[09/22] arm64: mte: Tags-aware clear_page() implementation

Message ID	20191211184027.20130-10-catalin.marinas@arm.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <SRS0=HwE+=2B=kvack.org=owner-linux-mm@kernel.org> DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F24E7206A5 From: Catalin Marinas <catalin.marinas@arm.com> To: linux-arm-kernel@lists.infradead.org Cc: Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>, Vincenzo Frascino <vincenzo.frascino@arm.com>, Szabolcs Nagy <szabolcs.nagy@arm.com>, Richard Earnshaw <Richard.Earnshaw@arm.com>, Kevin Brodsky <kevin.brodsky@arm.com>, Andrey Konovalov <andreyknvl@google.com>, linux-mm@kvack.org, linux-arch@vger.kernel.org Subject: [PATCH 09/22] arm64: mte: Tags-aware clear_page() implementation Date: Wed, 11 Dec 2019 18:40:14 +0000 Message-Id: <20191211184027.20130-10-catalin.marinas@arm.com> In-Reply-To: <20191211184027.20130-1-catalin.marinas@arm.com> References: <20191211184027.20130-1-catalin.marinas@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org Precedence: bulk
Series	arm64: Memory Tagging Extension user-space support \| expand [00/22] arm64: Memory Tagging Extension user-space support [01/22] mm: Reserve asm-generic prot flags 0x10 and 0x20 for arch use [02/22] kbuild: Add support for 'as-instr' to be used in Kconfig files [03/22] arm64: alternative: Allow alternative_insn to always issue the first instruction [04/22] arm64: Use macros instead of hard-coded constants for MAIR_EL1 [05/22] arm64: mte: system register definitions [06/22] arm64: mte: CPU feature detection and initial sysreg configuration [07/22] arm64: mte: Use Normal Tagged attributes for the linear map [08/22] arm64: mte: Assembler macros and default architecture for .S files [09/22] arm64: mte: Tags-aware clear_page() implementation [10/22] arm64: mte: Tags-aware copy_page() implementation [11/22] arm64: Tags-aware memcmp_pages() implementation [12/22] arm64: mte: Add specific SIGSEGV codes [13/22] arm64: mte: Handle synchronous and asynchronous tag check faults [14/22] mm: Introduce arch_calc_vm_flag_bits() [15/22] arm64: mte: Add PROT_MTE support to mmap() and mprotect() [16/22] mm: Introduce arch_validate_flags() [17/22] arm64: mte: Validate the PROT_MTE request via arch_validate_flags() [18/22] mm: Allow arm64 mmap(PROT_MTE) on RAM-based files [19/22] arm64: mte: Allow user control of the tag check mode via prctl() [20/22] arm64: mte: Allow user control of the excluded tags via prctl() [21/22] arm64: mte: Kconfig entry [22/22] arm64: mte: Add Memory Tagging Extension documentation

Message ID

20191211184027.20130-10-catalin.marinas@arm.com (mailing list archive)

State

New, archived

Headers

DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F24E7206A5
From: Catalin Marinas <catalin.marinas@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: Will Deacon <will@kernel.org>,
	Marc Zyngier <maz@kernel.org>,
	Vincenzo Frascino <vincenzo.frascino@arm.com>,
	Szabolcs Nagy <szabolcs.nagy@arm.com>,
	Richard Earnshaw <Richard.Earnshaw@arm.com>,
	Kevin Brodsky <kevin.brodsky@arm.com>,
	Andrey Konovalov <andreyknvl@google.com>,
	linux-mm@kvack.org,
	linux-arch@vger.kernel.org
Subject: [PATCH 09/22] arm64: mte: Tags-aware clear_page() implementation
Date: Wed, 11 Dec 2019 18:40:14 +0000
Message-Id: <20191211184027.20130-10-catalin.marinas@arm.com>
In-Reply-To: <20191211184027.20130-1-catalin.marinas@arm.com>
References: <20191211184027.20130-1-catalin.marinas@arm.com>
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
Sender: owner-linux-mm@kvack.org
Precedence: bulk

Series

arm64: Memory Tagging Extension user-space support | expand

Commit Message

Catalin Marinas Dec. 11, 2019, 6:40 p.m. UTC

From: Vincenzo Frascino <vincenzo.frascino@arm.com>

When the Memory Tagging Extension is enabled, the tags need to be set to
zero a page is cleared as they are visible to the user.

Introduce an MTE-aware clear_page() which clears the tags in addition to
data.

Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Co-developed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---
 arch/arm64/lib/clear_page.S | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/lib/clear_page.S b/arch/arm64/lib/clear_page.S
index 78a9ef66288a..575cea03f68a 100644
--- a/arch/arm64/lib/clear_page.S
+++ b/arch/arm64/lib/clear_page.S
@@ -5,7 +5,9 @@ 
 
 #include <linux/linkage.h>
 #include <linux/const.h>
+#include <asm/alternative.h>
 #include <asm/assembler.h>
+#include <asm/cpufeature.h>
 #include <asm/page.h>
 
 /*
@@ -19,8 +21,9 @@  ENTRY(clear_page)
 	and	w1, w1, #0xf
 	mov	x2, #4
 	lsl	x1, x2, x1
-
-1:	dc	zva, x0
+1:
+alternative_insn "dc zva, x0", "stzgm xzr, [x0]", \
+			 ARM64_MTE, IS_ENABLED(CONFIG_ARM64_MTE), 1
 	add	x0, x0, x1
 	tst	x0, #(PAGE_SIZE - 1)
 	b.ne	1b

[09/22] arm64: mte: Tags-aware clear_page() implementation

Commit Message

Patch