From patchwork Mon Feb 28 10:47:34 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anshuman Khandual X-Patchwork-Id: 12762768 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2F2ACC4167E for ; Mon, 28 Feb 2022 10:50:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231775AbiB1KvZ (ORCPT ); Mon, 28 Feb 2022 05:51:25 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47898 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234991AbiB1KvR (ORCPT ); Mon, 28 Feb 2022 05:51:17 -0500 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 1263B66AE0; Mon, 28 Feb 2022 02:50:19 -0800 (PST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id D633511FB; Mon, 28 Feb 2022 02:50:18 -0800 (PST) Received: from p8cg001049571a15.arm.com (unknown [10.163.47.185]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 479283F73D; Mon, 28 Feb 2022 02:50:11 -0800 (PST) From: Anshuman Khandual To: linux-mm@kvack.org, akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org, geert@linux-m68k.org, Anshuman Khandual , Christoph Hellwig , linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org, sparclinux@vger.kernel.org, linux-mips@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-s390@vger.kernel.org, linux-riscv@lists.infradead.org, linux-alpha@vger.kernel.org, linux-sh@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-csky@vger.kernel.org, linux-xtensa@linux-xtensa.org, linux-parisc@vger.kernel.org, openrisc@lists.librecores.org, linux-um@lists.infradead.org, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, linux-arch@vger.kernel.org Subject: [PATCH V3 11/30] mm/mmap: Drop protection_map[] Date: Mon, 28 Feb 2022 16:17:34 +0530 Message-Id: <1646045273-9343-12-git-send-email-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1646045273-9343-1-git-send-email-anshuman.khandual@arm.com> References: <1646045273-9343-1-git-send-email-anshuman.khandual@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org There are no other users for protection_map[]. Hence just drop this array construct and instead define __vm_get_page_prot() which will provide page protection map based on vm_flags combination switch. Cc: Andrew Morton Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual --- drivers/gpu/drm/drm_vm.c | 4 +-- include/linux/mm.h | 6 ---- mm/mmap.c | 63 ++++++++++++++++++++++++++-------------- 3 files changed, 44 insertions(+), 29 deletions(-) diff --git a/drivers/gpu/drm/drm_vm.c b/drivers/gpu/drm/drm_vm.c index e957d4851dc0..14862df7532f 100644 --- a/drivers/gpu/drm/drm_vm.c +++ b/drivers/gpu/drm/drm_vm.c @@ -482,7 +482,7 @@ static int drm_mmap_dma(struct file *filp, struct vm_area_struct *vma) #else /* Ye gads this is ugly. With more thought we could move this up higher and use - `protection_map' instead. */ + `vm_get_page_prot()' instead. */ vma->vm_page_prot = __pgprot(pte_val (pte_wrprotect @@ -566,7 +566,7 @@ static int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma) #else /* Ye gads this is ugly. With more thought we could move this up higher and use - `protection_map' instead. */ + `vm_get_page_prot()' instead. */ vma->vm_page_prot = __pgprot(pte_val (pte_wrprotect diff --git a/include/linux/mm.h b/include/linux/mm.h index 213cc569b192..ff74bd2d7850 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -418,12 +418,6 @@ extern unsigned int kobjsize(const void *objp); #endif #define VM_FLAGS_CLEAR (ARCH_VM_PKEY_FLAGS | VM_ARCH_CLEAR) -/* - * mapping from the currently active vm_flags protection bits (the - * low four bits) to a page protection mask.. - */ -extern pgprot_t protection_map[16]; - /* * The default fault flags that should be used by most of the * arch-specific page fault handlers. diff --git a/mm/mmap.c b/mm/mmap.c index f2310f6e7466..78eeac277a80 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -102,24 +102,6 @@ static void unmap_region(struct mm_struct *mm, * w: (no) no * x: (yes) yes */ -pgprot_t protection_map[16] __ro_after_init = { - [VM_NONE] = __P000, - [VM_READ] = __P001, - [VM_WRITE] = __P010, - [VM_WRITE | VM_READ] = __P011, - [VM_EXEC] = __P100, - [VM_EXEC | VM_READ] = __P101, - [VM_EXEC | VM_WRITE] = __P110, - [VM_EXEC | VM_WRITE | VM_READ] = __P111, - [VM_SHARED] = __S000, - [VM_SHARED | VM_READ] = __S001, - [VM_SHARED | VM_WRITE] = __S010, - [VM_SHARED | VM_WRITE | VM_READ] = __S011, - [VM_SHARED | VM_EXEC] = __S100, - [VM_SHARED | VM_EXEC | VM_READ] = __S101, - [VM_SHARED | VM_EXEC | VM_WRITE] = __S110, - [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = __S111 -}; #ifndef CONFIG_ARCH_HAS_FILTER_PGPROT static inline pgprot_t arch_filter_pgprot(pgprot_t prot) @@ -128,10 +110,49 @@ static inline pgprot_t arch_filter_pgprot(pgprot_t prot) } #endif +static inline pgprot_t __vm_get_page_prot(unsigned long vm_flags) +{ + switch (vm_flags & (VM_READ | VM_WRITE | VM_EXEC | VM_SHARED)) { + case VM_NONE: + return __P000; + case VM_READ: + return __P001; + case VM_WRITE: + return __P010; + case VM_READ | VM_WRITE: + return __P011; + case VM_EXEC: + return __P100; + case VM_EXEC | VM_READ: + return __P101; + case VM_EXEC | VM_WRITE: + return __P110; + case VM_EXEC | VM_READ | VM_WRITE: + return __P111; + case VM_SHARED: + return __S000; + case VM_SHARED | VM_READ: + return __S001; + case VM_SHARED | VM_WRITE: + return __S010; + case VM_SHARED | VM_READ | VM_WRITE: + return __S011; + case VM_SHARED | VM_EXEC: + return __S100; + case VM_SHARED | VM_EXEC | VM_READ: + return __S101; + case VM_SHARED | VM_EXEC | VM_WRITE: + return __S110; + case VM_SHARED | VM_EXEC | VM_READ | VM_WRITE: + return __S111; + default: + BUILD_BUG(); + } +} + pgprot_t vm_get_page_prot(unsigned long vm_flags) { - pgprot_t ret = __pgprot(pgprot_val(protection_map[vm_flags & - (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]) | + pgprot_t ret = __pgprot(pgprot_val(__vm_get_page_prot(vm_flags)) | pgprot_val(arch_vm_get_page_prot(vm_flags))); return arch_filter_pgprot(ret); @@ -1684,7 +1705,7 @@ SYSCALL_DEFINE1(old_mmap, struct mmap_arg_struct __user *, arg) /* * Some shared mappings will want the pages marked read-only * to track write events. If so, we'll downgrade vm_page_prot - * to the private version (using protection_map[] without the + * to the private version (using vm_get_page_prot() without the * VM_SHARED bit). */ int vma_wants_writenotify(struct vm_area_struct *vma, pgprot_t vm_page_prot)