From patchwork Tue Dec 20 16:26:05 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muhammad Usama Anjum X-Patchwork-Id: 13078041 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 49CB0C4332F for ; Tue, 20 Dec 2022 16:27:02 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5F33B8E0002; Tue, 20 Dec 2022 11:27:01 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 5A39F8E0001; Tue, 20 Dec 2022 11:27:01 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 41D308E0002; Tue, 20 Dec 2022 11:27:01 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 2A42C8E0001 for ; Tue, 20 Dec 2022 11:27:01 -0500 (EST) Received: from smtpin17.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id C38D51A0C91 for ; Tue, 20 Dec 2022 16:27:00 +0000 (UTC) X-FDA: 80263213800.17.236095B Received: from madras.collabora.co.uk (madras.collabora.co.uk [46.235.227.172]) by imf02.hostedemail.com (Postfix) with ESMTP id 05FA78000D for ; Tue, 20 Dec 2022 16:26:58 +0000 (UTC) Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=collabora.com header.s=mail header.b=obpNYqXU; spf=pass (imf02.hostedemail.com: domain of usama.anjum@collabora.com designates 46.235.227.172 as permitted sender) smtp.mailfrom=usama.anjum@collabora.com; dmarc=pass (policy=none) header.from=collabora.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1671553619; a=rsa-sha256; cv=none; b=hwcUM33XYpOo2DlXZXFg3lKgnTArIdhtrgl544G6ZJNf9mLnRZ38aYKKkTNpDWSCmQZZrx Rs7RIxv0Xpltlmth5GiQKBXx9wOV83AmVSY42jtEtBATpiuvttzv1k6au0G9YmaCtDZ4MF LwdbhqMBjdqRVcI2+evZHUQUpNDbEcs= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=pass header.d=collabora.com header.s=mail header.b=obpNYqXU; spf=pass (imf02.hostedemail.com: domain of usama.anjum@collabora.com designates 46.235.227.172 as permitted sender) smtp.mailfrom=usama.anjum@collabora.com; dmarc=pass (policy=none) header.from=collabora.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1671553619; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:references:dkim-signature; bh=63MUBQSRKRWBy6STj/BO4XxH++E/yGX4eJxJ7groMj4=; b=cbcBwUxglf9sbY6OV8m1bfHhSt7NGlRGX1ZZybO1j8Hb+w059h0/hD66xtkASiBDsDat4f RVqtk6aFm9kFqnDn/4qCRjgFvLReldRwDfJm6ZOzlNBX1Kc0xxOF7CjgMYYS0/8j89m2PW U/I3Ro6ubXJmaPonwkQbY711TMvKrHc= Received: from localhost.localdomain (unknown [39.45.25.143]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: usama.anjum) by madras.collabora.co.uk (Postfix) with ESMTPSA id 578166602CA0; Tue, 20 Dec 2022 16:26:51 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1671553617; bh=H/yXJ+C5YIAsByTqG2HS8f40ouw5wHWvBLV2umMJBWE=; h=From:To:Cc:Subject:Date:From; b=obpNYqXUxEOjSrti3bPlgqfPTuW193Kwt7bQmLKGZIF2Cphwe6FhH96wSqkBYI+wO BLqowYo3XgQgizNvWPC3Bo8tLXsFFvjKmIhzKjQBNgCO97+g9iz8PkqXbV4gyUMzi7 IIUOJM/DttOAyTk8V3cHjpLxQ9wb2lsRHCipat6mC+QqG1hAwELr5nkbubVovtuHpb v/aY1qpAvmZ+IY51RqJwi8eSdOIfDF2cw7SA5jyH6I84xkFtCxT/h1ffzChObZVvtS jX7IWUwHeGK5CmGp76KZYklz2rGuB/YWIWSMo3/kBQEzTgjeaLTnnOq1aBxVG6Fn0b hxpGnPL1ubLsQ== From: Muhammad Usama Anjum To: Alexander Viro , Eric Biederman , Kees Cook , Andrew Morton , Steven Rostedt , Masami Hiramatsu Cc: Muhammad Usama Anjum , kernel@collabora.com, peterx@redhat.com, david@redhat.com, Cyrill Gorcunov , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH RFC] mm: implement granular soft-dirty vma support Date: Tue, 20 Dec 2022 21:26:05 +0500 Message-Id: <20221220162606.1595355-1-usama.anjum@collabora.