diff mbox

IB/core: avoid 32-bit warning

Message ID 17269152.DqJfCm1LOx@wuerfel (mailing list archive)
State Accepted
Headers show

Commit Message

Arnd Bergmann Oct. 7, 2015, 12:29 p.m. UTC 
The INIT_UDATA() macro requires a pointer or unsigned long argument for
both input and output buffer, and all callers had a cast from when
the code was merged until a recent restructuring, so now we get

core/uverbs_cmd.c: In function 'ib_uverbs_create_cq':
core/uverbs_cmd.c:1481:66: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]

This makes the code behave as before by adding back the cast to
unsigned long.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 565197dd8fb1 ("IB/core: Extend ib_uverbs_create_cq")


--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Comments

Yann Droneaud Oct. 7, 2015, 1 p.m. UTC | #1 
Hi,

Le mercredi 07 octobre 2015 à 14:29 +0200, Arnd Bergmann a écrit :
> The INIT_UDATA() macro requires a pointer or unsigned long argument 
> for both input and output buffer, and all callers had a cast from 
> when the code was merged until a recent restructuring, so now we get
> 
> core/uverbs_cmd.c: In function 'ib_uverbs_create_cq':
> core/uverbs_cmd.c:1481:66: warning: cast to pointer from integer of
> different size [-Wint-to-pointer-cast]
> 
> This makes the code behave as before by adding back the cast to
> unsigned long.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> Fixes: 565197dd8fb1 ("IB/core: Extend ib_uverbs_create_cq")
> 

Reviewed-by: Yann Droneaud <ydroneaud@opteya.com>

> diff --git a/drivers/infiniband/core/uverbs_cmd.c
> b/drivers/infiniband/core/uverbs_cmd.c
> index be4cb9f04be3..88b3b78340f2 100644
> --- a/drivers/infiniband/core/uverbs_cmd.c
> +++ b/drivers/infiniband/core/uverbs_cmd.c
> @@ -1478,7 +1478,7 @@ ssize_t ib_uverbs_create_cq(struct
> ib_uverbs_file *file,
>  	if (copy_from_user(&cmd, buf, sizeof(cmd)))
>  		return -EFAULT;
>  
> -	INIT_UDATA(&ucore, buf, cmd.response, sizeof(cmd),
> sizeof(resp));
> +	INIT_UDATA(&ucore, buf, (unsigned long)cmd.response,
> sizeof(cmd), sizeof(resp));
>  
>  	INIT_UDATA(&uhw, buf + sizeof(cmd),
>  		   (unsigned long)cmd.response + sizeof(resp),
> 

Regards.
Sagi Grimberg Oct. 7, 2015, 1:19 p.m. UTC | #2 
On 10/7/2015 3:29 PM, Arnd Bergmann wrote:
> The INIT_UDATA() macro requires a pointer or unsigned long argument for
> both input and output buffer, and all callers had a cast from when
> the code was merged until a recent restructuring, so now we get
>
> core/uverbs_cmd.c: In function 'ib_uverbs_create_cq':
> core/uverbs_cmd.c:1481:66: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
>
> This makes the code behave as before by adding back the cast to
> unsigned long.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> Fixes: 565197dd8fb1 ("IB/core: Extend ib_uverbs_create_cq")
>
> diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
> index be4cb9f04be3..88b3b78340f2 100644
> --- a/drivers/infiniband/core/uverbs_cmd.c
> +++ b/drivers/infiniband/core/uverbs_cmd.c
> @@ -1478,7 +1478,7 @@ ssize_t ib_uverbs_create_cq(struct ib_uverbs_file *file,
>   	if (copy_from_user(&cmd, buf, sizeof(cmd)))
>   		return -EFAULT;
>
> -	INIT_UDATA(&ucore, buf, cmd.response, sizeof(cmd), sizeof(resp));
> +	INIT_UDATA(&ucore, buf, (unsigned long)cmd.response, sizeof(cmd), sizeof(resp));

Would it make sense to cast inside INIT_UDATA() and not have callers
worry about it?
--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Arnd Bergmann Oct. 7, 2015, 1:46 p.m. UTC | #3 
On Wednesday 07 October 2015 16:19:27 Sagi Grimberg wrote:
> On 10/7/2015 3:29 PM, Arnd Bergmann wrote:
> > The INIT_UDATA() macro requires a pointer or unsigned long argument for
> > both input and output buffer, and all callers had a cast from when
> > the code was merged until a recent restructuring, so now we get
> >
> > core/uverbs_cmd.c: In function 'ib_uverbs_create_cq':
> > core/uverbs_cmd.c:1481:66: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
> >
> > This makes the code behave as before by adding back the cast to
> > unsigned long.
> >
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> > Fixes: 565197dd8fb1 ("IB/core: Extend ib_uverbs_create_cq")
> >
> > diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
> > index be4cb9f04be3..88b3b78340f2 100644
> > --- a/drivers/infiniband/core/uverbs_cmd.c
> > +++ b/drivers/infiniband/core/uverbs_cmd.c
> > @@ -1478,7 +1478,7 @@ ssize_t ib_uverbs_create_cq(struct ib_uverbs_file *file,
> >       if (copy_from_user(&cmd, buf, sizeof(cmd)))
> >               return -EFAULT;
> >
> > -     INIT_UDATA(&ucore, buf, cmd.response, sizeof(cmd), sizeof(resp));
> > +     INIT_UDATA(&ucore, buf, (unsigned long)cmd.response, sizeof(cmd), sizeof(resp));
> 
> Would it make sense to cast inside INIT_UDATA() and not have callers
> worry about it?

If we want to do this properly, INIT_UDATA should be converted into a function
call that has the right types.

My patch doesn't try to do that here, it just restores the code to how it
was for the past 10 years.

	Arnd
--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Yann Droneaud Oct. 7, 2015, 1:46 p.m. UTC | #4 
Hi,

Le mercredi 07 octobre 2015 à 16:19 +0300, Sagi Grimberg a écrit :
> On 10/7/2015 3:29 PM, Arnd Bergmann wrote:
> > The INIT_UDATA() macro requires a pointer or unsigned long argument
> > for
> > both input and output buffer, and all callers had a cast from when
> > the code was merged until a recent restructuring, so now we get
> > 
> > core/uverbs_cmd.c: In function 'ib_uverbs_create_cq':
> > core/uverbs_cmd.c:1481:66: warning: cast to pointer from integer of
> > different size [-Wint-to-pointer-cast]
> > 
> > This makes the code behave as before by adding back the cast to
> > unsigned long.
> > 
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> > Fixes: 565197dd8fb1 ("IB/core: Extend ib_uverbs_create_cq")
> > 
> > diff --git a/drivers/infiniband/core/uverbs_cmd.c
> > b/drivers/infiniband/core/uverbs_cmd.c
> > index be4cb9f04be3..88b3b78340f2 100644
> > --- a/drivers/infiniband/core/uverbs_cmd.c
> > +++ b/drivers/infiniband/core/uverbs_cmd.c
> > @@ -1478,7 +1478,7 @@ ssize_t ib_uverbs_create_cq(struct
> > ib_uverbs_file *file,
> >   	if (copy_from_user(&cmd, buf, sizeof(cmd)))
> >   		return -EFAULT;
> > 
> > -	INIT_UDATA(&ucore, buf, cmd.response, sizeof(cmd),
> > sizeof(resp));
> > +	INIT_UDATA(&ucore, buf, (unsigned long)cmd.response,
> > sizeof(cmd), sizeof(resp));
> 
> Would it make sense to cast inside INIT_UDATA() and not have callers
> worry about it?

It's ... complicated. See INIT_UDATA_BUF_OR_NULL().

Awayway, I have patch to do the opposite, eg. explicitly cast u64 value
to (void __user *)(unsigned long) in the caller function instead, as it
allows some safer / new operations on the response buffer.

Regards.
Doug Ledford Oct. 21, 2015, 8:58 p.m. UTC | #5 
On 10/07/2015 09:46 AM, Yann Droneaud wrote:
> Hi,
> 
> Le mercredi 07 octobre 2015 à 16:19 +0300, Sagi Grimberg a écrit :
>> On 10/7/2015 3:29 PM, Arnd Bergmann wrote:
>>> The INIT_UDATA() macro requires a pointer or unsigned long argument
>>> for
>>> both input and output buffer, and all callers had a cast from when
>>> the code was merged until a recent restructuring, so now we get
>>>
>>> core/uverbs_cmd.c: In function 'ib_uverbs_create_cq':
>>> core/uverbs_cmd.c:1481:66: warning: cast to pointer from integer of
>>> different size [-Wint-to-pointer-cast]
>>>
>>> This makes the code behave as before by adding back the cast to
>>> unsigned long.
>>>
>>> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
>>> Fixes: 565197dd8fb1 ("IB/core: Extend ib_uverbs_create_cq")
>>>
>>> diff --git a/drivers/infiniband/core/uverbs_cmd.c
>>> b/drivers/infiniband/core/uverbs_cmd.c
>>> index be4cb9f04be3..88b3b78340f2 100644
>>> --- a/drivers/infiniband/core/uverbs_cmd.c
>>> +++ b/drivers/infiniband/core/uverbs_cmd.c
>>> @@ -1478,7 +1478,7 @@ ssize_t ib_uverbs_create_cq(struct
>>> ib_uverbs_file *file,
>>>   	if (copy_from_user(&cmd, buf, sizeof(cmd)))
>>>   		return -EFAULT;
>>>
>>> -	INIT_UDATA(&ucore, buf, cmd.response, sizeof(cmd),
>>> sizeof(resp));
>>> +	INIT_UDATA(&ucore, buf, (unsigned long)cmd.response,
>>> sizeof(cmd), sizeof(resp));
>>
>> Would it make sense to cast inside INIT_UDATA() and not have callers
>> worry about it?
> 
> It's ... complicated. See INIT_UDATA_BUF_OR_NULL().
> 
> Awayway, I have patch to do the opposite, eg. explicitly cast u64 value
> to (void __user *)(unsigned long) in the caller function instead, as it
> allows some safer / new operations on the response buffer.
> 
> Regards.
> 

I haven't seen this oether patch that Yann is talking about, so I've
taken this one.
diff mbox

Patch

diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
index be4cb9f04be3..88b3b78340f2 100644
--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -1478,7 +1478,7 @@  ssize_t ib_uverbs_create_cq(struct ib_uverbs_file *file,
 	if (copy_from_user(&cmd, buf, sizeof(cmd)))
 		return -EFAULT;
 
-	INIT_UDATA(&ucore, buf, cmd.response, sizeof(cmd), sizeof(resp));
+	INIT_UDATA(&ucore, buf, (unsigned long)cmd.response, sizeof(cmd), sizeof(resp));
 
 	INIT_UDATA(&uhw, buf + sizeof(cmd),
 		   (unsigned long)cmd.response + sizeof(resp),