From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kees Cook Subject: Re: [PATCH v7 11/11] arm64: mm: Display guarded pages in ptdump Date: Wed, 26 Feb 2020 13:38:53 -0800 Message-ID: <202002261338.9890367C@keescook> References: <20200226155714.43937-1-broonie@kernel.org> <20200226155714.43937-12-broonie@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pl1-f194.google.com ([209.85.214.194]:34866 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727550AbgBZViz (ORCPT ); Wed, 26 Feb 2020 16:38:55 -0500 Received: by mail-pl1-f194.google.com with SMTP id g6so229684plt.2 for ; Wed, 26 Feb 2020 13:38:55 -0800 (PST) Content-Disposition: inline In-Reply-To: <20200226155714.43937-12-broonie@kernel.org> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Mark Brown Cc: Catalin Marinas , Will Deacon , Alexander Viro , Paul Elliott , Peter Zijlstra , Yu-cheng Yu , Amit Kachhap , Vincenzo Frascino , Marc Zyngier , Eugene Syromiatnikov , Szabolcs Nagy , "H . J . Lu " , Andrew Jones , Arnd Bergmann , Jann Horn , Richard Henderson , Kristina =?utf-8?Q?Mart=C5=A1enko?= , Thomas Gleixner , Florian Weimer , Sudak On Wed, Feb 26, 2020 at 03:57:14PM +0000, Mark Brown wrote: > v8.5-BTI introduces the GP field in stage 1 translation tables which > indicates that blocks and pages with it set are guarded pages for which > branch target identification checks should be performed. Decode this > when dumping the page tables to aid debugging. > > Signed-off-by: Mark Brown Reviewed-by: Kees Cook -Kees > --- > arch/arm64/mm/dump.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c > index 860c00ec8bd3..78163b7a7dde 100644 > --- a/arch/arm64/mm/dump.c > +++ b/arch/arm64/mm/dump.c > @@ -145,6 +145,11 @@ static const struct prot_bits pte_bits[] = { > .val = PTE_UXN, > .set = "UXN", > .clear = " ", > + }, { > + .mask = PTE_GP, > + .val = PTE_GP, > + .set = "GP", > + .clear = " ", > }, { > .mask = PTE_ATTRINDX_MASK, > .val = PTE_ATTRINDX(MT_DEVICE_nGnRnE), > -- > 2.20.1 > -- Kees Cook From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl1-f194.google.com ([209.85.214.194]:34866 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727550AbgBZViz (ORCPT ); Wed, 26 Feb 2020 16:38:55 -0500 Received: by mail-pl1-f194.google.com with SMTP id g6so229684plt.2 for ; Wed, 26 Feb 2020 13:38:55 -0800 (PST) Date: Wed, 26 Feb 2020 13:38:53 -0800 From: Kees Cook Subject: Re: [PATCH v7 11/11] arm64: mm: Display guarded pages in ptdump Message-ID: <202002261338.9890367C@keescook> References: <20200226155714.43937-1-broonie@kernel.org> <20200226155714.43937-12-broonie@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200226155714.43937-12-broonie@kernel.org> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Mark Brown Cc: Catalin Marinas , Will Deacon , Alexander Viro , Paul Elliott , Peter Zijlstra , Yu-cheng Yu , Amit Kachhap , Vincenzo Frascino , Marc Zyngier , Eugene Syromiatnikov , Szabolcs Nagy , "H . J . Lu " , Andrew Jones , Arnd Bergmann , Jann Horn , Richard Henderson , Kristina =?utf-8?Q?Mart=C5=A1enko?= , Thomas Gleixner , Florian Weimer , Sudakshina Das , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-fsdevel@vger.kernel.org Message-ID: <20200226213853.tai05mkZaNB2TMyJFbxfragGREb5FGANsURbJ8vf7yg@z> On Wed, Feb 26, 2020 at 03:57:14PM +0000, Mark Brown wrote: > v8.5-BTI introduces the GP field in stage 1 translation tables which > indicates that blocks and pages with it set are guarded pages for which > branch target identification checks should be performed. Decode this > when dumping the page tables to aid debugging. > > Signed-off-by: Mark Brown Reviewed-by: Kees Cook -Kees > --- > arch/arm64/mm/dump.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c > index 860c00ec8bd3..78163b7a7dde 100644 > --- a/arch/arm64/mm/dump.c > +++ b/arch/arm64/mm/dump.c > @@ -145,6 +145,11 @@ static const struct prot_bits pte_bits[] = { > .val = PTE_UXN, > .set = "UXN", > .clear = " ", > + }, { > + .mask = PTE_GP, > + .val = PTE_GP, > + .set = "GP", > + .clear = " ", > }, { > .mask = PTE_ATTRINDX_MASK, > .val = PTE_ATTRINDX(MT_DEVICE_nGnRnE), > -- > 2.20.1 > -- Kees Cook