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 X-Rspam-User: X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 05FA78000D X-Stat-Signature: sqj4bxwoxdjpcirjhf3kjo4sy1awf47j X-HE-Tag: 1671553618-706108 X-HE-Meta: U2FsdGVkX1+FSH8aU3xbtDew4H9OIcEu+AHRadu9kC/BtcucAzbstKazcH9pDi4xTLnd0nt82OwHBvRL+VgtEQ3MpJfQpyq/Twc/XyO0GBoLFqL0k2WsivZoF2Ge0sfzCJoa3RTBURvuvNktf8wIpaWBt0IRrJK/vG2hPZQgtPA8eMiSUdmDuhQnriEAta/NTlfyQ27LXGeMByL02XQo8OkpAiF2fG3o4/7TCNq8Otgoq0+ptFesK1JO6PUgJBQc76pXDGlROGSFu/n3ImwvbQmOH9tB1dolF5VrO7cnqiZdsn0O3EQ5fSAJ8iSvFeNFMWmPwoYdNsKyNoFN1MJAOTsVTPBstvIrYZcNXewhIS7XQD/xVhRpkURIxcbZYI0PeBLVAjs/lfO4IdBEjKl8YebSpERbNDMvyO0IeKFEdbe/iS0LfpSkTpWcqMZF4Q8N9YviYa17if4EfVUtQa8kMOJ1vrLHgXu4vV24rzcA7n3aEvyfrobMpe0XZ+3U9optfvpiJU5ytMv2ZmA7VH2MsZAQx72NRpGQvmZ7L9aJ3Z/OxKsSOrSKwa+SYDrZdUFmiUych0HEuPQSJhX/F2U04eRM0eL+WEB2W1U5R/XFyIACjKvdkBAZbB1JlmOxpdXroFNX77PDpkbymNLWExnC6orkl/t7YlZUzUMFnEohyrrFuYVi31JtKy56guNmnzlkLojIICol7MKzGOuYKTosJy63nR09SNLeFC1Mlxxa8Akz8NIraqrk6FcX9EU2KO6v0jDOiLfBxyk5KQLscAMUBxdmWjXbAMv4Jenfl6r1hdmm1ccppAtDGdWD73XA6bjJzgRWd0JX+KI+jkS3kKNEoMrxAaoCTAhrNQxVSLUkWrThtUHJMbz7haILc3QGRbPP5ipyOAw6W9hgMDnpQR7qAGjojeK7Bp9H5TXBkB6Qyq7e7+wu2PTHI4fbqP3b/uRr8ywTzp2E+S8= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: The VM_SOFTDIRTY is used to mark a whole VMA soft-dirty. Sometimes soft-dirty and non-soft-dirty VMAs are merged making the non-soft-dirty region soft-dirty. This creates problems as the whole VMA region comes out to be soft-dirty while in-reality no there is no soft-dirty page. This can be solved by not merging the VMAs with different soft-dirty flags. But it has potential to cause regression as the number of VMAs can increase drastically. This patch introduces non-soft-dirty regions tracking on VMA level. The implementation is clean when non-soft-dirty regions are tracked. There is no overhead for cases when soft-dirty flag isn't used by the application. The real non-soft-dirty tracking in the VMA starts when the soft-dirty flag is cleared from the user side. Then the list is manipulated along with the VMA manipulations like split/merge/expand the VMAs. The sd flag is still shown in the smaps file. Only the softdirty will not show up in format strings as its corresponding VM_SOFTDIRTY has been removed which seems justified. Overall, this patch should correct the soft-dirty tracking on the VMA level. There shouldn't be any impact on the user's view other than now the user will not get affected by kernel's internal activity (VMA merging/splitting). Cc: Cyrill Gorcunov Signed-off-by: Muhammad Usama Anjum --- Cyrill has pointed to this kind of solution [1]. [1] https://lore.kernel.org/all/Y4W0axw0ZgORtfkt@grain --- fs/exec.c | 2 +- fs/proc/task_mmu.c | 52 ++++++++++----- include/linux/mm.h | 7 +- include/linux/mm_inline.h | 117 +++++++++++++++++++++++++++++++++ include/linux/mm_types.h | 7 ++ include/trace/events/mmflags.h | 7 -- kernel/fork.c | 4 ++ mm/gup.c | 6 +- mm/huge_memory.c | 8 +-- mm/internal.h | 