From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1947981AbcBRUUg (ORCPT ); Thu, 18 Feb 2016 15:20:36 -0500 Received: from terminus.zytor.com ([198.137.202.10]:46904 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1947090AbcBRUU3 (ORCPT ); Thu, 18 Feb 2016 15:20:29 -0500 Date: Thu, 18 Feb 2016 12:19:24 -0800 From: tip-bot for Dave Hansen Message-ID: Cc: peterz@infradead.org, hpa@zytor.com, mingo@kernel.org, brgerst@gmail.com, luto@amacapital.net, dave@sr71.net, bp@alien8.de, dave.hansen@linux.intel.com, akpm@linux-foundation.org, riel@redhat.com, dvlasenk@redhat.com, torvalds@linux-foundation.org, tglx@linutronix.de, linux-kernel@vger.kernel.org Reply-To: riel@redhat.com, akpm@linux-foundation.org, bp@alien8.de, dave.hansen@linux.intel.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, torvalds@linux-foundation.org, dvlasenk@redhat.com, hpa@zytor.com, peterz@infradead.org, dave@sr71.net, luto@amacapital.net, brgerst@gmail.com, mingo@kernel.org In-Reply-To: <20160212210210.FE483A42@viggo.jf.intel.com> References: <20160212210210.FE483A42@viggo.jf.intel.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:mm/pkeys] x86/mm/pkeys: Add arch-specific VMA protection bits Git-Commit-ID: 8f62c883222c9e3c06d60b5e55e307a3d1f18257 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 8f62c883222c9e3c06d60b5e55e307a3d1f18257 Gitweb: http://git.kernel.org/tip/8f62c883222c9e3c06d60b5e55e307a3d1f18257 Author: Dave Hansen AuthorDate: Fri, 12 Feb 2016 13:02:10 -0800 Committer: Ingo Molnar CommitDate: Thu, 18 Feb 2016 09:31:51 +0100 x86/mm/pkeys: Add arch-specific VMA protection bits Lots of things seem to do: vma->vm_page_prot = vm_get_page_prot(flags); and the ptes get created right from things we pull out of ->vm_page_prot. So it is very convenient if we can store the protection key in flags and vm_page_prot, just like the existing permission bits (_PAGE_RW/PRESENT). It greatly reduces the amount of plumbing and arch-specific hacking we have to do in generic code. This also takes the new PROT_PKEY{0,1,2,3} flags and turns *those* in to VM_ flags for vma->vm_flags. The protection key values are stored in 4 places: 1. "prot" argument to system calls 2. vma->vm_flags, filled from the mmap "prot" 3. vma->vm_page prot, filled from vma->vm_flags 4. the PTE itself. The pseudocode for these for steps are as follows: mmap(PROT_PKEY*) vma->vm_flags = ... | arch_calc_vm_prot_bits(mmap_prot); vma->vm_page_prot = ... | arch_vm_get_page_prot(vma->vm_flags); pte = pfn | vma->vm_page_prot Note that this provides a new definitions for x86: arch_vm_get_page_prot() Signed-off-by: Dave Hansen Reviewed-by: Thomas Gleixner Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Hansen Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Rik van Riel Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20160212210210.FE483A42@viggo.jf.intel.com Signed-off-by: Ingo Molnar --- arch/x86/include/asm/mmu_context.h | 11 +++++++++++ arch/x86/include/asm/pgtable_types.h | 12 ++++++++++-- arch/x86/include/uapi/asm/mman.h | 16 ++++++++++++++++ include/linux/mm.h | 7 +++++++ 4 files changed, 44 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h index bfd9b2a..94c4c8b 100644 --- a/arch/x86/include/asm/mmu_context.h +++ b/arch/x86/include/asm/mmu_context.h @@ -275,4 +275,15 @@ static inline void arch_unmap(struct mm_struct *mm, struct vm_area_struct *vma, mpx_notify_unmap(mm, vma, start, end); } +static inline int vma_pkey(struct vm_area_struct *vma) +{ + u16 pkey = 0; +#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS + unsigned long vma_pkey_mask = VM_PKEY_BIT0 | VM_PKEY_BIT1 | + VM_PKEY_BIT2 | VM_PKEY_BIT3; + pkey = (vma->vm_flags & vma_pkey_mask) >> VM_PKEY_SHIFT; +#endif + return pkey; +} + #endif /* _ASM_X86_MMU_CONTEXT_H */ diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h index cae10ba..8c35cf0 100644 --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -115,7 +115,12 @@ #define _KERNPG_TABLE (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | \ _PAGE_DIRTY) -/* Set of bits not changed in pte_modify */ +/* + * Set of bits not changed in pte_modify. The pte's + * protection key is treated like _PAGE_RW, for + * instance, and is *not* included in this mask since + * pte_modify() does modify it. + */ #define _PAGE_CHG_MASK (PTE_PFN_MASK | _PAGE_PCD | _PAGE_PWT | \ _PAGE_SPECIAL | _PAGE_ACCESSED | _PAGE_DIRTY | \ _PAGE_SOFT_DIRTY) @@ -231,7 +236,10 @@ enum page_cache_mode { /* Extracts the PFN from a (pte|pmd|pud|pgd)val_t of a 4KB page */ #define PTE_PFN_MASK ((pteval_t)PHYSICAL_PAGE_MASK) -/* Extracts the flags from a (pte|pmd|pud|pgd)val_t of a 4KB page */ +/* + * Extracts the flags from a (pte|pmd|pud|pgd)val_t + * This includes the protection key value. + */ #define PTE_FLAGS_MASK (~PTE_PFN_MASK) typedef struct pgprot { pgprotval_t pgprot; } pgprot_t; diff --git a/arch/x86/include/uapi/asm/mman.h b/arch/x86/include/uapi/asm/mman.h index 513b05f..e8562e0 100644 --- a/arch/x86/include/uapi/asm/mman.h +++ b/arch/x86/include/uapi/asm/mman.h @@ -6,6 +6,22 @@ #define MAP_HUGE_2MB (21 << MAP_HUGE_SHIFT) #define MAP_HUGE_1GB (30 << MAP_HUGE_SHIFT) +#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS +/* + * Take the 4 protection key bits out of the vma->vm_flags + * value and turn them in to the bits that we can put in + * to a pte. + * + * Only override these if Protection Keys are available + * (which is only on 64-bit). + */ +#define arch_vm_get_page_prot(vm_flags) __pgprot( \ + ((vm_flags) & VM_PKEY_BIT0 ? _PAGE_PKEY_BIT0 : 0) | \ + ((vm_flags) & VM_PKEY_BIT1 ? _PAGE_PKEY_BIT1 : 0) | \ + ((vm_flags) & VM_PKEY_BIT2 ? _PAGE_PKEY_BIT2 : 0) | \ + ((vm_flags) & VM_PKEY_BIT3 ? _PAGE_PKEY_BIT3 : 0)) +#endif + #include #endif /* _ASM_X86_MMAN_H */ diff --git a/include/linux/mm.h b/include/linux/mm.h index 54d173b..3056369 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -183,6 +183,13 @@ extern unsigned int kobjsize(const void *objp); #if defined(CONFIG_X86) # define VM_PAT VM_ARCH_1 /* PAT reserves whole VMA at once (x86) */ +#if defined (CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS) +# define VM_PKEY_SHIFT VM_HIGH_ARCH_BIT_0 +# define VM_PKEY_BIT0 VM_HIGH_ARCH_0 /* A protection key is a 4-bit value */ +# define VM_PKEY_BIT1 VM_HIGH_ARCH_1 +# define VM_PKEY_BIT2 VM_HIGH_ARCH_2 +# define VM_PKEY_BIT3 VM_HIGH_ARCH_3 +#endif #elif defined(CONFIG_PPC) # define VM_SAO VM_ARCH_1 /* Strong Access Ordering (powerpc) */ #elif defined(CONFIG_PARISC)