From: Marco Elver <elver@google.com>
To: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Alexander Potapenko <glider@google.com>,
"H. Peter Anvin" <hpa@zytor.com>,
"Paul E . McKenney" <paulmck@kernel.org>,
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>,
Dmitry 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 <Jonathan.Cameron@huawei.com>,
Jonathan Corbet <corbet@lwn.net>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Kees Cook <keescook@chromium.org>,
Mark Rutland <mark.rutland@arm.com>,
Pekka Enberg <penberg@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
SeongJae Park <sjpark@amazon.com>,
Thomas Gleixner <tglx@linutronix.de>,
Vlastimil Babka <vbabka@suse.cz>, Will Deacon <will@kernel.org>,
"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 01/10] mm: add Kernel Electric-Fence infrastructure
Date: Tue, 29 Sep 2020 15:49:24 +0200 [thread overview]
Message-ID: <CANpmjNOFpFkrSMFezcBFJODwBK5vRi8sSEzS3AvyFu3Y0ZqgVA@mail.gmail.com> (raw)
In-Reply-To: <CAAeHK+y0aPAZ8zheD5vWFDR-9YCTR251i0F1pZ9QfXuiaW0r8w@mail.gmail.com>
On Tue, 29 Sep 2020 at 15:48, Andrey Konovalov <andreyknvl@google.com> wrote:
> On Tue, Sep 29, 2020 at 3:11 PM Marco Elver <elver@google.com> wrote:
> >
> > On Tue, Sep 29, 2020 at 02:42PM +0200, Andrey Konovalov wrote:
> > [...]
> > > > + */
> > > > + index = (addr - (unsigned long)__kfence_pool) / (PAGE_SIZE * 2) - 1;
> > >
> > > Why do we subtract 1 here? We do have the metadata entry reserved for something?
> >
> > Above the declaration of __kfence_pool it says:
> >
> > * We allocate an even number of pages, as it simplifies calculations to map
> > * address to metadata indices; effectively, the very first page serves as an
> > * extended guard page, but otherwise has no special purpose.
> >
> > Hopefully that clarifies the `- 1` here.
>
> So there are two guard pages at the beginning and only then a page
> that holds an object?
Yes, correct.
WARNING: multiple messages have this Message-ID (diff)
From: Marco Elver <elver@google.com>
To: Andrey Konovalov <andreyknvl@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
Hillf Danton <hdanton@sina.com>,
"open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Linux Memory Management List <linux-mm@kvack.org>,
Eric Dumazet <edumazet@google.com>,
Alexander Potapenko <glider@google.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Christoph Lameter <cl@linux.com>, Will Deacon <will@kernel.org>,
SeongJae Park <sjpark@amazon.com>,
Jonathan Corbet <corbet@lwn.net>,
the arch/x86 maintainers <x86@kernel.org>,
kasan-dev <kasan-dev@googlegroups.com>,
Ingo Molnar <mingo@redhat.com>, Vlastimil Babka <vbabka@suse.cz>,
David Rientjes <rientjes@google.com>,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
Kees Cook <keescook@chromium.org>,
"Paul E . McKenney" <paulmck@kernel.org>,
Jann Horn <jannh@google.com>, Borislav Petkov <bp@alien8.de>,
Andy Lutomirski <luto@kernel.org>,
Jonathan Cameron <Jonathan.Cameron@huawei.com>,
Thomas Gleixner <tglx@linutronix.de>,
Andrew Morton <akpm@linux-foundation.org>,
Dmitry Vyukov <dvyukov@google.com>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
LKML <linux-kernel@vger.kernel.org>,
Pekka Enberg <penberg@kernel.org>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>
Subject: Re: [PATCH v3 01/10] mm: add Kernel Electric-Fence infrastructure
Date: Tue, 29 Sep 2020 15:49:24 +0200 [thread overview]
Message-ID: <CANpmjNOFpFkrSMFezcBFJODwBK5vRi8sSEzS3AvyFu3Y0ZqgVA@mail.gmail.com> (raw)
In-Reply-To: <CAAeHK+y0aPAZ8zheD5vWFDR-9YCTR251i0F1pZ9QfXuiaW0r8w@mail.gmail.com>
On Tue, 29 Sep 2020 at 15:48, Andrey Konovalov <andreyknvl@google.com> wrote:
> On Tue, Sep 29, 2020 at 3:11 PM Marco Elver <elver@google.com> wrote:
> >
> > On Tue, Sep 29, 2020 at 02:42PM +0200, Andrey Konovalov wrote:
> > [...]
