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From: Szabolcs Nagy <nsz@port70.net>
To: "H.J. Lu via Libc-alpha" <libc-alpha@sourceware.org>
Cc: Andrea Corallo <andrea.corallo@arm.com>, nd <nd@arm.com>,
	Wilco Dijkstra <Wilco.Dijkstra@arm.com>
Subject: Re: [PATCH] aarch64: MTE compatible strchrnul
Date: Thu, 4 Jun 2020 21:48:37 +0200	[thread overview]
Message-ID: <20200604194837.GA673948@port70.net> (raw)
In-Reply-To: <CAMe9rOqOdSfL153o5=Kr3ng9m6eb61zzOaxEyy5RgE1-WqpiCQ@mail.gmail.com>

* H.J. Lu via Libc-alpha <libc-alpha@sourceware.org> [2020-06-04 05:04:23 -0700]:
> On Wed, Jun 3, 2020 at 9:02 AM Andrea Corallo <andrea.corallo@arm.com> wrote:
> > Adhemerval Zanella <adhemerval.zanella@linaro.org> writes:
> > > Besides it the commit message does not give an overall description of
> > > which changes it does to the generic implementation neither the requirements
> > > of MTE support.
> >
> > I'll improve the commit message as suggested.  Regarding the MTE
> > requirements given the function is backward compatible not sure what
> > should be mentioned.
> >
> 
> My impression is if some object files aren't MTE compatible, you can't enable
> MTE in the executable.  Is that correct?

there can be code that is not mte compatible that would
crash when memory tagging and tag checking are enabled.
currently there is no object file marking for compatibility.

i think we should mention in the commit message in what
way the old code is incompatible with mte (e.g. it does
out of bound loads that can go across a tag granule
boundaries which can cause tag check failures with mte)

  reply	other threads:[~2020-06-04 19:48 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-03  9:43 Andrea Corallo
2020-06-03 11:27 ` Florian Weimer
2020-06-03 14:14   ` Andrea Corallo
2020-06-03 14:24     ` Florian Weimer
2020-06-03 14:33       ` Adhemerval Zanella
2020-06-03 14:53         ` Szabolcs Nagy
2020-06-03 15:03           ` Szabolcs Nagy
2020-06-03 15:04           ` Adhemerval Zanella
2020-06-03 15:04         ` Florian Weimer
2020-06-03 15:18           ` Szabolcs Nagy
2020-06-03 15:24             ` Florian Weimer
2020-06-03 14:40 ` Adhemerval Zanella
2020-06-03 16:01   ` Andrea Corallo
2020-06-04 12:04     ` H.J. Lu
2020-06-04 19:48       ` Szabolcs Nagy [this message]
2020-06-04 20:03         ` H.J. Lu
2020-06-05  7:38           ` Szabolcs Nagy
2020-06-05  8:45             ` Wilco Dijkstra
2020-06-05 16:25               ` Szabolcs Nagy

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