From: Catalin Marinas <catalin.marinas@arm.com>
To: Dave Hansen <dave.hansen@intel.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>,
linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org,
linux-mm@kvack.org, linux-arch@vger.kernel.org,
linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org,
Will Deacon <will.deacon@arm.com>,
Andrey Konovalov <andreyknvl@google.com>,
Szabolcs Nagy <szabolcs.nagy@arm.com>
Subject: Re: [PATCH v6 1/2] arm64: Define Documentation/arm64/tagged-address-abi.rst
Date: Fri, 2 Aug 2019 11:08:35 +0100 [thread overview]
Message-ID: <20190802100835.GA4175@arrakis.emea.arm.com> (raw)
In-Reply-To: <b74e7ce7-d58a-68a0-2f28-6648ec6302c0@intel.com>
Hi Dave,
On Wed, Jul 31, 2019 at 09:43:46AM -0700, Dave Hansen wrote:
> On 7/25/19 6:50 AM, Vincenzo Frascino wrote:
> > With the relaxed ABI proposed through this document, it is now possible
> > to pass tagged pointers to the syscalls, when these pointers are in
> > memory ranges obtained by an anonymous (MAP_ANONYMOUS) mmap().
>
> I don't see a lot of description of why this restriction is necessary.
> What's the problem with supporting MAP_SHARED?
We could support MAP_SHARED | MAP_ANONYMOUS (and based on some internal
discussions, this would be fine with the hardware memory tagging as
well). What we don't want in the ABI is to support file mmap() for
top-byte-ignore (or MTE). If you see a use-case, please let us know.
--
Catalin
next prev parent reply other threads:[~2019-08-02 10:08 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <cover.1563904656.git.andreyknvl@google.com>
2019-07-25 13:50 ` [PATCH v6 0/2] arm64 relaxed ABI Vincenzo Frascino
2019-07-25 13:50 ` [PATCH v6 1/2] arm64: Define Documentation/arm64/tagged-address-abi.rst Vincenzo Frascino
2019-07-30 10:32 ` Kevin Brodsky
2019-07-30 13:25 ` Vincenzo Frascino
2019-07-30 13:57 ` Kevin Brodsky
2019-07-30 14:24 ` Vincenzo Frascino
2019-07-30 14:48 ` Kevin Brodsky
2019-07-31 16:43 ` Dave Hansen
2019-08-02 10:08 ` Catalin Marinas [this message]
2019-07-25 13:50 ` [PATCH v6 2/2] arm64: Relax Documentation/arm64/tagged-pointers.rst Vincenzo Frascino
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