Re: [git pull] stackprotector re-enabling patches

From: Ingo Molnar
Date: Sat Jan 03 2009 - 17:44:34 EST



* Arjan van de Ven <arjan@xxxxxxxxxxxxx> wrote:

> On Sat, 3 Jan 2009 13:55:13 -0800
> Arjan van de Ven <arjan@xxxxxxxxxxxxx> wrote:
>
> > On Sat, 3 Jan 2009 22:43:53 +0100
> > Ingo Molnar <mingo@xxxxxxx> wrote:
> > >
> > > diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
> > > index 10d6cc3..28f1114 100644
> > > --- a/arch/x86/Kconfig.debug
> > > +++ b/arch/x86/Kconfig.debug
> > > @@ -117,6 +117,7 @@ config DEBUG_RODATA
> > > config DEBUG_RODATA_TEST
> > > bool "Testcase for the DEBUG_RODATA feature"
> > > depends on DEBUG_RODATA
> > > + default y
> > > help
> > > This option enables a testcase for the DEBUG_RODATA
> > > feature as well as for the change_page_attr()
> >
> > I think this chunk isn't meant to be there...
>
> actually never mind.
> it does make sense in general (in fact, I'd be tempted to remove the
> KConfig for this one and just always do the check)

yes. The reason why this change went into the stackprotector tree was
because it was the same pattern: security feature breaking because it
didnt have efficient self-tests - while attackers obviously never notified
us that it's broken.

DEBUG_RODATA had similar bugs: it didnt work correctly in some cases and
nothing really tested that so we had long latency of bugs. So i turned on
that self-test too. [and that did catch some bugs, which you fixed, many
moons ago ;-) ]

Ingo
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