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 X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6F813C433DB for ; Tue, 30 Mar 2021 08:49:20 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E21B961935 for ; Tue, 30 Mar 2021 08:49:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E21B961935 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-m68k.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:Cc:To:Subject:Message-ID:Date:From:In-Reply-To: References:MIME-Version:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=p1DexAxXLU/U+hxPe++Hxk1LtZtYT2PqDJimOE9fKe0=; b=NRW/l4au7X4pEp+8mQ6CW+riS 0JGxwhIpKHGe8fncg6Ke60KwSbqCLwFPH8P8+lIowTDloX6RgRiEPK2nIxRUJ2wlR/depTDOKc75E tKxtn5tqJVIAuIaOs7HRCKigcPbdLFGcAgGqebx5BO0X/hMNW+S0eyD1gb4ztnHRLnZHtDj6EQZai CBp1qGzDsv/oIW1FLjanPAMUa5RO2c5In/OnKQfWApC8WZQJIf1XQcnUuDh2XZAHr23MzlBoKlCDe yLy4znU4C4o/7OIZIpQxOMu1PTPgBJ8kSx9Yw/wp3Po3eS/foMdibvn2W7wJx6w9Ds9RTl6rVvVTn 13Eoui6rQ==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lRA2Q-0035FV-67; Tue, 30 Mar 2021 08:47:50 +0000 Received: from mail-vs1-f50.google.com ([209.85.217.50]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lRA2K-0035EZ-2Y for linux-arm-kernel@lists.infradead.org; Tue, 30 Mar 2021 08:47:45 +0000 Received: by mail-vs1-f50.google.com with SMTP id a15so7757175vsi.0 for ; Tue, 30 Mar 2021 01:47:43 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=sxUH3IjCnMtE13f5BNtq/hjr1gesYuX/E5GZMUz0yds=; b=N6OoPFsg2WrZYPhPgcUaA6msMAhKZWGm9kH6ZeHtfTsMFvo9fytrES69kfJ0bM5gmr 0ct9IYRolst+iYgD4uYCtnqArn5x4cP/mXSWGLBomLS2eye+vc9Fx7Laby3eEv4nLhTo SIsdjsWh6NWmC2MU/0LqNLEufyPqUV1znAL/vs+YZyrmOuEXosonHAwPVtb2TbuC7Ja5 SjAFOK3l48xDBrqqPpzE9bSqAYTNm4p2hSnsPD5woq5Ub9A6JilzLkQKeZ+RFrwpXqEI r0jiD7SGYIc3yuEZ/NiSMIm2upRQExsELr74b4fAPq2lZlm6lOSqf/GU+Anr4rdllZEf jp6w== X-Gm-Message-State: AOAM5328Up8jRofLbkjiqRB0rtga2ChxKbnjhl0xTk0xQqT+iqd29nok XTrg7nB4l48T4sU+f98rTPPdR7lKmZgo4H1vD8ngT+6Vmac= X-Google-Smtp-Source: ABdhPJwyDgXefZhQiDJpSFUZTRYEdTAHiPHnDPrtg5qKXF/kBFrkU7MoHWoBWgOVh0uBHnM1qAYOVWHSped6pZ465rI= X-Received: by 2002:a67:efd0:: with SMTP id s16mr17396017vsp.3.1617094062980; Tue, 30 Mar 2021 01:47:42 -0700 (PDT) MIME-Version: 1.0 References: <20210312173811.58284-1-vladimir.murzin@arm.com> <20210312173811.58284-2-vladimir.murzin@arm.com> In-Reply-To: <20210312173811.58284-2-vladimir.murzin@arm.com> From: Geert Uytterhoeven Date: Tue, 30 Mar 2021 10:47:31 +0200 Message-ID: Subject: Re: [PATCH v4 1/2] arm64: Support execute-only permissions with Enhanced PAN To: Vladimir Murzin Cc: Linux ARM , Kees Cook , Dave Martin , Catalin Marinas , Will Deacon X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210330_094744_188175_9F5F0864 X-CRM114-Status: GOOD ( 24.84 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Vladimir, On Fri, Mar 12, 2021 at 6:47 PM Vladimir Murzin wrote: > Enhanced Privileged Access Never (EPAN) allows Privileged Access Never > to be used with Execute-only mappings. > > Absence of such support was a reason for 24cecc377463 ("arm64: Revert > support for execute-only user mappings"). Thus now it can be revisited > and re-enabled. > > Cc: Kees Cook > Cc: Catalin Marinas > Signed-off-by: Vladimir Murzin Thanks for your patch, which is now commit 18107f8a2df6bf1c ("arm64: Support execute-only permissions with Enhanced PAN") in arm64/for-next. > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -1060,6 +1060,9 @@ config ARCH_WANT_HUGE_PMD_SHARE > config ARCH_HAS_CACHE_LINE_SIZE > def_bool y > > +config ARCH_HAS_FILTER_PGPROT > + def_bool y > + > config ARCH_ENABLE_SPLIT_PMD_PTLOCK > def_bool y if PGTABLE_LEVELS > 2 > > @@ -1683,6 +1686,20 @@ config ARM64_MTE > > endmenu > > +menu "ARMv8.7 architectural features" > + > +config ARM64_EPAN > + bool "Enable support for Enhanced Privileged Access Never (EPAN)" > + default y > + depends on ARM64_PAN > + help > + Enhanced Privileged Access Never (EPAN) allows Privileged > + Access Never to be used with Execute-only mappings. Does EPAN require more hardware support than PAN, which is part of the ARMv8.1 Extensions according to the help text for ARM64_PAN? If yes, it is a good idea to document that here, so people know if it makes sense to enable this option for their hardware. Thanks! > + > + The feature is detected at runtime, and will remain disabled > + if the cpu does not implement the feature. > +endmenu > + Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel