linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Mark Rutland <mark.rutland@arm.com>
To: Alexander Potapenko <glider@google.com>
Cc: Will Deacon <will@kernel.org>, Marco Elver <elver@google.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	"H. Peter Anvin" <hpa@zytor.com>,
	"Paul E. McKenney" <paulmck@kernel.org>,
	Andrey Konovalov <andreyknvl@google.com>,
	Andrey Ryabinin <aryabinin@virtuozzo.com>,
	Andy Lutomirski <luto@kernel.org>, Borislav Petkov <bp@alien8.de>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Christoph Lameter <cl@linux.com>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	David Rientjes <rientjes@google.com>,
	Dmitriy Vyukov <dvyukov@google.com>,
	Eric Dumazet <edumazet@google.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Hillf Danton <hdanton@sina.com>, Ingo Molnar <mingo@redhat.com>,
	Jann Horn <jannh@google.com>,
	Jonathan.Cameron@huawei.com, Jonathan Corbet <corbet@lwn.net>,
	Joonsoo Kim <iamjoonsoo.kim@lge.com>,
	Kees Cook <keescook@chromium.org>,
	Pekka Enberg <penberg@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	sjpark@amazon.com, Thomas Gleixner <tglx@linutronix.de>,
	Vlastimil Babka <vbabka@suse.cz>,
	the arch/x86 maintainers <x86@kernel.org>,
	"open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	kasan-dev <kasan-dev@googlegroups.com>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	Linux Memory Management List <linux-mm@kvack.org>
Subject: Re: [PATCH v3 03/10] arm64, kfence: enable KFENCE for ARM64
Date: Tue, 29 Sep 2020 15:02:26 +0100	[thread overview]
Message-ID: <20200929140226.GB53442@C02TD0UTHF1T.local> (raw)
In-Reply-To: <CAG_fn=WXknUnNmyniy_UE7daivSNmy0Da2KzNmX4wcmXC2Z_Mg@mail.gmail.com>

On Fri, Sep 25, 2020 at 05:25:11PM +0200, Alexander Potapenko wrote:
> Will,
> 
> > Given that the pool is relatively small (i.e. when compared with our virtual
> > address space), dedicating an area of virtual space sounds like it makes
> > the most sense here. How early do you need it to be available?
> 
> How do we assign struct pages to a fixed virtual space area (I'm
> currently experimenting with 0xffff7f0000000000-0xffff7f0000200000)?

You don't.

There should be a struct page for each of the /physical/ pages, and
these can be found:

* via the physical address, using phyts_to_page() or pfn_to_page()
* via the linear/direct map, using virt_to_page()
* via the vmalloc page tables using vmalloc_to_page()

If you need virt_to_page() to work, the address has to be part of the
linear/direct map.

If you need to find the struct page for something that's part of the
kernel image you can use virt_to_page(lm_alias(x)).

> Looks like filling page table entries (similarly to what's being done
> in arch/arm64/mm/kasan_init.c) is not enough.
> I thought maybe vmemmap_populate() would do the job, but it didn't
> (virt_to_pfn() still returns invalid PFNs).

As above, I think lm_alias() will solve the problem here. Please see
that and CONFIG_DEBUG_VIRTUAL.

Thanks,
Mark.

  reply	other threads:[~2020-09-29 14:02 UTC|newest]

