From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yu-cheng Yu Subject: Re: [PATCH v7 25/27] mm/mmap: Add Shadow stack pages to memory accounting Date: Tue, 11 Jun 2019 12:22:48 -0700 Message-ID: References: <20190606200646.3951-1-yu-cheng.yu@intel.com> <20190606200646.3951-26-yu-cheng.yu@intel.com> <1cfc7396-ca90-1933-34ad-b3d43ae52e08@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1cfc7396-ca90-1933-34ad-b3d43ae52e08@intel.com> Sender: linux-kernel-owner@vger.kernel.org To: Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Borislav Petkov , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz List-Id: linux-arch.vger.kernel.org On Tue, 2019-06-11 at 10:55 -0700, Dave Hansen wrote: > On 6/6/19 1:06 PM, Yu-cheng Yu wrote: > > --- a/mm/mmap.c > > +++ b/mm/mmap.c > > @@ -1703,6 +1703,9 @@ static inline int accountable_mapping(struct file > > *file, vm_flags_t vm_flags) > > if (file && is_file_hugepages(file)) > > return 0; > > > > + if (arch_copy_pte_mapping(vm_flags)) > > + return 1; > > + > > return (vm_flags & (VM_NORESERVE | VM_SHARED | VM_WRITE)) == > > VM_WRITE; > > } > > > > @@ -3319,6 +3322,8 @@ void vm_stat_account(struct mm_struct *mm, vm_flags_t > > flags, long npages) > > mm->stack_vm += npages; > > else if (is_data_mapping(flags)) > > mm->data_vm += npages; > > + else if (arch_copy_pte_mapping(flags)) > > + mm->data_vm += npages; > > } > > This classifies shadow stack as data instead of stack. That seems a wee > bit counterintuitive. Why did you make this choice? I don't recall the reason; I will change it to stack and test it out. Yu-cheng From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga14.intel.com ([192.55.52.115]:2866 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404808AbfFKTa6 (ORCPT ); Tue, 11 Jun 2019 15:30:58 -0400 Message-ID: Subject: Re: [PATCH v7 25/27] mm/mmap: Add Shadow stack pages to memory accounting From: Yu-cheng Yu Date: Tue, 11 Jun 2019 12:22:48 -0700 In-Reply-To: <1cfc7396-ca90-1933-34ad-b3d43ae52e08@intel.com> References: <20190606200646.3951-1-yu-cheng.yu@intel.com> <20190606200646.3951-26-yu-cheng.yu@intel.com> <1cfc7396-ca90-1933-34ad-b3d43ae52e08@intel.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Borislav Petkov , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , "Ravi V. Shankar" , Vedvyas Shanbhogue , Dave Martin Message-ID: <20190611192248.jDEw6db49lHlwOAIshh0doDOqcicQMgK6QLeCtecUKc@z> On Tue, 2019-06-11 at 10:55 -0700, Dave Hansen wrote: > On 6/6/19 1:06 PM, Yu-cheng Yu wrote: > > --- a/mm/mmap.c > > +++ b/mm/mmap.c > > @@ -1703,6 +1703,9 @@ static inline int accountable_mapping(struct file > > *file, vm_flags_t vm_flags) > > if (file && is_file_hugepages(file)) > > return 0; > > > > + if (arch_copy_pte_mapping(vm_flags)) > > + return 1; > > + > > return (vm_flags & (VM_NORESERVE | VM_SHARED | VM_WRITE)) == > > VM_WRITE; > > } > > > > @@ -3319,6 +3322,8 @@ void vm_stat_account(struct mm_struct *mm, vm_flags_t > > flags, long npages) > > mm->stack_vm += npages; > > else if (is_data_mapping(flags)) > > mm->data_vm += npages; > > + else if (arch_copy_pte_mapping(flags)) > > + mm->data_vm += npages; > > } > > This classifies shadow stack as data instead of stack. That seems a wee > bit counterintuitive. Why did you make this choice? I don't recall the reason; I will change it to stack and test it out. Yu-cheng