From: Catalin Marinas <catalin.marinas@arm.com>
To: Randy Dunlap <rdunlap@infradead.org>
Cc: linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org,
linux-arch@vger.kernel.org, Will Deacon <will@kernel.org>,
Dave P Martin <Dave.Martin@arm.com>,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
Szabolcs Nagy <szabolcs.nagy@arm.com>,
Kevin Brodsky <kevin.brodsky@arm.com>,
Andrey Konovalov <andreyknvl@google.com>,
Peter Collingbourne <pcc@google.com>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH v8 27/28] arm64: mte: Kconfig entry
Date: Tue, 25 Aug 2020 12:10:59 +0100 [thread overview]
Message-ID: <20200825111059.GB22233@C02TF0J2HF1T.local> (raw)
In-Reply-To: <2e73f87b-f5fe-5ccf-1b5f-c916703356e0@infradead.org>
On Mon, Aug 24, 2020 at 11:44:50AM -0700, Randy Dunlap wrote:
> On 8/24/20 11:27 AM, Catalin Marinas wrote:
> > index 6d232837cbee..10cf81d70657 100644
> > --- a/arch/arm64/Kconfig
> > +++ b/arch/arm64/Kconfig
> > @@ -1664,6 +1664,37 @@ config ARCH_RANDOM
> > provides a high bandwidth, cryptographically secure
> > hardware random number generator.
> >
> > +config ARM64_AS_HAS_MTE
> > + # Binutils gained initial support for MTE in 2.32.0. However, a
> > + # late architecture addition (LDGM/STGM) is only supported in
> > + # the newer 2.32.x and 2.33 versions.
> > + def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
>
> Would you mind translating that for me?
> Yes, I read the v7 Notes, but that only helped a little bit.
The initial MTE support in binutils 2.32.0, testable above with ".arch
armv8.5-a+memtag", was incomplete. Historically, I think it was based on
a beta version of the architecture but before the final architecture
release (ARMv8.5), MTE gained a couple of new instructions: STGM/LDGM.
Since there are binutils versions out there which don't understand STGM
even though they claim to support .arch armv8.5-a+memtag, it's better
for the above check to include the STGM instruction.
I'll see if I can make the comment above clearer.
> > + bool "Memory Tagging Extension support"
> > + default y
> > + depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
> > + select ARCH_USES_HIGH_VMA_FLAGS
> > + help
> > + Memory Tagging (part of the ARMv8.5 Extensions) provides
> > + architectural support for run-time, always-on detection of
>
> runtime,
> as is used below.
Thanks.
--
Catalin
next prev parent reply other threads:[~2020-08-25 11:11 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-24 18:27 [PATCH v8 00/28] arm64: Memory Tagging Extension user-space support Catalin Marinas
2020-08-24 18:27 ` [PATCH v8 01/28] arm64: mte: system register definitions Catalin Marinas
2020-08-24 18:27 ` [PATCH v8 02/28] arm64: mte: Use Normal Tagged attributes for the linear map Catalin Marinas
2020-08-24 18:27 ` [PATCH v8 03/28] arm64: mte: CPU feature detection and initial sysreg configuration Catalin Marinas
2020-08-25 8:53 ` Marc Zyngier
2020-08-25 10:54 ` Catalin Marinas
2020-08-25 13:53 ` Marc Zyngier
2020-08-26 17:08 ` Catalin Marinas
2020-09-04 10:10 ` Marc Zyngier
2020-08-26 15:24 ` Catalin Marinas
2020-08-24 18:27 ` [PATCH v8 04/28] arm64: mte: Add specific SIGSEGV codes Catalin Marinas
2020-08-24 18:27 ` [PATCH v8 05/28] arm64: mte: Handle synchronous and asynchronous tag check faults Catalin Marinas
2020-08-24 18:27 ` [PATCH v8 06/28] mm: Add PG_arch_2 page flag Catalin Marinas
2020-08-24 18:27 ` [PATCH v8 07/28] mm: Preserve the PG_arch_2 flag in __split_huge_page_tail() Catalin Marinas
2020-08-24 18:27 ` [PATCH v8 08/28] arm64: mte: Clear the tags when a page is mapped in user-space with PROT_MTE Catalin Marinas
2020-08-24 18:27 ` [PATCH v8 09/28] arm64: mte: Tags-aware copy_{user_,}highpage() implementations Catalin Marinas
2020-08-24 18:27 ` [PATCH v8 10/28] arm64: Avoid unnecessary clear_user_page() indirection Catalin Marinas
2020-08-24 18:27 ` [PATCH v8 11/28] arm64: mte: Tags-aware aware memcmp_pages() implementation Catalin Marinas
2020-08-24 18:27 ` [PATCH v8 12/28] mm: Introduce arch_calc_vm_flag_bits() Catalin Marinas
2020-08-24 18:27 ` [PATCH v8 13/28] arm64: mte: Add PROT_MTE support to mmap() and mprotect() Catalin Marinas
2020-08-24 18:27 ` [PATCH v8 14/28] mm: Introduce arch_validate_flags() Catalin Marinas
2020-08-24 18:27 ` [PATCH v8 15/28] arm64: mte: Validate the PROT_MTE request via arch_validate_flags() Catalin Marinas
2020-08-24 18:27 ` [PATCH v8 16/28] mm: Allow arm64 mmap(PROT_MTE) on RAM-based files Catalin Marinas
2020-08-24 18:27 ` [PATCH v8 17/28] arm64: mte: Allow user control of the tag check mode via prctl() Catalin Marinas
2020-08-24 18:27 ` [PATCH v8 18/28] arm64: mte: Allow user control of the generated random tags " Catalin Marinas
2020-08-24 18:27 ` [PATCH v8 19/28] arm64: mte: Restore the GCR_EL1 register after a suspend Catalin Marinas
2020-08-24 18:27 ` [PATCH v8 20/28] arm64: mte: Allow {set,get}_tagged_addr_ctrl() on non-current tasks Catalin Marinas
2020-08-24 18:27 ` [PATCH v8 21/28] arm64: mte: ptrace: Add PTRACE_{PEEK,POKE}MTETAGS support Catalin Marinas
2020-08-24 18:27 ` [PATCH v8 22/28] arm64: mte: ptrace: Add NT_ARM_TAGGED_ADDR_CTRL regset Catalin Marinas
2020-08-24 18:27 ` [PATCH v8 23/28] fs: Handle intra-page faults in copy_mount_options() Catalin Marinas
2020-08-24 18:27 ` [PATCH v8 24/28] mm: Add arch hooks for saving/restoring tags Catalin Marinas
2020-08-24 18:27 ` [PATCH v8 25/28] arm64: mte: Enable swap of tagged pages Catalin Marinas
2020-08-24 18:27 ` [PATCH v8 26/28] arm64: mte: Save tags when hibernating Catalin Marinas
2020-08-24 18:27 ` [PATCH v8 27/28] arm64: mte: Kconfig entry Catalin Marinas
2020-08-24 18:44 ` Randy Dunlap
2020-08-25 11:10 ` Catalin Marinas [this message]
2020-08-24 18:27 ` [PATCH v8 28/28] arm64: mte: Add Memory Tagging Extension documentation Catalin Marinas
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