From patchwork Mon Jan 9 06:45:16 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muhammad Usama Anjum X-Patchwork-Id: 13093078 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 6C979C5479D for ; Mon, 9 Jan 2023 06:46:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229865AbjAIGq2 (ORCPT ); Mon, 9 Jan 2023 01:46:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50080 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233367AbjAIGqV (ORCPT ); Mon, 9 Jan 2023 01:46:21 -0500 Received: from madras.collabora.co.uk (madras.collabora.co.uk [46.235.227.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 95FCEE089; Sun, 8 Jan 2023 22:46:19 -0800 (PST) Received: from localhost.localdomain (unknown [39.45.24.179]) (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 315D56602CFD; Mon, 9 Jan 2023 06:46:10 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1673246778; bh=JQzaSeft94fKcTZHvuDEmY5KWznaYxMJmSkGHi+xwMQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jobxg6BMU/NWAoTZRTTtlRpr1xMPhjBxUQfhaRXgcLYiJUpcoBTc1ed83xMDvoGmv 65dl2Iy3GvnGq3MjpmihRhGNu2TPbbpradsfdtYbCOv15534QrHLo0MroCqoBBh+VO h+nO3kbOidu5mNLFz5MnmF37VOXMou9kuaSBVwu/1Ztrufavm96N2OObVnOzzcR/kH 0b59zh7obtrBqDKG2kchpfMwMx3sEUVqpav/L5nC518RPZsH3aMoNmY1maCCizrnAG NToeO1z0WdALPg2lueo+2X/KkOnHJOqD6PkHyl2xgShTBPhpdqzGIP+nejHhfyo7rK GGIHLhNmexKMQ== From: Muhammad Usama Anjum To: Peter Xu , David Hildenbrand , Andrew Morton , =?utf-8?b?TWljaGHFgiBNaXJvc8WC?= =?utf-8?b?YXc=?= , Andrei Vagin , Danylo Mocherniuk , Paul Gofman , Cyrill Gorcunov Cc: Alexander Viro , Shuah Khan , Christian Brauner , Yang Shi , Vlastimil Babka , "Liam R . Howlett" , Yun Zhou , Suren Baghdasaryan , Alex Sierra , Muhammad Usama Anjum , Matthew Wilcox , Pasha Tatashin , Mike Rapoport , Nadav Amit , Axel Rasmussen , "Gustavo A . R . Silva" , Dan Williams , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, Greg KH , kernel@collabora.com Subject: [PATCH v7 1/4] userfaultfd: Add UFFD WP Async support Date: Mon, 9 Jan 2023 11:45:16 +0500 Message-Id: <20230109064519.3555250-2-usama.anjum@collabora.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230109064519.3555250-1-usama.anjum@collabora.com> References: <20230109064519.3555250-1-usama.anjum@collabora.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Add new WP Async mode (UFFDIO_WRITEPROTECT_MODE_ASYNC_WP) which resolves the page faults on its own. It can be used to track that which pages have been written to from the time the pages were write protected. It is very efficient way to track the changes as uffd is by nature pte/pmd based. UFFD WP (UFFDIO_WRITEPROTECT_MODE_WP) sends the page faults to the userspace where the pages which have been written-to can be tracked. But it is not efficient. This is why this async version is being added. After setting the WP Async, the pages which have been written to can be found in the pagemap file or information can be obtained from the PAGEMAP_IOCTL (see next patches). Signed-off-by: Muhammad Usama Anjum --- fs/userfaultfd.c | 150 +++++++++++++++++-------------- include/uapi/linux/userfaultfd.h | 6 ++ 2 files changed, 90 insertions(+), 66 deletions(-) diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index 15a5bf765d43..be5e10d15058 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -69,6 +69,7 @@ struct userfaultfd_ctx { unsigned int features; /* released */ bool released; + bool async; /* memory mappings are changing because of non-cooperative event */ atomic_t mmap_changing; /* mm with one ore more vmas attached to this userfaultfd_ctx */ @@ -497,80 +498,93 @@ vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason) /* take the reference before dropping the mmap_lock */ userfaultfd_ctx_get(ctx); + if (ctx->async) { + // Resolve page fault of this page + unsigned long addr = (ctx->features & UFFD_FEATURE_EXACT_ADDRESS) ? + vmf->real_address : vmf->address; + struct vm_area_struct *dst_vma = find_vma(ctx->mm, addr); + size_t s = PAGE_SIZE; + + if (dst_vma->vm_flags & VM_HUGEPAGE) { + s = HPAGE_SIZE; + addr &= HPAGE_MASK; + } - init_waitqueue_func_entry(&uwq.wq, userfaultfd_wake_function); - uwq.wq.private = current; - uwq.msg = userfault_msg(vmf->address, vmf->real_address, vmf->flags, - reason, ctx->features); - uwq.ctx = ctx; - uwq.waken = false; - - blocking_state = userfaultfd_get_blocking_state(vmf->flags); + ret = mwriteprotect_range(ctx->mm, addr, s, false, &ctx->mmap_changing); + } else { + init_waitqueue_func_entry(&uwq.wq, userfaultfd_wake_function); + uwq.wq.private = current; + uwq.msg = userfault_msg(vmf->address, vmf->real_address, vmf->flags, + reason, ctx->features); + uwq.ctx = ctx; + uwq.waken = false; - /* - * Take the vma lock now, in order to safely call - * userfaultfd_huge_must_wait() later. Since acquiring the - * (sleepable) vma lock can modify the current task state, that - * must be before explicitly calling set_current_state(). - */ - if (is_vm_hugetlb_page(vma)) - hugetlb_vma_lock_read(vma); + blocking_state = userfaultfd_get_blocking_state(vmf->flags); - spin_lock_irq(&ctx->fault_pending_wqh.lock); - /* - * After the __add_wait_queue the uwq is visible to userland - * through poll/read(). - */ - __add_wait_queue(&ctx->fault_pending_wqh, &uwq.wq); - /* - * The smp_mb() after __set_current_state prevents the reads - * following the spin_unlock to happen before the list_add in - * __add_wait_queue. - */ - set_current_state(blocking_state); - spin_unlock_irq(&ctx->fault_pending_wqh.lock); + /* + * Take the vma lock now, in order to safely call + * userfaultfd_huge_must_wait() later. Since acquiring the + * (sleepable) vma lock can modify the current task state, that + * must be before explicitly calling set_current_state(). + */ + if (is_vm_hugetlb_page(vma)) + hugetlb_vma_lock_read(vma); - if (!is_vm_hugetlb_page(vma)) - must_wait = userfaultfd_must_wait(ctx, vmf->address, vmf->flags, - reason); - else - must_wait = userfaultfd_huge_must_wait(ctx, vma, - vmf->address, - vmf->flags, reason); - if (is_vm_hugetlb_page(vma)) - hugetlb_vma_unlock_read(vma); - mmap_read_unlock(mm); + spin_lock_irq(&ctx->fault_pending_wqh.lock); + /* + * After the __add_wait_queue the uwq is visible to userland + * through poll/read(). + */ + __add_wait_queue(&ctx->fault_pending_wqh, &uwq.wq); + /* + * The smp_mb() after __set_current_state prevents the reads + * following the spin_unlock to happen before the list_add in + * __add_wait_queue. + */ + set_current_state(blocking_state); + spin_unlock_irq(&ctx->fault_pending_wqh.lock); - if (likely(must_wait && !READ_ONCE(ctx->released))) { - wake_up_poll(&ctx->fd_wqh, EPOLLIN); - schedule(); - } + if (!is_vm_hugetlb_page(vma)) + must_wait = userfaultfd_must_wait(ctx, vmf->address, vmf->flags, + reason); + else + must_wait = userfaultfd_huge_must_wait(ctx, vma, + vmf->address, + vmf->flags, reason); + if (is_vm_hugetlb_page(vma)) + hugetlb_vma_unlock_read(vma); + mmap_read_unlock(mm); + + if (likely(must_wait && !READ_ONCE(ctx->released))) { + wake_up_poll(&ctx->fd_wqh, EPOLLIN); + schedule(); + } - __set_current_state(TASK_RUNNING); + __set_current_state(TASK_RUNNING); - /* - * Here we race with the list_del; list_add in - * userfaultfd_ctx_read(), however because we don't ever run - * list_del_init() to refile across the two lists, the prev - * and next pointers will never point to self. list_add also - * would never let any of the two pointers to point to - * self. So list_empty_careful won't risk to see both pointers - * pointing to self at any time during the list refile. The - * only case where list_del_init() is called is the full - * removal in the wake function and there we don't re-list_add - * and it's fine not to block on the spinlock. The uwq on this - * kernel stack can be released after the list_del_init. - */ - if (!list_empty_careful(&uwq.wq.entry)) { - spin_lock_irq(&ctx->fault_pending_wqh.lock); /* - * No need of list_del_init(), the uwq on the stack - * will be freed shortly anyway. + * Here we race with the list_del; list_add in + * userfaultfd_ctx_read(), however because we don't ever run + * list_del_init() to refile across the two lists, the prev + * and next pointers will never point to self. list_add also + * would never let any of the two pointers to point to + * self. So list_empty_careful won't risk to see both pointers + * pointing to self at any time during the list refile. The + * only case where list_del_init() is called is the full + * removal in the wake function and there we don't re-list_add + * and it's fine not to block on the spinlock. The uwq on this + * kernel stack can be released after the list_del_init. */ - list_del(&uwq.wq.entry); - spin_unlock_irq(&ctx->fault_pending_wqh.lock); + if (!list_empty_careful(&uwq.wq.entry)) { + spin_lock_irq(&ctx->fault_pending_wqh.lock); + /* + * No need of list_del_init(), the uwq on the stack + * will be freed shortly anyway. + */ + list_del(&uwq.wq.entry); + spin_unlock_irq(&ctx->fault_pending_wqh.lock); + } } - /* * ctx may go away after this if the userfault pseudo fd is * already released. @@ -1861,11 +1875,14 @@ static int userfaultfd_writeprotect(struct userfaultfd_ctx *ctx, return ret; if (uffdio_wp.mode & ~(UFFDIO_WRITEPROTECT_MODE_DONTWAKE | - UFFDIO_WRITEPROTECT_MODE_WP)) + UFFDIO_WRITEPROTECT_MODE_WP | + UFFDIO_WRITEPROTECT_MODE_ASYNC_WP)) return -EINVAL; - mode_wp = uffdio_wp.mode & UFFDIO_WRITEPROTECT_MODE_WP; + mode_wp = uffdio_wp.mode & (UFFDIO_WRITEPROTECT_MODE_WP | + UFFDIO_WRITEPROTECT_MODE_ASYNC_WP); mode_dontwake = uffdio_wp.mode & UFFDIO_WRITEPROTECT_MODE_DONTWAKE; + ctx->async = uffdio_wp.mode & UFFDIO_WRITEPROTECT_MODE_ASYNC_WP; if (mode_wp && mode_dontwake) return -EINVAL; @@ -2126,6 +2143,7 @@ static int new_userfaultfd(int flags) ctx->flags = flags; ctx->features = 0; ctx->released = false; + ctx->async = false; atomic_set(&ctx->mmap_changing, 0); ctx->mm = current->mm; /* prevent the mm struct to be freed */ diff --git a/include/uapi/linux/userfaultfd.h b/include/uapi/linux/userfaultfd.h index 005e5e306266..b89665653861 100644 --- a/include/uapi/linux/userfaultfd.h +++ b/include/uapi/linux/userfaultfd.h @@ -284,6 +284,11 @@ struct uffdio_writeprotect { * UFFDIO_WRITEPROTECT_MODE_DONTWAKE: set the flag to avoid waking up * any wait thread after the operation succeeds. * + * UFFDIO_WRITEPROTECT_MODE_ASYNC_WP: set the flag to write protect a + * range, the flag is unset automatically when the page is written. + * This is used to track which pages have been written to from the + * time the memory was write protected. + * * NOTE: Write protecting a region (WP=1) is unrelated to page faults, * therefore DONTWAKE flag is meaningless with WP=1. Removing write * protection (WP=0) in response to a page fault wakes the faulting @@ -291,6 +296,7 @@ struct uffdio_writeprotect { */ #define UFFDIO_WRITEPROTECT_MODE_WP ((__u64)1<<0) #define UFFDIO_WRITEPROTECT_MODE_DONTWAKE ((__u64)1<<1) +#define UFFDIO_WRITEPROTECT_MODE_ASYNC_WP ((__u64)1<<2) __u64 mode; }; From patchwork Mon Jan 9 06:45:17 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muhammad Usama Anjum X-Patchwork-Id: 13093079 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 EA9F4C5479D for ; Mon, 9 Jan 2023 06:46:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234276AbjAIGqc (ORCPT ); Mon, 9 Jan 2023 01:46:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50198 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234287AbjAIGq2 (ORCPT ); Mon, 9 Jan 2023 01:46:28 -0500 Received: from madras.collabora.co.uk (madras.collabora.co.uk [46.235.227.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C5EC81274A; Sun, 8 Jan 2023 22:46:26 -0800 (PST) Received: from localhost.localdomain (unknown [39.45.24.179]) (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 AAE616602D55; Mon, 9 Jan 2023 06:46:18 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1673246785; bh=aJpqFZ4Z39PMY3EcUlB4erYuWBre3v1i5y5YelnRvyg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mXTIh0sImkx5pLx3K9a8ImYkW5z2Rrl2aD88JkC+GfF7XcpOmvPUQBJutyxUEFWOy 93dPVXljJ1g7XaaHIWfB6wDXP/siNTnmhaacnpFaZq5QKOhgq3Mmwcs8+OaQ6Z68VE FpJvtZkUqwGF2fnSiNvP7O4V5zJOsRawxTA9Ggj388SYN4H/YVFHSErncxHfFWKcqV SVASdMc0d+Qd5oHtJaHR4ufaoLSpg01S1nYEvUNLULcJELCFioQlNIZ5mdqj/1ZwuS VCNgd7svrcXFnl+pIbAAwz1EUWZtfz2NLFfXpKBszEvIQCncFNuYLnv1dulL3LWjBe WUIR/1dYXol3g== From: Muhammad Usama Anjum To: Peter Xu , David Hildenbrand , Andrew Morton , =?utf-8?b?TWljaGHFgiBNaXJvc8WC?= =?utf-8?b?YXc=?= , Andrei Vagin , Danylo Mocherniuk , Paul Gofman , Cyrill Gorcunov Cc: Alexander Viro , Shuah Khan , Christian Brauner , Yang Shi , Vlastimil Babka , "Liam R . Howlett" , Yun Zhou , Suren Baghdasaryan , Alex Sierra , Muhammad Usama Anjum , Matthew Wilcox , Pasha Tatashin , Mike Rapoport , Nadav Amit , Axel Rasmussen , "Gustavo A . R . Silva" , Dan Williams , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, Greg KH , kernel@collabora.com Subject: [PATCH v7 2/4] userfaultfd: split mwriteprotect_range() Date: Mon, 9 Jan 2023 11:45:17 +0500 Message-Id: <20230109064519.3555250-3-usama.anjum@collabora.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230109064519.3555250-1-usama.anjum@collabora.com> References: <20230109064519.3555250-1-usama.anjum@collabora.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Split mwriteprotect_range() to create a unlocked version. This will be used in the next patch to write protect a memory area. Add a helper function, wp_range_async() as well. Signed-off-by: Muhammad Usama Anjum --- fs/userfaultfd.c | 11 ++++++++++ include/linux/userfaultfd_k.h | 10 +++++++++ mm/userfaultfd.c | 40 ++++++++++++++++++++++------------- 3 files changed, 46 insertions(+), 15 deletions(-) diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index be5e10d15058..5ff5ff4314e3 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -1967,6 +1967,17 @@ static int userfaultfd_continue(struct userfaultfd_ctx *ctx, unsigned long arg) return ret; } +int wp_range_async(struct vm_area_struct *vma, unsigned long start, unsigned long len) +{ + struct userfaultfd_ctx *ctx = vma->vm_userfaultfd_ctx.ctx; + + if (!ctx) + return -1; + + ctx->async = true; + return __mwriteprotect_range(ctx->mm, start, len, true, &ctx->mmap_changing); +} + static inline unsigned int uffd_ctx_features(__u64 user_features) { /* diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h index 9df0b9a762cc..fba05a32f8e9 100644 --- a/include/linux/userfaultfd_k.h +++ b/include/linux/userfaultfd_k.h @@ -73,6 +73,9 @@ extern ssize_t mcopy_continue(struct mm_struct *dst_mm, unsigned long dst_start, extern int mwriteprotect_range(struct mm_struct *dst_mm, unsigned long start, unsigned long len, bool enable_wp, atomic_t *mmap_changing); +extern int __mwriteprotect_range(struct mm_struct *dst_mm, + unsigned long start, unsigned long len, + bool enable_wp, atomic_t *mmap_changing); extern void uffd_wp_range(struct mm_struct *dst_mm, struct vm_area_struct *vma, unsigned long start, unsigned long len, bool enable_wp); @@ -179,6 +182,8 @@ extern int userfaultfd_unmap_prep(struct mm_struct *mm, unsigned long start, unsigned long end, struct list_head *uf); extern void userfaultfd_unmap_complete(struct mm_struct *mm, struct list_head *uf); +extern int wp_range_async(struct vm_area_struct *vma, unsigned long start, + unsigned long len); #else /* CONFIG_USERFAULTFD */ @@ -274,6 +279,11 @@ static inline bool uffd_disable_fault_around(struct vm_area_struct *vma) return false; } +int wp_range_async(struct vm_area_struct *vma, unsigned long start, unsigned long len) +{ + return -1; +} + #endif /* CONFIG_USERFAULTFD */ static inline bool pte_marker_entry_uffd_wp(swp_entry_t entry) diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index 65ad172add27..9d8a43faf764 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -734,25 +734,13 @@ void uffd_wp_range(struct mm_struct *dst_mm, struct vm_area_struct *dst_vma, tlb_finish_mmu(&tlb); } -int mwriteprotect_range(struct mm_struct *dst_mm, unsigned long start, - unsigned long len, bool enable_wp, - atomic_t *mmap_changing) +int __mwriteprotect_range(struct mm_struct *dst_mm, unsigned long start, + unsigned long len, bool enable_wp, + atomic_t *mmap_changing) { struct vm_area_struct *dst_vma; unsigned long page_mask; int err; - - /* - * Sanitize the command parameters: - */ - BUG_ON(start & ~PAGE_MASK); - BUG_ON(len & ~PAGE_MASK); - - /* Does the address range wrap, or is the span zero-sized? */ - BUG_ON(start + len <= start); - - mmap_read_lock(dst_mm); - /* * If memory mappings are changing because of non-cooperative * operation (e.g. mremap) running in parallel, bail out and @@ -783,6 +771,28 @@ int mwriteprotect_range(struct mm_struct *dst_mm, unsigned long start, err = 0; out_unlock: + return err; +} + +int mwriteprotect_range(struct mm_struct *dst_mm, unsigned long start, + unsigned long len, bool enable_wp, + atomic_t *mmap_changing) +{ + int err; + + /* + * Sanitize the command parameters: + */ + BUG_ON(start & ~PAGE_MASK); + BUG_ON(len & ~PAGE_MASK); + + /* Does the address range wrap, or is the span zero-sized? */ + BUG_ON(start + len <= start); + + mmap_read_lock(dst_mm); + + err = __mwriteprotect_range(dst_mm, start, len, enable_wp, mmap_changing); + mmap_read_unlock(dst_mm); return err; } From patchwork Mon Jan 9 06:45:18 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muhammad Usama Anjum X-Patchwork-Id: 13093080 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 72C45C5479D for ; Mon, 9 Jan 2023 06:46:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235078AbjAIGq5 (ORCPT ); Mon, 9 Jan 2023 01:46:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50468 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233619AbjAIGqw (ORCPT ); Mon, 9 Jan 2023 01:46:52 -0500 Received: from madras.collabora.co.uk (madras.collabora.co.uk [46.235.227.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8336912756; Sun, 8 Jan 2023 22:46:36 -0800 (PST) Received: from localhost.localdomain (unknown [39.45.24.179]) (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 44BDD6602CFC; Mon, 9 Jan 2023 06:46:26 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1673246795; bh=Np+ZtLaFllUYcndXEgjufpXh3S+MF6aB4Jb1Rdh2gSo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BdJWo6iTfDzVTebeIQsDrUDM7b5WC0Ci52SpGP4Ky0xl1zZAVZCcZ3viXhoXxj1U2 5uQGBaqjXfNCc0gmfSXdCs2NwaPax+GnMSwlODn20wt9HA+AjhOH2hE+9rs8t5lMeu zttSf1RsnV5PaMcjqTUBQSjIdaI5Rksya/9BAl9nIdfnhmvdF57By6S0T6cdQ47JOt x0rBQN17irdmibeBzELm7PzDK/inxSjWsdXv/18ZIXQR4z+pAwmkWLC0prfErp0WCe 3V8OpNO5Ov76Och961n29PCLbQkxHj2pm0jOTmE693H3vOEaDHI9GfPygk+XeV4phx +PJHLjfi4xscw== From: Muhammad Usama Anjum To: Peter Xu , David Hildenbrand , Andrew Morton , =?utf-8?b?TWljaGHFgiBNaXJvc8WC?= =?utf-8?b?YXc=?= , Andrei Vagin , Danylo Mocherniuk , Paul Gofman , Cyrill Gorcunov Cc: Alexander Viro , Shuah Khan , Christian Brauner , Yang Shi , Vlastimil Babka , "Liam R . Howlett" , Yun Zhou , Suren Baghdasaryan , Alex Sierra , Muhammad Usama Anjum , Matthew Wilcox , Pasha Tatashin , Mike Rapoport , Nadav Amit , Axel Rasmussen , "Gustavo A . R . Silva" , Dan Williams , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, Greg KH , kernel@collabora.com Subject: [PATCH v7 3/4] fs/proc/task_mmu: Implement IOCTL to get and/or the clear info about PTEs Date: Mon, 9 Jan 2023 11:45:18 +0500 Message-Id: <20230109064519.3555250-4-usama.anjum@collabora.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230109064519.3555250-1-usama.anjum@collabora.com> References: <20230109064519.3555250-1-usama.anjum@collabora.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org This IOCTL, PAGEMAP_SCAN on pagemap file can be used to get and/or clear the info about page table entries. The following operations are supported in this ioctl: - Get the information if the pages have been written-to (PAGE_IS_Wt), file mapped (PAGE_IS_FILE), present (PAGE_IS_PRESENT) or swapped (PAGE_IS_SWAPPED). - Write-protect the pages (PAGEMAP_WP_ENGAGE) to start finding which pages have been written-to. - Find pages which have been written-to and write protect the pages (atomic PAGE_IS_NOT_WP + PAGEMAP_WP_ENGAGE) The uffd should have been registered on the memory range before performing any WP/WT (Write Protect/Writtern-To) related operations with the IOCTL. struct pagemap_scan_args is used as the argument of the IOCTL. In this struct: - The range is specified through start and len. - The output buffer and size is specified as vec and vec_len. - The optional maximum requested pages are specified in the max_pages. - The flags can be specified in the flags field. The PAGEMAP_WP_ENGAGE is the only added flag at this time. - The masks are specified in required_mask, anyof_mask, excluded_ mask and return_mask. This IOCTL can be extended to get information about more PTE bits. This patch has evolved from a basic patch from Gabriel Krisman Bertazi. Signed-off-by: Muhammad Usama Anjum --- Changes in v7: - Rebase on top of latest next - Fix some corner cases - Base soft-dirty on the uffd wp async - Update the terminologies - Optimize the memory usage inside the ioctl Changes in v6: - Rename variables and update comments - Make IOCTL independent of soft_dirty config - Change masks and bitmap type to _u64 - Improve code quality Changes in v5: - Remove tlb flushing even for clear operation Changes in v4: - Update the interface and implementation Changes in v3: - Tighten the user-kernel interface by using explicit types and add more error checking Changes in v2: - Convert the interface from syscall to ioctl - Remove pidfd support as it doesn't make sense in ioctl --- fs/proc/task_mmu.c | 300 ++++++++++++++++++++++++++++++++++ include/uapi/linux/fs.h | 50 ++++++ tools/include/uapi/linux/fs.h | 50 ++++++ 3 files changed, 400 insertions(+) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index e35a0398db63..ba70faadf403 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include @@ -1135,6 +1136,22 @@ static inline void clear_soft_dirty(struct vm_area_struct *vma, } #endif +static inline bool is_pte_uffd_wp(pte_t pte) +{ + if ((pte_present(pte) && pte_uffd_wp(pte)) || + (is_swap_pte(pte) && pte_swp_uffd_wp(pte))) + return true; + return false; +} + +static inline bool is_pmd_uffd_wp(pmd_t pmd) +{ + if ((pmd_present(pmd) && pmd_uffd_wp(pmd)) || + (is_swap_pmd(pmd) && pmd_swp_uffd_wp(pmd))) + return true; + return false; +} + #if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE) static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma, unsigned long addr, pmd_t *pmdp) @@ -1763,11 +1780,294 @@ static int pagemap_release(struct inode *inode, struct file *file) return 0; } +#define PAGEMAP_OP_MASK (PAGE_IS_WT | PAGE_IS_FILE | \ + PAGE_IS_PRESENT | PAGE_IS_SWAPPED) +#define PAGEMAP_NONWT_OP_MASK (PAGE_IS_FILE | PAGE_IS_PRESENT | PAGE_IS_SWAPPED) +#define IS_WP_ENGAGE_OP(a) (a->flags & PAGEMAP_WP_ENGAGE) +#define IS_GET_OP(a) (a->vec) +#define PAGEMAP_SCAN_BITMAP(wt, file, present, swap) \ + (wt | file << 1 | present << 2 | swap << 3) +#define IS_WT_REQUIRED(a) \ + ((a->required_mask & PAGE_IS_WT) || \ + (a->anyof_mask & PAGE_IS_WT)) + +struct pagemap_scan_private { + struct page_region *vec; + struct page_region prev; + unsigned long vec_len, vec_index; + unsigned int max_pages, found_pages, flags; + unsigned long required_mask, anyof_mask, excluded_mask, return_mask; +}; + +static int pagemap_scan_test_walk(unsigned long start, unsigned long end, struct mm_walk *walk) +{ + struct pagemap_scan_private *p = walk->private; + struct vm_area_struct *vma = walk->vma; + + if (IS_WT_REQUIRED(p) && !vma_can_userfault(vma, vma->vm_flags)) + return -EPERM; + if (IS_GET_OP(p) && p->max_pages && (p->found_pages == p->max_pages)) + return -ENOSPC; + if (vma->vm_flags & VM_PFNMAP) + return 1; + return 0; +} + +static inline int add_to_out(bool wt, bool file, bool pres, bool swap, + struct pagemap_scan_private *p, unsigned long addr, unsigned int len) +{ + unsigned long bitmap, cur = PAGEMAP_SCAN_BITMAP(wt, file, pres, swap); + bool cpy = true; + struct page_region *prev = &p->prev; + + if (p->required_mask) + cpy = ((p->required_mask & cur) == p->required_mask); + if (cpy && p->anyof_mask) + cpy = (p->anyof_mask & cur); + if (cpy && p->excluded_mask) + cpy = !(p->excluded_mask & cur); + bitmap = cur & p->return_mask; + if (cpy && bitmap) { + if ((prev->len) && (prev->bitmap == bitmap) && + (prev->start + prev->len * PAGE_SIZE == addr)) { + prev->len += len; + p->found_pages += len; + } else if (p->vec_index < p->vec_len) { + if (prev->len) { + memcpy(&p->vec[p->vec_index], prev, sizeof(struct page_region)); + p->vec_index++; + } + prev->start = addr; + prev->len = len; + prev->bitmap = bitmap; + p->found_pages += len; + } else { + return -ENOSPC; + } + } + return 0; +} + +static inline int export_prev_to_out(struct pagemap_scan_private *p, struct page_region __user *vec, + unsigned long *vec_index) +{ + struct page_region *prev = &p->prev; + + if (prev->len) { + if (copy_to_user(&vec[*vec_index], prev, sizeof(struct page_region))) + return -EFAULT; + p->vec_index++; + (*vec_index)++; + prev->len = 0; + } + return 0; +} + +static inline int pagemap_scan_pmd_entry(pmd_t *pmd, unsigned long addr, + unsigned long end, struct mm_walk *walk) +{ + struct pagemap_scan_private *p = walk->private; + struct vm_area_struct *vma = walk->vma; + unsigned long start = addr; + unsigned int len; + spinlock_t *ptl; + int ret = 0; + pte_t *pte; + bool pmd_wt; + + if ((walk->vma->vm_end < addr) || (p->max_pages && p->found_pages == p->max_pages)) + return 0; + end = min(end, walk->vma->vm_end); + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + ptl = pmd_trans_huge_lock(pmd, vma); + if (ptl) { + pmd_wt = !is_pmd_uffd_wp(*pmd); + /* + * Break huge page into small pages if operation needs to be performed is + * on a portion of the huge page or the return buffer cannot store complete + * data. + */ + if (pmd_wt && (IS_WP_ENGAGE_OP(p) && (end - addr < HPAGE_SIZE))) { + spin_unlock(ptl); + split_huge_pmd(vma, pmd, addr); + goto process_smaller_pages; + } + if (IS_GET_OP(p)) { + len = (end - addr)/PAGE_SIZE; + if (p->max_pages && p->found_pages + len > p->max_pages) + len = p->max_pages - p->found_pages; + + ret = add_to_out(pmd_wt, vma->vm_file, pmd_present(*pmd), + is_swap_pmd(*pmd), p, addr, len); + if (ret) { + spin_unlock(ptl); + return ret; + } + } + spin_unlock(ptl); + if (IS_WP_ENGAGE_OP(p) && pmd_wt) { + BUG_ON(start & ~HPAGE_MASK); + + ret = wp_range_async(vma, addr, HPAGE_SIZE); + } + return ret; + } +process_smaller_pages: + if (pmd_trans_unstable(pmd)) + return 0; +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ + + pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); + for (; addr < end && !ret && (!p->max_pages || (p->found_pages < p->max_pages)) + ; pte++, addr += PAGE_SIZE) { + if (IS_GET_OP(p)) { + ret = add_to_out(!is_pte_uffd_wp(*pte), vma->vm_file, pte_present(*pte), + is_swap_pte(*pte), p, addr, 1); + if (ret) + break; + } + } + pte_unmap_unlock(pte - 1, ptl); + if (IS_WP_ENGAGE_OP(p)) { + BUG_ON(start & ~PAGE_MASK); + ret = wp_range_async(vma, start, addr - start); + } + + cond_resched(); + return ret; +} + +static int pagemap_scan_pte_hole(unsigned long addr, unsigned long end, int depth, + struct mm_walk *walk) +{ + struct pagemap_scan_private *p = walk->private; + struct vm_area_struct *vma = walk->vma; + unsigned int len; + int ret = 0; + + if (vma) { + len = (end - addr)/PAGE_SIZE; + if (p->max_pages && p->found_pages + len > p->max_pages) + len = p->max_pages - p->found_pages; + ret = add_to_out(false, vma->vm_file, false, false, p, addr, len); + } + + return ret; +} + +static const struct mm_walk_ops pagemap_scan_ops = { + .test_walk = pagemap_scan_test_walk, + .pmd_entry = pagemap_scan_pmd_entry, + .pte_hole = pagemap_scan_pte_hole, +}; + +static long do_pagemap_cmd(struct mm_struct *mm, struct pagemap_scan_arg *arg) +{ + unsigned long empty_slots, vec_index = 0; + unsigned long __user start, end; + unsigned long __start, __end; + struct page_region __user *vec; + struct pagemap_scan_private p; + int ret; + + start = (unsigned long)untagged_addr(arg->start); + vec = (struct page_region *)untagged_addr(arg->vec); + if ((!IS_ALIGNED(start, PAGE_SIZE)) || (!access_ok((void __user *)start, arg->len))) + return -EINVAL; + if (IS_GET_OP(arg) && ((arg->vec_len == 0) || + (!access_ok((void __user *)vec, arg->vec_len * sizeof(struct page_region))))) + return -ENOMEM; + if ((arg->flags & ~PAGEMAP_WP_ENGAGE) || (arg->required_mask & ~PAGEMAP_OP_MASK) || + (arg->anyof_mask & ~PAGEMAP_OP_MASK) || (arg->excluded_mask & ~PAGEMAP_OP_MASK) || + (arg->return_mask & ~PAGEMAP_OP_MASK)) + return -EINVAL; + if (IS_GET_OP(arg) && ((!arg->required_mask && !arg->anyof_mask && !arg->excluded_mask) || + !arg->return_mask)) + return -EINVAL; + /* The non-WT flags cannot be obtained if PAGEMAP_WP_ENGAGE is also specified. */ + if (IS_WP_ENGAGE_OP(arg) && ((arg->required_mask & PAGEMAP_NONWT_OP_MASK) || + (arg->anyof_mask & PAGEMAP_NONWT_OP_MASK))) + return -EINVAL; + + end = start + arg->len; + p.max_pages = arg->max_pages; + p.found_pages = 0; + p.flags = arg->flags; + p.required_mask = arg->required_mask; + p.anyof_mask = arg->anyof_mask; + p.excluded_mask = arg->excluded_mask; + p.return_mask = arg->return_mask; + p.prev.len = 0; + p.vec_len = (PAGEMAP_WALK_SIZE >> PAGE_SHIFT); + + if (IS_GET_OP(arg)) { + p.vec = kmalloc_array(p.vec_len, sizeof(struct page_region), GFP_KERNEL); + if (!p.vec) + return -ENOMEM; + } else { + p.vec = NULL; + } + + __start = __end = start; + while (__end < end) { + p.vec_index = 0; + empty_slots = arg->vec_len - vec_index; + if (p.vec_len > empty_slots) + p.vec_len = empty_slots; + + __end = (__start + PAGEMAP_WALK_SIZE) & PAGEMAP_WALK_MASK; + if (__end > end) + __end = end; + + mmap_read_lock(mm); + ret = walk_page_range(mm, __start, __end, &pagemap_scan_ops, &p); + mmap_read_unlock(mm); + + if (!(!ret || ret == -ENOSPC)) + goto free_data; + + __start = __end; + if (IS_GET_OP(arg) && p.vec_index) { + if (copy_to_user(&vec[vec_index], p.vec, + p.vec_index * sizeof(struct page_region))) { + ret = -EFAULT; + goto free_data; + } + vec_index += p.vec_index; + } + } + ret = export_prev_to_out(&p, vec, &vec_index); + if (!ret) + ret = vec_index; +free_data: + if (IS_GET_OP(arg)) + kfree(p.vec); + + return ret; +} + +static long pagemap_scan_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct pagemap_scan_arg __user *uarg = (struct pagemap_scan_arg __user *)arg; + struct mm_struct *mm = file->private_data; + struct pagemap_scan_arg argument; + + if (cmd == PAGEMAP_SCAN) { + if (copy_from_user(&argument, uarg, sizeof(struct pagemap_scan_arg))) + return -EFAULT; + return do_pagemap_cmd(mm, &argument); + } + return -EINVAL; +} + const struct file_operations proc_pagemap_operations = { .llseek = mem_lseek, /* borrow this */ .read = pagemap_read, .open = pagemap_open, .release = pagemap_release, + .unlocked_ioctl = pagemap_scan_ioctl, + .compat_ioctl = pagemap_scan_ioctl, }; #endif /* CONFIG_PROC_PAGE_MONITOR */ diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h index b7b56871029c..6d03a903a745 100644 --- a/include/uapi/linux/fs.h +++ b/include/uapi/linux/fs.h @@ -305,4 +305,54 @@ typedef int __bitwise __kernel_rwf_t; #define RWF_SUPPORTED (RWF_HIPRI | RWF_DSYNC | RWF_SYNC | RWF_NOWAIT |\ RWF_APPEND) +/* Pagemap ioctl */ +#define PAGEMAP_SCAN _IOWR('f', 16, struct pagemap_scan_arg) + +/* Bits are set in the bitmap of the page_region and masks in pagemap_scan_args */ +#define PAGE_IS_WT (1 << 0) +#define PAGE_IS_FILE (1 << 1) +#define PAGE_IS_PRESENT (1 << 2) +#define PAGE_IS_SWAPPED (1 << 3) + +/* + * struct page_region - Page region with bitmap flags + * @start: Start of the region + * @len: Length of the