Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752427AbdGYPAl (ORCPT ); Tue, 25 Jul 2017 11:00:41 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:48946 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752068AbdGYPAk (ORCPT ); Tue, 25 Jul 2017 11:00:40 -0400 Date: Tue, 25 Jul 2017 15:59:04 +0100 From: Mark Rutland To: Dave Martin Cc: linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org, arnd@arndb.de, jiong.wang@arm.com, marc.zyngier@arm.com, catalin.marinas@arm.com, suzuki.poulose@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, kvmarm@lists.cs.columbia.edu, christoffer.dall@linaro.org Subject: Re: [RFC 7/9] arm64: expose PAC bit positions via ptrace Message-ID: <20170725145903.GA20857@leverpostej> References: <1491232765-32501-1-git-send-email-mark.rutland@arm.com> <1491232765-32501-8-git-send-email-mark.rutland@arm.com> <20170725121145.GB6321@e103592.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170725121145.GB6321@e103592.cambridge.arm.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1293 Lines: 37 On Tue, Jul 25, 2017 at 01:11:48PM +0100, Dave Martin wrote: > On Mon, Apr 03, 2017 at 04:19:23PM +0100, Mark Rutland wrote: > > +/* > > + * The pointer bits used by a pointer authentication code. > > + * If we were to use tagged pointers, bits 63:56 would also apply. > > + */ > > +#define ptrauth_pac_mask() GENMASK(54, VA_BITS) > > Tagged pointers _are_ enabled for userspace by default, no? Yes; I'd meant s/tagged/untagged/. I've corrected this to: /* * The EL0 pointer bits used by a pointer authentication code. * This is dependent on TBI0 being enabled, or bits 63:56 would also apply. */ > > diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h > > index b59ee07..cae3d1e 100644 > > --- a/include/uapi/linux/elf.h > > +++ b/include/uapi/linux/elf.h > > @@ -414,6 +414,7 @@ > > #define NT_ARM_HW_BREAK 0x402 /* ARM hardware breakpoint registers */ > > #define NT_ARM_HW_WATCH 0x403 /* ARM hardware watchpoint registers */ > > #define NT_ARM_SYSTEM_CALL 0x404 /* ARM system call number */ > > +#define NT_ARM_PAC_MASK 0x405 /* ARM pointer authentication code masks */ > > The is the value tentatively assigned to NT_ARM_SVE. I must've generated this patch before I corrected this; my local branch (and kernel.org) have 0x406 here. Sorry about that. Mark.