From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F1AC2C4727D for ; Fri, 2 Oct 2020 14:07:01 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 90B47206DD for ; Fri, 2 Oct 2020 14:07:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 90B47206DD Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 00B636B006C; Fri, 2 Oct 2020 10:07:00 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id EFD28900002; Fri, 2 Oct 2020 10:06:59 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E12186B0071; Fri, 2 Oct 2020 10:06:59 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0038.hostedemail.com [216.40.44.38]) by kanga.kvack.org (Postfix) with ESMTP id B1EAC6B006C for ; Fri, 2 Oct 2020 10:06:59 -0400 (EDT) Received: from smtpin03.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 4431E180AD802 for ; Fri, 2 Oct 2020 14:06:59 +0000 (UTC) X-FDA: 77327161758.03.paper06_6005d04271a4 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin03.hostedemail.com (Postfix) with ESMTP id 16FED28A4EA for ; Fri, 2 Oct 2020 14:06:59 +0000 (UTC) X-HE-Tag: paper06_6005d04271a4 X-Filterd-Recvd-Size: 2555 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf18.hostedemail.com (Postfix) with ESMTP for ; Fri, 2 Oct 2020 14:06:58 +0000 (UTC) Received: from gaia (unknown [95.149.105.49]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1458C206DB; Fri, 2 Oct 2020 14:06:54 +0000 (UTC) Date: Fri, 2 Oct 2020 15:06:52 +0100 From: Catalin Marinas To: Andrey Konovalov Cc: Dmitry Vyukov , Vincenzo Frascino , kasan-dev@googlegroups.com, Andrey Ryabinin , Alexander Potapenko , Marco Elver , Evgenii Stepanov , Elena Petrova , Branislav Rankov , Kevin Brodsky , Will Deacon , Andrew Morton , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 29/39] arm64: mte: Switch GCR_EL1 in kernel entry and exit Message-ID: <20201002140652.GG7034@gaia> References: <1f2681fdff1aa1096df949cb8634a9be6bf4acc4.1601593784.git.andreyknvl@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1f2681fdff1aa1096df949cb8634a9be6bf4acc4.1601593784.git.andreyknvl@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, Oct 02, 2020 at 01:10:30AM +0200, Andrey Konovalov wrote: > diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c > index 7c67ac6f08df..d1847f29f59b 100644 > --- a/arch/arm64/kernel/mte.c > +++ b/arch/arm64/kernel/mte.c > @@ -23,6 +23,8 @@ > #include > #include > > +u64 gcr_kernel_excl __ro_after_init; > + > static void mte_sync_page_tags(struct page *page, pte_t *ptep, bool check_swap) > { > pte_t old_pte = READ_ONCE(*ptep); > @@ -120,6 +122,13 @@ void *mte_set_mem_tag_range(void *addr, size_t size, u8 tag) > return ptr; > } > > +void mte_init_tags(u64 max_tag) > +{ > + u64 incl = GENMASK(max_tag & MTE_TAG_MAX, 0); Nitpick: it's not obvious that MTE_TAG_MAX is a mask, so better write this as GENMASK(min(max_tag, MTE_TAG_MAX), 0). Otherwise it looks fine. Reviewed-by: Catalin Marinas