Re: net-2.6.17 rebased...

Re: net-2.6.17 rebased...

[Ian McDonald]

On 3/2/06, David S. Miller <davem@davemloft.net> wrote:
>
> This tree was getting crufty, so I rebased it today.
> It was actually a lot easier than I had anticipated.
>
>         master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6.17.git
>
Dave,

If you get a chance can you push the ccid3 divide by zero fix upstream
to Linus for 2.6.16 as it has no functionality changed and eliminates
a nasty little bug...

The commit for this is b6da19617f4ab610d3d90bcbdf65fa7e2b3d7b53 in your tree

I have also put at end of this e-mail after reapplying on linus tree
so above commit doesn't have fuzz...

[DCCP] ccid3: Divide by zero fix

In rare circumstances 0 is returned by dccp_li_hist_calc_i_mean which leads to
a divide by zero in ccid3_hc_rx_packet_recv. Explicitly check for zero return
now. Update copyright notice at same time.

Found by Arnaldo.

Signed-off-by: Ian McDonald <imcdnzl@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>

--- 2b82f96f1291c42ee9485465801f5f51897bec64
+++ ff426a9009993445a15cfcac6c88be1e39e07913
@@ -2,7 +2,7 @@
  *  net/dccp/ccids/ccid3.c
  *
  *  Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
- *  Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz>
+ *  Copyright (c) 2005-6 Ian McDonald <imcdnzl@gmail.com>
  *
  *  An implementation of the DCCP protocol
  *
@@ -1014,9 +1014,13 @@ static void ccid3_hc_rx_packet_recv(stru
 	p_prev = hcrx->ccid3hcrx_p;
 	
 	/* Calculate loss event rate */
-	if (!list_empty(&hcrx->ccid3hcrx_li_hist))
+	if (!list_empty(&hcrx->ccid3hcrx_li_hist)) {
+		u32 i_mean = dccp_li_hist_calc_i_mean(&hcrx->ccid3hcrx_li_hist);
+
 		/* Scaling up by 1000000 as fixed decimal */
-		hcrx->ccid3hcrx_p = 1000000 /
dccp_li_hist_calc_i_mean(&hcrx->ccid3hcrx_li_hist);
+		if (i_mean != 0)
+			hcrx->ccid3hcrx_p = 1000000 / i_mean;
+	}

 	if (hcrx->ccid3hcrx_p > p_prev) {
 		ccid3_hc_rx_send_feedback(sk);

Re: net-2.6.17 rebased...

[Ian McDonald]

F**k - just pasted in the wrong file. Trying again

On 3/2/06, Ian McDonald <imcdnzl@gmail.com> wrote:
> On 3/2/06, David S. Miller <davem@davemloft.net> wrote:
> >
> > This tree was getting crufty, so I rebased it today.
> > It was actually a lot easier than I had anticipated.
> >
> >         master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6.17.git
> >
> Dave,
>
> If you get a chance can you push the ccid3 divide by zero fix upstream
> to Linus for 2.6.16 as it has no functionality changed and eliminates
> a nasty little bug...
>
> The commit for this is b6da19617f4ab610d3d90bcbdf65fa7e2b3d7b53 in your tree
>
I have also put at end of this e-mail after reapplying on linus tree
so above commit doesn't have fuzz...

[DCCP] ccid3: Divide by zero fix

In rare circumstances 0 is returned by dccp_li_hist_calc_i_mean which leads to
a divide by zero in ccid3_hc_rx_packet_recv. Explicitly check for zero return
now. Update copyright notice at same time.

Found by Arnaldo.

