[PATCH] skbuff: fix compilation warnings in skb_dump()

[PATCH] skbuff: fix compilation warnings in skb_dump()

[Qian Cai]

The commit 6413139dfc64 ("skbuff: increase verbosity when dumping skb
data") introduced a few compilation warnings.

net/core/skbuff.c:766:32: warning: format specifies type 'unsigned
short' but the argument has type 'unsigned int' [-Wformat]
                       level, sk->sk_family, sk->sk_type,
sk->sk_protocol);
                                             ^~~~~~~~~~~
net/core/skbuff.c:766:45: warning: format specifies type 'unsigned
short' but the argument has type 'unsigned int' [-Wformat]
                       level, sk->sk_family, sk->sk_type,
sk->sk_protocol);
^~~~~~~~~~~~~~~

Fix them by using the proper types, and also fix some checkpatch
warnings by using pr_info().

WARNING: printk() should include KERN_<LEVEL> facility level
+		printk("%ssk family=%hu type=%u proto=%u\n",

Fixes: 6413139dfc64 ("skbuff: increase verbosity when dumping skb data")
Signed-off-by: Qian Cai <cai@lca.pw>
---
 net/core/skbuff.c | 44 ++++++++++++++++++++++----------------------
 1 file changed, 22 insertions(+), 22 deletions(-)

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 6f1e31f674a3..fa1e78f7bb96 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -740,30 +740,30 @@ void skb_dump(const char *level, const struct sk_buff *skb, bool full_pkt)
 	has_mac = skb_mac_header_was_set(skb);
 	has_trans = skb_transport_header_was_set(skb);
 
-	printk("%sskb len=%u headroom=%u headlen=%u tailroom=%u\n"
-	       "mac=(%d,%d) net=(%d,%d) trans=%d\n"
-	       "shinfo(txflags=%u nr_frags=%u gso(size=%hu type=%u segs=%hu))\n"
-	       "csum(0x%x ip_summed=%u complete_sw=%u valid=%u level=%u)\n"
-	       "hash(0x%x sw=%u l4=%u) proto=0x%04x pkttype=%u iif=%d\n",
-	       level, skb->len, headroom, skb_headlen(skb), tailroom,
-	       has_mac ? skb->mac_header : -1,
-	       has_mac ? skb_mac_header_len(skb) : -1,
-	       skb->network_header,
-	       has_trans ? skb_network_header_len(skb) : -1,
-	       has_trans ? skb->transport_header : -1,
-	       sh->tx_flags, sh->nr_frags,
-	       sh->gso_size, sh->gso_type, sh->gso_segs,
-	       skb->csum, skb->ip_summed, skb->csum_complete_sw,
-	       skb->csum_valid, skb->csum_level,
-	       skb->hash, skb->sw_hash, skb->l4_hash,
-	       ntohs(skb->protocol), skb->pkt_type, skb->skb_iif);
+	pr_info("%sskb len=%u headroom=%u headlen=%u tailroom=%u\n"
+		"mac=(%d,%d) net=(%d,%d) trans=%d\n"
+		"shinfo(txflags=%u nr_frags=%u gso(size=%hu type=%u segs=%hu))\n"
+		"csum(0x%x ip_summed=%u complete_sw=%u valid=%u level=%u)\n"
+		"hash(0x%x sw=%u l4=%u) proto=0x%04x pkttype=%u iif=%d\n",
+		level, skb->len, headroom, skb_headlen(skb), tailroom,
+		has_mac ? skb->mac_header : -1,
+		has_mac ? skb_mac_header_len(skb) : -1,
+		skb->network_header,
+		has_trans ? skb_network_header_len(skb) : -1,
+		has_trans ? skb->transport_header : -1,
+		sh->tx_flags, sh->nr_frags,
+		sh->gso_size, sh->gso_type, sh->gso_segs,
+		skb->csum, skb->ip_summed, skb->csum_complete_sw,
+		skb->csum_valid, skb->csum_level,
+		skb->hash, skb->sw_hash, skb->l4_hash,
+		ntohs(skb->protocol), skb->pkt_type, skb->skb_iif);
 