> > > > + */
> > > > + index = (addr - (unsigned long)__kfence_pool) / (PAGE_SIZE * 2) - 1;
> > >
> > > Why do we subtract 1 here? We do have the metadata entry reserved for something?
> >
> > Above the declaration of __kfence_pool it says:
> >
> > * We allocate an even number of pages, as it simplifies calculations to map
> > * address to metadata indices; effectively, the very first page serves as an
> > * extended guard page, but otherwise has no special purpose.
> >
> > Hopefully that clarifies the `- 1` here.
>
> So there are two guard pages at the beginning and only then a page
> that holds an object?
Yes, correct.
_______________________________________________
linux-arm-kernel mailing list
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http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-09-29 13:49 UTC|newest]
Thread overview: 135+ 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 ` Marco Elver
2020-09-21 13:26 ` Marco Elver
2020-09-21 13:26 ` [PATCH v3 01/10] mm: add Kernel Electric-Fence infrastructure Marco Elver
2020-09-21 13:26 ` Marco Elver
2020-09-21 13:26 ` Marco Elver
2020-09-25 11:23 ` SeongJae Park
2020-09-25 11:23 ` SeongJae Park
2020-09-25 11:31 ` Marco Elver
2020-09-25 11:31 ` Marco Elver
2020-09-25 11:31 ` Marco Elver
2020-09-29 12:42 ` Andrey Konovalov
2020-09-29 12:42 ` Andrey Konovalov
2020-09-29 12:42 ` Andrey Konovalov
2020-09-29 13:11 ` Marco Elver
2020-09-29 13:11 ` Marco Elver
2020-09-29 13:48 ` Andrey Konovalov
2020-09-29 13:48 ` Andrey Konovalov
2020-09-29 13:48 ` Andrey Konovalov
2020-09-29 13:49 ` Marco Elver [this message]
2020-09-29 13:49 ` Marco Elver
2020-09-29 13:49 ` Marco Elver
2020-09-29 14:01 ` Andrey Konovalov
2020-09-29 14:01 ` Andrey Konovalov
2020-09-29 14:01 ` Andrey Konovalov
2020-09-29 14:24 ` Mark Rutland
2020-09-29 14:24 ` Mark Rutland
2020-09-29 14:51 ` Marco Elver
2020-09-29 14:51 ` Marco Elver
2020-09-29 14:51 ` Marco Elver
2020-09-29 15:05 ` Mark Rutland
2020-09-29 15:05 ` Mark Rutland
2020-10-05 16:00 ` Alexander Potapenko
2020-10-05 16:00 ` Alexander Potapenko
2020-10-05 16:00 ` Alexander Potapenko
2020-10-05 16:49 ` Jann Horn
2020-10-05 16:49 ` Jann Horn
2020-10-05 16:49 ` Jann Horn
2020-09-29 15:51 ` Alexander Potapenko
2020-09-29 15:51 ` Alexander Potapenko
2020-09-29 15:51 ` Alexander Potapenko
2020-10-01 18:11 ` Mark Rutland
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 ` Marco Elver
2020-09-21 13:26 ` Marco Elver
2020-09-21 13:26 ` [PATCH v3 03/10] arm64, kfence: enable KFENCE for ARM64 Marco Elver
2020-09-21 13:26 ` Marco Elver
2020-09-21 13:26 ` Marco Elver
2020-09-21 14:31 ` Will Deacon
2020-09-21 14:31 ` Will Deacon
2020-09-21 14:58 ` Alexander Potapenko
2020-09-21 14:58 ` Alexander Potapenko
2020-09-21 14:58 ` Alexander Potapenko
2020-09-21 15:37 ` Alexander Potapenko
