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 42C5ECD5BD0 for ; Tue, 26 May 2026 11:17:22 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id AC05C6B0095; Tue, 26 May 2026 07:17:21 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A71756B0096; Tue, 26 May 2026 07:17:21 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 939126B0098; Tue, 26 May 2026 07:17:21 -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 84DBE6B0095 for ; Tue, 26 May 2026 07:17:21 -0400 (EDT) Received: from smtpin30.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 557631C04E6 for ; Tue, 26 May 2026 11:17:21 +0000 (UTC) X-FDA: 84809319882.30.DCD1FAE Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf11.hostedemail.com (Postfix) with ESMTP id 781FC40008 for ; Tue, 26 May 2026 11:17:19 +0000 (UTC) Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=arm.com header.s=foss header.b=kYDum7JD; spf=pass (imf11.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=1779794239; 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=u1xfeI5UbcpARDbBD8TDLZovNjPqioAZ09pYeuPOgdA=; b=l8jEL/uq3waSvbAxHlWBnmss9EdvMu10F8ffaSaieectwmqNu2psvaom60rbdVoynFHjaY gczCFt/jD3+LVwCh7w2z8KZeEEH7yyBOX8GXwxalF/XE4Wi74LqLgUtlJkTtrbRTVhXd/4 G4lZjEkh/f4EPu6giEFss3mGPkQmQn0= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1779794239; a=rsa-sha256; cv=none; b=IwMcUCqkTwac1Pu/W+nz6XCJCBpaNSBgLUDedi0MEfGM1E5TCEQ697UrICVtag/O6J0sa6 9c93zWxXVVp6b3OD3F1TjT/sHKkxjKMID1VriKS+2U+gTAgo4kcXDwBfrzBoCKYYNSyKvp DWbZnBfi8TnfheMSfdsiKMw5hm8hekQ= ARC-Authentication-Results: i=1; imf11.hostedemail.com; dkim=pass header.d=arm.com header.s=foss header.b=kYDum7JD; spf=pass (imf11.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 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 5E98D1758; Tue, 26 May 2026 04:17:13 -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 88BBA3F7D8; Tue, 26 May 2026 04:17:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1779794238; bh=UwGP8FTfDtcj8k/6otcjhFkm2uk3iMrLq2Ub63GdAmQ=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=kYDum7JD8BN3F/bfeXiGQwXx9/bw+hWDCcf5LcKprddW3ywsAFLQcsCYoWyZavHVz RiYMUKq6kQ7cBWaHcBwylnL5NcSnPczX97fXLS85/OfjyokkcLH18Kidpj2C+mZe1Y nIjI5QIN7YvHBow691as3+q62zEyZwXFa9Xaq6WE= From: Kevin Brodsky Date: Tue, 26 May 2026 12:15:53 +0100 Subject: [PATCH RFC v8 04/24] arm64: Introduce por_elx_set_pkey_perms() helper MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260526-kpkeys-v8-4-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=2402; i=kevin.brodsky@arm.com; s=20260427; h=from:subject:message-id; bh=UwGP8FTfDtcj8k/6otcjhFkm2uk3iMrLq2Ub63GdAmQ=; b=iNDhKZ/+umpUiUNJPWK7f2x2rMi9D0xslG07vIaFgag3HFaD2j/WlP0ym9AnI7XdrVTqwYda9 08E+w4HgatnA1jD6pQrU2nmM4y16457jqH6B51zJTPi328yTHNQhgsS X-Developer-Key: i=kevin.brodsky@arm.com; a=ed25519; pk=N2QG+eJKrvkNovwhhwJhnJ4+ScVfsGCHldmqLfcMTFs= X-Rspam-User: X-Rspamd-Queue-Id: 781FC40008 X-Stat-Signature: z7k6eb7b1hoo467ur1rd6bmbenu855or X-Rspamd-Server: rspam06 X-HE-Tag: 1779794239-31147 X-HE-Meta: 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 lGzWRbA3 WA+dlf3gL//0UxY+RMBiziNTB7wqjWZL0GJYJSDfqqJYWrFykNLkGf+j7oqsWZ22+lfbQX4x4KXpHLZtBJ0FHWmJNxl7LmUEnrisdyLwXAR5K1pchStv+G5ZObI6E28l50wdOXwaFhuLJLtQdnb6BKet+bULPvdKm2EWzZxIyo1M4XVKqyRGFDQmh52CcVT6cBBQAgqPsEtAb0tXN0+9q7P30oDq8VeoHperSzRwmIVDLu1iLbobcZ376Srxxwxma4IQCGHr0HAgb5ZW3SiNAKfNNz2bLUz9ss3Wy9IvjV4ZH+TVzKRFwX4r9fy0qErDlEI/HfFaPfXTNEHo= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Introduce a helper that sets the permissions of a given pkey (POIndex) in the POR_ELx format, and make use of it in arch_set_user_pkey_access(). Signed-off-by: Kevin Brodsky --- arch/arm64/include/asm/por.h | 7 +++++++ arch/arm64/mm/mmu.c | 26 ++++++++++---------------- 2 files changed, 17 insertions(+), 16 deletions(-) diff --git a/arch/arm64/include/asm/por.h b/arch/arm64/include/asm/por.h index d913d5b529e4..bffb4d2b1246 100644 --- a/arch/arm64/include/asm/por.h +++ b/arch/arm64/include/asm/por.h @@ -31,4 +31,11 @@ static inline bool por_elx_allows_exec(u64 por, u8 pkey) return perm & POE_X; } +static inline u64 por_elx_set_pkey_perms(u64 por, u8 pkey, u64 perms) +{ + u64 shift = POR_ELx_PERM_SHIFT(pkey); + + return (por & ~(POE_MASK << shift)) | (perms << shift); +} + #endif /* _ASM_ARM64_POR_H */ diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index dd85e093ffdb..493310cf0486 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -2339,8 +2339,8 @@ void __cpu_replace_ttbr1(pgd_t *pgdp, bool cnp) #ifdef CONFIG_ARCH_HAS_PKEYS int arch_set_user_pkey_access(int pkey, unsigned long init_val) { - u64 new_por; - u64 old_por; + u64 new_perms; + u64 por; if (!system_supports_poe()) return -ENOSPC; @@ -2354,25 +2354,19 @@ int arch_set_user_pkey_access(int pkey, unsigned long init_val) return -EINVAL; /* Set the bits we need in POR: */ - new_por = POE_RWX; + new_perms = POE_RWX; if (init_val & PKEY_DISABLE_WRITE) - new_por &= ~POE_W; + new_perms &= ~POE_W; if (init_val & PKEY_DISABLE_ACCESS) - new_por &= ~POE_RW; + new_perms &= ~POE_RW; if (init_val & PKEY_DISABLE_READ) - new_por &= ~POE_R; + new_perms &= ~POE_R; if (init_val & PKEY_DISABLE_EXECUTE) - new_por &= ~POE_X; + new_perms &= ~POE_X; - /* Shift the bits in to the correct place in POR for pkey: */ - new_por = POR_ELx_PERM_PREP(pkey, new_por); - - /* Get old POR and mask off any old bits in place: */ - old_por = read_sysreg_s(SYS_POR_EL0); - old_por &= ~(POE_MASK << POR_ELx_PERM_SHIFT(pkey)); - - /* Write old part along with new part: */ - write_sysreg_s(old_por | new_por, SYS_POR_EL0); + por = read_sysreg_s(SYS_POR_EL0); + por = por_elx_set_pkey_perms(por, pkey, new_perms); + write_sysreg_s(por, SYS_POR_EL0); return 0; } -- 2.51.2