From: Andy Lutomirski <luto@amacapital.net>
To: Arnd Bergmann <arnd@arndb.de>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
X86 ML <x86@kernel.org>, Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
Andi Kleen <ak@linux.intel.com>,
Dave Hansen <dave.hansen@intel.com>,
linux-arch <linux-arch@vger.kernel.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Linux API <linux-api@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>
Subject: Re: [RFC, PATCHv2 29/29] mm, x86: introduce RLIMIT_VADDR
Date: Tue, 3 Jan 2017 14:09:16 -0800 [thread overview]
Message-ID: <CALCETrXmdAnbgjsxw=qTbP2PhVCzE8v3y5XMt8DVa4P9DowsGA@mail.gmail.com> (raw)
In-Reply-To: <21511994.eBlbEPoKOz@wuerfel>
On Tue, Jan 3, 2017 at 2:07 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> On Tuesday, January 3, 2017 10:29:33 AM CET Andy Lutomirski wrote:
>>
>> Hmm. What if we approached this a bit differently? We could add a
>> single new personality bit ADDR_LIMIT_EXPLICIT. Setting this bit
>> cause PER_LINUX32_3GB etc to be automatically cleared.
>
> Both the ADDR_LIMIT_32BIT and ADDR_LIMIT_3GB flags I guess?
Yes.
>
>> When
>> ADDR_LIMIT_EXPLICIT is in effect, prctl can set a 64-bit numeric
>> limit. If ADDR_LIMIT_EXPLICIT is cleared, the prctl value stops being
>> settable and reading it via prctl returns whatever is implied by the
>> other personality bits.
>
> I don't see anything wrong with it, but I'm a bit confused now
> what this would be good for, compared to using just prctl.
>
> Is this about setuid clearing the personality but not the prctl,
> or something else?
It's to avid ambiguity as to what happens if you set ADDR_LIMIT_32BIT
and use the prctl. ISTM it would be nice for the semantics to be
fully defined in all cases.
--Andy
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next prev parent reply other threads:[~2017-01-03 22:09 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-27 1:53 [PATCHv2 00/29] 5-level paging Kirill A. Shutemov
2016-12-27 1:53 ` [PATCHv2 01/29] x86/cpufeature: Add 5-level paging detecton Kirill A. Shutemov
2016-12-27 1:53 ` [PATCHv2 02/29] asm-generic: introduce 5level-fixup.h Kirill A. Shutemov
2017-01-27 11:06 ` Vlastimil Babka
2017-01-27 11:30 ` Kirill A. Shutemov
2016-12-27 1:53 ` [PATCHv2 03/29] asm-generic: introduce __ARCH_USE_5LEVEL_HACK Kirill A. Shutemov
2017-01-27 13:24 ` Vlastimil Babka
2017-01-27 13:55 ` Kirill A. Shutemov
2016-12-27 1:53 ` [PATCHv2 04/29] arch, mm: convert all architectures to use 5level-fixup.h Kirill A. Shutemov
2016-12-27 1:53 ` [PATCHv2 05/29] asm-generic: introduce <asm-generic/pgtable-nop4d.h> Kirill A. Shutemov
2016-12-27 1:53 ` [PATCHv2 06/29] mm: convert generic code to 5-level paging Kirill A. Shutemov
2016-12-27 1:53 ` [PATCHv2 07/29] mm: introduce __p4d_alloc() Kirill A. Shutemov
2016-12-27 1:53 ` [PATCHv2 08/29] x86: basic changes into headers for 5-level paging Kirill A. Shutemov
2016-12-27 1:53 ` [PATCHv2 09/29] x86: trivial portion of 5-level paging conversion Kirill A. Shutemov
2016-12-27 1:53 ` [PATCHv2 10/29] x86/gup: add 5-level paging support Kirill A. Shutemov
2016-12-27 1:53 ` [PATCHv2 11/29] x86/ident_map: " Kirill A. Shutemov