22 ++++++- mm/mmap.c | 45 +++++-------- mm/mprotect.c | 4 +- 12 files changed, 214 insertions(+), 67 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index ab913243a367..30616601567c 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -270,7 +270,7 @@ static int __bprm_mm_init(struct linux_binprm *bprm) BUILD_BUG_ON(VM_STACK_FLAGS & VM_STACK_INCOMPLETE_SETUP); vma->vm_end = STACK_TOP_MAX; vma->vm_start = vma->vm_end - PAGE_SIZE; - vma->vm_flags = VM_SOFTDIRTY | VM_STACK_FLAGS | VM_STACK_INCOMPLETE_SETUP; + vma->vm_flags = VM_STACK_FLAGS | VM_STACK_INCOMPLETE_SETUP; vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); err = insert_vm_struct(mm, vma); diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index f444da25e2e2..bdb4eaf21986 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -683,9 +683,6 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma) [ilog2(VM_DONTDUMP)] = "dd", #ifdef CONFIG_ARM64_BTI [ilog2(VM_ARM64_BTI)] = "bt", -#endif -#ifdef CONFIG_MEM_SOFT_DIRTY - [ilog2(VM_SOFTDIRTY)] = "sd", #endif [ilog2(VM_MIXEDMAP)] = "mm", [ilog2(VM_HUGEPAGE)] = "hg", @@ -723,6 +720,10 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma) seq_putc(m, ' '); } } + + /* non_sd_reg isn't initialized for vsyscall vma */ + if (is_nsdr_list_initialized(&vma->non_sd_reg) && is_vma_sd(vma)) + seq_puts(m, "sd"); seq_putc(m, '\n'); } @@ -1299,10 +1300,24 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, if (type == CLEAR_REFS_SOFT_DIRTY) { mas_for_each(&mas, vma, ULONG_MAX) { - if (!(vma->vm_flags & VM_SOFTDIRTY)) - continue; - vma->vm_flags &= ~VM_SOFTDIRTY; - vma_set_page_prot(vma); + struct non_sd_reg *r; + + if (list_empty(&vma->non_sd_reg)) { + r = kmalloc(sizeof(struct non_sd_reg), GFP_KERNEL); + list_add(&r->nsdr_head, &vma->non_sd_reg); + } else if (list_is_singular(&vma->non_sd_reg)) { + r = list_first_entry(&vma->non_sd_reg, + struct non_sd_reg, nsdr_head); + } else { + while (!list_is_singular(&vma->non_sd_reg)) { + r = list_first_entry(&vma->non_sd_reg, + struct non_sd_reg, nsdr_head); + list_del(&r->nsdr_head); + kfree(r); + } + } + r->start = vma->vm_start; + r->end = vma->vm_end; } inc_tlb_flush_pending(mm); @@ -1397,10 +1412,13 @@ static int pagemap_pte_hole(unsigned long start, unsigned long end, if (!vma) break; - /* Addresses in the VMA. */ - if (vma->vm_flags & VM_SOFTDIRTY) - pme = make_pme(0, PM_SOFT_DIRTY); for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) { + /* Addresses in the VMA. */ + if (is_vma_addr_sd(vma, addr)) + pme = make_pme(0, PM_SOFT_DIRTY); + else + pme = make_pme(0, 0); + err = add_to_pagemap(addr, &pme, pm); if (err) goto out; @@ -1458,7 +1476,7 @@ static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm, flags |= PM_FILE; if (page && !migration && page_mapcount(page) == 1) flags |= PM_MMAP_EXCLUSIVE; - if (vma->vm_flags & VM_SOFTDIRTY) + if (is_vma_addr_sd(vma, addr)) flags |= PM_SOFT_DIRTY; return make_pme(frame, flags); @@ -1481,7 +1499,7 @@ static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end, pmd_t pmd = *pmdp; struct page *page = NULL; - if (vma->vm_flags & VM_SOFTDIRTY) + if (is_vma_addr_sd(vma, addr)) flags |= PM_SOFT_DIRTY; if (pmd_present(pmd)) { @@ -1578,9 +1596,6 @@ static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask, int err = 0; pte_t pte; - if (vma->vm_flags & VM_SOFTDIRTY) - flags |= PM_SOFT_DIRTY; - pte = huge_ptep_get(ptep); if (pte_present(pte)) { struct page *page = pte_page(pte); @@ -1603,7 +1618,12 @@ static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask, } for (; addr != end; addr += PAGE_SIZE) { - pagemap_entry_t pme = make_pme(frame, flags); + pagemap_entry_t pme; + + if (is_vma_addr_sd(vma, addr)) + pme = make_pme(frame, flags | PM_SOFT_DIRTY); + else + pme = make_pme(frame, flags); err = add_to_pagemap(addr, &pme, pm); if (err) diff --git a/include/linux/mm.h b/include/linux/mm.h index 517225fce10f..a2f11aa96d90 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -287,12 +287,6 @@ extern unsigned int kobjsize(const void *objp); #define VM_WIPEONFORK 0x02000000 /* Wipe VMA contents in child. */ #define VM_DONTDUMP 0x04000000 /* Do not include in the core dump */ -#ifdef CONFIG_MEM_SOFT_DIRTY -# define VM_SOFTDIRTY 0x08000000 /* Not soft dirty clean area */ -#else -# define VM_SOFTDIRTY 0 -#endif - #define VM_MIXEDMAP 0x10000000 /* Can contain "struct page" and pure PFN pages */ #define VM_HUGEPAGE 0x20000000 /* MADV_HUGEPAGE marked this vma */ #define VM_NOHUGEPAGE 0x40000000 /* MADV_NOHUGEPAGE marked this vma */ @@ -609,6 +603,7 @@ static inline void vma_init(struct vm_area_struct *vma, struct mm_struct *mm) vma->vm_mm = mm; vma->vm_ops = &dummy_vm_ops; INIT_LIST_HEAD(&vma->anon_vma_chain); + INIT_LIST_HEAD(&vma->non_sd_reg); } static inline void vma_set_anonymous(struct vm_area_struct *vma) diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h index e8ed225d8f7c..d515c2a9b10a 100644 --- a/include/linux/mm_inline.h +++ b/include/linux/mm_inline.h @@ -578,4 +578,121 @@ pte_install_uffd_wp_if_needed(struct vm_area_struct *vma, unsigned long addr, #endif } +static inline int nsdr_clone(struct vm_area_struct *new_vma, struct vm_area_struct *vma) +{ + struct non_sd_reg *r, *reg; + + list_for_each_entry(r, &vma->non_sd_reg, nsdr_head) { + reg = kmalloc(sizeof(struct non_sd_reg), GFP_KERNEL); + if (!reg) + return -ENOMEM; + reg->start = r->start; + reg->end = r->end; + list_add_tail(®->nsdr_head, &new_vma->non_sd_reg); + } + return 0; +} + +static inline void nsdr_clear(struct vm_area_struct *vma) +{ + struct non_sd_reg *r, *r_tmp; + + list_for_each_entry_safe(r, r_tmp, &vma->non_sd_reg, nsdr_head) { + list_del(&r->nsdr_head); + kfree(r); + } +} + +static inline bool is_vma_range_sd(struct vm_area_struct *vma, unsigned long addr, + unsigned long end) +{ + struct non_sd_reg *r; + + list_for_each_entry(r, &vma->non_sd_reg, nsdr_head) { + if (addr >= r->start && end <= r->end) + return false; + } + return true; +} + +static inline bool is_vma_addr_sd(struct vm_area_struct *vma, unsigned long addr) +{ + struct non_sd_reg *r; + + list_for_each_entry(r, &vma->non_sd_reg, nsdr_head) { + if (addr >= r->start && addr < r->end) + return false; + } + return true; +} + +static inline bool is_vma_sd(struct vm_area_struct *vma) +{ + struct non_sd_reg *r; + + if (list_is_singular(&vma->non_sd_reg)) { + r = list_first_entry(&vma->non_sd_reg, struct