From: "igor.stoppa@gmail.com" <igor.stoppa@gmail.com>
To: Kees Cook <keescook@chromium.org>
Cc: Igor Stoppa <igor.stoppa@huawei.com>,
Ahmed Soliman <ahmedsoliman@mena.vt.edu>,
linux-integrity <linux-integrity@vger.kernel.org>,
Kernel Hardening <kernel-hardening@lists.openwall.com>,
Linux-MM <linux-mm@kvack.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [RFC PATCH v4 00/12] hardening: statically allocated protected memory
Date: Tue, 12 Feb 2019 05:08:03 +0400 [thread overview]
Message-ID: <CAH2bzCRZ5xYOT0R8piqZx4mSGj1_8fNG=Ce4UU8i6F7mYD9m9Q@mail.gmail.com> (raw)
In-Reply-To: <CAGXu5jLqmYRUVLb7-jPsN4onO5UNH+D6qOF=9TOiVjJa-=DnZQ@mail.gmail.com>
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On Tue, 12 Feb 2019, 4.47 Kees Cook <keescook@chromium.org wrote:
> On Mon, Feb 11, 2019 at 4:37 PM Igor Stoppa <igor.stoppa@gmail.com> wrote:
> >
> >
> >
> > On 12/02/2019 02:09, Kees Cook wrote:
> > > On Mon, Feb 11, 2019 at 3:28 PM Igor Stoppa <igor.stoppa@gmail.com>
> wrote:
> > > It looked like only the memset() needed architecture support. Is there
> > > a reason for not being able to implement memset() in terms of an
> > > inefficient put_user() loop instead? That would eliminate the need for
> > > per-arch support, yes?
> >
> > So far, yes, however from previous discussion about power arch, I
> > understood this implementation would not be so easy to adapt.
> > Lacking other examples where the extra mapping could be used, I did not
> > want to add code without a use case.
> >
> > Probably both arm and x86 32 bit could do, but I would like to first get
> > to the bitter end with memory protection (the other 2 thirds).
> >
> > Mostly, I hated having just one arch and I also really wanted to have
> arm64.
>
> Right, I meant, if you implemented the _memset() case with put_user()
> in this version, you could drop the arch-specific _memset() and shrink
> the patch series. Then you could also enable this across all the
> architectures in one patch. (Would you even need the Kconfig patches,
> i.e. won't this "Just Work" on everything with an MMU?)
>
I had similar thoughts, but this answer [1] deflated my hopes (if I
understood it correctly).
It seems that each arch needs to be massaged in separately.
--
igor
[1] https://www.openwall.com/lists/kernel-hardening/2018/12/12/15
>
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next prev parent reply other threads:[~2019-02-12 1:08 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-11 23:27 [RFC PATCH v4 00/12] hardening: statically allocated protected memory Igor Stoppa
2019-02-11 23:27 ` [RFC PATCH v4 01/12] __wr_after_init: Core and default arch Igor Stoppa
2019-02-12 2:39 ` Matthew Wilcox
2019-02-12 7:20 ` Igor Stoppa
2019-02-11 23:27 ` [RFC PATCH v4 02/12] __wr_after_init: x86_64: memset_user() Igor Stoppa
2019-02-11 23:27 ` [RFC PATCH v4 03/12] __wr_after_init: x86_64: randomize mapping offset Igor Stoppa
2019-02-11 23:27 ` [RFC PATCH v4 04/12] __wr_after_init: x86_64: enable Igor Stoppa
2019-02-11 23:27 ` [RFC PATCH v4 05/12] __wr_after_init: arm64: memset_user() Igor Stoppa
2019-02-11 23:27 ` [RFC PATCH v4 06/12] __wr_after_init: arm64: enable Igor Stoppa
2019-02-11 23:27 ` [RFC PATCH v4 07/12] __wr_after_init: Documentation: self-protection Igor Stoppa
2019-02-11 23:27 ` [RFC PATCH v4 08/12] __wr_after_init: lkdtm test Igor Stoppa
2019-02-11 23:27 ` [RFC PATCH v4 09/12] __wr_after_init: rodata_test: refactor tests Igor Stoppa
2019-02-11 23:27 ` [RFC PATCH v4 10/12] __wr_after_init: rodata_test: test __wr_after_init Igor Stoppa
2019-02-11 23:27 ` [RFC PATCH v4 11/12] __wr_after_init: test write rare functionality Igor Stoppa
2019-02-11 23:27 ` [RFC PATCH v4 12/12] IMA: turn ima_policy_flags into __wr_after_init Igor Stoppa
2019-02-12 0:09 ` [RFC PATCH v4 00/12] hardening: statically allocated protected memory Kees Cook
2019-02-12 0:37 ` Igor Stoppa
2019-02-12 0:46 ` Kees Cook
2019-02-12 1:08 ` igor.stoppa [this message]
2019-02-12 1:26 ` Kees Cook
2019-02-12 7:09 ` Igor Stoppa
2019-02-12 22:39 ` Kees Cook
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