[PATCH] Staging: octeon: Avoid several usecases of strcpy

[PATCH] Staging: octeon: Avoid several usecases of strcpy

[Sandro Volery]

strcpy was used multiple times in strcpy to write into dev->name.
I replaced them with strscpy.

Signed-off-by: Sandro Volery <sandro@volery.com>
---
 drivers/staging/octeon/ethernet.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/staging/octeon/ethernet.c b/drivers/staging/octeon/ethernet.c
index 8889494adf1f..cf8e9a23ebf9 100644
--- a/drivers/staging/octeon/ethernet.c
+++ b/drivers/staging/octeon/ethernet.c
@@ -784,7 +784,7 @@ static int cvm_oct_probe(struct platform_device *pdev)
 			priv->imode = CVMX_HELPER_INTERFACE_MODE_DISABLED;
 			priv->port = CVMX_PIP_NUM_INPUT_PORTS;
 			priv->queue = -1;
-			strcpy(dev->name, "pow%d");
+			strscpy(dev->name, "pow%d", sizeof(dev->name));
 			for (qos = 0; qos < 16; qos++)
 				skb_queue_head_init(&priv->tx_free_list[qos]);
 			dev->min_mtu = VLAN_ETH_ZLEN - mtu_overhead;
@@ -856,39 +856,39 @@ static int cvm_oct_probe(struct platform_device *pdev)
 
 			case CVMX_HELPER_INTERFACE_MODE_NPI:
 				dev->netdev_ops = &cvm_oct_npi_netdev_ops;
-				strcpy(dev->name, "npi%d");
+				strscpy(dev->name, "npi%d", sizeof(dev->name));
 				break;
 
 			case CVMX_HELPER_INTERFACE_MODE_XAUI:
 				dev->netdev_ops = &cvm_oct_xaui_netdev_ops;
-				strcpy(dev->name, "xaui%d");
+				strscpy(dev->name, "xaui%d", sizeof(dev->name));
 				break;
 
 			case CVMX_HELPER_INTERFACE_MODE_LOOP:
 				dev->netdev_ops = &cvm_oct_npi_netdev_ops;
-				strcpy(dev->name, "loop%d");
+				strscpy(dev->name, "loop%d", sizeof(dev->name));
 				break;
 
 			case CVMX_HELPER_INTERFACE_MODE_SGMII:
 				priv->phy_mode = PHY_INTERFACE_MODE_SGMII;
 				dev->netdev_ops = &cvm_oct_sgmii_netdev_ops;
-				strcpy(dev->name, "eth%d");
+				strscpy(dev->name, "eth%d", sizeof(dev->name));
 				break;
 
 			case CVMX_HELPER_INTERFACE_MODE_SPI:
 				dev->netdev_ops = &cvm_oct_spi_netdev_ops;
-				strcpy(dev->name, "spi%d");
+				strscpy(dev->name, "spi%d", sizeof(dev->name));
 				break;
 
 			case CVMX_HELPER_INTERFACE_MODE_GMII:
 				priv->phy_mode = PHY_INTERFACE_MODE_GMII;
 				dev->netdev_ops = &cvm_oct_rgmii_netdev_ops;
-				strcpy(dev->name, "eth%d");
+				strscpy(dev->name, "eth%d", sizeof(dev->name));
 				break;
 
 			case CVMX_HELPER_INTERFACE_MODE_RGMII:
 				dev->netdev_ops = &cvm_oct_rgmii_netdev_ops;
-				strcpy(dev->name, "eth%d");
+				strscpy(dev->name, "eth%d", sizeof(dev->name));
 				cvm_set_rgmii_delay(priv, interface,
 						    port_index);
 				break;
-- 
2.23.0

Re: [PATCH] Staging: octeon: Avoid several usecases of strcpy

[Dan Carpenter]

