[Info-vax] DCL crashing bug update

[Simon Clubley]

On 2017-07-25, Volker Halle <volker_halle at hotmail.com> wrote:
> The DCL process crash happens in [DCL]RECALLSUB GLOBAL Routine dcl$put_segment in the following instruction stream:
>
> SDA> exa/ins 7AF98598-20;20
> DCL+8A578:      STQ             FP,#X0018(SP)
> DCL+8A57C:      BIS             R31,SP,FP
> DCL+8A580:      BIS             R31,R27,R1
> DCL+8A584:      LDL             R9,#XFFD8(R10)
> DCL+8A588:      ADDL            R9,#X02,R9
> DCL+8A58C:      SUBL            R9,R18,R18
> DCL+8A590:      CMPULT          R9,R16,R19
> DCL+8A594:      CMOVEQ          R19,R18,R9
> DCL+8A598:      LDQ_U           R21,(R9)       <<< ACCVIO here
>
> I'll leave it to the current DCL maintainer to debug and fix this
> 'artificially created problem'.
>

You are correct that it is an artificially created problem.

Unfortunately, those are also the types of problems that have a habit
of exposing security issues because someone didn't anticipate some
particular input sequence during the design process.

Simon.

-- 
Simon Clubley, clubley at remove_me.eisner.decus.org-Earth.UFP
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