region + * bitmap: Bits sets for the region + */ +struct page_region { + __u64 start; + __u64 len; + __u64 bitmap; +}; + +/* + * struct pagemap_scan_arg - Pagemap ioctl argument + * @start: Starting address of the region + * @len: Length of the region (All the pages in this length are included) + * @vec: Address of page_region struct array for output + * @vec_len: Length of the page_region struct array + * @max_pages: Optional max return pages + * @flags: Flags for the IOCTL + * @required_mask: Required mask - All of these bits have to be set in the PTE + * @anyof_mask: Any mask - Any of these bits are set in the PTE + * @excluded_mask: Exclude mask - None of these bits are set in the PTE + * @return_mask: Bits that are to be reported in page_region + */ +struct pagemap_scan_arg { + __u64 start; + __u64 len; + __u64 vec; + __u64 vec_len; + __u32 max_pages; + __u32 flags; + __u64 required_mask; + __u64 anyof_mask; + __u64 excluded_mask; + __u64 return_mask; +}; + +/* Special flags */ +#define PAGEMAP_WP_ENGAGE (1 << 0) + #endif /* _UAPI_LINUX_FS_H */ diff --git a/tools/include/uapi/linux/fs.h b/tools/include/uapi/linux/fs.h index b7b56871029c..6d03a903a745 100644 --- a/tools/include/uapi/linux/fs.h +++ b/tools/include/uapi/linux/fs.h @@ -305,4 +305,54 @@ typedef int __bitwise __kernel_rwf_t; #define RWF_SUPPORTED (RWF_HIPRI | RWF_DSYNC | RWF_SYNC | RWF_NOWAIT |\ RWF_APPEND) +/* Pagemap ioctl */ +#define PAGEMAP_SCAN _IOWR('f', 16, struct pagemap_scan_arg) + +/* Bits are set in the bitmap of the page_region and masks in pagemap_scan_args */ +#define PAGE_IS_WT (1 << 0) +#define PAGE_IS_FILE (1 << 1) +#define PAGE_IS_PRESENT (1 << 2) +#define PAGE_IS_SWAPPED (1 << 3) + +/* + * struct page_region - Page region with bitmap flags + * @start: Start of the region + * @len: Length of the region + * bitmap: Bits sets for the region + */ +struct page_region { + __u64 start; + __u64 len; + __u64 bitmap; +}; + +/* + * struct pagemap_scan_arg - Pagemap ioctl argument + * @start: Starting address of the region + * @len: Length of the region (All the pages in this length are included) + * @vec: Address of page_region struct array for output + * @vec_len: Length of the page_region struct array + * @max_pages: Optional max return pages + * @flags: Flags for the IOCTL + * @required_mask: Required mask - All of these bits have to be set in the PTE + * @anyof_mask: Any mask - Any of these bits are set in the PTE + * @excluded_mask: Exclude mask - None of these bits are set in the PTE + * @return_mask: Bits that are to be reported in page_region + */ +struct pagemap_scan_arg { + __u64 start; + __u64 len; + __u64 vec; + __u64 vec_len; + __u32 max_pages; + __u32 flags; + __u64 required_mask; + __u64 anyof_mask; + __u64 excluded_mask; + __u64 return_mask; +}; + +/* Special flags */ +#define PAGEMAP_WP_ENGAGE (1 << 0) + #endif /* _UAPI_LINUX_FS_H */ From patchwork Mon Jan 9 06:45:19 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muhammad Usama Anjum X-Patchwork-Id: 13093081 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 11B91C54EBD for ; Mon, 9 Jan 2023 06:47:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236374AbjAIGrS (ORCPT ); Mon, 9 Jan 2023 01:47:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50284 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236219AbjAIGq4 (ORCPT ); Mon, 9 Jan 2023 01:46:56 -0500 Received: from madras.collabora.co.uk (madras.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e5ab]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4A82712767; Sun, 8 Jan 2023 22:46:44 -0800 (PST) Received: from localhost.localdomain (unknown [39.45.24.179]) (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 DE84D6602D52; Mon, 9 Jan 2023 06:46:35 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1673246803; bh=udTHgMSkizavWzpOjmfViYOsyZHjlSYHhoe8mo1WZXU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TKRh6jo2QVioC6jpOuUQX0x4Odm2L6UyZTtbLsfU2sYmwswbpmw7q4/HTGoe4IujY TxBfyPYUNApWvuI/lB+eKSEx2tP1aWRMHrRlQMPRreCmb+JC70OGjLPZiB3HSar3xN K7/sueYthams0mlnhnw7//JdwpB+cwbcvUTtuDkiviAqupSxv9Jdhj4KbCzDJfhrBE 1eSWoRERQb1Y99szHLi6K4yKzqUHAN3dOPZxGcMN//PhD0bh9mY+1QAABORgIb8QE/ jNSG5AtC6/1eqnXdhJGnQZeZjZmrLMbpbrtwubavSdBFeLpXJQ5EA/WQs6KXQh2Id1 eUPcGxqTXN0VA== From: Muhammad Usama Anjum To: Peter Xu , David Hildenbrand , Andrew Morton , =?utf-8?b?TWljaGHFgiBNaXJvc8WC?= =?utf-8?b?YXc=?= , Andrei Vagin , Danylo Mocherniuk , Paul Gofman , Cyrill Gorcunov Cc: Alexander Viro , Shuah Khan , Christian Brauner , Yang Shi , Vlastimil Babka , "Liam R . Howlett" , Yun Zhou , Suren Baghdasaryan , Alex Sierra , Muhammad Usama Anjum , Matthew Wilcox , Pasha Tatashin , Mike Rapoport , Nadav Amit , Axel Rasmussen , "Gustavo A . R . Silva" , Dan Williams , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, Greg KH , kernel@collabora.com Subject: [PATCH v7 4/4] selftests: vm: add pagemap ioctl tests Date: Mon, 9 Jan 2023 11:45:19 +0500 Message-Id: <20230109064519.3555250-5-usama.anjum@collabora.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230109064519.3555250-1-usama.anjum@collabora.com> References: <20230109064519.3555250-1-usama.anjum@collabora.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Add pagemap ioctl tests. Add several different types of tests to judge the correction of the interface. Signed-off-by: Muhammad Usama Anjum --- Chages in v7: - Add and update all test cases Changes in v6: - Rename variables Changes in v4: - Updated all the tests to conform to new IOCTL Changes in v3: - Add another test to do sanity of flags Changes in v2: - Update the tests to use the ioctl interface instead of syscall TAP version 13 1..54 ok 1 sanity_tests_sd wrong flag specified ok 2 sanity_tests_sd wrong mask specified ok 3 sanity_tests_sd wrong return mask specified ok 4 sanity_tests_sd mixture of correct and wrong flag ok 5 sanity_tests_sd Clear area with larger vec size ok 6 sanity_tests_sd Repeated pattern of dirty and non-dirty pages ok 7 sanity_tests_sd Repeated pattern of dirty and non-dirty pages in parts ok 8 sanity_tests_sd Two regions ok 9 Page testing: all new pages must be soft dirty ok 10 Page testing: all pages must not be soft dirty ok 11 Page testing: all pages dirty other than first and the last one ok 12 Page testing: only middle page dirty ok 13 Page testing: only two middle pages dirty ok 14 Page testing: only get 2 dirty pages and clear them as well ok 15 Page testing: Range clear only ok 16 Large Page testing: all new pages must be soft dirty ok 17 Large Page testing: all pages must not be soft dirty ok 18 Large Page testing: all pages dirty other than first and the last one ok 19 Large Page testing: only middle page dirty ok 20 Large Page testing: only two middle pages dirty ok 21 Large Page testing: only get 2 dirty pages and clear them as well ok 22 Large Page testing: Range clear only ok 23 Huge page testing: all new pages must be soft dirty ok 24 Huge page testing: all pages must not be soft dirty ok 25 Huge page testing: all pages dirty other than first and the last one ok 26 Huge page testing: only middle page dirty ok 27 Huge page testing: only two middle pages dirty ok 28 Huge page testing: only get 2 dirty pages and clear them as well ok 29 Huge page testing: Range clear only ok 30 hpage_unit_tests all new huge page must be dirty ok 31 hpage_unit_tests all the huge page must not be dirty ok 32 hpage_unit_tests all the huge page must be dirty and clear ok 33 hpage_unit_tests only middle page dirty ok 34 hpage_unit_tests clear first half of huge page ok 35 hpage_unit_tests clear first half of huge page with limited buffer ok 36 hpage_unit_tests clear second half huge page ok 37 Test test_simple ok 38 mprotect_tests Both pages dirty ok 39 mprotect_tests Both pages are not soft dirty ok 40 mprotect_tests Both pages dirty after remap and mprotect ok 41 mprotect_tests Clear and make the pages dirty ok 42 sanity_tests clear op can only be specified with PAGE_IS_WT ok 43 sanity_tests required_mask specified ok 44 sanity_tests anyof_mask specified ok 45 sanity_tests excluded_mask specified ok 46 sanity_tests required_mask and anyof_mask specified ok 47 sanity_tests Get sd and present pages with anyof_mask ok 48 sanity_tests Get all the pages with required_mask ok 49 sanity_tests Get sd and present pages with required_mask and anyof_mask ok 50 sanity_tests Don't get sd pages ok 51 sanity_tests Don't get present pages ok 52 sanity_tests Find dirty present pages with return mask ok 53 sanity_tests Memory mapped file ok 54 unmapped_region_tests Get status of pages # Totals: pass:54 fail:0 xfail:0 xpass:0 skip:0 error:0 --- tools/testing/selftests/vm/.gitignore | 1 + tools/testing/selftests/vm/Makefile | 5 +- tools/testing/selftests/vm/pagemap_ioctl.c | 884 +++++++++++++++++++++ 3 files changed, 888 insertions(+), 2 deletions(-) create mode 100644 tools/testing/selftests/vm/pagemap_ioctl.c diff --git a/tools/testing/selftests/vm/.gitignore b/tools/testing/selftests/vm/.gitignore index 1f8c36a9fa10..9e7e0ae26582 100644 --- a/tools/testing/selftests/vm/.gitignore +++ b/tools/testing/selftests/vm/.gitignore @@ -17,6 +17,7 @@ mremap_dontunmap mremap_test on-fault-limit transhuge-stress +pagemap_ioctl protection_keys protection_keys_32 protection_keys_64 diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile index 89c14e41bd43..54c074440a1b 100644 --- a/tools/testing/selftests/vm/Makefile +++ b/tools/testing/selftests/vm/Makefile @@ -24,9 +24,8 @@ MACHINE ?= $(shell echo $(uname_M) | sed -e 's/aarch64.*/arm64/' -e 's/ppc64.*/p # things despite using incorrect values such as an *occasionally* incomplete # LDLIBS. MAKEFLAGS += --no-builtin-rules - CFLAGS = -Wall -I $(top_srcdir) -I $(top_srcdir)/usr/include $(EXTRA_CFLAGS) $(KHDR_INCLUDES) -LDLIBS = -lrt -lpthread +LDLIBS = -lrt -lpthread -lm TEST_GEN_FILES = cow TEST_GEN_FILES += compaction_test TEST_GEN_FILES += gup_test @@ -52,6 +51,7 @@ TEST_GEN_FILES += on-fault-limit TEST_GEN_FILES += thuge-gen TEST_GEN_FILES += transhuge-stress TEST_GEN_FILES += userfaultfd +TEST_GEN_PROGS += pagemap_ioctl TEST_GEN_PROGS += soft-dirty TEST_GEN_PROGS += split_huge_page_test TEST_GEN_FILES += ksm_tests @@ -103,6 +103,7 @@ $(OUTPUT)/cow: vm_util.c $(OUTPUT)/khugepaged: vm_util.c $(OUTPUT)/ksm_functional_tests: vm_util.c $(OUTPUT)/madv_populate: vm_util.c +$(OUTPUT)/pagemap_ioctl: vm_util.c $(OUTPUT)/soft-dirty: vm_util.c $(OUTPUT)/split_huge_page_test: vm_util.c $(OUTPUT)/userfaultfd: vm_util.c diff --git a/tools/testing/selftests/vm/pagemap_ioctl.c b/tools/testing/selftests/vm/pagemap_ioctl.c new file mode 100644 index 000000000000..668faa042e76 --- /dev/null +++ b/tools/testing/selftests/vm/pagemap_ioctl.c @@ -0,0 +1,884 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include +#include "vm_util.h" +#include "../kselftest.h" +#include +#include +#include +#include +#include +#include +#include + +#define PAGEMAP_OP_MASK (PAGE_IS_WT | PAGE_IS_FILE | \ + PAGE_IS_PRESENT | PAGE_IS_SWAPPED) +#define PAGEMAP_NON_WT_MASK (PAGE_IS_FILE | PAGE_IS_PRESENT | \ + PAGE_IS_SWAPPED) + +#define TEST_ITERATIONS 10 +#define PAGEMAP "/proc/self/pagemap" +int pagemap_fd; +int uffd; +int page_size; +int hpage_size; + +static long pagemap_ioctl(void *start, int len, void *vec, int vec_len, int flag, + int max_pages, long required_mask, long anyof_mask, long excluded_mask, + long return_mask) +{ + struct pagemap_scan_arg arg; + int ret; + + arg.start = (uintptr_t)start; + arg.len = len; + arg.vec = (uintptr_t)vec; + arg.vec_len = vec_len; + arg.flags = flag; + arg.max_pages = max_pages; + arg.required_mask = required_mask; + arg.anyof_mask = anyof_mask; + arg.excluded_mask = excluded_mask; + arg.return_mask = return_mask; + + ret = ioctl(pagemap_fd, PAGEMAP_SCAN, &arg); + + return ret; +} + +int init_uffd(void) +{ + struct uffdio_api uffdio_api; + + uffd = syscall(323, O_CLOEXEC | O_NONBLOCK); + if (uffd == -1) + ksft_exit_fail_msg("uffd syscall failed\n"); + + uffdio_api.api = UFFD_API; + uffdio_api.features = 0; + if (ioctl(uffd, UFFDIO_API, &uffdio_api)) + ksft_exit_fail_msg("UFFDIO_API\n"); + + if (uffdio_api.api != UFFD_API) + ksft_exit_fail_msg("UFFDIO_API error %llu\n", uffdio_api.api); + + return 0; +} + +int wp_init(void *lpBaseAddress, int dwRegionSize) +{ + struct uffdio_register uffdio_register; + struct uffdio_writeprotect wp; + + /* TODO: can it be avoided? Write protect doesn't engage on the pages if they aren't + * present already. The pages can be made present by writing to them. + */ + memset(lpBaseAddress, -1, dwRegionSize); + + uffdio_register.range.start = (unsigned long)lpBaseAddress; + uffdio_register.range.len = dwRegionSize; + uffdio_register.mode = UFFDIO_REGISTER_MODE_WP; + if (ioctl(uffd, UFFDIO_REGISTER, &uffdio_register) == -1) + ksft_exit_fail_msg("ioctl(UFFDIO_REGISTER)\n"); + + if (!(uffdio_register.ioctls & UFFDIO_WRITEPROTECT)) + ksft_exit_fail_msg("ioctl set is incorrect\n"); + + if (rand() % 2) { + wp.range.start = (unsigned long)lpBaseAddress; + wp.range.len = dwRegionSize; + wp.mode = UFFDIO_WRITEPROTECT_MODE_ASYNC_WP; + + if (ioctl(uffd, UFFDIO_WRITEPROTECT, &wp) == -1) + ksft_exit_fail_msg("ioctl(UFFDIO_WRITEPROTECT)\n"); + } else { + if (pagemap_ioctl(lpBaseAddress, dwRegionSize, NULL, 0, PAGEMAP_WP_ENGAGE, 0, + 0, 0, 0, 0) < 0) + ksft_exit_fail_msg("error %d %d %s\n", 1, errno, strerror(errno)); + } + return 0; +} + +int wp_free(void *lpBaseAddress, int dwRegionSize) +{ + struct uffdio_register uffdio_register; + + uffdio_register.range.start = (unsigned long)lpBaseAddress; + uffdio_register.range.len = dwRegionSize; + uffdio_register.mode = UFFDIO_REGISTER_MODE_WP; + if (ioctl(uffd, UFFDIO_UNREGISTER, &uffdio_register.range)) + ksft_exit_fail_msg("ioctl unregister failure\n"); + return 0; +} + +int clear_softdirty_wp(void *lpBaseAddress, int dwRegionSize) +{ + struct uffdio_writeprotect wp; + + if (rand() % 2) { + wp.range.start = (unsigned long)lpBaseAddress; + wp.range.len = dwRegionSize; + wp.mode = UFFDIO_WRITEPROTECT_MODE_ASYNC_WP; + + if (ioctl(uffd, UFFDIO_WRITEPROTECT, &wp) == -1) + ksft_exit_fail_msg("ioctl(UFFDIO_WRITEPROTECT)\n"); + } else { + if (pagemap_ioctl(lpBaseAddress, dwRegionSize, NULL, 0, PAGEMAP_WP_ENGAGE, 0, + 0, 0, 0, 0) < 0) + ksft_exit_fail_msg("error %d %d %s\n", 1, errno, strerror(errno)); + } + return 0; +} + +int sanity_tests_sd(void) +{ + char *mem, *m[2]; + int mem_size, vec_size, ret, ret2, ret3, i, num_pages = 10; + struct page_region *vec; + + vec_size = 100; + mem_size = num_pages * page_size; + + vec = malloc(sizeof(struct page_region) * vec_size); + if (!vec) + ksft_exit_fail_msg("error nomem\n"); + mem = mmap(NULL, mem_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0); + if (mem == MAP_FAILED) + ksft_exit_fail_msg("error nomem\n"); + + wp_init(mem, mem_size); + + /* 1. wrong operation */ + ksft_test_result(pagemap_ioctl(mem, mem_size, vec, vec_size, -1, + 0, PAGE_IS_WT, 0, 0, PAGE_IS_WT) < 0, + "%s wrong flag specified\n", __func__); + ksft_test_result(pagemap_ioctl(mem, mem_size, vec, vec_size, 8, + 0, 0x1111, 0, 0, PAGE_IS_WT) < 0, + "%s wrong mask specified\n", __func__); + ksft_test_result(pagemap_ioctl(mem, mem_size, vec, vec_size, 0, + 0, PAGE_IS_WT, 0, 0, 0x1000) < 0, + "%s wrong return mask specified\n", __func__); + ksft_test_result(pagemap_ioctl(mem, mem_size, vec, vec_size, + PAGEMAP_WP_ENGAGE | 0x32, + 0, PAGE_IS_WT, 0, 0, PAGE_IS_WT) < 0, + "%s mixture of correct and wrong flag\n", __func__); + + /* 2. Clear area with larger vec size */ + ret = pagemap_ioctl(mem, mem_size, vec, vec_size, PAGEMAP_WP_ENGAGE, 0, + PAGE_IS_WT, 0, 0, PAGE_IS_WT); + ksft_test_result(ret >= 0, "%s Clear area with larger vec size\n", __func__); + + /* 3. Repeated pattern of dirty and non-dirty pages */ + for (i = 0; i < mem_size; i += 2 * page_size) + mem[i]++; + + ret = pagemap_ioctl(mem, mem_size, vec, vec_size, 0, 0, PAGE_IS_WT, 