From patchwork Sun Nov 19 16:57:12 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandru Elisei X-Patchwork-Id: 13460577 Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id A0E9710E5; Sun, 19 Nov 2023 08:59:14 -0800 (PST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 90D471007; Sun, 19 Nov 2023 09:00:00 -0800 (PST) Received: from e121798.cable.virginm.net (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 64C553F6C4; Sun, 19 Nov 2023 08:59:09 -0800 (PST) From: Alexandru Elisei To: catalin.marinas@arm.com, will@kernel.org, oliver.upton@linux.dev, maz@kernel.org, james.morse@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, arnd@arndb.de, akpm@linux-foundation.org, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, mhiramat@kernel.org, rppt@kernel.org, hughd@google.com Cc: pcc@google.com, steven.price@arm.com, anshuman.khandual@arm.com, vincenzo.frascino@arm.com, david@redhat.com, eugenis@google.com, kcc@google.com, hyesoo.yu@samsung.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org Subject: [PATCH RFC v2 18/27] arm64: mte: Reserve tag block for the zero page Date: Sun, 19 Nov 2023 16:57:12 +0000 Message-Id: <20231119165721.9849-19-alexandru.elisei@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231119165721.9849-1-alexandru.elisei@arm.com> References: <20231119165721.9849-1-alexandru.elisei@arm.com> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On arm64, the zero page receives special treatment by having the tagged flag set on MTE initialization, not when the page is mapped in a process address space. Reserve the corresponding tag block when tag storage management is being activated. Signed-off-by: Alexandru Elisei --- arch/arm64/kernel/mte_tag_storage.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm64/kernel/mte_tag_storage.c b/arch/arm64/kernel/mte_tag_storage.c index 833480048170..a1cc239f7211 100644 --- a/arch/arm64/kernel/mte_tag_storage.c +++ b/arch/arm64/kernel/mte_tag_storage.c @@ -393,6 +393,8 @@ static int __init mte_tag_storage_activate_regions(void) totalcma_pages += range_len(tag_range); } + reserve_tag_storage(ZERO_PAGE(0), 0, GFP_HIGHUSER_MOVABLE); + return 0; out_disabled: