From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kees Cook Subject: Re: [PATCH v9 12/13] mm: smaps: Report arm64 guarded pages in smaps Date: Thu, 12 Mar 2020 17:00:29 -0700 Message-ID: <202003121700.C10E9E5@keescook> References: <20200311192608.40095-1-broonie@kernel.org> <20200311192608.40095-13-broonie@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20200311192608.40095-13-broonie@kernel.org> Sender: linux-kernel-owner@vger.kernel.org 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 List-Id: linux-arch.vger.kernel.org On Wed, Mar 11, 2020 at 07:26:07PM +0000, Mark Brown wrote: > From: Daniel Kiss > > The arm64 Branch Target Identification support is activated by marking > executable pages as guarded pages. Report pages mapped this way in > smaps to aid diagnostics. > > Signed-off-by: Daniel Kiss Reviewed-by: Kees Cook -Kees > Signed-off-by: Mark Brown > --- > Documentation/filesystems/proc.txt | 1 + > fs/proc/task_mmu.c | 3 +++ > 2 files changed, 4 insertions(+) > > diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt > index 99ca040e3f90..ed5465d0f435 100644 > --- a/Documentation/filesystems/proc.txt > +++ b/Documentation/filesystems/proc.txt > @@ -519,6 +519,7 @@ manner. The codes are the following: > hg - huge page advise flag > nh - no-huge page advise flag > mg - mergable advise flag > + bt - arm64 BTI guarded page > > Note that there is no guarantee that every flag and associated mnemonic will > be present in all further kernel releases. Things get changed, the flags may > diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c > index 3ba9ae83bff5..1e3409c484d1 100644 > --- a/fs/proc/task_mmu.c > +++ b/fs/proc/task_mmu.c > @@ -668,6 +668,9 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma) > [ilog2(VM_ARCH_1)] = "ar", > [ilog2(VM_WIPEONFORK)] = "wf", > [ilog2(VM_DONTDUMP)] = "dd", > +#ifdef CONFIG_ARM64_BTI > + [ilog2(VM_ARM64_BTI)] = "bt", > +#endif > #ifdef CONFIG_MEM_SOFT_DIRTY > [ilog2(VM_SOFTDIRTY)] = "sd", > #endif > -- > 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]:38807 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726830AbgCMAAc (ORCPT ); Thu, 12 Mar 2020 20:00:32 -0400 Received: by mail-pl1-f194.google.com with SMTP id w3so3335757plz.5 for ; Thu, 12 Mar 2020 17:00:31 -0700 (PDT) Date: Thu, 12 Mar 2020 17:00:29 -0700 From: Kees Cook Subject: Re: [PATCH v9 12/13] mm: smaps: Report arm64 guarded pages in smaps Message-ID: <202003121700.C10E9E5@keescook> References: <20200311192608.40095-1-broonie@kernel.org> <20200311192608.40095-13-broonie@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200311192608.40095-13-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, Daniel Kiss Message-ID: <20200313000029.O7W7gB-JSu0LDWaczur7bMopI9ClaRwpXP1awiCZr_0@z> On Wed, Mar 11, 2020 at 07:26:07PM +0000, Mark Brown wrote: > From: Daniel Kiss > > The arm64 Branch Target Identification support is activated by marking > executable pages as guarded pages. Report pages mapped this way in > smaps to aid diagnostics. > > Signed-off-by: Daniel Kiss Reviewed-by: Kees Cook -Kees > Signed-off-by: Mark Brown > --- > Documentation/filesystems/proc.txt | 1 + > fs/proc/task_mmu.c | 3 +++ > 2 files changed, 4 insertions(+) > > diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt > index 99ca040e3f90..ed5465d0f435 100644 > --- a/Documentation/filesystems/proc.txt > +++ b/Documentation/filesystems/proc.txt > @@ -519,6 +519,7 @@ manner. The codes are the following: > hg - huge page advise flag > nh - no-huge page advise flag > mg - mergable advise flag > + bt - arm64 BTI guarded page > > Note that there is no guarantee that every flag and associated mnemonic will > be present in all further kernel releases. Things get changed, the flags may > diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c > index 3ba9ae83bff5..1e3409c484d1 100644 > --- a/fs/proc/task_mmu.c > +++ b/fs/proc/task_mmu.c > @@ -668,6 +668,9 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma) > [ilog2(VM_ARCH_1)] = "ar", > [ilog2(VM_WIPEONFORK)] = "wf", > [ilog2(VM_DONTDUMP)] = "dd", > +#ifdef CONFIG_ARM64_BTI > + [ilog2(VM_ARM64_BTI)] = "bt", > +#endif > #ifdef CONFIG_MEM_SOFT_DIRTY > [ilog2(VM_SOFTDIRTY)] = "sd", > #endif > -- > 2.20.1 > -- Kees Cook