non_sd_reg, nsdr_head); + if (r->start == vma->vm_start && r->end == vma->vm_end) + return false; + } + return true; +} + +static inline bool is_nsdr_list_initialized(struct list_head *list) +{ + return (list->next != NULL); +} + +static inline void nsdr_move(struct vm_area_struct *vma_to, struct vm_area_struct *vma_from) +{ + struct non_sd_reg *r, *r_tmp; + + list_for_each_entry_safe(r, r_tmp, &vma_from->non_sd_reg, nsdr_head) + list_move_tail(&r->nsdr_head, &vma_to->non_sd_reg); +} + +static inline int nsdr_adjust_new_first(struct vm_area_struct *new, struct vm_area_struct *vma) +{ + struct non_sd_reg *r, *r_tmp, *reg; + unsigned long mid = vma->vm_start; + + list_for_each_entry_safe(r, r_tmp, &vma->non_sd_reg, nsdr_head) { + if (r->start < mid && r->end > mid) { + reg = kmalloc(sizeof(struct non_sd_reg), GFP_KERNEL); + if (!reg) + return -ENOMEM; + reg->start = r->start; + reg->end = mid; + list_add_tail(®->nsdr_head, &new->non_sd_reg); + + r->start = mid; + } else if (r->end <= mid) { + list_move_tail(&r->nsdr_head, &new->non_sd_reg); + } + } + return 0; +} + +static inline int nsdr_adjust_new_after(struct vm_area_struct *new, struct vm_area_struct *vma) +{ + struct non_sd_reg *r, *r_tmp, *reg; + unsigned long mid = vma->vm_end; + + list_for_each_entry_safe(r, r_tmp, &vma->non_sd_reg, nsdr_head) { + if (r->start < mid && r->end > mid) { + reg = kmalloc(sizeof(struct non_sd_reg), GFP_KERNEL); + if (!reg) + return -ENOMEM; + reg->start = mid; + reg->end = r->end; + list_add_tail(®->nsdr_head, &new->non_sd_reg); + + r->end = vma->vm_end; + } else if (r->start >= mid) { + list_move_tail(&r->nsdr_head, &new->non_sd_reg); + } + } + return 0; +} + #endif diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 3b8475007734..c4e2dfc75d26 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -595,8 +595,15 @@ struct vm_area_struct { struct mempolicy *vm_policy; /* NUMA policy for the VMA */ #endif struct vm_userfaultfd_ctx vm_userfaultfd_ctx; + struct list_head non_sd_reg; } __randomize_layout; +struct non_sd_reg { + struct list_head nsdr_head; + unsigned long start; + unsigned long end; +}; + struct kioctx_table; struct mm_struct { struct { diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h index 412b5a46374c..75cd0da07673 100644 --- a/include/trace/events/mmflags.h +++ b/include/trace/events/mmflags.h @@ -151,12 +151,6 @@ IF_HAVE_PG_SKIP_KASAN_POISON(PG_skip_kasan_poison, "skip_kasan_poison") #define __VM_ARCH_SPECIFIC_1 {VM_ARCH_1, "arch_1" } #endif -#ifdef CONFIG_MEM_SOFT_DIRTY -#define IF_HAVE_VM_SOFTDIRTY(flag,name) {flag, name }, -#else -#define IF_HAVE_VM_SOFTDIRTY(flag,name) -#endif - #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_MINOR # define IF_HAVE_UFFD_MINOR(flag, name) {flag, name}, #else @@ -191,7 +185,6 @@ IF_HAVE_UFFD_MINOR(VM_UFFD_MINOR, "uffd_minor" ) \ __VM_ARCH_SPECIFIC_1 , \ {VM_WIPEONFORK, "wipeonfork" }, \ {VM_DONTDUMP, "dontdump" }, \ -IF_HAVE_VM_SOFTDIRTY(VM_SOFTDIRTY, "softdirty" ) \ {VM_MIXEDMAP, "mixedmap" }, \ {VM_HUGEPAGE, "hugepage" }, \ {VM_NOHUGEPAGE, "nohugepage" }, \ diff --git a/kernel/fork.c b/kernel/fork.c index 9f7fe3541897..3f8d2c30efbf 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -474,6 +474,7 @@ struct vm_area_struct *vm_area_dup(struct vm_area_struct *orig) */ *new = data_race(*orig); INIT_LIST_HEAD(&new->anon_vma_chain); + INIT_LIST_HEAD(&new->non_sd_reg); dup_anon_vma_name(orig, new); } return new; @@ -481,6 +482,7 @@ struct vm_area_struct *vm_area_dup(struct vm_area_struct *orig) void vm_area_free(struct vm_area_struct *vma) { + nsdr_clear(vma); free_anon_vma_name(vma); kmem_cache_free(vm_area_cachep, vma); } @@ -650,6 +652,8 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm, retval = dup_userfaultfd(tmp, &uf); if (retval) goto fail_nomem_anon_vma_fork; + if (nsdr_clone(tmp, mpnt)) + goto fail_nomem_anon_vma_fork; if (tmp->vm_flags & VM_WIPEONFORK) { /* * VM_WIPEONFORK gets a clean slate in the child. diff --git a/mm/gup.c b/mm/gup.c index c2c2c6dbcfcf..aec7a0ea98b7 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -496,7 +496,7 @@ static int follow_pfn_pte(struct vm_area_struct *vma, unsigned long address, /* FOLL_FORCE can write to even unwritable PTEs in COW mappings. */ static inline bool can_follow_write_pte(pte_t pte, struct page *page, struct vm_area_struct *vma, - unsigned int flags) + unsigned int flags, unsigned long addr) { /* If the pte is writable, we can write to the page. */ if (pte_write(pte)) @@ -526,7 +526,7 @@ static inline bool can_follow_write_pte(pte_t pte, struct page *page, return false; /* ... and a write-fault isn't required for other reasons. */ - if (vma_soft_dirty_enabled(vma) && !pte_soft_dirty(pte)) + if (vma_addr_soft_dirty_enabled(vma, addr, PAGE_SIZE) && !pte_soft_dirty(pte)) return false; return !userfaultfd_pte_wp(vma, pte); } @@ -562,7 +562,7 @@ static struct page *follow_page_pte(struct vm_area_struct *vma, * have to worry about pte_devmap() because they are never anon. */ if ((flags & FOLL_WRITE) && - !can_follow_write_pte(pte, page, vma, flags)) { + !can_follow_write_pte(pte, page, vma, flags, address)) { page = NULL; goto out; } diff --git a/mm/huge_memory.c b/mm/huge_memory.c index abe6cfd92ffa..a6f74e5535bd 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1405,7 +1405,7 @@ static inline bool can_change_pmd_writable(struct vm_area_struct *vma, return false; /* Do we need write faults for softdirty tracking? */ - if (vma_soft_dirty_enabled(vma) && !pmd_soft_dirty(pmd)) + if (vma_addr_soft_dirty_enabled(vma, addr, HPAGE_SIZE) && !pmd_soft_dirty(pmd)) return false; /* Do we need write faults for uffd-wp tracking? */ @@ -1425,7 +1425,7 @@ static inline bool can_change_pmd_writable(struct vm_area_struct *vma, /* FOLL_FORCE can write to even unwritable PMDs in COW mappings. */ static inline bool can_follow_write_pmd(pmd_t pmd, struct page *page, struct vm_area_struct *vma, - unsigned int flags) + unsigned int flags, unsigned long addr) { /* If the pmd is writable, we can write to the page. */ if (pmd_write(pmd)) @@ -1455,7 +1455,7 @@ static inline bool can_follow_write_pmd(pmd_t pmd, struct page *page, return false; /* ... and a write-fault isn't required for other reasons. */ - if (vma_soft_dirty_enabled(vma) && !pmd_soft_dirty(pmd)) + if (vma_addr_soft_dirty_enabled(vma, addr, PAGE_SIZE) && !pmd_soft_dirty(pmd)) return false; return !userfaultfd_huge_pmd_wp(vma, pmd); } @@ -1475,7 +1475,7 @@ struct page *follow_trans_huge_pmd(struct vm_area_struct *vma, VM_BUG_ON_PAGE(!PageHead(page) && !is_zone_device_page(page), page); if ((flags & FOLL_WRITE) && - !can_follow_write_pmd(*pmd, page, vma, flags)) + !can_follow_write_pmd(*pmd, page, vma, flags, addr)) return NULL; /* Avoid dumping huge zero page */ diff --git a/mm/internal.h b/mm/internal.h index bcf75a8b032d..35f682ce7b17 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -12,6 +12,7 @@ #include #include #include +#include struct folio_batch; @@ -830,6 +831,25 @@ struct folio *try_grab_folio(struct page *page, int refs, unsigned int flags); extern bool mirrored_kernelcore; +static inline bool vma_addr_soft_dirty_enabled(struct vm_area_struct *vma, + unsigned long addr, unsigned long end) +{ + /* + * NOTE: we must check this before VM_SOFTDIRTY on soft-dirty + * enablements, because when without soft-dirty being compiled in, + * VM_SOFTDIRTY is defined as 0x0, then !(vm_flags & VM_SOFTDIRTY) + * will be constantly true. + */ + if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY)) + return false; + + /* + * Soft-dirty is kind of special: its tracking is enabled when the + * vma flags not set. + */ + return !(is_vma_range_sd(vma, addr, end)); +} + static inline bool vma_soft_dirty_enabled(struct vm_area_struct *vma) { /* @@ -845,7 +865,7 @@ static inline bool vma_soft_dirty_enabled(struct vm_area_struct *vma) * Soft-dirty is kind of special: its tracking is enabled when the * vma flags not set. */ - return !(vma->vm_flags & VM_SOFTDIRTY); + return !(is_vma_sd(vma)); } #endif /* __MM_INTERNAL_H */ diff --git a/mm/mmap.c b/mm/mmap.c index 5d54cde108c0..687fbc19ee8e 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -587,6 +587,7 @@ inline int vma_expand(struct ma_state *mas, struct vm_area_struct *vma, } if (remove_next) { + nsdr_move(vma, next); if (file) { uprobe_munmap(next, next->vm_start, next->vm_end); fput(file); @@ -868,15 +869,7 @@ static inline int is_mergeable_vma(struct vm_area_struct *vma, struct vm_userfaultfd_ctx vm_userfaultfd_ctx, struct anon_vma_name *anon_name) { - /* - * VM_SOFTDIRTY should not prevent from VMA merging, if we - * match the flags but dirty bit -- the caller should mark - * merged VMA as dirty. If dirty bit won't be excluded from - * comparison, we increase pressure on the memory system forcing - * the kernel to generate new VMAs when old one could be - * extended instead. - */ - if ((vma->vm_flags ^ vm_flags) & ~VM_SOFTDIRTY) + if (vma->vm_flags ^ vm_flags) return 0; if (vma->vm_file != file) return 0; @@ -1050,6 +1043,9 @@ struct vm_area_struct *vma_merge(struct mm_struct *mm, err = __vma_adjust(prev, prev->vm_start, next->vm_end, prev->vm_pgoff, NULL, prev); + if (err) + return NULL; + err = nsdr_adjust_new_first(prev, next); res = prev; } else if (merge_prev) { /* cases 2, 5, 7 */ err = __vma_adjust(prev, prev->vm_start, @@ -1092,7 +1088,7 @@ 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_ACCESS_FLAGS | VM_SOFTDIRTY)) && + !