Signed-off-by: Ian McDonald <imcdnzl@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>

diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index aa68e0a..35d1d34 100644
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -2,7 +2,7 @@
  *  net/dccp/ccids/ccid3.c
  *
  *  Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
- *  Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz>
+ *  Copyright (c) 2005-6 Ian McDonald <imcdnzl@gmail.com>
  *
  *  An implementation of the DCCP protocol
  *
@@ -1033,9 +1033,13 @@ static void ccid3_hc_rx_packet_recv(stru
 	p_prev = hcrx->ccid3hcrx_p;
 	
 	/* Calculate loss event rate */
-	if (!list_empty(&hcrx->ccid3hcrx_li_hist))
+	if (!list_empty(&hcrx->ccid3hcrx_li_hist)) {
+		u32 i_mean = dccp_li_hist_calc_i_mean(&hcrx->ccid3hcrx_li_hist);
+
 		/* Scaling up by 1000000 as fixed decimal */
-		hcrx->ccid3hcrx_p = 1000000 /
dccp_li_hist_calc_i_mean(&hcrx->ccid3hcrx_li_hist);
+		if (i_mean != 0)
+			hcrx->ccid3hcrx_p = 1000000 / i_mean;
+	}

 	if (hcrx->ccid3hcrx_p > p_prev) {
 		ccid3_hc_rx_send_feedback(sk);

Re: net-2.6.17 rebased...

[Ian McDonald]

[-- Attachment #1: Type: text/plain, Size: 1010 bytes --]

And *** again... someone pointed out my mailer is wrapping lines. I'll
go hide in the corner and beat myself up. This time attached as I
can't get gmail to defeat line wrapping. I promise I'll get it right
next patch so I don't humiliate myself quite so much next time

Dave,
If you get a chance can you push the ccid3 divide by zero fix upstream
to Linus for 2.6.16 as it has no functionality changed and eliminates
a nasty little bug...
The commit for this is b6da19617f4ab610d3d90bcbdf65fa7e2b3d7b53 in your tree

I have also put at end of this e-mail after reapplying on linus tree
so above commit doesn't have fuzz...

[DCCP] ccid3: Divide by zero fix

In rare circumstances 0 is returned by dccp_li_hist_calc_i_mean which leads to
a divide by zero in ccid3_hc_rx_packet_recv. Explicitly check for zero return
now. Update copyright notice at same time.

Found by Arnaldo.

Signed-off-by: Ian McDonald <imcdnzl@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: div.diff --]
[-- Type: text/x-patch; name="div.diff", Size: 1007 bytes --]

diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index aa68e0a..35d1d34 100644
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -2,7 +2,7 @@
  *  net/dccp/ccids/ccid3.c
  *
  *  Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
- *  Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz>
+ *  Copyright (c) 2005-6 Ian McDonald <imcdnzl@gmail.com>
  *
  *  An implementation of the DCCP protocol
  *
@@ -1033,9 +1033,13 @@ static void ccid3_hc_rx_packet_recv(stru
 	p_prev = hcrx->ccid3hcrx_p;
 	
 	/* Calculate loss event rate */
-	if (!list_empty(&hcrx->ccid3hcrx_li_hist))
+	if (!list_empty(&hcrx->ccid3hcrx_li_hist)) {
+		u32 i_mean = dccp_li_hist_calc_i_mean(&hcrx->ccid3hcrx_li_hist);
+
 		/* Scaling up by 1000000 as fixed decimal */
-		hcrx->ccid3hcrx_p = 1000000 / dccp_li_hist_calc_i_mean(&hcrx->ccid3hcrx_li_hist);
+		if (i_mean != 0)
+			hcrx->ccid3hcrx_p = 1000000 / i_mean;
+	}
 
 	if (hcrx->ccid3hcrx_p > p_prev) {
 		ccid3_hc_rx_send_feedback(sk);

Re: net-2.6.17 rebased...

[David S. Miller]

From: "Ian McDonald" <imcdnzl@gmail.com>
Date: Thu, 2 Mar 2006 13:48:18 +1300

> If you get a chance can you push the ccid3 divide by zero fix upstream
> to Linus for 2.6.16 as it has no functionality changed and eliminates
> a nasty little bug...
> The commit for this is b6da19617f4ab610d3d90bcbdf65fa7e2b3d7b53 in your tree

Done, thanks.