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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 36D06C3DA64 for ; Thu, 1 Aug 2024 11:02:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=tsRZdZjTI7yJDnLfipw85i+gL5lETb+dSWGzwOgUmtk=; b=sEtucZUfxY69MGXZsrcP7X1VzV +eAsSmgTnCQepaBaiy3+R5zGJcXNs7Z2ZlmZuzqR08Zf5a0NeBdNIeOGYga8ir7u4EzETZdefesOV K/+UMQH9b0YfStZBlCryfqZb3plNRh/Lph3/3vFbKWgZ0gdV8DVubV/c3tC0DuPf58ERY2H1J5D2S a48qe3SjY1cuk+u0nydr8+KLKW/40AcgSYFeI+F81wWHrjfVZeFOfcqwvbH/QmpCDpf9CEwaXDqG6 l0CiqLl1oyy3YcOKb/XkLVcjU5GWwpG2FauewcjRWXXaqS/uppGBnTMvYZzJWWSgzf22SSG/+unVH NvFp97gw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sZTZe-00000004qPd-1rq6; Thu, 01 Aug 2024 11:02:22 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sZTYl-00000004q3f-456a for linux-arm-kernel@lists.infradead.org; Thu, 01 Aug 2024 11:01:29 +0000 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 570E215A1; Thu, 1 Aug 2024 04:01:52 -0700 (PDT) Received: from e133380.arm.com (e133380.arm.com [10.1.197.55]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id BCA383F5A1; Thu, 1 Aug 2024 04:01:23 -0700 (PDT) Date: Thu, 1 Aug 2024 12:01:18 +0100 From: Dave Martin To: Joey Gouly Cc: linux-arm-kernel@lists.infradead.org, akpm@linux-foundation.org, aneesh.kumar@kernel.org, aneesh.kumar@linux.ibm.com, bp@alien8.de, broonie@kernel.org, catalin.marinas@arm.com, christophe.leroy@csgroup.eu, dave.hansen@linux.intel.com, hpa@zytor.com, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, maz@kernel.org, mingo@redhat.com, mpe@ellerman.id.au, naveen.n.rao@linux.ibm.com, npiggin@gmail.com, oliver.upton@linux.dev, shuah@kernel.org, szabolcs.nagy@arm.com, tglx@linutronix.de, will@kernel.org, x86@kernel.org, kvmarm@lists.linux.dev Subject: Re: [PATCH v4 13/29] arm64: convert protection key into vm_flags and pgprot values Message-ID: References: <20240503130147.1154804-1-joey.gouly@arm.com> <20240503130147.1154804-14-joey.gouly@arm.com> <20240801105502.GA841837@e124191.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240801105502.GA841837@e124191.cambridge.arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240801_040128_079433_408C0C20 X-CRM114-Status: GOOD ( 21.36 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Aug 01, 2024 at 11:55:02AM +0100, Joey Gouly wrote: > On Thu, Jul 25, 2024 at 04:49:50PM +0100, Dave Martin wrote: > > On Fri, May 03, 2024 at 02:01:31PM +0100, Joey Gouly wrote: > > > Modify arch_calc_vm_prot_bits() and vm_get_page_prot() such that the pkey > > > value is set in the vm_flags and then into the pgprot value. > > > > > > Signed-off-by: Joey Gouly > > > Cc: Catalin Marinas > > > Cc: Will Deacon > > > --- > > > arch/arm64/include/asm/mman.h | 8 +++++++- > > > arch/arm64/mm/mmap.c | 9 +++++++++ > > > 2 files changed, 16 insertions(+), 1 deletion(-) > > > > > > diff --git a/arch/arm64/include/asm/mman.h b/arch/arm64/include/asm/mman.h > > > index 5966ee4a6154..ecb2d18dc4d7 100644 > > > --- a/arch/arm64/include/asm/mman.h > > > +++ b/arch/arm64/include/asm/mman.h > > > @@ -7,7 +7,7 @@ > > > #include > > > > > > static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot, > > > - unsigned long pkey __always_unused) > > > + unsigned long pkey) > > > { > > > unsigned long ret = 0; > > > > > > @@ -17,6 +17,12 @@ static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot, > > > if (system_supports_mte() && (prot & PROT_MTE)) > > > ret |= VM_MTE; > > > > > > +#if defined(CONFIG_ARCH_HAS_PKEYS) > > > + ret |= pkey & 0x1 ? VM_PKEY_BIT0 : 0; > > > + ret |= pkey & 0x2 ? VM_PKEY_BIT1 : 0; > > > + ret |= pkey & 0x4 ? VM_PKEY_BIT2 : 0; > > > > Out of interest, is this as bad as it looks or does the compiler turn > > it into a shift and mask? > > Yeah, (gcc 13.2) produces good code here (this is do_mprotect_pkey after removing a lot of branching): > > and w0, w0, #0x7 > orr x1, x1, x0, lsl #32 Neat, good ol' gcc! Cheers ---Dave