On Wed, Sep 11, 2019 at 08:23:59AM +0200, Sandro Volery wrote:
> strcpy was used multiple times in strcpy to write into dev->name.
> I replaced them with strscpy.
> 
> Signed-off-by: Sandro Volery <sandro@volery.com>
> ---
>  drivers/staging/octeon/ethernet.c | 16 ++++++++--------
>  1 file changed, 8 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/staging/octeon/ethernet.c b/drivers/staging/octeon/ethernet.c
> index 8889494adf1f..cf8e9a23ebf9 100644
> --- a/drivers/staging/octeon/ethernet.c
> +++ b/drivers/staging/octeon/ethernet.c
> @@ -784,7 +784,7 @@ static int cvm_oct_probe(struct platform_device *pdev)
>  			priv->imode = CVMX_HELPER_INTERFACE_MODE_DISABLED;
>  			priv->port = CVMX_PIP_NUM_INPUT_PORTS;
>  			priv->queue = -1;
> -			strcpy(dev->name, "pow%d");
> +			strscpy(dev->name, "pow%d", sizeof(dev->name));

Is there a program which is generating a warning for this code?  We know
that "pow%d" is 6 characters and static analysis tools can understand
this code fine so we know it's safe.

regards,
dan carpenter

Re: [PATCH] Staging: octeon: Avoid several usecases of strcpy

[Sandro Volery]

> On 11 Sep 2019, at 10:52, Dan Carpenter <dan.carpenter@oracle.com> wrote:
> 
> On Wed, Sep 11, 2019 at 08:23:59AM +0200, Sandro Volery wrote:
>> strcpy was used multiple times in strcpy to write into dev->name.
>> I replaced them with strscpy.
>> 
>> Signed-off-by: Sandro Volery <sandro@volery.com>
>> ---
>> drivers/staging/octeon/ethernet.c | 16 ++++++++--------
>> 1 file changed, 8 insertions(+), 8 deletions(-)
>> 
>> diff --git a/drivers/staging/octeon/ethernet.c b/drivers/staging/octeon/ethernet.c
>> index 8889494adf1f..cf8e9a23ebf9 100644
>> --- a/drivers/staging/octeon/ethernet.c
>> +++ b/drivers/staging/octeon/ethernet.c
>> @@ -784,7 +784,7 @@ static int cvm_oct_probe(struct platform_device *pdev)
>>            priv->imode = CVMX_HELPER_INTERFACE_MODE_DISABLED;
>>            priv->port = CVMX_PIP_NUM_INPUT_PORTS;
>>            priv->queue = -1;
>> -            strcpy(dev->name, "pow%d");
>> +            strscpy(dev->name, "pow%d", sizeof(dev->name));
> 
> Is there a program which is generating a warning for this code?  We know
> that "pow%d" is 6 characters and static analysis tools can understand
> this code fine so we know it's safe.

Well I was confused too but checkpatch complained about 
it so I figured I'd clean it up quick

Re: [PATCH] Staging: octeon: Avoid several usecases of strcpy

[Dan Carpenter]

On Wed, Sep 11, 2019 at 11:04:38AM +0200, Sandro Volery wrote:
> 
> 
> > On 11 Sep 2019, at 10:52, Dan Carpenter <dan.carpenter@oracle.com> wrote:
> > 
> > On Wed, Sep 11, 2019 at 08:23:59AM +0200, Sandro Volery wrote:
> >> strcpy was used multiple times in strcpy to write into dev->name.
> >> I replaced them with strscpy.
> >> 
> >> Signed-off-by: Sandro Volery <sandro@volery.com>
> >> ---
> >> drivers/staging/octeon/ethernet.c | 16 ++++++++--------
> >> 1 file changed, 8 insertions(+), 8 deletions(-)
> >> 
> >> diff --git a/drivers/staging/octeon/ethernet.c b/drivers/staging/octeon/ethernet.c
> >> index 8889494adf1f..cf8e9a23ebf9 100644
> >> --- a/drivers/staging/octeon/ethernet.c
> >> +++ b/drivers/staging/octeon/ethernet.c
> >> @@ -784,7 +784,7 @@ static int cvm_oct_probe(struct platform_device *pdev)
> >>            priv->imode = CVMX_HELPER_INTERFACE_MODE_DISABLED;
> >>            priv->port = CVMX_PIP_NUM_INPUT_PORTS;
> >>            priv->queue = -1;
> >> -            strcpy(dev->name, "pow%d");
> >> +            strscpy(dev->name, "pow%d", sizeof(dev->name));
> > 
> > Is there a program which is generating a warning for this code?  We know
> > that "pow%d" is 6 characters and static analysis tools can understand
> > this code fine so we know it's safe.
> 
> Well I was confused too but checkpatch complained about 
> it so I figured I'd clean it up quick

