From: John Hubbard <jhubbard@nvidia.com> To: Kees Cook <keescook@chromium.org>, Michal Hocko <mhocko@kernel.org>, Michael Kerrisk <mtk.manpages@gmail.com> Cc: Rasmus Villemoes <rasmus.villemoes@prevas.dk>, Michael Ellerman <mpe@ellerman.id.au>, 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>, Florian Weimer <fweimer@redhat.com>, Abdul Haleem <abdhalee@linux.vnet.ibm.com>, Joel Stanley <joel@jms.id.au>, Matthew Wilcox <willy@infradead.org> Subject: Re: [PATCH 0/2] mm: introduce MAP_FIXED_SAFE Date: Wed, 6 Dec 2017 17:08:19 -0800 [thread overview] Message-ID: <c427dc00-2835-a475-1ef5-f5550c4113a0@nvidia.com> (raw) In-Reply-To: <CAGXu5jKGsAjwF7nE_vjaWPnG0QJRx_qFeiSBLRg_g73iUJ-pwA@mail.gmail.com> On 12/06/2017 04:19 PM, Kees Cook wrote: > On Wed, Dec 6, 2017 at 1:08 AM, Michal Hocko <mhocko@kernel.org> wrote: >> On Wed 06-12-17 08:33:37, Rasmus Villemoes wrote: >>> On 2017-12-06 05:50, Michael Ellerman wrote: >>>> Michal Hocko <mhocko@kernel.org> writes: >>>> >>>>> On Wed 29-11-17 14:25:36, Kees Cook wrote: >>>>> It is safe in a sense it doesn't perform any address space dangerous >>>>> operations. mmap is _inherently_ about the address space so the context >>>>> should be kind of clear. >>>> >>>> So now you have to define what "dangerous" means. >>>> >>>>>> MAP_FIXED_UNIQUE >>>>>> MAP_FIXED_ONCE >>>>>> MAP_FIXED_FRESH >>>>> >>>>> Well, I can open a poll for the best name, but none of those you are >>>>> proposing sound much better to me. Yeah, naming sucks... >>> >>> I also don't like the _SAFE name - MAP_FIXED in itself isn't unsafe [1], >>> but I do agree that having a way to avoid clobbering (parts of) an >>> existing mapping is quite useful. Since we're bikeshedding names, how >>> about MAP_FIXED_EXCL, in analogy with the O_ flag. >> >> I really give up on the name discussion. I will take whatever the >> majority comes up with. I just do not want this (useful) funtionality >> get bikeched to death. > > Yup, I really want this to land too. What do people think of Matthew > Wilcox's MAP_REQUIRED ? MAP_EXACT isn't exact, and dropping "FIXED" > out of the middle seems sensible to me. +1, MAP_REQUIRED does sound like the best one so far, yes. Sorry if I contributed to any excessive bikeshedding. :) thanks, john h > > MIchael, any suggestions with your API hat on? > > -Kees >
WARNING: multiple messages have this Message-ID (diff)
From: John Hubbard <jhubbard@nvidia.com> To: Kees Cook <keescook@chromium.org>, Michal Hocko <mhocko@kernel.org>, Michael Kerrisk <mtk.manpages@gmail.com> Cc: Rasmus Villemoes <rasmus.villemoes@prevas.dk>, Michael Ellerman <mpe@ellerman.id.au>, 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>, Florian Weimer <fweimer@redhat.com>, Abdul Haleem <abdhalee@linux.vnet.ibm.com>, Joel Stanley <joel@jms.id.au>, Matthew Wilcox <willy@infradead.org> Subject: Re: [PATCH 0/2] mm: introduce MAP_FIXED_SAFE Date: Wed, 6 Dec 2017 17:08:19 -0800 [thread overview] Message-ID: <c427dc00-2835-a475-1ef5-f5550c4113a0@nvidia.com> (raw) In-Reply-To: <CAGXu5jKGsAjwF7nE_vjaWPnG0QJRx_qFeiSBLRg_g73iUJ-pwA@mail.gmail.com> On 12/06/2017 04:19 PM, Kees Cook wrote: > On Wed, Dec 6, 2017 at 1:08 AM, Michal Hocko <mhocko@kernel.org> wrote: >> On Wed 06-12-17 08:33:37, Rasmus Villemoes wrote: >>> On 2017-12-06 05:50, Michael Ellerman wrote: >>>> Michal Hocko <mhocko@kernel.org> writes: >>>> >>>>> On Wed 29-11-17 14:25:36, Kees Cook wrote: >>>>> It is safe in a sense it doesn't perform any address space dangerous >>>>> operations. mmap is _inherently_ about the address space so the context >>>>> should be kind of clear. >>>> >>>> So now you have to define what "dangerous" means. >>>> >>>>>> MAP_FIXED_UNIQUE >>>>>> MAP_FIXED_ONCE >>>>>> MAP_FIXED_FRESH >>>>> >>>>> Well, I can open a poll for the best name, but none of those you are >>>>> proposing sound much better to me. Yeah, naming sucks... >>> >>> I also don't like the _SAFE name - MAP_FIXED in itself isn't unsafe [1], >>> but I do agree that having a way to avoid clobbering (parts of) an >>> existing mapping is quite useful. Since we're bikeshedding names, how >>> about MAP_FIXED_EXCL, in analogy with the O_ flag. >> >> I really give up on the name discussion. I will take whatever the >> majority comes up with. I just do not want this (useful) funtionality >> get bikeched to death. > > Yup, I really want this to land too. What do people think of Matthew > Wilcox's MAP_REQUIRED ? MAP_EXACT isn't exact, and dropping "FIXED" > out of the middle seems sensible to me. +1, MAP_REQUIRED does sound like the best one so far, yes. Sorry if I contributed to any excessive bikeshedding. :) thanks, john h > > MIchael, any suggestions with your API hat on? > > -Kees > -- 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:[~2017-12-07 1:08 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 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 [this message] 2017-12-07 1:08 ` John Hubbard
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