2010-05-18 05:22:28

by David Miller

Subject: [PATCH 2/6] crypto: Fix scatterwalk_done() test.

We are done with the scattergather entry when the walk offset goes
past sg->offset + sg->length, not when it crosses a page boundary.

There is a similarly queer test in the second half of
scatterwalk_pagedone() that probably needs some scrutiny.

Signed-off-by: David S. Miller <[email protected]>
---
crypto/scatterwalk.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/crypto/scatterwalk.c b/crypto/scatterwalk.c
index 3de89a4..b3acf4f 100644
--- a/crypto/scatterwalk.c
+++ b/crypto/scatterwalk.c
@@ -68,7 +68,7 @@ static void scatterwalk_pagedone(struct scatter_walk *walk, int out,

void scatterwalk_done(struct scatter_walk *walk, int out, int more)
{
- if (!offset_in_page(walk->offset) || !more)
+ if (walk->offset >= walk->sg->offset + walk->sg->length || !more)
scatterwalk_pagedone(walk, out, more);
}
EXPORT_SYMBOL_GPL(scatterwalk_done);
--
1.7.0.4

2010-05-19 04:05:16

by Herbert Xu

Subject: Re: [PATCH 2/6] crypto: Fix scatterwalk_done() test.

On Mon, May 17, 2010 at 10:22:37PM -0700, David Miller wrote:
>
> We are done with the scattergather entry when the walk offset goes
> past sg->offset + sg->length, not when it crosses a page boundary.

Thanks for catching this!

> There is a similarly queer test in the second half of
> scatterwalk_pagedone() that probably needs some scrutiny.

I double-checked that one but can't see any problems yet.

> diff --git a/crypto/scatterwalk.c b/crypto/scatterwalk.c
> index 3de89a4..b3acf4f 100644
> --- a/crypto/scatterwalk.c
> +++ b/crypto/scatterwalk.c
> @@ -68,7 +68,7 @@ static void scatterwalk_pagedone(struct scatter_walk *walk, int out,
>
> void scatterwalk_done(struct scatter_walk *walk, int out, int more)
> {
> - if (!offset_in_page(walk->offset) || !more)
> + if (walk->offset >= walk->sg->offset + walk->sg->length || !more)
> scatterwalk_pagedone(walk, out, more);

I think we need to keep the original test as well as otherwise
if we hit a page boundary while the sg spans over a page (that
can happen with a linearised jumbo skb->head for example) then
we'd be screwed.

So I'm going to commit this patch instead. Let me know if you
see any other issues with it.

diff --git a/crypto/scatterwalk.c b/crypto/scatterwalk.c
index 3de89a4..41e529a 100644
--- a/crypto/scatterwalk.c
+++ b/crypto/scatterwalk.c
@@ -68,7 +68,7 @@ static void scatterwalk_pagedone(struct scatter_walk *walk, int out,

void scatterwalk_done(struct scatter_walk *walk, int out, int more)
{
- if (!offset_in_page(walk->offset) || !more)
+ if (!(scatterwalk_pagelen(walk) & (PAGE_SIZE - 1)) || !more)
scatterwalk_pagedone(walk, out, more);
}
EXPORT_SYMBOL_GPL(scatterwalk_done);

Thanks,
--
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

2010-05-19 05:54:20

by David Miller

Subject: Re: [PATCH 2/6] crypto: Fix scatterwalk_done() test.

From: Herbert Xu <[email protected]>
Date: Wed, 19 May 2010 14:05:13 +1000

> So I'm going to commit this patch instead. Let me know if you
> see any other issues with it.

Looks good:

Acked-by: David S. Miller <[email protected]>