From patchwork Thu Mar 5 06:50:14 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anshuman Khandual X-Patchwork-Id: 1249439 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 48Y1kw15dQz9sPK for ; Thu, 5 Mar 2020 17:56:56 +1100 (AEDT) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=arm.com Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 48Y1kv6RwwzDqhD for ; Thu, 5 Mar 2020 17:56:55 +1100 (AEDT) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=arm.com (client-ip=217.140.110.172; helo=foss.arm.com; envelope-from=anshuman.khandual@arm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=arm.com Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lists.ozlabs.org (Postfix) with ESMTP id 48Y1c55qbDzDqkS for ; Thu, 5 Mar 2020 17:51:01 +1100 (AEDT) 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 DFF9E4B2; Wed, 4 Mar 2020 22:50:58 -0800 (PST) Received: from p8cg001049571a15.arm.com (unknown [10.163.1.88]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 1E2853F534; Wed, 4 Mar 2020 22:54:46 -0800 (PST) From: Anshuman Khandual To: linux-mm@kvack.org Subject: [PATCH 2/2] mm/vma: Introduce VM_ACCESS_FLAGS Date: Thu, 5 Mar 2020 12:20:14 +0530 Message-Id: <1583391014-8170-3-git-send-email-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1583391014-8170-1-git-send-email-anshuman.khandual@arm.com> References: <1583391014-8170-1-git-send-email-anshuman.khandual@arm.com> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Catalin Marinas , Dave Hansen , Heiko Carstens , devel@driverdev.osuosl.org, linux-s390@vger.kernel.org, Yoshinori Sato , hughd@google.com, Russell King , Ley Foon Tan , vbabka@suse.cz, Mark Salter , Anshuman Khandual , Rob Springer , Thomas Gleixner , Guan Xuetao , linux-arm-kernel@lists.infradead.org, Nick Hu , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, Andrew Morton , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" There are many places where all basic VMA access flags (read, write, exec) are initialized or checked against as a group. One such example is during page fault. Existing vma_is_accessible() wrapper already creates the notion of VMA accessibility as a group access permissions. Hence lets just create VM_ACCESS_FLAGS (VM_READ|VM_WRITE|VM_EXEC) which will not only reduce code duplication but also extend the VMA accessibility concept in general. Cc: Russell King CC: Catalin Marinas CC: Mark Salter Cc: Nick Hu CC: Ley Foon Tan Cc: Michael Ellerman Cc: Heiko Carstens Cc: Yoshinori Sato Cc: Guan Xuetao Cc: Dave Hansen Cc: Thomas Gleixner Cc: Rob Springer Cc: Greg Kroah-Hartman Cc: Andrew Morton Cc: linux-arm-kernel@lists.infradead.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: devel@driverdev.osuosl.org Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual Reviewed-by: Vlastimil Babka --- arch/arm/mm/fault.c | 2 +- arch/arm64/mm/fault.c | 2 +- arch/nds32/mm/fault.c | 2 +- arch/powerpc/mm/book3s64/pkeys.c | 2 +- arch/s390/mm/fault.c | 2 +- arch/unicore32/mm/fault.c | 2 +- arch/x86/mm/pkeys.c | 2 +- drivers/staging/gasket/gasket_core.c | 2 +- include/linux/mm.h | 6 +++++- mm/mmap.c | 2 +- mm/mprotect.c | 4 ++-- 11 files changed, 16 insertions(+), 12 deletions(-) diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index bd0f4821f7e1..2c71028d9d6b 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -189,7 +189,7 @@ void do_bad_area(unsigned long addr, unsigned int fsr, struct pt_regs *regs) */ static inline bool access_error(unsigned int fsr, struct vm_area_struct *vma) { - unsigned int mask = VM_READ | VM_WRITE | VM_EXEC; + unsigned int mask = VM_ACCESS_FLAGS; if ((fsr & FSR_WRITE) && !(fsr & FSR_CM)) mask = VM_WRITE; diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 85566d32958f..63f31206a12e 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -445,7 +445,7 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, const struct fault_info *inf; struct mm_struct *mm = current->mm; vm_fault_t fault, major = 0; - unsigned long vm_flags = VM_READ | VM_WRITE | VM_EXEC; + unsigned long vm_flags = VM_ACCESS_FLAGS; unsigned int mm_flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; if (kprobe_page_fault(regs, esr)) diff --git a/arch/nds32/mm/fault.c b/arch/nds32/mm/fault.c index 906dfb25353c..55387a31bf42 100644 --- a/arch/nds32/mm/fault.c +++ b/arch/nds32/mm/fault.c @@ -79,7 +79,7 @@ void do_page_fault(unsigned long entry, unsigned long addr, struct vm_area_struct *vma; int si_code; vm_fault_t fault; - unsigned int mask = VM_READ | VM_WRITE | VM_EXEC; + unsigned int mask = VM_ACCESS_FLAGS; unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; error_code = error_code & (ITYPE_mskINST | ITYPE_mskETYPE); diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c index 59e0ebbd8036..11fd52b24f68 100644 --- a/arch/powerpc/mm/book3s64/pkeys.c +++ b/arch/powerpc/mm/book3s64/pkeys.c @@ -315,7 +315,7 @@ int __execute_only_pkey(struct mm_struct *mm) static inline bool vma_is_pkey_exec_only(struct vm_area_struct *vma) { /* Do this check first since the vm_flags should be hot */ - if ((vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC)) != VM_EXEC) + if ((vma->vm_flags & VM_ACCESS_FLAGS) != VM_EXEC) return false; return (vma_pkey(vma) == vma->vm_mm->context.execute_only_pkey); diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index 7b0bb475c166..b2cb3c0d0e1a 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -584,7 +584,7 @@ void do_dat_exception(struct pt_regs *regs) int access; vm_fault_t fault; - access = VM_READ | VM_EXEC | VM_WRITE; + access = VM_ACCESS_FLAGS; fault = do_exception(regs, access); if (unlikely(fault)) do_fault_error(regs, access, fault); diff --git a/arch/unicore32/mm/fault.c b/arch/unicore32/mm/fault.c index 76342de9cf8c..fc27c274d358 100644 --- a/arch/unicore32/mm/fault.c +++ b/arch/unicore32/mm/fault.c @@ -149,7 +149,7 @@ void do_bad_area(unsigned long addr, unsigned int fsr, struct pt_regs *regs) */ static inline bool access_error(unsigned int fsr, struct vm_area_struct *vma) { - unsigned int mask = VM_READ | VM_WRITE | VM_EXEC; + unsigned int mask = VM_ACCESS_FLAGS; if (!(fsr ^ 0x12)) /* write? */ mask = VM_WRITE; diff --git a/arch/x86/mm/pkeys.c b/arch/x86/mm/pkeys.c index c6f84c0b5d7a..8873ed1438a9 100644 --- a/arch/x86/mm/pkeys.c +++ b/arch/x86/mm/pkeys.c @@ -63,7 +63,7 @@ int __execute_only_pkey(struct mm_struct *mm) static inline bool vma_is_pkey_exec_only(struct vm_area_struct *vma) { /* Do this check first since the vm_flags should be hot */ - if ((vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC)) != VM_EXEC) + if ((vma->vm_flags & VM_ACCESS_FLAGS) != VM_EXEC) return false; if (vma_pkey(vma) != vma->vm_mm->context.execute_only_pkey) return false; diff --git a/drivers/staging/gasket/gasket_core.c b/drivers/staging/gasket/gasket_core.c index be6b50f454b4..81bb7d58dc49 100644 --- a/drivers/staging/gasket/gasket_core.c +++ b/drivers/staging/gasket/gasket_core.c @@ -689,7 +689,7 @@ static bool gasket_mmap_has_permissions(struct gasket_dev *gasket_dev, /* Make sure that no wrong flags are set. */ requested_permissions = - (vma->vm_flags & (VM_WRITE | VM_READ | VM_EXEC)); + (vma->vm_flags & VM_ACCESS_FLAGS); if (requested_permissions & ~(bar_permissions)) { dev_dbg(gasket_dev->dev, "Attempting to map a region with requested permissions " diff --git a/include/linux/mm.h b/include/linux/mm.h index 3861524368a4..e89512f1c170 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -368,6 +368,10 @@ extern unsigned int kobjsize(const void *objp); #define VM_STACK_FLAGS (VM_STACK | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT) +/* VMA basic access permission flags */ +#define VM_ACCESS_FLAGS (VM_READ | VM_WRITE | VM_EXEC) + + /* * Special vmas that are non-mergable, non-mlock()able. * Note: mm/huge_memory.c VM_NO_THP depends on this definition. @@ -557,7 +561,7 @@ static inline bool vma_is_anonymous(struct vm_area_struct *vma) static inline bool vma_is_accessible(struct vm_area_struct *vma) { - return vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC); + return vma->vm_flags & VM_ACCESS_FLAGS; } #ifdef CONFIG_SHMEM diff --git a/mm/mmap.c b/mm/mmap.c index 0d295f49b24d..57f74ade19a0 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1221,7 +1221,7 @@ static int anon_vma_compatible(struct vm_area_struct *a, struct vm_area_struct * return a->vm_end == b->vm_start && mpol_equal(vma_policy(a), vma_policy(b)) && a->vm_file == b->vm_file && - !((a->vm_flags ^ b->vm_flags) & ~(VM_READ|VM_WRITE|VM_EXEC|VM_SOFTDIRTY)) && + !((a->vm_flags ^ b->vm_flags) & ~(VM_ACCESS_FLAGS | VM_SOFTDIRTY)) && b->vm_pgoff == a->vm_pgoff + ((b->vm_start - a->vm_start) >> PAGE_SHIFT); } diff --git a/mm/mprotect.c b/mm/mprotect.c index 7a8e84f86831..8fbb7e7c08a5 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -359,7 +359,7 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev, */ if (arch_has_pfn_modify_check() && (vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) && - (newflags & (VM_READ|VM_WRITE|VM_EXEC)) == 0) { + (newflags & VM_ACCESS_FLAGS) == 0) { pgprot_t new_pgprot = vm_get_page_prot(newflags); error = walk_page_range(current->mm, start, end, @@ -538,7 +538,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len, newflags |= (vma->vm_flags & ~mask_off_old_flags); /* newflags >> 4 shift VM_MAY% in place of VM_% */ - if ((newflags & ~(newflags >> 4)) & (VM_READ | VM_WRITE | VM_EXEC)) { + if ((newflags & ~(newflags >> 4)) & VM_ACCESS_FLAGS) { error = -EACCES; goto out; }