[PATCH net] sctp: declare struct sctp_stream before using it

[PATCH net] sctp: declare struct sctp_stream before using it

[Xin Long]

sctp_stream_free uses struct sctp_stream as a param, but struct sctp_stream
is defined after it's declaration.

This patch is to declare struct sctp_stream before sctp_stream_free.

Fixes: a83863174a61 ("sctp: prepare asoc stream for stream reconf")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
 include/net/sctp/structs.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index 4f64519..592dece 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -83,6 +83,7 @@ struct sctp_bind_addr;
 struct sctp_ulpq;
 struct sctp_ep_common;
 struct crypto_shash;
+struct sctp_stream;
 
 
 #include <net/sctp/tsnmap.h>
-- 
2.1.0

Re: [PATCH net] sctp: declare struct sctp_stream before using it

[Neil Horman]

On Mon, Mar 20, 2017 at 05:46:27PM +0800, Xin Long wrote:
> sctp_stream_free uses struct sctp_stream as a param, but struct sctp_stream
> is defined after it's declaration.
> 
> This patch is to declare struct sctp_stream before sctp_stream_free.
> 
> Fixes: a83863174a61 ("sctp: prepare asoc stream for stream reconf")
> Signed-off-by: Xin Long <lucien.xin@gmail.com>
> ---
>  include/net/sctp/structs.h | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
> index 4f64519..592dece 100644
> --- a/include/net/sctp/structs.h
> +++ b/include/net/sctp/structs.h
> @@ -83,6 +83,7 @@ struct sctp_bind_addr;
>  struct sctp_ulpq;
>  struct sctp_ep_common;
>  struct crypto_shash;
> +struct sctp_stream;
>  
>  
>  #include <net/sctp/tsnmap.h>
> -- 
> 2.1.0
> 
> 

Not sure I follow.  did we run into a compilation failure here?

Neil

Re: [PATCH net] sctp: declare struct sctp_stream before using it

[Xin Long]

On Mon, Mar 20, 2017 at 9:29 PM, Neil Horman <nhorman@tuxdriver.com> wrote:
> On Mon, Mar 20, 2017 at 05:46:27PM +0800, Xin Long wrote:
>> sctp_stream_free uses struct sctp_stream as a param, but struct sctp_stream
>> is defined after it's declaration.
>>
>> This patch is to declare struct sctp_stream before sctp_stream_free.
>>
>> Fixes: a83863174a61 ("sctp: prepare asoc stream for stream reconf")
>> Signed-off-by: Xin Long <lucien.xin@gmail.com>
>> ---
>>  include/net/sctp/structs.h | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
>> index 4f64519..592dece 100644
>> --- a/include/net/sctp/structs.h
>> +++ b/include/net/sctp/structs.h
>> @@ -83,6 +83,7 @@ struct sctp_bind_addr;
>>  struct sctp_ulpq;
>>  struct sctp_ep_common;
>>  struct crypto_shash;
>> +struct sctp_stream;
>>
>>
>>  #include <net/sctp/tsnmap.h>
>> --
>> 2.1.0
>>
>>
>
> Not sure I follow.  did we run into a compilation failure here?
no compilation err was found, even now.

because of
struct sctp_stream *sctp_stream_new(__u16 incnt, __u16 outcnt, gfp_t gfp);
void sctp_stream_free(struct sctp_stream *stream);

I'm not sure why gcc did not complain, but when I moved sctp_stream_new
below sctp_stream_free:
void sctp_stream_free(struct sctp_stream *stream);
struct sctp_stream *sctp_stream_new(__u16 incnt, __u16 outcnt, gfp_t gfp);

the err showed up.

So the better thing we should do is to declare struct sctp_stream to
avoid this potential issue.

Besides, I'm planing to change the return value type of sctp_stream_new.
after which, the issue will be exposed.

>
> Neil
>

Re: [PATCH net] sctp: declare struct sctp_stream before using it

[Neil Horman]

On Mon, Mar 20, 2017 at 10:33:57PM +0800, Xin Long wrote:
> On Mon, Mar 20, 2017 at 9:29 PM, Neil Horman <nhorman@tuxdriver.com> wrote:
> > On Mon, Mar 20, 2017 at 05:46:27PM +0800, Xin Long wrote:
> >> sctp_stream_free uses struct sctp_stream as a param, but struct sctp_stream
> >> is defined after it's declaration.
> >>
> >> This patch is to declare struct sctp_stream before sctp_stream_free.
> >>
> >> Fixes: a83863174a61 ("sctp: prepare asoc stream for stream reconf")
> >> Signed-off-by: Xin Long <lucien.xin@gmail.com>
> >> ---
> >>  include/net/sctp/structs.h | 1 +
> >>  1 file changed, 1 insertion(+)
> >>
> >> diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
> >> index 4f64519..592dece 100644
> >> --- a/include/net/sctp/structs.h
> >> +++ b/include/net/sctp/structs.h
> >> @@ -83,6 +83,7 @@ struct sctp_bind_addr;
> >>  struct sctp_ulpq;
> >>  struct sctp_ep_common;
> >>  struct crypto_shash;
> >> +struct sctp_stream;
> >>
> >>
> >>  #include <net/sctp/tsnmap.h>
> >> --
> >> 2.1.0
> >>
> >>
> >
> > Not sure I follow.  did we run into a compilation failure here?
> no compilation err was found, even now.
> 
> because of
> struct sctp_stream *sctp_stream_new(__u16 incnt, __u16 outcnt, gfp_t gfp);
> void sctp_stream_free(struct sctp_stream *stream);
> 
> I'm not sure why gcc did not complain, but when I moved sctp_stream_new
> below sctp_stream_free:
> void sctp_stream_free(struct sctp_stream *stream);
> struct sctp_stream *sctp_stream_new(__u16 incnt, __u16 outcnt, gfp_t gfp);
> 
> the err showed up.
> 
odd, its almost like gcc considered the return value of sctp_stream_new to be a
forward declaration of the struct.

Anywho, can't hurt to make this chagne
Acked-by: Neil Horman <nhorman@tuxdriver.com>

> So the better thing we should do is to declare struct sctp_stream to
> avoid this potential issue.
> 
> Besides, I'm planing to change the return value type of sctp_stream_new.
> after which, the issue will be exposed.
> 
> >
> > Neil
> >
> 

Re: [PATCH net] sctp: declare struct sctp_stream before using it

[David Miller]

From: Xin Long <lucien.xin@gmail.com>
Date: Mon, 20 Mar 2017 17:46:27 +0800

> sctp_stream_free uses struct sctp_stream as a param, but struct sctp_stream
> is defined after it's declaration.
> 
> This patch is to declare struct sctp_stream before sctp_stream_free.
> 
> Fixes: a83863174a61 ("sctp: prepare asoc stream for stream reconf")
> Signed-off-by: Xin Long <lucien.xin@gmail.com>

Applied.