> @@ -2168,11 +2168,11 @@ atmel_hsmc_nand_controller_init(struct a
>  
>  	nc->irq = of_irq_get(np, 0);
>  	of_node_put(np);
> -	if (nc->irq < 0) {
> +	if (nc->irq <= 0) {
>  		if (nc->irq != -EPROBE_DEFER)
>  			dev_err(dev, "Failed to get IRQ number (err = %d)\n",
>  				nc->irq);
> -		return nc->irq;
> +		return nc->irq ?: -ENXIO;
>  	}
>  
>  	np = of_parse_phandle(dev->of_node, "atmel,nfc-io", 0);
> 

Re: [PATCH] mtd: nand: atmel: fix of_irq_get() error check

[Sergei Shtylyov]

On 8/10/2017 12:59 PM, Boris Brezillon wrote:

>> of_irq_get() may return 0 as well as negative error number on failure,
>> while the driver only checks for the negative values.  The driver would
>> then call devm_request_irq() for IRQ0  in its probe method and never get
>> a valid interrupt.
>>
>> Check for 'nc->irq <= 0' instead and return -ENXIO from the driver's probe
>> iff of_irq_get() returned 0.
>>
>> Fixes: f88fc122cc34 ("mtd: nand: Cleanup/rework the atmel_nand driver")
>> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
>>
>> ---
>> The patch is against the 'master' branch of the 'linux-mtd.git' repo --
>> the 'nand/fixes'  branch seems too old...
>>
>>   drivers/mtd/nand/atmel/nand-controller.c |   12 ++++++------
>>   1 file changed, 6 insertions(+), 6 deletions(-)
>>
>> Index: linux-mtd/drivers/mtd/nand/atmel/nand-controller.c
>> ===================================================================
>> --- linux-mtd.orig/drivers/mtd/nand/atmel/nand-controller.c
>> +++ linux-mtd/drivers/mtd/nand/atmel/nand-controller.c
>> @@ -2078,11 +2078,11 @@ atmel_hsmc_nand_controller_legacy_init(s
>>   	}
>>   
>>   	nc->irq = of_irq_get(nand_np, 0);
>> -	if (nc->irq < 0) {
>> -		ret = nc->irq;
>> -		if (ret != -EPROBE_DEFER)
>> +	if (nc->irq <= 0) {
>> +		if (nc->irq != -EPROBE_DEFER)
>>   			dev_err(dev, "Failed to get IRQ number (err = %d)\n",
>> -				ret);
>> +				nc->irq);
> 
> nc->irq can be 0 here which doesn't make any sense for an error return
> code, so I'd suggest to still use ret and move the 'ret = nc->irq ?:
> -ENXIO' line before doing the != -EPROBE_DEFER test.

    I tried to keep reporting the original of_irq_get() result. Can change it 
if you prefer it another way...

>> +		ret = nc->irq ?: -ENXIO;
> 
> Why ENXIO and not EINVAL?

    That's what platform_get_irq() (another of_irq_get() user) returns if it 
doesn't find the IRQ resource.

>>   		goto out;
>>   	}
>>   
[...]
MBR, Sergei

Re: [PATCH] mtd: nand: atmel: fix of_irq_get() error check

[Boris Brezillon]

Le Thu, 10 Aug 2017 13:12:09 +0300,
Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> a écrit :

> On 8/10/2017 12:59 PM, Boris Brezillon wrote:
> 
> >> of_irq_get() may return 0 as well as negative error number on failure,
> >> while the driver only checks for the negative values.  The driver would
> >> then call devm_request_irq() for IRQ0  in its probe method and never get
> >> a valid interrupt.
> >>
> >> Check for 'nc->irq <= 0' instead and return -ENXIO from the driver's probe
> >> iff of_irq_get() returned 0.
> >>
> >> Fixes: f88fc122cc34 ("mtd: nand: Cleanup/rework the atmel_nand driver")
> >> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
> >>
> >> ---
> >> The patch is against the 'master' branch of the 'linux-mtd.git' repo --
> >> the 'nand/fixes'  branch seems too old...
> >>
> >>   drivers/mtd/nand/atmel/nand-controller.c |   12 ++++++------
> >>   1 file changed, 6 insertions(+), 6 deletions(-)
> >>
> >> Index: linux-mtd/drivers/mtd/nand/atmel/nand-controller.c
> >> ===================================================================
> >> --- linux-mtd.orig/drivers/mtd/nand/atmel/nand-controller.c
> >> +++ linux-mtd/drivers/mtd/nand/atmel/nand-controller.c
> >> @@ -2078,11 +2078,11 @@ atmel_hsmc_nand_controller_legacy_init(s
> >>   	}
> >>   
> >>   	nc->irq = of_irq_get(nand_np, 0);
> >> -	if (nc->irq < 0) {
> >> -		ret = nc->irq;
> >> -		if (ret != -EPROBE_DEFER)
> >> +	if (nc->irq <= 0) {
> >> +		if (nc->irq != -EPROBE_DEFER)
> >>   			dev_err(dev, "Failed to get IRQ number (err = %d)\n",
> >> -				ret);
> >> +				nc->irq);  
> > 
> > nc->irq can be 0 here which doesn't make any sense for an error return
> > code, so I'd suggest to still use ret and move the 'ret = nc->irq ?:
> > -ENXIO' line before doing the != -EPROBE_DEFER test.  
> 
>     I tried to keep reporting the original of_irq_get() result. Can change it 
> if you prefer it another way...

Yep, I prefer to have an error core here. No need to send a new
version, I already fixed the patch when applying.

BTW, it's applied to nand/next not nand/fixes because this bug does not
really impact users as long as the 'interrupts' property is correctly
defined in the DT (which AFAICT is the case).

> 
> >> +		ret = nc->irq ?: -ENXIO;  
> > 
> > Why ENXIO and not EINVAL?  
> 
>     That's what platform_get_irq() (another of_irq_get() user) returns if it 
> doesn't find the IRQ resource.

Okay.

> 
> >>   		goto out;
> >>   	}
> >>     
> [...]
> MBR, Sergei