[PATCH next] net: netfilter: nfnetlink_cthelper: Remove 'const' and '&' to avoid warnings

[PATCH next] net: netfilter: nfnetlink_cthelper: Remove 'const' and '&' to avoid warnings

[Chen Gang]

The related code can be simplified, and also can avoid related warnings
(with allmodconfig under parisc):

    CC [M]  net/netfilter/nfnetlink_cthelper.o
  net/netfilter/nfnetlink_cthelper.c: In function ‘nfnl_cthelper_from_nlattr’:
  net/netfilter/nfnetlink_cthelper.c:97:9: warning: passing argument 1 o ‘memcpy’ discards ‘const’ qualifier from pointer target type [-Wdiscarded-array-qualifiers]
    memcpy(&help->data, nla_data(attr), help->helper->data_len);
           ^
  In file included from include/linux/string.h:17:0,
                   from include/uapi/linux/uuid.h:25,
                   from include/linux/uuid.h:23,
                   from include/linux/mod_devicetable.h:12,
                   from ./arch/parisc/include/asm/hardware.h:4,
                   from ./arch/parisc/include/asm/processor.h:15,
                   from ./arch/parisc/include/asm/spinlock.h:6,
                   from ./arch/parisc/include/asm/atomic.h:21,
                   from include/linux/atomic.h:4,
                   from ./arch/parisc/include/asm/bitops.h:12,
                   from include/linux/bitops.h:36,
                   from include/linux/kernel.h:10,
                   from include/linux/list.h:8,
                   from include/linux/module.h:9,
                   from net/netfilter/nfnetlink_cthelper.c:11:
  ./arch/parisc/include/asm/string.h:8:8: note: expected ‘void *’ but argument is of type ‘const char (*)[]’
   void * memcpy(void * dest,const void *src,size_t count);
          ^

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
---
 net/netfilter/nfnetlink_cthelper.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/nfnetlink_cthelper.c b/net/netfilter/nfnetlink_cthelper.c
index 9e287cb..a5599fc 100644
--- a/net/netfilter/nfnetlink_cthelper.c
+++ b/net/netfilter/nfnetlink_cthelper.c
@@ -86,7 +86,7 @@ nfnl_cthelper_parse_tuple(struct nf_conntrack_tuple *tuple,
 static int
 nfnl_cthelper_from_nlattr(struct nlattr *attr, struct nf_conn *ct)
 {
-	const struct nf_conn_help *help = nfct_help(ct);
+	struct nf_conn_help *help = nfct_help(ct);
 
 	if (attr == NULL)
 		return -EINVAL;
@@ -94,7 +94,7 @@ nfnl_cthelper_from_nlattr(struct nlattr *attr, struct nf_conn *ct)
 	if (help->helper->data_len == 0)
 		return -EINVAL;
 
-	memcpy(&help->data, nla_data(attr), help->helper->data_len);
+	memcpy(help->data, nla_data(attr), help->helper->data_len);
 	return 0;
 }
 
-- 
1.7.9.5

Re: [PATCH next] net: netfilter: nfnetlink_cthelper: Remove 'const' and '&' to avoid warnings

[Pablo Neira Ayuso]

On Wed, Dec 24, 2014 at 11:04:54PM +0800, Chen Gang wrote:
> The related code can be simplified, and also can avoid related warnings
> (with allmodconfig under parisc):
> 
>     CC [M]  net/netfilter/nfnetlink_cthelper.o
>   net/netfilter/nfnetlink_cthelper.c: In function ‘nfnl_cthelper_from_nlattr’:
>   net/netfilter/nfnetlink_cthelper.c:97:9: warning: passing argument 1 o ‘memcpy’ discards ‘const’ qualifier from pointer target type [-Wdiscarded-array-qualifiers]
>     memcpy(&help->data, nla_data(attr), help->helper->data_len);
>            ^
>   In file included from include/linux/string.h:17:0,
>                    from include/uapi/linux/uuid.h:25,
>                    from include/linux/uuid.h:23,
>                    from include/linux/mod_devicetable.h:12,
>                    from ./arch/parisc/include/asm/hardware.h:4,
>                    from ./arch/parisc/include/asm/processor.h:15,
>                    from ./arch/parisc/include/asm/spinlock.h:6,
>                    from ./arch/parisc/include/asm/atomic.h:21,
>                    from include/linux/atomic.h:4,
>                    from ./arch/parisc/include/asm/bitops.h:12,
>                    from include/linux/bitops.h:36,
>                    from include/linux/kernel.h:10,
>                    from include/linux/list.h:8,
>                    from include/linux/module.h:9,
>                    from net/netfilter/nfnetlink_cthelper.c:11:
>   ./arch/parisc/include/asm/string.h:8:8: note: expected ‘void *’ but argument is of type ‘const char (*)[]’
>    void * memcpy(void * dest,const void *src,size_t count);
>           ^

Applied, thanks.