Patchwork Staging: dst: fix 'Client is not allowed' on sparc

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Submitter Alexander Beregalov
Date Dec. 13, 2009, 2:55 p.m.
Message ID <1260716147-1569-1-git-send-email-a.beregalov@gmail.com>
Download mbox | patch
Permalink /patch/41034/
State Not Applicable
Delegated to: David Miller
Headers show

Comments

Alexander Beregalov - Dec. 13, 2009, 2:55 p.m.
Not for applying, only describe the problem.


There is a warning on sparc
 Kernel unaligned access at TPC[6c0dec] inet_getname+0x4c/0xc0
which goes from
	net/ipv4/af_inet.c:
	int inet_getname(
		...
		*uaddr_len = sizeof(*sin);

sizeof(*sin) is 16, but inet_getname sets sa_data_len to 0.
That is why client is denied to access the device.
inet_getname() does not read uaddr_len, only
writes, so move initialization of sa_data_len after it.
Make struct saddr aligned similar to
struct __kernel_sockaddr_storage. This fixes the warning.

---
 drivers/staging/dst/export.c |    2 +-
 include/linux/dst.h          |    4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)
Evgeniy Polyakov - Dec. 16, 2009, 6:24 p.m.
Hi Alexander.

Sorry for late response.
Your patch looks good, I will forward it to GregKH for inclusion.
Thank you.

On Sun, Dec 13, 2009 at 05:55:47PM +0300, Alexander Beregalov (a.beregalov@gmail.com) wrote:
> 
> Not for applying, only describe the problem.
> 
> 
> There is a warning on sparc
>  Kernel unaligned access at TPC[6c0dec] inet_getname+0x4c/0xc0
> which goes from
> 	net/ipv4/af_inet.c:
> 	int inet_getname(
> 		...
> 		*uaddr_len = sizeof(*sin);
> 
> sizeof(*sin) is 16, but inet_getname sets sa_data_len to 0.
> That is why client is denied to access the device.
> inet_getname() does not read uaddr_len, only
> writes, so move initialization of sa_data_len after it.
> Make struct saddr aligned similar to
> struct __kernel_sockaddr_storage. This fixes the warning.
> 
> ---
>  drivers/staging/dst/export.c |    2 +-
>  include/linux/dst.h          |    4 ++--
>  2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/staging/dst/export.c b/drivers/staging/dst/export.c
> index c324230..4644804 100644
> --- a/drivers/staging/dst/export.c
> +++ b/drivers/staging/dst/export.c
> @@ -166,12 +166,12 @@ static struct dst_state *dst_accept_client(struct dst_state *st)
>  	}
>  	new->socket = sock;
>  
> -	new->ctl.addr.sa_data_len = sizeof(struct sockaddr);
>  	err = kernel_getpeername(sock, (struct sockaddr *)&new->ctl.addr,
>  			(int *)&new->ctl.addr.sa_data_len);
>  	if (err)
>  		goto err_out_put;
>  
> +	new->ctl.addr.sa_data_len = sizeof(struct sockaddr);	
>  	new->permissions = dst_check_permissions(st, new);
>  	if (new->permissions == 0) {
>  		err = -EPERM;
> diff --git a/include/linux/dst.h b/include/linux/dst.h
> index e26fed8..454b15a 100644
> --- a/include/linux/dst.h
> +++ b/include/linux/dst.h
> @@ -74,10 +74,10 @@ struct saddr {
>  	/* address family, AF_xxx	*/
>  	unsigned short		sa_family;
>  	/* 14 bytes of protocol address	*/
> -	char			sa_data[SADDR_MAX_DATA];
> +	char			sa_data[SADDR_MAX_DATA - sizeof(unsigned short)];
>  	/* Number of bytes used in sa_data */
>  	unsigned short		sa_data_len;
> -};
> +} __attribute__((aligned(16)));	/* sizeof(struct sockaddr) */
>  
>  /* Address structure */
>  struct dst_network_ctl
> -- 
> 1.6.5.6
Alexander Beregalov - Dec. 16, 2009, 7:05 p.m.
2009/12/16 Evgeniy Polyakov <zbr@ioremap.net>:
> Hi Alexander.
>
> Sorry for late response.
> Your patch looks good, I will forward it to GregKH for inclusion.

But how does inet_getname() set sa_data_len to 0.
I can't imagine.
My patch is a workaround, not a fix.

Btw, it does not work on sparc anyway, it needs further digging.