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-21 13:26 [PATCH v3 00/10] KFENCE: A low-overhead sampling-based memory safety error detector Marco Elver
2020-09-21 13:26 ` [PATCH v3 01/10] mm: add Kernel Electric-Fence infrastructure Marco Elver
2020-09-25 11:23   ` SeongJae Park
2020-09-25 11:31     ` Marco Elver
2020-09-29 12:42   ` Andrey Konovalov
2020-09-29 13:11     ` Marco Elver
2020-09-29 13:48       ` Andrey Konovalov
2020-09-29 13:49         ` Marco Elver
2020-09-29 14:01           ` Andrey Konovalov
2020-09-29 14:24   ` Mark Rutland
2020-09-29 14:51     ` Marco Elver
2020-09-29 15:05       ` Mark Rutland
2020-10-05 16:00         ` Alexander Potapenko
2020-10-05 16:49           ` Jann Horn
2020-09-29 15:51     ` Alexander Potapenko
2020-10-01 18:11       ` Mark Rutland
2020-09-21 13:26 ` [PATCH v3 02/10] x86, kfence: enable KFENCE for x86 Marco Elver
2020-09-21 13:26 ` [PATCH v3 03/10] arm64, kfence: enable KFENCE for ARM64 Marco Elver
2020-09-21 14:31   ` Will Deacon
2020-09-21 14:58     ` Alexander Potapenko
2020-09-21 15:37       ` Alexander Potapenko
2020-09-21 17:43         ` Will Deacon
2020-09-22  9:56           ` Marco Elver
2020-09-29 13:53             ` Mark Rutland
2020-09-29 16:52               ` Alexander Potapenko
2020-09-25 15:25     ` Alexander Potapenko
2020-09-29 14:02       ` Mark Rutland [this message]
2020-10-01 11:24         ` Alexander Potapenko
2020-10-01 17:57           ` Mark Rutland
2020-10-08  9:40             ` Marco Elver
2020-10-08 10:45               ` Mark Rutland
2020-10-14 19:12                 ` Marco Elver
2020-10-15 13:39                   ` Mark Rutland
2020-10-15 14:15                     ` Marco Elver
2020-09-28 11:53     ` Marco Elver
2020-09-29 14:27   ` Mark Rutland
2020-09-29 17:04     ` Alexander Potapenko
2020-09-21 13:26 ` [PATCH v3 04/10] mm, kfence: insert KFENCE hooks for SLAB Marco Elver
2020-09-21 13:26 ` [PATCH v3 05/10] mm, kfence: insert KFENCE hooks for SLUB Marco Elver
2020-09-21 13:26 ` [PATCH v3 06/10] kfence, kasan: make KFENCE compatible with KASAN Marco Elver
2020-09-29 12:20   ` Andrey Konovalov
2020-09-29 13:13     ` Alexander Potapenko
2020-09-21 13:26 ` [PATCH v3 07/10] kfence, kmemleak: make KFENCE compatible with KMEMLEAK Marco Elver
2020-09-21 13:26 ` [PATCH v3 08/10] kfence, lockdep: make KFENCE compatible with lockdep Marco Elver
2020-09-21 13:26 ` [PATCH v3 09/10] kfence, Documentation: add KFENCE documentation Marco Elver
2020-09-21 13:26 ` [PATCH v3 10/10] kfence: add test suite Marco Elver
2020-09-21 17:13   ` Paul E. McKenney
2020-09-21 17:37     ` Marco Elver
2020-09-21 17:48       ` Paul E. McKenney
2020-09-21 13:38 ` [PATCH v3 00/10] KFENCE: A low-overhead sampling-based memory safety error detector Dmitry Vyukov

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200929140226.GB53442@C02TD0UTHF1T.local \
    --to=mark.rutland@arm.com \
    --cc=Jonathan.Cameron@huawei.com \
    --cc=akpm@linux-foundation.org \
    --cc=andreyknvl@google.com \
    --cc=aryabinin@virtuozzo.com \
    --cc=bp@alien8.de \
    --cc=catalin.marinas@arm.com \
    --cc=cl@linux.com \
    --cc=corbet@lwn.net \
    --cc=dave.hansen@linux.intel.com \
    --cc=dvyukov@google.com \
    --cc=edumazet@google.com \
    --cc=elver@google.com \
    --cc=glider@google.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=hdanton@sina.com \
    --cc=hpa@zytor.com \
    --cc=iamjoonsoo.kim@lge.com \
    --cc=jannh@google.com \
    --cc=kasan-dev@googlegroups.com \
    --cc=keescook@chromium.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-doc@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=luto@kernel.org \
    --cc=mingo@redhat.com \
    --cc=paulmck@kernel.org \
    --cc=penberg@kernel.org \
    --cc=peterz@infradead.org \
    --cc=rientjes@google.com \
    --cc=sjpark@amazon.com \
    --cc=tglx@linutronix.de \
    --cc=vbabka@suse.cz \
    --cc=will@kernel.org \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).