Re: crypto: ablk_decrypt causes BUG in scatterwalk

[Dmitry Vyukov]

On Tue, Jan 12, 2016 at 2:23 PM, Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote:
> On Tue, Jan 12, 2016 at 2:16 PM, Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> wrote:
>> On Tue, Jan 12, 2016 at 10:27:44AM +0100, Dmitry Vyukov wrote:
>>> Hello,
>>>
>>> The following program cause BUG in scatterwalk:
>>
>> Weird, I can't reproduce the crash.  Can you perhaps convert this to
>> a non-racy reproduction, possibly by using strace to find the order
>> of execution that leads to the crash?
>
>
> Concurrent execution seems to be important to reproduce the crash. I
> wasn't able to reproduce it in single-threaded mode.
> Try to run it in a tight parallel loop for some time.


I've extracted another reproducer:
https://gist.githubusercontent.com/dvyukov/94aed45494edf1dff0a8/raw/a31f439fdcdd8a8905235a9bce6e5863ca8ccf68/gistfile1.txt

I don't know whether there is a simpler way to run a reproducer in a
tight parallel loop, but I use:
$ go get golang.org/x/tools/cmd/stress
$ GOPATH/bin/stress -p 16 ./a.out

It triggers the BUG within seconds for me.