From: Florian Weimer <fweimer@redhat.com>
To: John Hubbard <jhubbard@nvidia.com>,
Matthew Wilcox <willy@infradead.org>,
Michael Ellerman <mpe@ellerman.id.au>
Cc: Cyril Hrubis <chrubis@suse.cz>, Michal Hocko <mhocko@kernel.org>,
Kees Cook <keescook@chromium.org>,
Linux API <linux-api@vger.kernel.org>,
Khalid Aziz <khalid.aziz@oracle.com>,
Andrew Morton <akpm@linux-foundation.org>,
Russell King - ARM Linux <linux@armlinux.org.uk>,
Andrea Arcangeli <aarcange@redhat.com>,
Linux-MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
linux-arch <linux-arch@vger.kernel.org>,
Abdul Haleem <abdhalee@linux.vnet.ibm.com>,
Joel Stanley <joel@jms.id.au>
Subject: Re: [PATCH 0/2] mm: introduce MAP_FIXED_SAFE
Date: Wed, 6 Dec 2017 09:54:30 +0100 [thread overview]
Message-ID: <66677640-5c4a-0758-9560-e45de2d5ba06@redhat.com> (raw)
In-Reply-To: <27ee1755-76d8-f086-5760-9c973b31108a@nvidia.com>
On 12/06/2017 09:06 AM, John Hubbard wrote:
> On 12/05/2017 11:35 PM, Florian Weimer wrote:
>> On 12/06/2017 08:33 AM, John Hubbard wrote:
>>> In that case, maybe:
>>>
>>> MAP_EXACT
>>>
>>> ? ...because that's the characteristic behavior.
>>
>> Is that true? mmap still silently rounding up the length to the page size, I assume, so even that name is misleading.
>
> Hi Florian,
>
> Not as far as I can tell, it's not doing that.
>
> For both MAP_FIXED, and this new flag, the documented (and actual)
> behavior is *not* to do any such rounding. Instead, the requested
> input address is required to be page-aligned itself, and mmap()
> should be honoring the exact addr.
I meant the length, not the address.
Florian
WARNING: multiple messages have this Message-ID (diff)
From: Florian Weimer <fweimer-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
To: John Hubbard <jhubbard-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>,
Matthew Wilcox <willy-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>,
Michael Ellerman <mpe-Gsx/Oe8HsFggBc27wqDAHg@public.gmane.org>
Cc: Cyril Hrubis <chrubis-AlSwsSmVLrQ@public.gmane.org>,
Michal Hocko <mhocko-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
Kees Cook <keescook-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>,
Linux API <linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
Khalid Aziz <khalid.aziz-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>,
Andrew Morton
<akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>,
Russell King - ARM Linux
<linux-I+IVW8TIWO2tmTQ+vhA3Yw@public.gmane.org>,
Andrea Arcangeli
<aarcange-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
Linux-MM <linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org>,
LKML <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
linux-arch <linux-arch-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
Abdul Haleem
<abdhalee-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>,
Joel Stanley <joel-U3u1mxZcP9KHXe+LvDLADg@public.gmane.org>
Subject: Re: [PATCH 0/2] mm: introduce MAP_FIXED_SAFE
Date: Wed, 6 Dec 2017 09:54:30 +0100 [thread overview]
Message-ID: <66677640-5c4a-0758-9560-e45de2d5ba06@redhat.com> (raw)
In-Reply-To: <27ee1755-76d8-f086-5760-9c973b31108a-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
On 12/06/2017 09:06 AM, John Hubbard wrote:
> On 12/05/2017 11:35 PM, Florian Weimer wrote:
>> On 12/06/2017 08:33 AM, John Hubbard wrote:
>>> In that case, maybe:
>>>
>>> MAP_EXACT
>>>
>>> ? ...because that's the characteristic behavior.
>>
>> Is that true? mmap still silently rounding up the length to the page size, I assume, so even that name is misleading.
>
> Hi Florian,
>
> Not as far as I can tell, it's not doing that.
>
> For both MAP_FIXED, and this new flag, the documented (and actual)
> behavior is *not* to do any such rounding. Instead, the requested
> input address is required to be page-aligned itself, and mmap()
> should be honoring the exact addr.
I meant the length, not the address.
Florian
WARNING: multiple messages have this Message-ID (diff)
From: Florian Weimer <fweimer@redhat.com>
To: John Hubbard <jhubbard@nvidia.com>,
Matthew Wilcox <willy@infradead.org>,
Michael Ellerman <mpe@ellerman.id.au>
Cc: Cyril Hrubis <chrubis@suse.cz>, Michal Hocko <mhocko@kernel.org>,
Kees Cook <keescook@chromium.org>,
Linux API <linux-api@vger.kernel.org>,
Khalid Aziz <khalid.aziz@oracle.com>,
Andrew Morton <akpm@linux-foundation.org>,
Russell King - ARM Linux <linux@armlinux.org.uk>,
Andrea Arcangeli <aarcange@redhat.com>,
Linux-MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
linux-arch <linux-arch@vger.kernel.org>,
Abdul Haleem <abdhalee@linux.vnet.ibm.com>,
Joel Stanley <joel@jms.id.au>
Subject: Re: [PATCH 0/2] mm: introduce MAP_FIXED_SAFE
Date: Wed, 6 Dec 2017 09:54:30 +0100 [thread overview]
Message-ID: <66677640-5c4a-0758-9560-e45de2d5ba06@redhat.com> (raw)
In-Reply-To: <27ee1755-76d8-f086-5760-9c973b31108a@nvidia.com>
On 12/06/2017 09:06 AM, John Hubbard wrote:
> On 12/05/2017 11:35 PM, Florian Weimer wrote:
>> On 12/06/2017 08:33 AM, John Hubbard wrote:
>>> In that case, maybe:
>>>
>>> A A A A MAP_EXACT
>>>
>>> ? ...because that's the characteristic behavior.
>>
>> Is that true?A mmap still silently rounding up the length to the page size, I assume, so even that name is misleading.
>
> Hi Florian,
>
> Not as far as I can tell, it's not doing that.
>
> For both MAP_FIXED, and this new flag, the documented (and actual)
> behavior is *not* to do any such rounding. Instead, the requested
> input address is required to be page-aligned itself, and mmap()
> should be honoring the exact addr.
I meant the length, not the address.
Florian
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2017-12-06 8:54 UTC|newest]
Thread overview: 117+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-29 14:42 [PATCH 0/2] mm: introduce MAP_FIXED_SAFE Michal Hocko
2017-11-29 14:42 ` Michal Hocko
2017-11-29 14:42 ` Michal Hocko
2017-11-29 14:42 ` [PATCH 1/2] " Michal Hocko
2017-11-29 14:42 ` Michal Hocko
2017-11-29 14:42 ` Michal Hocko
2017-12-06 5:15 ` Michael Ellerman
2017-12-06 5:15 ` Michael Ellerman
2017-12-06 9:27 ` Michal Hocko
2017-12-06 9:27 ` Michal Hocko
2017-12-06 10:02 ` Michal Hocko
2017-12-06 10:02 ` Michal Hocko
2017-12-07 12:07 ` Pavel Machek
2017-12-07 12:07 ` Pavel Machek
2017-11-29 14:42 ` [PATCH 2/2] fs, elf: drop MAP_FIXED usage from elf_map Michal Hocko
2017-11-29 14:42 ` Michal Hocko
2017-11-29 14:42 ` Michal Hocko
2017-11-29 17:45 ` Khalid Aziz
2017-11-29 17:45 ` Khalid Aziz
2018-05-29 22:21 ` Mike Kravetz
2018-05-30 8:02 ` Michal Hocko
2018-05-30 15:00 ` Mike Kravetz
2018-05-30 16:25 ` Michal Hocko
2018-05-31 0:51 ` Mike Kravetz
2018-05-31 9:24 ` Michal Hocko
2018-05-31 21:46 ` Mike Kravetz
2017-11-29 14:45 ` [PATCH] mmap.2: document new MAP_FIXED_SAFE flag Michal Hocko
2017-11-29 14:45 ` Michal Hocko
2017-11-29 14:45 ` Michal Hocko
2017-11-30 3:16 ` John Hubbard
2017-11-30 3:16 ` John Hubbard
2017-11-30 3:16 ` John Hubbard
2017-11-30 8:23 ` Michal Hocko
2017-11-30 8:23 ` Michal Hocko
2017-11-30 8:24 ` [PATCH v2] " Michal Hocko
2017-11-30 8:24 ` Michal Hocko
2017-11-30 8:24 ` Michal Hocko
2017-11-30 8:24 ` Michal Hocko
