From patchwork Fri Apr 23 13:16:38 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 12220377 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E47C5C433ED for ; Fri, 23 Apr 2021 13:18:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BDF6361445 for ; Fri, 23 Apr 2021 13:18:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242712AbhDWNTL (ORCPT ); Fri, 23 Apr 2021 09:19:11 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:21103 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242731AbhDWNTL (ORCPT ); Fri, 23 Apr 2021 09:19:11 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1619183914; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=to3jmwMXXFbhc7/LVzTZ18LjP83fsxZIox1HwqIBnjY=; b=VCQ20nG+1r/zeV22JeDKZjNzgzE4LpgJRM4zrXOym+BhhZ01VIdfBoolZUFMCM6NySPKRL dJXyUq2fy/jYbq8DyGUFYeJp0scPrEs3zBuIwvQyvJJG3Ra9rFyj40VL5C7HgzN9TlMsck wLldlUBWiUnB4FU6ImSORXgcf/hD2S8= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-493-RnIVNeHfNt6x64Pr4MSbLA-1; Fri, 23 Apr 2021 09:18:31 -0400 X-MC-Unique: RnIVNeHfNt6x64Pr4MSbLA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id F04CA107ACCA; Fri, 23 Apr 2021 13:18:25 +0000 (UTC) Received: from t480s.redhat.com (ovpn-112-41.ams2.redhat.com [10.36.112.41]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1A6A960BE5; Fri, 23 Apr 2021 13:18:10 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: David Hildenbrand , Andrew Morton , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Alexander Viro , Alexey Dobriyan , Steven Rostedt , Peter Zijlstra , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Petr Mladek , Sergey Senozhatsky , Andy Shevchenko , Rasmus Villemoes , Kees Cook , "Eric W. Biederman" , Greg Ungerer , Geert Uytterhoeven , Mike Rapoport , Vlastimil Babka , Vincenzo Frascino , Chinwen Chang , Michel Lespinasse , Catalin Marinas , "Matthew Wilcox (Oracle)" , Huang Ying , Jann Horn , Feng Tang , Kevin Brodsky , Michael Ellerman , Shawn Anastasio , Steven Price , Nicholas Piggin , Christian Brauner , Jens Axboe , Gabriel Krisman Bertazi , Peter Xu , Suren Baghdasaryan , Shakeel Butt , Marco Elver , Daniel Jordan , Nicolas Viennot , Thomas Cedeno , Collin Fijalkovich , Michal Hocko , linux-api@vger.kernel.org, x86@kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH RFC 5/7] mm: remove VM_DENYWRITE Date: Fri, 23 Apr 2021 15:16:38 +0200 Message-Id: <20210423131640.20080-6-david@redhat.com> In-Reply-To: <20210423131640.20080-1-david@redhat.com> References: <20210423131640.20080-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org All in-tree users of MAP_DENYWRITE are gone. MAP_DENYWRITE cannot be set from user space, so all users are gone; let's remove it. Signed-off-by: David Hildenbrand --- fs/proc/task_mmu.c | 1 - include/linux/mm.h | 1 - include/linux/mman.h | 1 - include/trace/events/mmflags.h | 1 - kernel/events/core.c | 2 -- kernel/fork.c | 3 --- lib/test_printf.c | 5 ++--- mm/mmap.c | 27 +++------------------------ 8 files changed, 5 insertions(+), 36 deletions(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index e862cab69583..2710703c39b0 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -621,7 +621,6 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma) [ilog2(VM_MAYSHARE)] = "ms", [ilog2(VM_GROWSDOWN)] = "gd", [ilog2(VM_PFNMAP)] = "pf", - [ilog2(VM_DENYWRITE)] = "dw", [ilog2(VM_LOCKED)] = "lo", [ilog2(VM_IO)] = "io", [ilog2(VM_SEQ_READ)] = "sr", diff --git a/include/linux/mm.h b/include/linux/mm.h index 043702972e5f..cdad125af9fa 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -274,7 +274,6 @@ extern unsigned int kobjsize(const void *objp); #define VM_GROWSDOWN 0x00000100 /* general info on the segment */ #define VM_UFFD_MISSING 0x00000200 /* missing pages tracking */ #define VM_PFNMAP 0x00000400 /* Page-ranges managed without "struct page", just pure PFN */ -#define VM_DENYWRITE 0x00000800 /* ETXTBSY on write attempts.. */ #define VM_UFFD_WP 0x00001000 /* wrprotect pages tracking */ #define VM_LOCKED 0x00002000 diff --git a/include/linux/mman.h b/include/linux/mman.h index ebb09a964272..bd9aadda047b 100644 --- a/include/linux/mman.h +++ b/include/linux/mman.h @@ -153,7 +153,6 @@ static inline unsigned long calc_vm_flag_bits(unsigned long flags) { return _calc_vm_trans(flags, MAP_GROWSDOWN, VM_GROWSDOWN ) | - _calc_vm_trans(flags, MAP_DENYWRITE, VM_DENYWRITE ) | _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED ) | _calc_vm_trans(flags, MAP_SYNC, VM_SYNC ) | arch_calc_vm_flag_bits(flags); diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h index 67018d367b9f..e1721ce6381d 100644 --- a/include/trace/events/mmflags.h +++ b/include/trace/events/mmflags.h @@ -149,7 +149,6 @@ IF_HAVE_PG_ARCH_2(PG_arch_2, "arch_2" ) {VM_GROWSDOWN, "growsdown" }, \ {VM_UFFD_MISSING, "uffd_missing" }, \ {VM_PFNMAP, "pfnmap" }, \ - {VM_DENYWRITE, "denywrite" }, \ {VM_UFFD_WP, "uffd_wp" }, \ {VM_LOCKED, "locked" }, \ {VM_IO, "io" }, \ diff --git a/kernel/events/core.c b/kernel/events/core.c index 3dfd463f1831..1ed3eb7aa4c9 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -8184,8 +8184,6 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) else flags = MAP_PRIVATE; - if (vma->vm_flags & VM_DENYWRITE) - flags |= MAP_DENYWRITE; if (vma->vm_flags & VM_LOCKED) flags |= MAP_LOCKED; if (is_vm_hugetlb_page(vma)) diff --git a/kernel/fork.c b/kernel/fork.c index 0681f2973667..fda43ba05d91 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -556,12 +556,9 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm, tmp->vm_flags &= ~(VM_LOCKED | VM_LOCKONFAULT); file = tmp->vm_file; if (file) { - struct inode *inode = file_inode(file); struct address_space *mapping = file->f_mapping; get_file(file); - if (tmp->vm_flags & VM_DENYWRITE) - put_write_access(inode); i_mmap_lock_write(mapping); if (tmp->vm_flags & VM_SHARED) mapping_allow_writable(mapping); diff --git a/lib/test_printf.c b/lib/test_printf.c index 95a2f82427c7..54f0583dc45d 100644 --- a/lib/test_printf.c +++ b/lib/test_printf.c @@ -596,9 +596,8 @@ flags(void) test("uptodate|dirty|lru|active|swapbacked", "%pGp", &flags); - flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC - | VM_DENYWRITE; - test("read|exec|mayread|maywrite|mayexec|denywrite", "%pGv", &flags); + flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; + test("read|exec|mayread|maywrite|mayexec", "%pGv", &flags); gfp = GFP_TRANSHUGE; test("GFP_TRANSHUGE", "%pGg", &gfp); diff --git a/mm/mmap.c b/mm/mmap.c index 882f8ee4af1f..b335f8907568 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -142,8 +142,6 @@ void vma_set_page_prot(struct vm_area_struct *vma) static void __remove_shared_vm_struct(struct vm_area_struct *vma, struct file *file, struct address_space *mapping) { - if (vma->vm_flags & VM_DENYWRITE) - allow_write_access(file); if (vma->vm_flags & VM_SHARED) mapping_unmap_writable(mapping); @@ -660,8 +658,6 @@ static void __vma_link_file(struct vm_area_struct *vma) if (file) { struct address_space *mapping = file->f_mapping; - if (vma->vm_flags & VM_DENYWRITE) - put_write_access(file_inode(file)); if (vma->vm_flags & VM_SHARED) mapping_allow_writable(mapping); @@ -1785,22 +1781,12 @@ unsigned long mmap_region(struct file *file, unsigned long addr, vma->vm_pgoff = pgoff; if (file) { - if (vm_flags & VM_DENYWRITE) { - error = deny_write_access(file); - if (error) - goto free_vma; - } if (vm_flags & VM_SHARED) { error = mapping_map_writable(file->f_mapping); if (error) - goto allow_write_and_free_vma; + goto free_vma; } - /* ->mmap() can change vma->vm_file, but must guarantee that - * vma_link() below can deny write-access if VM_DENYWRITE is set - * and map writably if VM_SHARED is set. This usually means the - * new file must not have been exposed to user-space, yet. - */ vma->vm_file = get_file(file); error = call_mmap(file, vma); if (error) @@ -1857,13 +1843,9 @@ unsigned long mmap_region(struct file *file, unsigned long addr, vma_link(mm, vma, prev, rb_link, rb_parent); /* Once vma denies write, undo our temporary denial count */ - if (file) { unmap_writable: - if (vm_flags & VM_SHARED) - mapping_unmap_writable(file->f_mapping); - if (vm_flags & VM_DENYWRITE) - allow_write_access(file); - } + if (file && vm_flags & VM_SHARED) + mapping_unmap_writable(file->f_mapping); file = vma->vm_file; out: perf_event_mmap(vma); @@ -1903,9 +1885,6 @@ unsigned long mmap_region(struct file *file, unsigned long addr, charged = 0; if (vm_flags & VM_SHARED) mapping_unmap_writable(file->f_mapping); -allow_write_and_free_vma: - if (vm_flags & VM_DENYWRITE) - allow_write_access(file); free_vma: vm_area_free(vma); unacct_error: