[PATCH 0/7] fix error return code

[PATCH 0/7] fix error return code

[Julia Lawall]

The complate semantic patch that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@ok exists@
identifier f,ret,i;
expression e;
constant c;
@@

// identify a function that returns a negative return value at least once.
f(...) {
... when any
(
return -c@i;
|
ret = -c@i;
... when != ret = e
return ret;
|
if (ret < 0) { ... return ret; }
)
... when any
}

@r exists@
identifier ret,ok.f,fn;
expression e1,e2,e3,e4,e5,e6,x;
statement S,S1;
position p1,p2,p3;
@@

// identify a case where the return variable is set to a non-negative value
// and then returned in error-handling code
f(...) {
... when any
(
if@p1 (\(ret < 0\|ret != 0\))
 { ... return ret; }
|
ret@p1 = 0
)
... when != \(ret = e1\|ret++\|ret--\|ret+=e1\|ret-=e1\)
    when != &ret
    when any
(
 if (<+... ret = e5 ...+>) S1
|
 if (<+... &ret ...+>) S1
|
if@p2(<+...x = fn(...)...+>)
 {
  ... when != ret = e6
      when forall
 return@p3 ret;
}
|
break;
|
x = fn(...)
... when != \(ret = e4\|ret++\|ret--\|ret+=e4\|ret-=e4\)
    when != &ret
(
 if (<+... ret = e3 ...+>) S
|
 if (<+... &ret ...+>) S
|
if@p2(<+...\(x != 0\|x < 0\|x == NULL\|IS_ERR(x)\)...+>)
 {
  ... when != ret = e2
      when forall
 return@p3 ret;
}
)
)
... when any
}

@printer depends on r@
position p;
identifier ok.f,pr;
constant char [] c;
@@

f(...) { <...pr@p(...,c,...)...> }

@bad0 exists@
identifier r.ret,ok.f,g != {ERR_PTR,IS_ERR};
position p != printer.p;
@@

f(...) { ... when any
g@p(...,ret,...)
... when any
 }

@bad depends on !bad0 exists@
position r.p1,r.p2;
statement S1,S2;
identifier r.ret;
expression e1;
@@

// ignore the above if there is some path where the variable is set to
// something else
(
if@p1 (\(ret < 0\|ret != 0\)) S1
|
ret@p1 = 0
)
... when any
 \(ret = e1\|ret++\|ret--\|ret+=e1\|ret-=e1\|&ret\)
... when any
if@p2(...) S2

@bad1 depends on !bad0 && !bad exists@
position r.p2;
statement S2;
identifier r.ret;
expression e1;
constant c;
@@

ret = -c
... when != \(ret = e1\|ret++\|ret--\|ret+=e1\|ret-=e1\)
    when != &ret
    when any
if@p2(...) S2

@bad2 depends on !bad0 && !bad && !bad1 exists@
position r.p1,r.p2;
identifier r.ret;
expression e1;
statement S2;
constant c;
@@

// likewise ignore it if there has been an intervening return
ret@p1 = 0
... when != if (...) { ... ret = e1 ... return ret; }
    when != if (...) { ... return -c; }
    when any
if@p2(...) S2

@script:python depends on !bad0 && !bad && !bad1 && !bad2@
p1 << r.p1;
p2 << r.p2;
p3 << r.p3;
@@

cocci.print_main("",p1)
cocci.print_secs("",p2)
cocci.print_secs("",p3)
// </smpl>