2017-11-30 18:31 ` John Hubbard
2017-11-30 18:31 ` John Hubbard
2017-11-30 18:31 ` John Hubbard
2017-11-30 18:39 ` Michal Hocko
2017-11-30 18:39 ` Michal Hocko
2017-11-29 15:13 ` [PATCH 0/2] mm: introduce MAP_FIXED_SAFE Rasmus Villemoes
2017-11-29 15:13 ` Rasmus Villemoes
2017-11-29 15:13 ` Rasmus Villemoes
2017-11-29 15:50 ` Michal Hocko
2017-11-29 15:50 ` Michal Hocko
2017-11-29 15:50 ` Michal Hocko
2017-11-29 22:15 ` Kees Cook
2017-11-29 22:15 ` Kees Cook
2017-11-29 22:12 ` Kees Cook
2017-11-29 22:12 ` Kees Cook
2017-11-29 22:25 ` Kees Cook
2017-11-29 22:25 ` Kees Cook
2017-11-30 6:58 ` Michal Hocko
2017-11-30 6:58 ` Michal Hocko
2017-11-30 6:58 ` Michal Hocko
2017-12-01 15:26 ` Cyril Hrubis
2017-12-01 15:26 ` Cyril Hrubis
2017-12-06 4:51 ` Michael Ellerman
2017-12-06 4:51 ` Michael Ellerman
2017-12-06 4:54 ` Matthew Wilcox
2017-12-06 4:54 ` Matthew Wilcox
2017-12-06 7:03 ` Matthew Wilcox
2017-12-06 7:03 ` Matthew Wilcox
2017-12-06 7:33 ` John Hubbard
2017-12-06 7:33 ` John Hubbard
2017-12-06 7:35 ` Florian Weimer
2017-12-06 7:35 ` Florian Weimer
2017-12-06 7:35 ` Florian Weimer
2017-12-06 8:06 ` John Hubbard
2017-12-06 8:06 ` John Hubbard
2017-12-06 8:06 ` John Hubbard
2017-12-06 8:06 ` John Hubbard
2017-12-06 8:54 ` Florian Weimer [this message]
2017-12-06 8:54 ` Florian Weimer
2017-12-06 8:54 ` Florian Weimer
2017-12-07 5:46 ` Michael Ellerman
2017-12-07 5:46 ` Michael Ellerman
2017-12-07 5:46 ` Michael Ellerman
2017-12-07 19:14 ` Kees Cook
2017-12-07 19:14 ` Kees Cook
2017-12-07 19:57 ` Matthew Wilcox
2017-12-07 19:57 ` Matthew Wilcox
2017-12-07 19:57 ` Matthew Wilcox
2017-12-08 8:33 ` Michal Hocko
2017-12-08 8:33 ` Michal Hocko
2017-12-08 20:13 ` Kees Cook
2017-12-08 20:13 ` Kees Cook
2017-12-08 20:13 ` Kees Cook
2017-12-08 20:57 ` Matthew Wilcox
2017-12-08 20:57 ` Matthew Wilcox
2017-12-08 20:57 ` Matthew Wilcox
2017-12-08 11:08 ` Michael Ellerman
2017-12-08 11:08 ` Michael Ellerman
2017-12-08 14:27 ` Pavel Machek
2017-12-08 20:31 ` Cyril Hrubis
2017-12-08 20:31 ` Cyril Hrubis
2017-12-08 20:31 ` Cyril Hrubis
2017-12-08 20:47 ` Florian Weimer
2017-12-08 20:47 ` Florian Weimer
2017-12-08 20:47 ` Florian Weimer
2017-12-08 14:33 ` David Laight
2017-12-08 14:33 ` David Laight
2017-12-06 4:50 ` Michael Ellerman
2017-12-06 4:50 ` Michael Ellerman
2017-12-06 7:33 ` Rasmus Villemoes
2017-12-06 7:33 ` Rasmus Villemoes
2017-12-06 7:33 ` Rasmus Villemoes
2017-12-06 9:08 ` Michal Hocko
2017-12-06 9:08 ` Michal Hocko
2017-12-06 9:08 ` Michal Hocko
2017-12-07 0:19 ` Kees Cook
2017-12-07 0:19 ` Kees Cook
2017-12-07 1:08 ` John Hubbard
2017-12-07 1:08 ` John Hubbard
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=66677640-5c4a-0758-9560-e45de2d5ba06@redhat.com \
--to=fweimer@redhat.com \
--cc=aarcange@redhat.com \
--cc=abdhalee@linux.vnet.ibm.com \
--cc=akpm@linux-foundation.org \
--cc=chrubis@suse.cz \
--cc=jhubbard@nvidia.com \
--cc=joel@jms.id.au \
--cc=keescook@chromium.org \
--cc=khalid.aziz@oracle.com \
--cc=linux-api@vger.kernel.org \
--cc=linux-arch@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux@armlinux.org.uk \
--cc=mhocko@kernel.org \
--cc=mpe@ellerman.id.au \
--cc=willy@infradead.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.