((a->vm_flags ^ b->vm_flags) & ~(VM_ACCESS_FLAGS)) && b->vm_pgoff == a->vm_pgoff + ((b->vm_start - a->vm_start) >> PAGE_SHIFT); } @@ -2236,8 +2232,14 @@ int __split_vma(struct mm_struct *mm, struct vm_area_struct *vma, err = vma_adjust(vma, vma->vm_start, addr, vma->vm_pgoff, new); /* Success. */ - if (!err) - return 0; + if (!err) { + if (new_below) + err = nsdr_adjust_new_first(new, vma); + else + err = nsdr_adjust_new_after(new, vma); + if (!err) + return err; + } /* Avoid vm accounting in close() operation */ new->vm_start = new->vm_end; @@ -2728,17 +2730,6 @@ unsigned long mmap_region(struct file *file, unsigned long addr, if (file) uprobe_mmap(vma); - /* - * New (or expanded) vma always get soft dirty status. - * Otherwise user-space soft-dirty page tracker won't - * be able to distinguish situation when vma area unmapped, - * then new mapped in-place (which must be aimed as - * a completely new data area). - */ - vma->vm_flags |= VM_SOFTDIRTY; - - vma_set_page_prot(vma); - validate_mm(mm); return addr; @@ -2947,7 +2938,7 @@ static int do_brk_flags(struct ma_state *mas, struct vm_area_struct *vma, */ if (vma && (!vma->anon_vma || list_is_singular(&vma->anon_vma_chain)) && - ((vma->vm_flags & ~VM_SOFTDIRTY) == flags)) { + (vma->vm_flags == flags)) { mas_set_range(mas, vma->vm_start, addr + len - 1); if (mas_preallocate(mas, vma, GFP_KERNEL)) goto unacct_fail; @@ -2958,7 +2949,6 @@ static int do_brk_flags(struct ma_state *mas, struct vm_area_struct *vma, anon_vma_interval_tree_pre_update_vma(vma); } vma->vm_end = addr + len; - vma->vm_flags |= VM_SOFTDIRTY; mas_store_prealloc(mas, vma); if (vma->anon_vma) { @@ -2991,7 +2981,6 @@ static int do_brk_flags(struct ma_state *mas, struct vm_area_struct *vma, mm->data_vm += len >> PAGE_SHIFT; if (flags & VM_LOCKED) mm->locked_vm += (len >> PAGE_SHIFT); - vma->vm_flags |= VM_SOFTDIRTY; validate_mm(mm); return 0; @@ -3224,6 +3213,8 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap, new_vma->vm_pgoff = pgoff; if (vma_dup_policy(vma, new_vma)) goto out_free_vma; + if (nsdr_clone(new_vma, vma)) + goto out_free_vma; if (anon_vma_clone(new_vma, vma)) goto out_free_mempol; if (new_vma->vm_file) @@ -3395,7 +3386,7 @@ static struct vm_area_struct *__install_special_mapping( vma->vm_start = addr; vma->vm_end = addr + len; - vma->vm_flags = vm_flags | mm->def_flags | VM_DONTEXPAND | VM_SOFTDIRTY; + vma->vm_flags = vm_flags | mm->def_flags | VM_DONTEXPAND; vma->vm_flags &= VM_LOCKED_CLEAR_MASK; vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); diff --git a/mm/mprotect.c b/mm/mprotect.c index ce6119456d54..562d017aa9ff 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -52,7 +52,7 @@ bool can_change_pte_writable(struct vm_area_struct *vma, unsigned long addr, return false; /* Do we need write faults for softdirty tracking? */ - if (vma_soft_dirty_enabled(vma) && !pte_soft_dirty(pte)) + if (vma_addr_soft_dirty_enabled(vma, addr, addr + PAGE_SIZE) && !pte_soft_dirty(pte)) return false; /* Do we need write faults for uffd-wp tracking? */ @@ -610,7 +610,7 @@ mprotect_fixup(struct mmu_gather *tlb, struct vm_area_struct *vma, vma->vm_userfaultfd_ctx, anon_vma_name(vma)); if (*pprev) { vma = *pprev; - VM_WARN_ON((vma->vm_flags ^ newflags) & ~VM_SOFTDIRTY); + VM_WARN_ON(vma->vm_flags ^ newflags); goto success; }