---

 drivers/block/rsxx/core.c                                     |    1 
 drivers/block/umem.c                                          |    5 +++-
 drivers/cdrom/gdrom.c                                         |    8 +++++-
 drivers/net/ethernet/ti/cpsw.c                                |    8 +++++-
 drivers/soc/ti/knav_qmss_queue.c                              |    1 
 drivers/soc/ti/wkup_m3_ipc.c                                  |    1 
 drivers/usb/gadget/legacy/acm_ms.c                            |    4 ++-
 drivers/usb/gadget/legacy/audio.c                             |    4 ++-
 drivers/usb/gadget/legacy/cdc2.c                              |    4 ++-
 drivers/usb/gadget/legacy/ether.c                             |    4 ++-
 drivers/usb/gadget/legacy/hid.c                               |    4 ++-
 drivers/usb/gadget/legacy/mass_storage.c                      |    4 ++-
 drivers/usb/gadget/legacy/ncm.c                               |    4 ++-
 drivers/video/fbdev/omap2/omapfb/displays/encoder-tpd12s015.c |   12 +++++++---
 14 files changed, 49 insertions(+), 15 deletions(-)

[PATCH 6/7] drivers: net: cpsw: fix error return code

[Julia Lawall]

Return a negative error code on failure.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
identifier ret; expression e1,e2;
@@
(
if (\(ret < 0\|ret != 0\))
 { ... return ret; }
|
ret = 0
)
... when != ret = e1
    when != &ret
*if(...)
{
  ... when != ret = e2
      when forall
 return ret;
}
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

---
 drivers/net/ethernet/ti/cpsw.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index 3409e80..6a76992 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -2448,8 +2448,10 @@ static int cpsw_probe(struct platform_device *pdev)
 
 	/* RX IRQ */
 	irq = platform_get_irq(pdev, 1);
-	if (irq < 0)
+	if (irq < 0) {
+		ret = -ENOENT;
 		goto clean_ale_ret;
+	}
 
 	priv->irqs_table[0] = irq;
 	ret = devm_request_irq(&pdev->dev, irq, cpsw_rx_interrupt,
@@ -2461,8 +2463,10 @@ static int cpsw_probe(struct platform_device *pdev)
 
 	/* TX IRQ */
 	irq = platform_get_irq(pdev, 2);
-	if (irq < 0)
+	if (irq < 0) {
+		ret = -ENOENT;
 		goto clean_ale_ret;
+	}
 
 	priv->irqs_table[1] = irq;
 	ret = devm_request_irq(&pdev->dev, irq, cpsw_tx_interrupt,

Re: [PATCH 6/7] drivers: net: cpsw: fix error return code

[Sergei Shtylyov]

Hello.

On 12/26/2015 6:28 PM, Julia Lawall wrote:

> Return a negative error code on failure.
>
> A simplified version of the semantic match that finds this problem is as
> follows: (http://coccinelle.lip6.fr/)
>
> // <smpl>
> @@
> identifier ret; expression e1,e2;
> @@
> (
> if (\(ret < 0\|ret != 0\))
>   { ... return ret; }
> |
> ret = 0
> )
> ... when != ret = e1
>      when != &ret
> *if(...)
> {
>    ... when != ret = e2
>        when forall
>   return ret;
> }
> // </smpl>
>
> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
>
> ---
>   drivers/net/ethernet/ti/cpsw.c |    8 ++++++--
>   1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
> index 3409e80..6a76992 100644
> --- a/drivers/net/ethernet/ti/cpsw.c
> +++ b/drivers/net/ethernet/ti/cpsw.c
> @@ -2448,8 +2448,10 @@ static int cpsw_probe(struct platform_device *pdev)
>
>   	/* RX IRQ */
>   	irq = platform_get_irq(pdev, 1);
> -	if (irq < 0)
> +	if (irq < 0) {
> +		ret = -ENOENT;

    Why not just propagate an error returned by that function?

>   		goto clean_ale_ret;
> +	}
>
>   	priv->irqs_table[0] = irq;
>   	ret = devm_request_irq(&pdev->dev, irq, cpsw_rx_interrupt,
> @@ -2461,8 +2463,10 @@ static int cpsw_probe(struct platform_device *pdev)
>
>   	/* TX IRQ */
>   	irq = platform_get_irq(pdev, 2);
> -	if (irq < 0)
> +	if (irq < 0) {
> +		ret = -ENOENT;

    Likewise?

