[klibc] valgrind ipconfig work

[maximilian attems]

On Mon, Apr 26, 2010 at 10:07:11AM -0700, Mike Waychison wrote:
> maximilian attems wrote:
> >this is just on the common path, need to checkout others too,
> >but a start:
> >
> >commit 5501109f6597f2bbed17a264b247c36220362dfb
> >Author: maximilian attems <max at stro.at>
> >Date:   Mon Apr 26 08:07:51 2010 +0200
> >
> >    [klibc] ipconfig: Fix valgrind errors
> >    
> >    valgrind was rightfully complaining on ipconfig eth0:
> >    ERROR SUMMARY: 5 errors from 4 contexts (suppressed: 0 from 0)
> >    
> >    all errors where stack allocations pointing to unitialized values,
> >    now:
> >    ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0
> >    
> >    as bonus cleanup a bit coding style of packet_send().
> >    
> >    Signed-off-by: maximilian attems <max at stro.at>
> >
> >diff --git a/usr/kinit/ipconfig/netdev.c b/usr/kinit/ipconfig/netdev.c
> >index 6e3014f..e203d0c 100644
> >--- a/usr/kinit/ipconfig/netdev.c
> >+++ b/usr/kinit/ipconfig/netdev.c
> >@@ -43,6 +43,7 @@ static int netdev_sif_addr(struct ifreq *ifr, int cmd, 
> >uint32_t addr)
> > {
> > 	struct sockaddr_in sin;
> > 
> >+	memset(&sin, 0, sizeof(sin));
> > 	sin.sin_family = AF_INET;
> > 	sin.sin_addr.s_addr = addr;
> > 
> >diff --git a/usr/kinit/ipconfig/packet.c b/usr/kinit/ipconfig/packet.c
> >index 508c7ba..4df5431 100644
> >--- a/usr/kinit/ipconfig/packet.c
> >+++ b/usr/kinit/ipconfig/packet.c
> >@@ -114,16 +114,18 @@ static char *ntoa(uint32_t addr)
> > int packet_send(struct netdev *dev, struct iovec *iov, int iov_len)
> > {
> > 	struct sockaddr_ll sll;
> 
> I believe valgrind is just complaining about sll being uninitialized here.
>
>         struct sockaddr_ll sll = {0};

yep msg.msg_name unintialized
 
> 
> Alternatively, we could move the initialization of sll's fields up into 
> a static initializer as well.

indeed this sounds good, will update patch to do that.
 
> The static initializer below will zero-fill the rest of the msg structure.
> 
> >-	struct msghdr msg = {
> >-		.msg_name	= &sll,
> >-		.msg_namelen	= sizeof(sll),
> >-		.msg_iov	= iov,
> >-		.msg_iovlen	= iov_len,
> >-		.msg_control	= NULL,
> >-		.msg_controllen	= 0,
> >-		.msg_flags	= 0
> >-	};
> > 	int i, len = 0;
> >+	struct msghdr msg;
> >+
> >+	memset(&sll, 0, sizeof(sll));
> >+
> >+	msg.msg_name = &sll;
> >+	msg.msg_namelen = sizeof(sll);
> >+	msg.msg_iov = iov;
> >+	msg.msg_iovlen = iov_len;
> >+	msg.msg_control = NULL;
> >+	msg.msg_controllen = 0;
> >+	msg.msg_flags = 0;
> > 
> > 	if (cfg_local_port != LOCAL_PORT) {
> > 		ipudp_hdrs.udp.source = htons(cfg_local_port);
> >

thanks for review,
will splitup the patch with added valgrind warning.
checked some other ipconfig invocations since and couldn't trigger other
valgrind errors, so aboves should be good.