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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 82C7ECD5BD2 for ; Tue, 26 May 2026 11:17:27 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C6E5F6B0098; Tue, 26 May 2026 07:17:26 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C45FC6B0099; Tue, 26 May 2026 07:17:26 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B5C076B009B; Tue, 26 May 2026 07:17:26 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id A14C36B0098 for ; Tue, 26 May 2026 07:17:26 -0400 (EDT) Received: from smtpin08.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 6C7F01A03D4 for ; Tue, 26 May 2026 11:17:26 +0000 (UTC) X-FDA: 84809320092.08.ABDC2BD Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf24.hostedemail.com (Postfix) with ESMTP id 837B2180004 for ; Tue, 26 May 2026 11:17:24 +0000 (UTC) Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=arm.com header.s=foss header.b=p57PsWH7; spf=pass (imf24.hostedemail.com: domain of kevin.brodsky@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=kevin.brodsky@arm.com; dmarc=pass (policy=none) header.from=arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1779794244; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=x9danRDBw1AQtwV1J30XI0czBEF8V99fPLYQxI09Agg=; b=VXD4JHNU8elxY1MjhXVvvnadNv0GFjxE+HNsLwhieGH8NuPD8cH1gY1g7XUXeUSB7L4GHS 3687w2ZjH5+zKD6Irh2cdoUSnYKpRioEDX3/bbBJXQNKXbyqWp6wlaorD9yHO9RHoJ+ieJ gSXKSVX0oZ8Ex6amP+TpDI9WrhJHr2w= ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=pass header.d=arm.com header.s=foss header.b=p57PsWH7; spf=pass (imf24.hostedemail.com: domain of kevin.brodsky@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=kevin.brodsky@arm.com; dmarc=pass (policy=none) header.from=arm.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1779794244; a=rsa-sha256; cv=none; b=Bnl5hC/RsJSp69dRezVCIolRcLhE7qw79kBfxcQRAd/iftx1oJ6gM7DDf3wPZAhAfXclzC cEs2Gua/3kcUinjwurv2NU1AREEx0fGBp6pBm196uU6UnOA1imSJfTGqn14hCwNRRIT2v7 7PxOfTByLqfqzcGfueItNKOrGf1qLd4= 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 82706169C; Tue, 26 May 2026 04:17:18 -0700 (PDT) Received: from localhost.localdomain (e123572-lin.cambridge.arm.com [10.1.194.54]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B87673F7D8; Tue, 26 May 2026 04:17:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1779794243; bh=ScOjJcY4lUZi/QiKcDOuYUVGfjH/6STcb98MmPgtlWs=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=p57PsWH7Zc/0vwIDEqRb6A8BMGopx8BzxIos9wA6VwJhaJ74/w2g0vmBB0HSm4yEq Z544DK5JqY1WHW0NhjUxiSdJRwI0NSQsMWUca6nP0uuvJLCB8CDP7bOM6XWqXvidh2 nk+vL2A631mKhZf/REEEg2LSG+IZ9Q9hz/WFjSiA= From: Kevin Brodsky Date: Tue, 26 May 2026 12:15:54 +0100 Subject: [PATCH RFC v8 05/24] arm64: Implement asm/kpkeys.h using POE MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260526-kpkeys-v8-5-eaaacdacc67c@arm.com> References: <20260526-kpkeys-v8-0-eaaacdacc67c@arm.com> In-Reply-To: <20260526-kpkeys-v8-0-eaaacdacc67c@arm.com> To: linux-hardening@vger.kernel.org Cc: Kevin Brodsky , Andrew Morton , Andy Lutomirski , Catalin Marinas , Dave Hansen , "David Hildenbrand (Arm)" , Ira Weiny , Jann Horn , Jeff Xu , Joey Gouly , Kees Cook , Linus Walleij , Marc Zyngier , Mark Brown , Matthew Wilcox , Maxwell Bland , "Mike Rapoport (IBM)" , Peter Zijlstra , Pierre Langlois , Quentin Perret , Rick Edgecombe , Ryan Roberts , Vlastimil Babka , Will Deacon , Yang Shi , Yeoreum Yun , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, x86@kernel.org, Lorenzo Stoakes , Thomas Gleixner X-Mailer: b4 0.15.2 X-Developer-Signature: v=1; a=ed25519-sha256; t=1779794212; l=2665; i=kevin.brodsky@arm.com; s=20260427; h=from:subject:message-id; bh=ScOjJcY4lUZi/QiKcDOuYUVGfjH/6STcb98MmPgtlWs=; b=/HffIylQMDpk1TSgqL1d4Ijti+SGSoyeaOj5/vNUNbYO173PNGvrz3r/7wIUBVck2GnvXCYDK vKmtmOhZJymC2zZtCSQRF67bKDlRhR58WkFHN2xAnO6o1s7iyG2GAdG X-Developer-Key: i=kevin.brodsky@arm.com; a=ed25519; pk=N2QG+eJKrvkNovwhhwJhnJ4+ScVfsGCHldmqLfcMTFs= X-Rspam-User: X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 837B2180004 X-Stat-Signature: i3q7zxum1hadqhr3yu4amdc8xjd9e35n X-HE-Tag: 1779794244-670904 X-HE-Meta: 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 EtFZXw3Q BLt0TavZ/carZsJ1zBGM6/ZUPXyvcsmA0E3mbwZaPIZaYOEeo82tqMmh1OLJE4xNSHzRtNUrPnwNEbTYlPm0QMjQ+okNe8rJCdrzFEM16O3UDFHjsOuprAPucXXl0bIwheqVATD+06pvubgbQQd/nvwtNUn6u/2RWk2Uso+QBa5vRdgJ8hXzxF7i4SRUsAC9AFoIhygbov9tTh9rAoO11+EVM6i21e2h4OlDXcGSm936dMx2SkauTLfiXvaLcMhRnqUEO Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Implement the kpkeys interface if CONFIG_ARM64_POE is enabled. The permissions for KPKEYS_PKEY_DEFAULT (pkey 0) are set to RWX as this pkey is also used for code mappings. To allow to be included from assembly, also add appropriate #ifdef's to . Signed-off-by: Kevin Brodsky --- arch/arm64/include/asm/kpkeys.h | 59 +++++++++++++++++++++++++++++++++++++++++ arch/arm64/include/asm/por.h | 4 +++ 2 files changed, 63 insertions(+) diff --git a/arch/arm64/include/asm/kpkeys.h b/arch/arm64/include/asm/kpkeys.h new file mode 100644 index 000000000000..4dbfeb3dfcfe --- /dev/null +++ b/arch/arm64/include/asm/kpkeys.h @@ -0,0 +1,59 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef __ASM_KPKEYS_H +#define __ASM_KPKEYS_H + +#include +#include +#include + +#include + +/* + * Equivalent to por_set_kpkeys_context(0, KPKEYS_CTX_DEFAULT), but can also be + * used in assembly. + */ +#define POR_EL1_INIT POR_ELx_PERM_PREP(KPKEYS_PKEY_DEFAULT, POE_RWX) + +#ifndef __ASSEMBLY__ + +static inline bool arch_supports_kpkeys(void) +{ + return system_supports_poe(); +} + +#ifdef CONFIG_ARM64_POE + +static inline u64 por_set_kpkeys_context(u64 por, int ctx) +{ + por = por_elx_set_pkey_perms(por, KPKEYS_PKEY_DEFAULT, POE_RWX); + + return por; +} + +static __always_inline void __kpkeys_set_pkey_reg_nosync(u64 pkey_reg) +{ + write_sysreg_s(pkey_reg, SYS_POR_EL1); +} + +static __always_inline u64 arch_kpkeys_set_context(int ctx) +{ + u64 prev_por = read_sysreg_s(SYS_POR_EL1); + u64 new_por = por_set_kpkeys_context(prev_por, ctx); + + __kpkeys_set_pkey_reg_nosync(new_por); + isb(); + + return prev_por; +} + +static __always_inline void arch_kpkeys_restore_pkey_reg(u64 pkey_reg) +{ + __kpkeys_set_pkey_reg_nosync(pkey_reg); + isb(); +} + +#endif /* CONFIG_ARM64_POE */ + +#endif /* __ASSEMBLY__ */ + +#endif /* __ASM_KPKEYS_H */ diff --git a/arch/arm64/include/asm/por.h b/arch/arm64/include/asm/por.h index bffb4d2b1246..58dce4b8021b 100644 --- a/arch/arm64/include/asm/por.h +++ b/arch/arm64/include/asm/por.h @@ -10,6 +10,8 @@ #define POR_EL0_INIT POR_ELx_PERM_PREP(0, POE_RWX) +#ifndef __ASSEMBLY__ + static inline bool por_elx_allows_read(u64 por, u8 pkey) { u8 perm = POR_ELx_PERM_GET(pkey, por); @@ -38,4 +40,6 @@ static inline u64 por_elx_set_pkey_perms(u64 por, u8 pkey, u64 perms) return (por & ~(POE_MASK << shift)) | (perms << shift); } +#endif /* __ASSEMBLY__ */ + #endif /* _ASM_ARM64_POR_H */ -- 2.51.2