0, 0, + PAGE_IS_WT); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + ksft_test_result(ret == mem_size/(page_size * 2), + "%s Repeated pattern of dirty and non-dirty pages\n", __func__); + + /* 4. Repeated pattern of dirty and non-dirty pages in parts */ + ret = pagemap_ioctl(mem, mem_size, vec, num_pages/5, PAGEMAP_WP_ENGAGE, + num_pages/2 - 2, PAGE_IS_WT, 0, 0, PAGE_IS_WT); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + ret2 = pagemap_ioctl(mem, mem_size, vec, 2, 0, 0, PAGE_IS_WT, 0, 0, + PAGE_IS_WT); + if (ret2 < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret2, errno, strerror(errno)); + + ret3 = pagemap_ioctl(mem, mem_size, vec, num_pages/2, 0, 0, PAGE_IS_WT, 0, 0, + PAGE_IS_WT); + if (ret3 < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret3, errno, strerror(errno)); + + ksft_test_result((ret + ret3) == num_pages/2 && ret2 == 2, + "%s Repeated pattern of dirty and non-dirty pages in parts\n", __func__); + + wp_free(mem, mem_size); + munmap(mem, mem_size); + + /* 5. Two regions */ + m[0] = mmap(NULL, mem_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0); + if (m[0] == MAP_FAILED) + ksft_exit_fail_msg("error nomem\n"); + m[1] = mmap(NULL, mem_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0); + if (m[1] == MAP_FAILED) + ksft_exit_fail_msg("error nomem\n"); + + wp_init(m[0], mem_size); + wp_init(m[1], mem_size); + + memset(m[0], 'a', mem_size); + memset(m[1], 'b', mem_size); + + ret = pagemap_ioctl(m[0], mem_size, NULL, 0, PAGEMAP_WP_ENGAGE, 0, + 0, 0, 0, 0); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + ret = pagemap_ioctl(m[1], mem_size, vec, 1, 0, 0, PAGE_IS_WT, 0, 0, + PAGE_IS_WT); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + ksft_test_result(ret == 1 && vec[0].len == mem_size/page_size, + "%s Two regions\n", __func__); + + wp_free(m[0], mem_size); + wp_free(m[1], mem_size); + munmap(m[0], mem_size); + munmap(m[1], mem_size); + + free(vec); + return 0; +} + +int base_tests(char *prefix, char *mem, int mem_size, int skip) +{ + int vec_size, ret, dirty, dirty2; + struct page_region *vec, *vec2; + + if (skip) { + ksft_test_result_skip("%s all new pages must be soft dirty\n", prefix); + ksft_test_result_skip("%s all pages must not be soft dirty\n", prefix); + ksft_test_result_skip("%s all pages dirty other than first and the last one\n", + prefix); + ksft_test_result_skip("%s only middle page dirty\n", prefix); + ksft_test_result_skip("%s only two middle pages dirty\n", prefix); + ksft_test_result_skip("%s only get 2 dirty pages and clear them as well\n", prefix); + ksft_test_result_skip("%s Range clear only\n", prefix); + return 0; + } + + vec_size = mem_size/page_size; + vec = malloc(sizeof(struct page_region) * vec_size); + vec2 = malloc(sizeof(struct page_region) * vec_size); + + /* 1. all new pages must be not be soft dirty */ + dirty = pagemap_ioctl(mem, mem_size, vec, 1, PAGEMAP_WP_ENGAGE, vec_size - 2, + PAGE_IS_WT, 0, 0, PAGE_IS_WT); + if (dirty < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty, errno, strerror(errno)); + + dirty2 = pagemap_ioctl(mem, mem_size, vec2, 1, PAGEMAP_WP_ENGAGE, 0, + PAGE_IS_WT, 0, 0, PAGE_IS_WT); + if (dirty2 < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty2, errno, strerror(errno)); + + ksft_test_result(dirty == 0 && dirty2 == 0, + "%s all new pages must be soft dirty\n", prefix); + + /* 2. all pages must not be soft dirty */ + dirty = pagemap_ioctl(mem, mem_size, vec, 1, 0, 0, PAGE_IS_WT, 0, 0, + PAGE_IS_WT); + if (dirty < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty, errno, strerror(errno)); + + ksft_test_result(dirty == 0, "%s all pages must not be soft dirty\n", prefix); + + /* 3. all pages dirty other than first and the last one */ + memset(mem + page_size, 0, mem_size - (2 * page_size)); + + dirty = pagemap_ioctl(mem, mem_size, vec, 1, 0, 0, PAGE_IS_WT, 0, 0, + PAGE_IS_WT); + if (dirty < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty, errno, strerror(errno)); + + ksft_test_result(dirty == 1 && vec[0].len >= vec_size - 2 && vec[0].len <= vec_size, + "%s all pages dirty other than first and the last one\n", prefix); + + /* 4. only middle page dirty */ + clear_softdirty_wp(mem, mem_size); + mem[vec_size/2 * page_size]++; + + dirty = pagemap_ioctl(mem, mem_size, vec, vec_size, 0, 0, PAGE_IS_WT, 0, 0, + PAGE_IS_WT); + if (dirty < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty, errno, strerror(errno)); + + if (check_huge_anon(mem, mem_size/hpage_size, hpage_size)) + ksft_test_result(dirty == 1 && vec[0].len >= 1, + "%s only middle page dirty\n", prefix); + else + ksft_test_result(vec[0].start == (uintptr_t)(mem + vec_size/2 * page_size), + "%s only middle page dirty\n", prefix); + + /* 5. only two middle pages dirty and walk over only middle pages */ + clear_softdirty_wp(mem, mem_size); + mem[vec_size/2 * page_size]++; + mem[(vec_size/2 + 1) * page_size]++; + + dirty = pagemap_ioctl(&mem[vec_size/2 * page_size], 2 * page_size, vec, 1, 0, 0, + PAGE_IS_WT, 0, 0, PAGE_IS_WT); + if (dirty < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty, errno, strerror(errno)); + + ksft_test_result(dirty == 1 && vec[0].start == (uintptr_t)(&mem[vec_size/2 * page_size]) && + vec[0].len == 2, + "%s only two middle pages dirty\n", prefix); + + /* 6. only get 2 dirty pages and clear them as well */ + memset(mem, -1, mem_size); + + /* get and clear second and third pages */ + ret = pagemap_ioctl(mem + page_size, 2 * page_size, vec, 1, PAGEMAP_WP_ENGAGE, + 2, PAGE_IS_WT, 0, 0, PAGE_IS_WT); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + dirty = pagemap_ioctl(mem, mem_size, vec2, vec_size, 0, 0, + PAGE_IS_WT, 0, 0, PAGE_IS_WT); + if (dirty < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty, errno, strerror(errno)); + + ksft_test_result(ret == 1 && vec[0].len == 2 && + vec[0].start == (uintptr_t)(mem + page_size) && + dirty == 2 && vec2[0].len == 1 && vec2[0].start == (uintptr_t)mem && + vec2[1].len == vec_size - 3 && + vec2[1].start == (uintptr_t)(mem + 3 * page_size), + "%s only get 2 dirty pages and clear them as well\n", prefix); + + /* 7. Range clear only */ + memset(mem, -1, mem_size); + + dirty = pagemap_ioctl(mem, mem_size, NULL, 0, PAGEMAP_WP_ENGAGE, 0, + 0, 0, 0, 0); + if (dirty < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty, errno, strerror(errno)); + + dirty2 = pagemap_ioctl(mem, mem_size, vec, vec_size, 0, 0, + PAGE_IS_WT, 0, 0, PAGE_IS_WT); + if (dirty2 < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty2, errno, strerror(errno)); + + ksft_test_result(dirty == 0 && dirty2 == 0, "%s Range clear only\n", + prefix); + + free(vec); + free(vec2); + return 0; +} + +void *gethugepage(int map_size) +{ + int ret; + char *map; + + map = memalign(hpage_size, map_size); + if (!map) + ksft_exit_fail_msg("memalign failed %d %s\n", errno, strerror(errno)); + + ret = madvise(map, map_size, MADV_HUGEPAGE); + if (ret) + ksft_exit_fail_msg("madvise failed %d %d %s\n", ret, errno, strerror(errno)); + + wp_init(map, map_size); + + if (check_huge_anon(map, map_size/hpage_size, hpage_size)) + return map; + + free(map); + return NULL; + +} + +int hpage_unit_tests(void) +{ + char *map; + int ret; + size_t num_pages = 10; + int map_size = hpage_size * num_pages; + int vec_size = map_size/page_size; + struct page_region *vec, *vec2; + + vec = malloc(sizeof(struct page_region) * vec_size); + vec2 = malloc(sizeof(struct page_region) * vec_size); + if (!vec || !vec2) + ksft_exit_fail_msg("malloc failed\n"); + + map = gethugepage(map_size); + if (map) { + /* 1. all new huge page must not be dirty */ + ret = pagemap_ioctl(map, map_size, vec, vec_size, PAGEMAP_WP_ENGAGE, 0, + PAGE_IS_WT, 0, 0, PAGE_IS_WT); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + ksft_test_result(ret == 0, "%s all new huge page must be dirty\n", __func__); + + /* 2. all the huge page must not be dirty */ + ret = pagemap_ioctl(map, map_size, vec, vec_size, 0, 