Ah.  It's a new checkpatch warning.  I don't care in that case.  I'm
fine with replacing all of these in that case.

regards,
dan carpenter

Re: [PATCH] Staging: octeon: Avoid several usecases of strcpy

[Sandro Volery]

On 11 Sep 2019, at 11:17, Dan Carpenter <dan.carpenter@oracle.com> wrote:
> 
> On Wed, Sep 11, 2019 at 11:04:38AM +0200, Sandro Volery wrote:
>> 
>> 
>>>> On 11 Sep 2019, at 10:52, Dan Carpenter <dan.carpenter@oracle.com> wrote:
>>> 
>>> On Wed, Sep 11, 2019 at 08:23:59AM +0200, Sandro Volery wrote:
>>>> strcpy was used multiple times in strcpy to write into dev->name.
>>>> I replaced them with strscpy.
>>>> 
>>>> Signed-off-by: Sandro Volery <sandro@volery.com>
>>>> ---
>>>> drivers/staging/octeon/ethernet.c | 16 ++++++++--------
>>>> 1 file changed, 8 insertions(+), 8 deletions(-)
>>>> 
>>>> diff --git a/drivers/staging/octeon/ethernet.c b/drivers/staging/octeon/ethernet.c
>>>> index 8889494adf1f..cf8e9a23ebf9 100644
>>>> --- a/drivers/staging/octeon/ethernet.c
>>>> +++ b/drivers/staging/octeon/ethernet.c
>>>> @@ -784,7 +784,7 @@ static int cvm_oct_probe(struct platform_device *pdev)
>>>>           priv->imode = CVMX_HELPER_INTERFACE_MODE_DISABLED;
>>>>           priv->port = CVMX_PIP_NUM_INPUT_PORTS;
>>>>           priv->queue = -1;
>>>> -            strcpy(dev->name, "pow%d");
>>>> +            strscpy(dev->name, "pow%d", sizeof(dev->name));
>>> 
>>> Is there a program which is generating a warning for this code?  We know
>>> that "pow%d" is 6 characters and static analysis tools can understand
>>> this code fine so we know it's safe.
>> 
>> Well I was confused too but checkpatch complained about 
>> it so I figured I'd clean it up quick
> 
> Ah.  It's a new checkpatch warning.  I don't care in that case.  I'm
> fine with replacing all of these in that case.

Alright thanks. Can you review this?

Thanks,
Sandro V

Re: [PATCH] Staging: octeon: Avoid several usecases of strcpy

[Dan Carpenter]

On Wed, Sep 11, 2019 at 11:21:44AM +0200, Sandro Volery wrote:
> 
> On 11 Sep 2019, at 11:17, Dan Carpenter <dan.carpenter@oracle.com> wrote:
> > 
> > On Wed, Sep 11, 2019 at 11:04:38AM +0200, Sandro Volery wrote:
> >> 
> >> 
> >>>> On 11 Sep 2019, at 10:52, Dan Carpenter <dan.carpenter@oracle.com> wrote:
> >>> 
> >>> On Wed, Sep 11, 2019 at 08:23:59AM +0200, Sandro Volery wrote:
> >>>> strcpy was used multiple times in strcpy to write into dev->name.
> >>>> I replaced them with strscpy.
> >>>> 
> >>>> Signed-off-by: Sandro Volery <sandro@volery.com>
> >>>> ---
> >>>> drivers/staging/octeon/ethernet.c | 16 ++++++++--------
> >>>> 1 file changed, 8 insertions(+), 8 deletions(-)
> >>>> 
> >>>> diff --git a/drivers/staging/octeon/ethernet.c b/drivers/staging/octeon/ethernet.c
> >>>> index 8889494adf1f..cf8e9a23ebf9 100644
> >>>> --- a/drivers/staging/octeon/ethernet.c
> >>>> +++ b/drivers/staging/octeon/ethernet.c
> >>>> @@ -784,7 +784,7 @@ static int cvm_oct_probe(struct platform_device *pdev)
> >>>>           priv->imode = CVMX_HELPER_INTERFACE_MODE_DISABLED;
> >>>>           priv->port = CVMX_PIP_NUM_INPUT_PORTS;
> >>>>           priv->queue = -1;
> >>>> -            strcpy(dev->name, "pow%d");
> >>>> +            strscpy(dev->name, "pow%d", sizeof(dev->name));
> >>> 
> >>> Is there a program which is generating a warning for this code?  We know
> >>> that "pow%d" is 6 characters and static analysis tools can understand
> >>> this code fine so we know it's safe.
> >> 
> >> Well I was confused too but checkpatch complained about 
> >> it so I figured I'd clean it up quick
> > 
> > Ah.  It's a new checkpatch warning.  I don't care in that case.  I'm
> > fine with replacing all of these in that case.
> 
> Alright thanks. Can you review this?
> 

Sure.

Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>

regards,
dan carpenter

Re: [PATCH] Staging: octeon: Avoid several usecases of strcpy

[Rasmus Villemoes]

On 11/09/2019 11.16, Dan Carpenter wrote:
> On Wed, Sep 11, 2019 at 11:04:38AM +0200, Sandro Volery wrote:
>>
>>
>>> On 11 Sep 2019, at 10:52, Dan Carpenter <dan.carpenter@oracle.com> wrote:
>>>
>>> On Wed, Sep 11, 2019 at 08:23:59AM +0200, Sandro Volery wrote:
>>>> strcpy was used multiple times in strcpy to write into dev->name.
>>>> I replaced them with strscpy.

Yes, that's obviously what the patch does. The commit log is supposed to
explain _why_.

>>>> Signed-off-by: Sandro Volery <sandro@volery.com>
>>>> ---
>>>> drivers/staging/octeon/ethernet.c | 16 ++++++++--------
>>>> 1 file changed, 8 insertions(+), 8 deletions(-)
>>>>
>>>> diff --git a/drivers/staging/octeon/ethernet.c b/drivers/staging/octeon/ethernet.c
>>>> index 8889494adf1f..cf8e9a23ebf9 100644
>>>> --- a/drivers/staging/octeon/ethernet.c
>>>> +++ b/drivers/staging/octeon/ethernet.c
>>>> @@ -784,7 +784,7 @@ static int cvm_oct_probe(struct platform_device *pdev)
>>>>            priv->imode = CVMX_HELPER_INTERFACE_MODE_DISABLED;
>>>>            priv->port = CVMX_PIP_NUM_INPUT_PORTS;
>>>>            priv->queue = -1;
>>>> -            strcpy(dev->name, "pow%d");
>>>> +            strscpy(dev->name, "pow%d", sizeof(dev->name));
>>>
>>> Is there a program which is generating a warning for this code?  We know
>>> that "pow%d" is 6 characters and static analysis tools can understand
>>> this code fine so we know it's safe.
>>
>> Well I was confused too but checkpatch complained about 
>> it so I figured I'd clean it up quick
> 
> Ah.  It's a new checkpatch warning.  I don't care in that case.  I'm
> fine with replacing all of these in that case.

But why? It actually gives _less_ compile-time checking (gcc and all
static tools know perfectly well what strcpy is and does, but knows
nothing of strscpy). And using sizeof() instead of ARRAY_SIZE() means a
future reader is not even sure dev->name is not just a pointer.

Moreover, it's very likely also a runtime and .text pessimization, again
because gcc knows what strcpy does, so it can just do a few immediate
stores (e.g. 0x25776f70 for the "pow%" part) instead of emitting an
actual function call.

Rasmus