[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=5fEH=2B=lists.infradead.org=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@kernel.org> DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5754C20663 From: Catalin Marinas <catalin.marinas@arm.com> To: linux-arm-kernel@lists.infradead.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 summary: Content analysis details: (0.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at https://www.dnswl.org/, no trust [217.140.110.172 listed in list.dnswl.org] 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.0 SPF_PASS SPF: sender matches SPF record Precedence: list Cc: linux-arch@vger.kernel.org, Richard Earnshaw <Richard.Earnshaw@arm.com>, Szabolcs Nagy <szabolcs.nagy@arm.com>, Marc Zyngier <maz@kernel.org>, Kevin Brodsky <kevin.brodsky@arm.com>, linux-mm@kvack.org, Andrey Konovalov <andreyknvl@google.com>, Vincenzo Frascino <vincenzo.frascino@arm.com>, Will Deacon <will@kernel.org> Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" <linux-arm-kernel-bounces@lists.infradead.org> Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org
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)

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DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5754C20663
From: Catalin Marinas <catalin.marinas@arm.com>
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 09/22] arm64: mte: Tags-aware clear_page() implementation
Date: Wed, 11 Dec 2019 18:40:14 +0000
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 Szabolcs Nagy <szabolcs.nagy@arm.com>, Marc Zyngier <maz@kernel.org>,
 Kevin Brodsky <kevin.brodsky@arm.com>, linux-mm@kvack.org,
 Andrey Konovalov <andreyknvl@google.com>,
 Vincenzo Frascino <vincenzo.frascino@arm.com>, Will Deacon <will@kernel.org>
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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