 	if (dev)
-		printk("%sdev name=%s feat=0x%pNF\n",
-		       level, dev->name, &dev->features);
+		pr_info("%sdev name=%s feat=0x%pNF\n",
+			level, dev->name, &dev->features);
 	if (sk)
-		printk("%ssk family=%hu type=%hu proto=%hu\n",
-		       level, sk->sk_family, sk->sk_type, sk->sk_protocol);
+		pr_info("%ssk family=%hu type=%u proto=%u\n",
+			level, sk->sk_family, sk->sk_type, sk->sk_protocol);
 
 	if (full_pkt && headroom)
 		print_hex_dump(level, "skb headroom: ", DUMP_PREFIX_OFFSET,
@@ -801,7 +801,7 @@ void skb_dump(const char *level, const struct sk_buff *skb, bool full_pkt)
 	}
 
 	if (full_pkt && skb_has_frag_list(skb)) {
-		printk("skb fraglist:\n");
+		pr_info("skb fraglist:\n");
 		skb_walk_frags(skb, list_skb)
 			skb_dump(level, list_skb, true);
 	}
-- 
1.8.3.1

Re: [PATCH] skbuff: fix compilation warnings in skb_dump()

[Willem de Bruijn]

On Tue, Jul 16, 2019 at 4:56 PM Qian Cai <cai@lca.pw> wrote:
>
> The commit 6413139dfc64 ("skbuff: increase verbosity when dumping skb
> data") introduced a few compilation warnings.
>
> net/core/skbuff.c:766:32: warning: format specifies type 'unsigned
> short' but the argument has type 'unsigned int' [-Wformat]
>                        level, sk->sk_family, sk->sk_type,
> sk->sk_protocol);
>                                              ^~~~~~~~~~~
> net/core/skbuff.c:766:45: warning: format specifies type 'unsigned
> short' but the argument has type 'unsigned int' [-Wformat]
>                        level, sk->sk_family, sk->sk_type,
> sk->sk_protocol);
> ^~~~~~~~~~~~~~~

Ah, I looked at sk_family (skc_family), which is type unsigned short.

But sk_type and sk_protocol are defined as

 unsigned int            sk_padding : 1,
                                sk_kern_sock : 1,
                                sk_no_check_tx : 1,
                                sk_no_check_rx : 1,
                                sk_userlocks : 4,
                                sk_protocol  : 8,
                                sk_type      : 16;

So %u is indeed needed instead of %hu.

> Fix them by using the proper types, and also fix some checkpatch
> warnings by using pr_info().
>
> WARNING: printk() should include KERN_<LEVEL> facility level
> +               printk("%ssk family=%hu type=%u proto=%u\n",

Converting printk to pr_info lowers all levels to KERN_INFO.

skb_dump takes an explicit parameter level to be able to log at
KERN_ERR or KERN_WARNING

I would like to avoid those checkpatch warnings, but this is not the
right approach.

> Fixes: 6413139dfc64 ("skbuff: increase verbosity when dumping skb data")

Thanks. For a v2, please mark the target branch, as [PATCH net v2].

Re: [PATCH] skbuff: fix compilation warnings in skb_dump()

[Joe Perches]

On Tue, 2019-07-16 at 17:04 +0200, Willem de Bruijn wrote:
> On Tue, Jul 16, 2019 at 4:56 PM Qian Cai <cai@lca.pw> wrote:
> > Fix them by using the proper types, and also fix some checkpatch
> > warnings by using pr_info().
> > 
> > WARNING: printk() should include KERN_<LEVEL> facility level
> > +               printk("%ssk family=%hu type=%u proto=%u\n",
> 
> Converting printk to pr_info lowers all levels to KERN_INFO.
> 
> skb_dump takes an explicit parameter level to be able to log at
> KERN_ERR or KERN_WARNING
> 
> I would like to avoid those checkpatch warnings, but this is not the
> right approach.

Just ignore checkpatch when it doesn't know that
the printk actually includes a KERN_<LEVEL> via
"%s...", level