netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: David Woodhouse <dwmw2@infradead.org>
To: David Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org, chas@cmf.nrl.navy.mil, krzysiek@podlesie.net
Subject: Re: [PATCH 00/17] ATM fixes for pppoatm/br2684
Date: Sun, 02 Dec 2012 00:40:47 +0000	[thread overview]
Message-ID: <1354408847.21562.365.camel@shinybook.infradead.org> (raw)
In-Reply-To: <1354383226.21562.351.camel@shinybook.infradead.org>

[-- Attachment #1: Type: text/plain, Size: 1676 bytes --]

On Sat, 2012-12-01 at 17:33 +0000, David Woodhouse wrote:
> 
> Very glad I added the BUILD_BUG_ON on the cb struct size now. Perhaps
> there should be a generic helper for that? Something like
>  skb_cb_cast(struct foo_cb, skb) could do it automatically...?

Something like this, perhaps? Using skb_cast_cb() would then make it
fairly much impossible to accidentally overflow the size of the skb cb.

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index f2af494..b4cb2cf 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -567,6 +567,11 @@ static inline struct rtable *skb_rtable(const struct sk_buff *skb)
 	return (struct rtable *)skb_dst(skb);
 }
 
+#define skb_cast_cb(skb, type)  ({				\
+	BUILD_BUG_ON(sizeof(type) > sizeof((skb)->cb));		\
+	(type *)(skb)->cb;					\
+	})
+
 extern void kfree_skb(struct sk_buff *skb);
 extern void skb_tx_error(struct sk_buff *skb);
 extern void consume_skb(struct sk_buff *skb);
diff --git a/drivers/atm/solos-pci.c b/drivers/atm/solos-pci.c
index 6619a8a..8dccf82 100644
--- a/drivers/atm/solos-pci.c
+++ b/drivers/atm/solos-pci.c
@@ -97,7 +97,7 @@ struct solos_skb_cb {
 };
 
 
-#define SKB_CB(skb)		((struct solos_skb_cb *)skb->cb)
+#define SKB_CB(skb)	skb_cast_cb(skb, struct solos_skb_cb)
 
 #define PKT_DATA	0
 #define PKT_COMMAND	1
@@ -1324,8 +1324,6 @@ static struct pci_driver fpga_driver = {
 
 static int __init solos_pci_init(void)
 {
-	BUILD_BUG_ON(sizeof(struct solos_skb_cb) > sizeof(((struct sk_buff *)0)->cb));
-
 	printk(KERN_INFO "Solos PCI Driver Version %s\n", VERSION);
 	return pci_register_driver(&fpga_driver);
 }


-- 
dwmw2


[-- Attachment #2: smime.p7s --]
[-- Type: application/x-pkcs7-signature, Size: 6171 bytes --]

  reply	other threads:[~2012-12-02  0:40 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-11-30  0:35 [PATCH 00/17] ATM fixes for pppoatm/br2684 David Woodhouse
2012-11-30  0:35 ` [PATCH 01/17] atm: add owner of push() callback to atmvcc David Woodhouse
2012-11-30  0:35 ` [PATCH 02/17] pppoatm: allow assign only on a connected socket David Woodhouse
2012-11-30  0:35 ` [PATCH 03/17] pppoatm: fix module_put() race David Woodhouse
2012-11-30  0:35 ` [PATCH 04/17] pppoatm: take ATM socket lock in pppoatm_send() David Woodhouse
2012-11-30  0:35 ` [PATCH 05/17] pppoatm: drop frames to not-ready vcc David Woodhouse
2012-11-30 10:27   ` Krzysztof Mazur
2012-11-30  0:35 ` [PATCH 06/17] pppoatm: do not inline pppoatm_may_send() David Woodhouse
2012-11-30  0:35 ` [PATCH 07/17] solos-pci: Wait for pending TX to complete when releasing vcc David Woodhouse
2012-12-02  0:17   ` [PATCH v2 " David Woodhouse
2012-11-30  0:35 ` [PATCH 08/17] br2684: don't send frames on not-ready vcc David Woodhouse
2012-11-30  0:35 ` [PATCH 09/17] atm: Add release_cb() callback to vcc David Woodhouse
2012-11-30  0:35 ` [PATCH 10/17] pppoatm: fix missing wakeup in pppoatm_send() David Woodhouse
2012-11-30  0:35 ` [PATCH 11/17] br2684: fix module_put() race David Woodhouse
2012-11-30  0:35 ` [PATCH 12/17] solos-pci: Fix leak of skb received for unknown vcc David Woodhouse
2012-11-30  0:35 ` [PATCH 13/17] br2684: allow assign only on a connected socket David Woodhouse
2012-11-30  0:35 ` [PATCH 14/17] pppoatm: optimise PPP channel wakeups after sock_owned_by_user() David Woodhouse
2012-11-30  0:35 ` [PATCH 15/17] solos-pci: clean up pclose() function David Woodhouse
2012-11-30  0:35 ` [PATCH 16/17] solos-pci: use GFP_KERNEL where possible, not GFP_ATOMIC David Woodhouse
2012-11-30  0:35 ` [PATCH 17/17] solos-pci: remove list_vccs() debugging function David Woodhouse
2012-11-30 10:44 ` [PATCH 00/17] ATM fixes for pppoatm/br2684 Krzysztof Mazur
2012-11-30 20:22   ` David Woodhouse
2012-12-01 16:43     ` David Miller
2012-12-01 16:44       ` David Miller
2012-12-01 16:48         ` David Woodhouse
2012-12-01 17:02           ` Chas Williams (CONTRACTOR)
2012-12-01 17:21             ` David Woodhouse
2012-12-02  1:57               ` Chas Williams (CONTRACTOR)
2012-12-02  2:17                 ` David Miller
2012-12-01 17:33         ` David Woodhouse
2012-12-02  0:40           ` David Woodhouse [this message]
2012-12-02  1:49             ` David Miller
2012-12-02  8:14               ` David Woodhouse
2012-12-02 21:29                 ` Checking struct size against sizeof(skb->cb) (was Re: [PATCH 00/17] ATM fixes for pppoatm/br2684) David Woodhouse
2012-12-20 14:03               ` skb->cb size checks " David Woodhouse
2012-12-02  0:35         ` [PATCH 00/17] ATM fixes for pppoatm/br2684 David Woodhouse
2012-12-02  1:47           ` David Miller

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1354408847.21562.365.camel@shinybook.infradead.org \
    --to=dwmw2@infradead.org \
    --cc=chas@cmf.nrl.navy.mil \
    --cc=davem@davemloft.net \
    --cc=krzysiek@podlesie.net \
    --cc=netdev@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).