Re: [patch 32/37] CRYPTO: api: scatterwalk_copychunks() fails to advance through scatterlist

Herbert Xu
2007-03-31T02:16:12Z

On Sat, Mar 31, 2007 at 03:41:32AM +0200, Patrick McHardy wrote:
>
> > [CRYPTO] api: scatterwalk_copychunks() fails to advance through scatterlist
>
> This patch seems to cause some problems, I get reproducable freezes
> on the receiving system with net-2.6.22 when sending IPsec packets
> larger than the mtu (reproduced about 10 times). Reverting this
> patch seems to fix it. In a few cases the oops also occured on the
> sending system.
>
> Backtrace from UML (sending system):
>
> uml:~# ping 10.0.0.1 -s 20000
> PING 10.0.0.1 (10.0.0.1) 20000(20028) bytes of data.
> BUG: soft lockup detected on CPU#0!
> Call Trace:

Indeed. That patch was buggy. Sorry for not catching this earlier.

This should fix the problem.

[CRYPTO] api: Use the right value when advancing scatterwalk_copychunks

In the scatterwalk_copychunks loop, We should be advancing by
len_this_page and not nbytes. The latter is the total length.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Cheers,
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--
diff --git a/crypto/scatterwalk.c b/crypto/scatterwalk.c
index a664231..0f76175 100644
--- a/crypto/scatterwalk.c
+++ b/crypto/scatterwalk.c
@@ -91,7 +91,7 @@ void scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
memcpy_dir(buf, vaddr, len_this_page, out);
scatterwalk_unmap(vaddr, out);

- scatterwalk_advance(walk, nbytes);
+ scatterwalk_advance(walk, len_this_page);

if (nbytes == len_this_page)
break;