Re: warnings in current tree

Re: warnings in current tree

[David Miller]

From: David Miller <davem@davemloft.net>
Date: Tue, 21 Apr 2009 01:43:57 -0700 (PDT)


Sorry, duh, meant netfilter-devel :-)

> Can someone fix these up?  Thanks!
> 
> net/netfilter/nf_conntrack_netlink.c:1234: warning: 'helpname' may be used uninitialized in this function
> net/netfilter/nf_conntrack_netlink.c:991: warning: 'helpname' may be used uninitialized in this function
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Re: warnings in current tree

[Pablo Neira Ayuso]

[-- Attachment #1: Type: text/plain, Size: 637 bytes --]

Hi David!

David Miller wrote:
> From: David Miller <davem@davemloft.net>
> Date: Tue, 21 Apr 2009 01:43:57 -0700 (PDT)
> 
> Sorry, duh, meant netfilter-devel :-)
> 
>> Can someone fix these up?  Thanks!
>>
>> net/netfilter/nf_conntrack_netlink.c:1234: warning: 'helpname' may be used uninitialized in this function
>> net/netfilter/nf_conntrack_netlink.c:991: warning: 'helpname' may be used uninitialized in this function

Hm, weird, is this a "bogus punch"? I don't remember to have seen those
here and that code has not been modified recently.

Anyway, patch attached :).

-- 
"Los honestos son inadaptados sociales" -- Les Luthiers

[-- Attachment #2: ctnl-fix-warning-gcc.patch --]
[-- Type: text/x-diff, Size: 1384 bytes --]

netfilter: ctnetlink: fix gcc warning during compilation

From: Pablo Neira Ayuso <pablo@netfilter.org>

This patch fixes a (bogus?) gcc warning during compilation:

net/netfilter/nf_conntrack_netlink.c:1234: warning: 'helpname' may be used uninitialized in this function
net/netfilter/nf_conntrack_netlink.c:991: warning: 'helpname' may be used uninitialized in this function

In fact, helpname is initialized by ctnetlink_parse_help() so
I cannot see a way to use it without being initialized.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---

 net/netfilter/nf_conntrack_netlink.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)


diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 0ea36e0..fcf6e3b 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -988,7 +988,7 @@ ctnetlink_change_helper(struct nf_conn *ct, struct nlattr *cda[])
 {
 	struct nf_conntrack_helper *helper;
 	struct nf_conn_help *help = nfct_help(ct);
-	char *helpname;
+	char *helpname = NULL;
 	int err;
 
 	/* don't change helper of sibling connections */
@@ -1231,7 +1231,7 @@ ctnetlink_create_conntrack(struct nlattr *cda[],
 
 	rcu_read_lock();
  	if (cda[CTA_HELP]) {
- 		char *helpname;
+ 		char *helpname = NULL;
  
  		err = ctnetlink_parse_help(cda[CTA_HELP], &helpname);
  		if (err < 0)

Re: warnings in current tree

[David Miller]

From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Tue, 21 Apr 2009 12:54:06 +0200

> Hi David!
> 
> David Miller wrote:
>> From: David Miller <davem@davemloft.net>
>> Date: Tue, 21 Apr 2009 01:43:57 -0700 (PDT)
>> 
>> Sorry, duh, meant netfilter-devel :-)
>> 
>>> Can someone fix these up?  Thanks!
>>>
>>> net/netfilter/nf_conntrack_netlink.c:1234: warning: 'helpname' may be used uninitialized in this function
>>> net/netfilter/nf_conntrack_netlink.c:991: warning: 'helpname' may be used uninitialized in this function
> 
> Hm, weird, is this a "bogus punch"? I don't remember to have seen those
> here and that code has not been modified recently.
> 
> Anyway, patch attached :).

Applied, thanks :-)

The problem is when you pass the address of a local variable
to a function, which is then inlined and has non-trivial
control flow (as far as GCC is concerned), and this is the
way the variable is initialized.