2016-12-27 1:53 ` [PATCHv2 12/29] x86/mm: add support of p4d_t in vmalloc_fault() Kirill A. Shutemov
2016-12-27 1:53 ` [PATCHv2 13/29] x86/power: support p4d_t in hibernate code Kirill A. Shutemov
2016-12-27 1:53 ` [PATCHv2 14/29] x86/kexec: support p4d_t Kirill A. Shutemov
2016-12-27 1:53 ` [PATCHv2 15/29] x86: convert the rest of the code to " Kirill A. Shutemov
2016-12-27 1:54 ` [PATCHv2 16/29] x86: detect 5-level paging support Kirill A. Shutemov
2016-12-27 1:54 ` [PATCHv2 17/29] x86/asm: remove __VIRTUAL_MASK_SHIFT==47 assert Kirill A. Shutemov
2016-12-27 1:54 ` [PATCHv2 18/29] x86/mm: define virtual memory map for 5-level paging Kirill A. Shutemov
2016-12-27 1:54 ` [PATCHv2 19/29] x86/paravirt: make paravirt code support " Kirill A. Shutemov
2016-12-27 1:54 ` [PATCHv2 20/29] x86/mm: basic defines/helpers for CONFIG_X86_5LEVEL Kirill A. Shutemov
2016-12-27 1:54 ` [PATCHv2 21/29] x86/dump_pagetables: support 5-level paging Kirill A. Shutemov
2016-12-27 1:54 ` [PATCHv2 22/29] x86/mm: extend kasan to " Kirill A. Shutemov
2016-12-27 1:54 ` [PATCHv2 23/29] x86/espfix: " Kirill A. Shutemov
2016-12-27 1:54 ` [PATCHv2 24/29] x86/mm: add support of additional page table level during early boot Kirill A. Shutemov
2016-12-27 1:54 ` [PATCHv2 25/29] x86/mm: add sync_global_pgds() for configuration with 5-level paging Kirill A. Shutemov
2016-12-27 1:54 ` [PATCHv2 26/29] x86/mm: make kernel_physical_mapping_init() support " Kirill A. Shutemov
2016-12-27 1:54 ` [PATCHv2 27/29] x86/mm: add support for 5-level paging for KASLR Kirill A. Shutemov
2016-12-27 1:54 ` [PATCHv2 28/29] x86: enable 5-level paging support Kirill A. Shutemov
2016-12-27 1:54 ` [RFC, PATCHv2 29/29] mm, x86: introduce RLIMIT_VADDR Kirill A. Shutemov
2016-12-27 2:06 ` Andy Lutomirski
2016-12-27 2:24 ` Kirill A. Shutemov
2016-12-27 3:22 ` Andy Lutomirski
2017-01-02 9:09 ` Kirill A. Shutemov
2016-12-29 2:53 ` Carlos O'Donell
2016-12-31 2:08 ` Andy Lutomirski
2017-01-02 8:35 ` Kirill A. Shutemov
2017-01-13 20:11 ` H.J. Lu
2017-01-02 8:44 ` Arnd Bergmann
2017-01-03 6:08 ` Andy Lutomirski
2017-01-03 13:18 ` Arnd Bergmann
2017-01-03 18:29 ` Andy Lutomirski
2017-01-03 22:07 ` Arnd Bergmann
2017-01-03 22:09 ` Andy Lutomirski [this message]
2017-01-04 13:55 ` Arnd Bergmann
2017-01-03 16:04 ` Kirill A. Shutemov
2017-01-03 18:27 ` Andy Lutomirski
2017-01-04 14:19 ` Kirill A. Shutemov
2017-01-05 17:53 ` Andy Lutomirski
2017-01-05 19:13 ` Dave Hansen
2017-01-05 19:29 ` Kirill A. Shutemov
2017-01-05 19:39 ` Dave Hansen
2017-01-05 20:11 ` Kirill A. Shutemov
2017-01-05 20:14 ` Andy Lutomirski
2017-01-05 20:49 ` Dave Hansen
2017-01-05 21:27 ` Andy Lutomirski
2017-01-05 23:17 ` Dave Hansen
2017-01-11 14:29 ` Kirill A. Shutemov
2017-01-11 18:09 ` Andy Lutomirski
2017-01-11 18:37 ` Kirill A. Shutemov
2017-01-11 18:49 ` Dave Hansen
2017-01-11 19:20 ` Andy Lutomirski
2017-01-11 19:31 ` Linus Torvalds
2017-01-11 21:46 ` Andi Kleen
2017-01-11 19:32 ` Kirill A. Shutemov
2017-01-11 19:39 ` Linus Torvalds
2017-01-11 18:26 ` Dave Hansen
2017-01-05 16:57 ` [PATCHv2 00/29] 5-level paging Kirill A. Shutemov
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