> Thank you.
>
> On Sun, Dec 13, 2009 at 05:55:47PM +0300, Alexander Beregalov (a.beregalov@gmail.com) wrote:
>>
>> Not for applying, only describe the problem.
>>
>>
>> There is a warning on sparc
>>  Kernel unaligned access at TPC[6c0dec] inet_getname+0x4c/0xc0
>> which goes from
>>       net/ipv4/af_inet.c:
>>       int inet_getname(
>>               ...
>>               *uaddr_len = sizeof(*sin);
>>
>> sizeof(*sin) is 16, but inet_getname sets sa_data_len to 0.
>> That is why client is denied to access the device.
>> inet_getname() does not read uaddr_len, only
>> writes, so move initialization of sa_data_len after it.
>> Make struct saddr aligned similar to
>> struct __kernel_sockaddr_storage. This fixes the warning.
>>
>> ---
>>  drivers/staging/dst/export.c |    2 +-
>>  include/linux/dst.h          |    4 ++--
>>  2 files changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/staging/dst/export.c b/drivers/staging/dst/export.c
>> index c324230..4644804 100644
>> --- a/drivers/staging/dst/export.c
>> +++ b/drivers/staging/dst/export.c
>> @@ -166,12 +166,12 @@ static struct dst_state *dst_accept_client(struct dst_state *st)
>>       }
>>       new->socket = sock;
>>
>> -     new->ctl.addr.sa_data_len = sizeof(struct sockaddr);
>>       err = kernel_getpeername(sock, (struct sockaddr *)&new->ctl.addr,
>>                       (int *)&new->ctl.addr.sa_data_len);
>>       if (err)
>>               goto err_out_put;
>>
>> +     new->ctl.addr.sa_data_len = sizeof(struct sockaddr);
>>       new->permissions = dst_check_permissions(st, new);
>>       if (new->permissions == 0) {
>>               err = -EPERM;
>> diff --git a/include/linux/dst.h b/include/linux/dst.h
>> index e26fed8..454b15a 100644
>> --- a/include/linux/dst.h
>> +++ b/include/linux/dst.h
>> @@ -74,10 +74,10 @@ struct saddr {
>>       /* address family, AF_xxx       */
>>       unsigned short          sa_family;
>>       /* 14 bytes of protocol address */
>> -     char                    sa_data[SADDR_MAX_DATA];
>> +     char                    sa_data[SADDR_MAX_DATA - sizeof(unsigned short)];
>>       /* Number of bytes used in sa_data */
>>       unsigned short          sa_data_len;
>> -};
>> +} __attribute__((aligned(16)));      /* sizeof(struct sockaddr) */
>>
>>  /* Address structure */
>>  struct dst_network_ctl
>> --
>> 1.6.5.6
>
> --
>        Evgeniy Polyakov
>
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Patch

diff --git a/drivers/staging/dst/export.c b/drivers/staging/dst/export.c
index c324230..4644804 100644
--- a/drivers/staging/dst/export.c
+++ b/drivers/staging/dst/export.c
@@ -166,12 +166,12 @@  static struct dst_state *dst_accept_client(struct dst_state *st)
 	}
 	new->socket = sock;
 
-	new->ctl.addr.sa_data_len = sizeof(struct sockaddr);
 	err = kernel_getpeername(sock, (struct sockaddr *)&new->ctl.addr,
 			(int *)&new->ctl.addr.sa_data_len);
 	if (err)
 		goto err_out_put;
 
+	new->ctl.addr.sa_data_len = sizeof(struct sockaddr);	
 	new->permissions = dst_check_permissions(st, new);
 	if (new->permissions == 0) {
 		err = -EPERM;
diff --git a/include/linux/dst.h b/include/linux/dst.h
index e26fed8..454b15a 100644
--- a/include/linux/dst.h
+++ b/include/linux/dst.h
@@ -74,10 +74,10 @@  struct saddr {
 	/* address family, AF_xxx	*/
 	unsigned short		sa_family;
 	/* 14 bytes of protocol address	*/
-	char			sa_data[SADDR_MAX_DATA];
+	char			sa_data[SADDR_MAX_DATA - sizeof(unsigned short)];
 	/* Number of bytes used in sa_data */
 	unsigned short		sa_data_len;
-};
+} __attribute__((aligned(16)));	/* sizeof(struct sockaddr) */
 
 /* Address structure */
 struct dst_network_ctl