2020-09-21 15:37 ` Alexander Potapenko
2020-09-21 15:37 ` Alexander Potapenko
2020-09-21 17:43 ` Will Deacon
2020-09-21 17:43 ` Will Deacon
2020-09-22 9:56 ` Marco Elver
2020-09-22 9:56 ` Marco Elver
2020-09-22 9:56 ` Marco Elver
2020-09-29 13:53 ` Mark Rutland
2020-09-29 13:53 ` Mark Rutland
2020-09-29 16:52 ` Alexander Potapenko
2020-09-29 16:52 ` Alexander Potapenko
2020-09-29 16:52 ` Alexander Potapenko
2020-09-25 15:25 ` Alexander Potapenko
2020-09-25 15:25 ` Alexander Potapenko
2020-09-25 15:25 ` Alexander Potapenko
2020-09-29 14:02 ` Mark Rutland
2020-09-29 14:02 ` Mark Rutland
2020-10-01 11:24 ` Alexander Potapenko
2020-10-01 11:24 ` Alexander Potapenko
2020-10-01 11:24 ` Alexander Potapenko
2020-10-01 17:57 ` Mark Rutland
2020-10-01 17:57 ` Mark Rutland
2020-10-08 9:40 ` Marco Elver
2020-10-08 9:40 ` Marco Elver
2020-10-08 9:40 ` Marco Elver
2020-10-08 10:45 ` Mark Rutland
2020-10-08 10:45 ` Mark Rutland
2020-10-14 19:12 ` Marco Elver
2020-10-14 19:12 ` Marco Elver
2020-10-14 19:12 ` Marco Elver
2020-10-15 13:39 ` Mark Rutland
2020-10-15 13:39 ` Mark Rutland
2020-10-15 14:15 ` Marco Elver
2020-10-15 14:15 ` Marco Elver
2020-10-15 14:15 ` Marco Elver
2020-09-28 11:53 ` Marco Elver
2020-09-28 11:53 ` Marco Elver
2020-09-28 11:53 ` Marco Elver
2020-09-29 14:27 ` Mark Rutland
2020-09-29 14:27 ` Mark Rutland
2020-09-29 17:04 ` Alexander Potapenko
2020-09-29 17:04 ` Alexander Potapenko
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 ` Marco Elver
2020-09-21 13:26 ` 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 ` Marco Elver
2020-09-21 13:26 ` Marco Elver
2020-09-21 13:26 ` [PATCH v3 06/10] kfence, kasan: make KFENCE compatible with KASAN Marco Elver
2020-09-21 13:26 ` Marco Elver
2020-09-21 13:26 ` Marco Elver
2020-09-29 12:20 ` Andrey Konovalov
2020-09-29 12:20 ` Andrey Konovalov
2020-09-29 12:20 ` Andrey Konovalov
2020-09-29 13:13 ` Alexander Potapenko
2020-09-29 13:13 ` Alexander Potapenko
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 ` Marco Elver
2020-09-21 13:26 ` 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 ` Marco Elver
2020-09-21 13:26 ` Marco Elver
2020-09-21 13:26 ` [PATCH v3 09/10] kfence, Documentation: add KFENCE documentation Marco Elver
2020-09-21 13:26 ` Marco Elver
2020-09-21 13:26 ` Marco Elver
2020-09-21 13:26 ` [PATCH v3 10/10] kfence: add test suite Marco Elver
2020-09-21 13:26 ` Marco Elver
2020-09-21 13:26 ` Marco Elver
2020-09-21 17:13 ` Paul E. McKenney
2020-09-21 17:13 ` Paul E. McKenney
2020-09-21 17:37 ` Marco Elver
2020-09-21 17:37 ` Marco Elver
2020-09-21 17:37 ` Marco Elver
2020-09-21 17:48 ` Paul E. McKenney
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
2020-09-21 13:38 ` Dmitry Vyukov
2020-09-21 13:38 ` Dmitry Vyukov
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