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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 350D1C001DF for ; Tue, 1 Aug 2023 17:32:57 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B87DD94003D; Tue, 1 Aug 2023 13:32:56 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B10A6940010; Tue, 1 Aug 2023 13:32:56 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 98A9194003D; Tue, 1 Aug 2023 13:32:56 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 833AF940010 for ; Tue, 1 Aug 2023 13:32:56 -0400 (EDT) Received: from smtpin20.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 45873160610 for ; Tue, 1 Aug 2023 17:32:56 +0000 (UTC) X-FDA: 81076231152.20.6ED27A1 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf11.hostedemail.com (Postfix) with ESMTP id CED5140A57 for ; Tue, 1 Aug 2023 17:03:22 +0000 (UTC) Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=AA0UkNhQ; spf=pass (imf11.hostedemail.com: domain of rppt@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=none) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1690909403; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=rNqqoE7VYu9ueVY1r+VjeKbX/tuKgWJmH4QZB2iVOcU=; b=RBZO8LW24WRQA5dWTRdM1H3TagBZXll6fLtEkgbHguJwU3xTTGyqjNeZzcx9r31V33VSzs Qm7oEfH2moockDijkbbYFLtjIeyojupUpS05HPGz7tjpF3ZFYIqupLXqZy3SqKN6kCaHcx eKcQBfxcpp79c9Abds8XzhIM2NkTMjY= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1690909403; a=rsa-sha256; cv=none; b=HccG8xvwvU6jOZoJP3gp48sINzi/KjIPtWbwQqELcTs4ee87x9t3oZiEVCNUCOB21S5AYH VJ6ouzC3TpOkL0Nf2TpjMoMEINRpslNQd0Zx30UxIlq/JF1mz5nZg6p/546atneSHQC8pP 2T2PGtsbgEwtaBcWsdDO6YeaRp2IdnE= ARC-Authentication-Results: i=1; imf11.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=AA0UkNhQ; spf=pass (imf11.hostedemail.com: domain of rppt@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=none) header.from=kernel.org Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 7EDDC61633; Tue, 1 Aug 2023 17:03:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 14158C433C8; Tue, 1 Aug 2023 17:03:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1690909400; bh=n2/9ktpmINrFVuBWg1KAR2bAcG2NpG4kfEtaUDByDfs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=AA0UkNhQxwECDyCEaDtc6JhBhvuvyCYYCaSh4HblOm5/sFOqJy8oy4lzt1PHsqe/d TNp/HD+vd9HlKtv5qMTIS+koyMnH6IxwcAdwNwXp4F5+zwZgvrnFbpNoU+QmQ8b5J3 ddlGURjkJRGzvvXYAv/2/xdGEsvIazcCS7ipemT/wemv7xW5NPdaO+scLqNwkzr3kd QYfygusILQtsW8OYGbFyAk8m/i1xYFxg47ufEb41rqQx5La8ZysCvnd1hWLGpVELSo 6atnVwdyqVnvxRrlqLIxYCR2TAHb6qdezWZ2QfOYTjqX/DgeT6WtV9UpJOx4DAmJz+ ldxqcY8ezOQig== Date: Tue, 1 Aug 2023 20:02:31 +0300 From: Mike Rapoport To: Mark Brown Cc: Catalin Marinas , Will Deacon , Jonathan Corbet , Andrew Morton , Marc Zyngier , Oliver Upton , James Morse , Suzuki K Poulose , Arnd Bergmann , Oleg Nesterov , Eric Biederman , Kees Cook , Shuah Khan , "Rick P. Edgecombe" , Deepak Gupta , Ard Biesheuvel , Szabolcs Nagy , "H.J. Lu" , Paul Walmsley , Palmer Dabbelt , Albert Ou , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org Subject: Re: [PATCH v3 11/36] arm64/mm: Map pages for guarded control stack Message-ID: <20230801170231.GC2607694@kernel.org> References: <20230731-arm64-gcs-v3-0-cddf9f980d98@kernel.org> <20230731-arm64-gcs-v3-11-cddf9f980d98@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230731-arm64-gcs-v3-11-cddf9f980d98@kernel.org> X-Rspamd-Queue-Id: CED5140A57 X-Rspam-User: X-Stat-Signature: ocmx6csrerwgfehksj7n4hax76r9re4y X-Rspamd-Server: rspam03 X-HE-Tag: 1690909402-951959 X-HE-Meta: U2FsdGVkX19IzaIc7ZAL+yvw+mk9tkzzIyP+RLJFKpyTQMOTFyxUNu0/e6ZBHS9SswL/GN5Aaq0Bi0TEbSxoI+IM+qS1vN5MbBMfsXrFsBzsV8LqpsNbZKwJO6whNaEYt1mIUBC+9ztudT4AJT+fqYY7Ta55griqw3XPqhdP0eWe3Zo1iHN5slJKHwZNT9DuYSs8Hu/zcGR1THYHERpjlG8M5eIm103bjhEml5OcjTe9187G//COhnwehk2pzqylFvSlVCZbNEmJKasdljkI6RFXq6QPGMC194eQ0G0gcY5VYjHMV9MNpzilUzv295ufehOMc5UGhrn3UAAPW/+XQTEDwp/cHd4m845UV3XH5axouNnvhgdQgiBZcEniR2lMjEZHo3QcsGL/fISPixq9Feau3nvfLlTQ1Z7SZTSY4Oumhp4Nia/hTQvcrcrlxqyA627KlQCQ2bxM2owx31o+PQ0wjyDVrU9wbJ/FoIoGP52AOROHYigAh7M8kOUHbO7RcEpeF7VWj8oeTlD68f6NPGDSAVKJWZohvM6jB5CqooTUhZsrwYyKzaWx282xHGQxU2NoJDCfmH0fHq12s7g5Vp7CNVVGLTK4go3Hoqkhxt4dV4oXVeJ4jJwH+OwmZIwzzu8c/tQbHGJ2sHPJ/932iMg+vWvBJufMgvilYa7onZOL/Mby4bMNQYfz+WkXSEI5ohyjcF6ArCtSl1UrGGTZLtCyri0efN3jJZSivKMFCQTt3hwXAhjf2t0gjBFoM7laKs4sjER8ld5Of4U5HipKnwPPNAg8x1wu+8IgFejnYtet0hkvuhPu8StIKLoWD+Not7SczQZ9/gJ3tJjKPvhMbPaUNrGjQp9U+zbyCjYHdlgCL9GUDpusTnA3eVqfWp9f084QzMLahLimcmzweSInIznElAF1zb8AmX9gjeTyHBZLZVDVN14aGE1hqJV7pBKXahf3+vXUvKfPk8G1KIj xVp8iLkb yjdEGIKjniuABKN+ECQfrlTP9VXFfBlyGwgA+ctH3RNa4ms/x22i1ZqIktVmn/gftRxvSA8JCJhXwBEmvU6GbNRg/TWt3m9qqrtmU/lfjmC4tjfJrkWq+Y/mpJWEcn9V22p/wxzrUdm963N6Doeik/NohEjyF4C7w0fg3F96A4/U/HwBDzS6eOzCPD/t2xcSuDZqkJCbrsXp34rbbEG37zvFcVD3jpTtmxHT5jBBRay/SpDANnqtmPsGiX2kc+y5LIKRBfX/LknDoROlrMRBMXmXZIg+wIsSHN7JzCZnlhqA5JEEXTexEgt8479DSpkmymmbScESto/O1Py+6M+N17HA2FrANFbIdD2sV8co9g/scROu5jYh/PDackwrc5tKVNbfAaJ1fPtxCjhZd8H1uKUwWrklrTY7GMDI5riYiZGLsRhU= 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 Mon, Jul 31, 2023 at 02:43:20PM +0100, Mark Brown wrote: > Map pages flagged as being part of a GCS as such rather than using the > full set of generic VM flags. > > This is done using a conditional rather than extending the size of > protection_map since that would make for a very sparse array. > > Signed-off-by: Mark Brown > --- > arch/arm64/mm/mmap.c | 17 ++++++++++++++++- > 1 file changed, 16 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c > index 8f5b7ce857ed..e2ca770920ed 100644 > --- a/arch/arm64/mm/mmap.c > +++ b/arch/arm64/mm/mmap.c > @@ -79,8 +79,23 @@ arch_initcall(adjust_protection_map); > > pgprot_t vm_get_page_prot(unsigned long vm_flags) > { > - pteval_t prot = pgprot_val(protection_map[vm_flags & > + pteval_t prot; > + > + /* > + * If this is a GCS then only interpret VM_WRITE. > + * > + * TODO: Just make protection_map[] bigger? Nothing seems > + * ideal here. > + */ I think extending protection_map and updating adjust_protection_map() is cleaner and probably faster. > + if (system_supports_gcs() && (vm_flags & VM_SHADOW_STACK)) { > + if (vm_flags & VM_WRITE) > + prot = _PAGE_GCS; > + else > + prot = _PAGE_GCS_RO; > + } else { > + prot = pgprot_val(protection_map[vm_flags & > (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]); > + } > > if (vm_flags & VM_ARM64_BTI) > prot |= PTE_GP; > > -- > 2.30.2 > > -- Sincerely yours, Mike.