[...]

MBR, Sergei

Re: [PATCH 6/7] drivers: net: cpsw: fix error return code

[Julia Lawall]

> > diff --git a/drivers/net/ethernet/ti/cpsw.c
> > b/drivers/net/ethernet/ti/cpsw.c
> > index 3409e80..6a76992 100644
> > --- a/drivers/net/ethernet/ti/cpsw.c
> > +++ b/drivers/net/ethernet/ti/cpsw.c
> > @@ -2448,8 +2448,10 @@ static int cpsw_probe(struct platform_device *pdev)
> > 
> >   	/* RX IRQ */
> >   	irq = platform_get_irq(pdev, 1);
> > -	if (irq < 0)
> > +	if (irq < 0) {
> > +		ret = -ENOENT;
> 
>    Why not just propagate an error returned by that function?

OK, I did what was done a few lines before in the same function:

        ndev->irq = platform_get_irq(pdev, 1);
        if (ndev->irq < 0) {
		dev_err(priv->dev, "error getting irq resource\n");
                ret = -ENOENT;
                goto clean_ale_ret;
        }

Maybe they should all be changed?

julia

> >   		goto clean_ale_ret;
> > +	}
> > 
> >   	priv->irqs_table[0] = irq;
> >   	ret = devm_request_irq(&pdev->dev, irq, cpsw_rx_interrupt,
> > @@ -2461,8 +2463,10 @@ static int cpsw_probe(struct platform_device *pdev)
> > 
> >   	/* TX IRQ */
> >   	irq = platform_get_irq(pdev, 2);
> > -	if (irq < 0)
> > +	if (irq < 0) {
> > +		ret = -ENOENT;
> 
>    Likewise?
> 
> [...]
> 
> MBR, Sergei
> 
> 

Re: [PATCH 6/7] drivers: net: cpsw: fix error return code

[Sergei Shtylyov]

On 12/26/2015 8:40 PM, Julia Lawall wrote:

>>> diff --git a/drivers/net/ethernet/ti/cpsw.c
>>> b/drivers/net/ethernet/ti/cpsw.c
>>> index 3409e80..6a76992 100644
>>> --- a/drivers/net/ethernet/ti/cpsw.c
>>> +++ b/drivers/net/ethernet/ti/cpsw.c
>>> @@ -2448,8 +2448,10 @@ static int cpsw_probe(struct platform_device *pdev)
>>>
>>>    	/* RX IRQ */
>>>    	irq = platform_get_irq(pdev, 1);
>>> -	if (irq < 0)
>>> +	if (irq < 0) {
>>> +		ret = -ENOENT;
>>
>>     Why not just propagate an error returned by that function?
>
> OK, I did what was done a few lines before in the same function:
>
>          ndev->irq = platform_get_irq(pdev, 1);
>          if (ndev->irq < 0) {
> 		dev_err(priv->dev, "error getting irq resource\n");
>                  ret = -ENOENT;
>                  goto clean_ale_ret;
>          }
>
> Maybe they should all be changed?

    Yeah, I'd vote for it. I'm seeing no sense in overriding an actual error.

[...]

> julia

MBR, Sergei

[PATCH 6/7 v2] drivers: net: cpsw: fix error return code

[Julia Lawall]

Propagate the return value of platform_get_irq on failure.

A simplified version of the semantic match that finds the two cases where
no error code is returned at all is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
identifier ret; expression e1,e2;
@@
(
if (\(ret < 0\|ret != 0\))
 { ... return ret; }
|
ret = 0
)
... when != ret = e1
    when != &ret
*if(...)
{
  ... when != ret = e2
      when forall
 return ret;
}
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

---
v2: propagate platform_get_irq return value, at all calls

 drivers/net/ethernet/ti/cpsw.c |   10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index 3409e80..34ce7dc 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -2427,7 +2427,7 @@ static int cpsw_probe(struct platform_device *pdev)
 	ndev->irq = platform_get_irq(pdev, 1);
 	if (ndev->irq < 0) {
 		dev_err(priv->dev, "error getting irq resource\n");
-		ret = -ENOENT;
+		ret = ndev->irq;
 		goto clean_ale_ret;
 	}
 
@@ -2448,8 +2448,10 @@ static int cpsw_probe(struct platform_device *pdev)
 
 	/* RX IRQ */
 	irq = platform_get_irq(pdev, 1);
-	if (irq < 0)
+	if (irq < 0) {
+		ret = irq;
 		goto clean_ale_ret;
+	}
 
 	priv->irqs_table[0] = irq;
 	ret = devm_request_irq(&pdev->dev, irq, cpsw_rx_interrupt,
@@ -2461,8 +2463,10 @@ static int cpsw_probe(struct platform_device *pdev)
 
 	/* TX IRQ */
 	irq = platform_get_irq(pdev, 2);
-	if (irq < 0)
+	if (irq < 0) {
+		ret = irq;
 		goto clean_ale_ret;
+	}
 
 	priv->irqs_table[1] = irq;
 	ret = devm_request_irq(&pdev->dev, irq, cpsw_tx_interrupt,

Re: [PATCH 6/7] drivers: net: cpsw: fix error return code

[Sergei Shtylyov]

Hello.

On 12/26/2015 08:50 PM, Sergei Shtylyov wrote:

>>>> diff --git a/drivers/net/ethernet/ti/cpsw.c
>>>> b/drivers/net/ethernet/ti/cpsw.c
>>>> index 3409e80..6a76992 100644
>>>> --- a/drivers/net/ethernet/ti/cpsw.c
>>>> +++ b/drivers/net/ethernet/ti/cpsw.c
>>>> @@ -2448,8 +2448,10 @@ static int cpsw_probe(struct platform_device *pdev)
>>>>
>>>>        /* RX IRQ */
>>>>        irq = platform_get_irq(pdev, 1);
>>>> -    if (irq < 0)
>>>> +    if (irq < 0) {
>>>> +        ret = -ENOENT;
>>>
>>>     Why not just propagate an error returned by that function?
>>
>> OK, I did what was done a few lines before in the same function:
>>
>>          ndev->irq = platform_get_irq(pdev, 1);
>>          if (ndev->irq < 0) {
>>         dev_err(priv->dev, "error getting irq resource\n");
>>                  ret = -ENOENT;
>>                  goto clean_ale_ret;
>>          }
>>
>> Maybe they should all be changed?
>
>     Yeah, I'd vote for it. I'm seeing no sense in overriding an actual error.

    Hm, I decided to check drivers/base/dd.c and I think I maybe know the 
reason now: -ENXIO, usually returned by platform_get_irq(), is silently 
"swallowed" by really_probe(); to be precise, -ENODEV and -ENXIO are only 
reported with pr_debug(), while -ENOENT causes printk(KERN_WARNING, ...)...

> [...]
>
>> julia

MBR, Sergei

Re: [PATCH 6/7] drivers: net: cpsw: fix error return code

[Julia Lawall]

On Sat, 26 Dec 2015, Sergei Shtylyov wrote:

> Hello.
> 
> On 12/26/2015 08:50 PM, Sergei Shtylyov wrote:
> 
> > > > > diff --git a/drivers/net/ethernet/ti/cpsw.c
> > > > > b/drivers/net/ethernet/ti/cpsw.c
> > > > > index 3409e80..6a76992 100644
> > > > > --- a/drivers/net/ethernet/ti/cpsw.c
> > > > > +++ b/drivers/net/ethernet/ti/cpsw.c
> > > > > @@ -2448,8 +2448,10 @@ static int cpsw_probe(struct platform_device
> > > > > *pdev)
> > > > > 
> > > > >        /* RX IRQ */
> > > > >        irq = platform_get_irq(pdev, 1);
> > > > > -    if (irq < 0)
> > > > > +    if (irq < 0) {
> > > > > +        ret = -ENOENT;
> > > > 
> > > >     Why not just propagate an error returned by that function?
> > > 
> > > OK, I did what was done a few lines before in the same function:
> > > 
> > >          ndev->irq = platform_get_irq(pdev, 1);
> > >          if (ndev->irq < 0) {
> > >         dev_err(priv->dev, "error getting irq resource\n");
> > >                  ret = -ENOENT;
> > >                  goto clean_ale_ret;
> > >          }
> > > 
> > > Maybe they should all be changed?
> > 
> >     Yeah, I'd vote for it. I'm seeing no sense in overriding an actual
> > error.
> 
>    Hm, I decided to check drivers/base/dd.c and I think I maybe know the
> reason now: -ENXIO, usually returned by platform_get_irq(), is silently
> "swallowed" by really_probe(); to be precise, -ENODEV and -ENXIO are only
> reported with pr_debug(), while -ENOENT causes printk(KERN_WARNING, ...)...

Sorry, I'm confused...  What should it be?  v1 or v2?  Here are the counts 
of the different constants returned on failure of platform_get_irq:

ENODEV: 84
ENXIO: 67
EINVAL: 61
ENOENT: 29
EBUSY: 11
EIO: 2
EPROBE_DEFER: 1

julia

Re: [PATCH 6/7] drivers: net: cpsw: fix error return code

[Sergei Shtylyov]

On 12/26/2015 11:07 PM, Julia Lawall wrote:

>>>>>> diff --git a/drivers/net/ethernet/ti/cpsw.c
>>>>>> b/drivers/net/ethernet/ti/cpsw.c
>>>>>> index 3409e80..6a76992 100644
>>>>>> --- a/drivers/net/ethernet/ti/cpsw.c
>>>>>> +++ b/drivers/net/ethernet/ti/cpsw.c
>>>>>> @@ -2448,8 +2448,10 @@ static int cpsw_probe(struct platform_device
>>>>>> *pdev)
>>>>>>
>>>>>>         /* RX IRQ */
>>>>>>         irq = platform_get_irq(pdev, 1);
>>>>>> -    if (irq < 0)
>>>>>> +    if (irq < 0) {
>>>>>> +        ret = -ENOENT;
>>>>>
>>>>>      Why not just propagate an error returned by that function?
>>>>
>>>> OK, I did what was done a few lines before in the same function:
>>>>
>>>>           ndev->irq = platform_get_irq(pdev, 1);
>>>>           if (ndev->irq < 0) {
>>>>          dev_err(priv->dev, "error getting irq resource\n");
>>>>                   ret = -ENOENT;
>>>>                   goto clean_ale_ret;
>>>>           }
>>>>
>>>> Maybe they should all be changed?
>>>
>>>      Yeah, I'd vote for it. I'm seeing no sense in overriding an actual
>>> error.
>>
>>     Hm, I decided to check drivers/base/dd.c and I think I maybe know the
>> reason now: -ENXIO, usually returned by platform_get_irq(), is silently
>> "swallowed" by really_probe(); to be precise, -ENODEV and -ENXIO are only
>> reported with pr_debug(), while -ENOENT causes printk(KERN_WARNING, ...)...

> Sorry, I'm confused...  What should it be?  v1 or v2?  Here are the counts
> of the different constants returned on failure of platform_get_irq:

    I was somewhat confused myself but then I remembered about the deferred 
probing -- overriding error code basically just disables it in this case.

> ENODEV: 84
> ENXIO: 67

   Those 2 totally make no sense. :-)

> EINVAL: 61
> ENOENT: 29
> EBUSY: 11

    Hm...

> EIO: 2
> EPROBE_DEFER: 1

    Hm, and that last one is unconditional?

> julia

MBR, Sergei