0, + PAGE_IS_WT, 0, 0, PAGE_IS_WT); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + ksft_test_result(ret == 0, "%s all the huge page must not be dirty\n", __func__); + + /* 3. all the huge page must be dirty and clear dirty as well */ + memset(map, -1, map_size); + ret = pagemap_ioctl(map, map_size, vec, vec_size, PAGEMAP_WP_ENGAGE, 0, + PAGE_IS_WT, 0, 0, PAGE_IS_WT); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + ksft_test_result(ret == 1 && vec[0].start == (uintptr_t)map && + vec[0].len == vec_size && vec[0].bitmap == PAGE_IS_WT, + "%s all the huge page must be dirty and clear\n", __func__); + + /* 4. only middle page dirty */ + wp_free(map, map_size); + free(map); + map = gethugepage(map_size); + wp_init(map, map_size); + clear_softdirty_wp(map, map_size); + map[vec_size/2 * page_size]++; + + ret = pagemap_ioctl(map, map_size, vec, vec_size, 0, 0, + PAGE_IS_WT, 0, 0, PAGE_IS_WT); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + ksft_test_result(ret == 1 && vec[0].len > 0, + "%s only middle page dirty\n", __func__); + + wp_free(map, map_size); + free(map); + } else { + ksft_test_result_skip("all new huge page must be dirty\n"); + ksft_test_result_skip("all the huge page must not be dirty\n"); + ksft_test_result_skip("all the huge page must be dirty and clear\n"); + ksft_test_result_skip("only middle page dirty\n"); + } + + /* 5. clear first half of huge page */ + map = gethugepage(map_size); + if (map) { + + memset(map, 0, map_size); + + ret = pagemap_ioctl(map, map_size/2, NULL, 0, PAGEMAP_WP_ENGAGE, 0, + 0, 0, 0, 0); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + ret = pagemap_ioctl(map, map_size, vec, vec_size, 0, 0, + PAGE_IS_WT, 0, 0, PAGE_IS_WT); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + ksft_test_result(ret == 1 && vec[0].len == vec_size/2 && + vec[0].start == (uintptr_t)(map + map_size/2), + "%s clear first half of huge page\n", __func__); + wp_free(map, map_size); + free(map); + } else { + ksft_test_result_skip("clear first half of huge page\n"); + } + + /* 6. clear first half of huge page with limited buffer */ + map = gethugepage(map_size); + if (map) { + memset(map, 0, map_size); + + ret = pagemap_ioctl(map, map_size, vec, vec_size, PAGEMAP_WP_ENGAGE, + vec_size/2, PAGE_IS_WT, 0, 0, PAGE_IS_WT); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + ret = pagemap_ioctl(map, map_size, vec, vec_size, 0, 0, + PAGE_IS_WT, 0, 0, PAGE_IS_WT); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + ksft_test_result(ret == 1 && vec[0].len == vec_size/2 && + vec[0].start == (uintptr_t)(map + map_size/2), + "%s clear first half of huge page with limited buffer\n", + __func__); + wp_free(map, map_size); + free(map); + } else { + ksft_test_result_skip("clear first half of huge page with limited buffer\n"); + } + + /* 7. clear second half of huge page */ + map = gethugepage(map_size); + if (map) { + memset(map, -1, map_size); + ret = pagemap_ioctl(map + map_size/2, map_size/2, NULL, 0, PAGEMAP_WP_ENGAGE, + 0, 0, 0, 0, 0); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + ret = pagemap_ioctl(map, map_size, vec, vec_size, 0, 0, + PAGE_IS_WT, 0, 0, PAGE_IS_WT); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + ksft_test_result(ret == 1 && vec[0].len == vec_size/2, + "%s clear second half huge page\n", __func__); + wp_free(map, map_size); + free(map); + } else { + ksft_test_result_skip("clear second half huge page\n"); + } + + free(vec); + free(vec2); + return 0; +} + +int unmapped_region_tests(void) +{ + void *start = (void *)0x10000000; + int dirty, len = 0x00040000; + int vec_size = len / page_size; + struct page_region *vec = malloc(sizeof(struct page_region) * vec_size); + + /* 1. Get dirty pages */ + dirty = pagemap_ioctl(start, len, vec, vec_size, 0, 0, PAGEMAP_NON_WT_MASK, 0, 0, + PAGEMAP_NON_WT_MASK); + if (dirty < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty, errno, strerror(errno)); + + ksft_test_result(dirty >= 0, "%s Get status of pages\n", __func__); + + free(vec); + return 0; +} + +static void test_simple(void) +{ + int i; + char *map; + struct page_region vec; + + map = aligned_alloc(page_size, page_size); + if (!map) + ksft_exit_fail_msg("aligned_alloc failed\n"); + wp_init(map, page_size); + + clear_softdirty_wp(map, page_size); + + for (i = 0 ; i < TEST_ITERATIONS; i++) { + if (pagemap_ioctl(map, page_size, &vec, 1, 0, 0, + PAGE_IS_WT, 0, 0, PAGE_IS_WT) == 1) { + ksft_print_msg("dirty bit was 1, but should be 0 (i=%d)\n", i); + break; + } + + clear_softdirty_wp(map, page_size); + /* Write something to the page to get the dirty bit enabled on the page */ + map[0]++; + + if (pagemap_ioctl(map, page_size, &vec, 1, 0, 0, + PAGE_IS_WT, 0, 0, PAGE_IS_WT) == 0) { + ksft_print_msg("dirty bit was 0, but should be 1 (i=%d)\n", i); + break; + } + + clear_softdirty_wp(map, page_size); + } + wp_free(map, page_size); + free(map); + + ksft_test_result(i == TEST_ITERATIONS, "Test %s\n", __func__); +} + +int sanity_tests(void) +{ + char *mem, *fmem; + int mem_size, vec_size, ret; + struct page_region *vec; + + /* 1. wrong operation */ + mem_size = 10 * page_size; + vec_size = mem_size / page_size; + + vec = malloc(sizeof(struct page_region) * vec_size); + mem = mmap(NULL, mem_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0); + if (mem == MAP_FAILED || vec == MAP_FAILED) + ksft_exit_fail_msg("error nomem\n"); + + wp_init(mem, mem_size); + + ksft_test_result(pagemap_ioctl(mem, mem_size, vec, vec_size, PAGEMAP_WP_ENGAGE, 0, + PAGEMAP_OP_MASK, 0, 0, PAGEMAP_OP_MASK) < 0, + "%s clear op can only be specified with PAGE_IS_WT\n", __func__); + ksft_test_result(pagemap_ioctl(mem, mem_size, vec, vec_size, 0, 0, + PAGEMAP_OP_MASK, 0, 0, PAGEMAP_OP_MASK) >= 0, + "%s required_mask specified\n", __func__); + ksft_test_result(pagemap_ioctl(mem, mem_size, vec, vec_size, 0, 0, + 0, PAGEMAP_OP_MASK, 0, PAGEMAP_OP_MASK) >= 0, + "%s anyof_mask specified\n", __func__); + ksft_test_result(pagemap_ioctl(mem, mem_size, vec, vec_size, 0, 0, + 0, 0, PAGEMAP_OP_MASK, PAGEMAP_OP_MASK) >= 0, + "%s excluded_mask specified\n", __func__); + ksft_test_result(pagemap_ioctl(mem, mem_size, vec, vec_size, 0, 0, + PAGEMAP_OP_MASK, PAGEMAP_OP_MASK, 0, PAGEMAP_OP_MASK) >= 0, + "%s required_mask and anyof_mask specified\n", __func__); + wp_free(mem, mem_size); + munmap(mem, mem_size); + + /* 2. Get sd and present pages with anyof_mask */ + mem = mmap(NULL, mem_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0); + if (mem == MAP_FAILED) + ksft_exit_fail_msg("error nomem\n"); + wp_init(mem, mem_size); + + memset(mem, 0, mem_size); + + ret = pagemap_ioctl(mem, mem_size, vec, vec_size, 0, 0, + 0, PAGEMAP_OP_MASK, 0, PAGEMAP_OP_MASK); + ksft_test_result(ret >= 0 && vec[0].start == (uintptr_t)mem && vec[0].len == vec_size && + vec[0].bitmap == (PAGE_IS_WT | PAGE_IS_PRESENT), + "%s Get sd and present pages with anyof_mask\n", __func__); + + /* 3. Get sd and present pages with required_mask */ + ret = pagemap_ioctl(mem, mem_size, vec, vec_size, 0, 0, + PAGEMAP_OP_MASK, 0, 0, PAGEMAP_OP_MASK); + ksft_test_result(ret >= 0 && vec[0].start == (uintptr_t)mem && vec[0].len == vec_size && + vec[0].bitmap == (PAGE_IS_WT | PAGE_IS_PRESENT), + "%s Get all the pages with required_mask\n", __func__); + + /* 4. Get sd and present pages with required_mask and anyof_mask */ + ret = pagemap_ioctl(mem, mem_size, vec, vec_size, 0, 0, + PAGE_IS_WT, PAGE_IS_PRESENT, 0, PAGEMAP_OP_MASK); + ksft_test_result(ret >= 0 && vec[0].start == (uintptr_t)mem && vec[0].len == vec_size && + vec[0].bitmap == (PAGE_IS_WT | PAGE_IS_PRESENT), + "%s Get sd and present pages with required_mask and anyof_mask\n", + __func__); + + /* 5. Don't get sd pages */ + ret = pagemap_ioctl(mem, mem_size, vec, vec_size, 0, 0, + 0, 0, PAGE_IS_WT, PAGEMAP_OP_MASK); + ksft_test_result(ret == 0, "%s Don't get sd pages\n", __func__); + + /* 6. Don't get present pages */ + ret = pagemap_ioctl(mem, mem_size, vec, vec_size, 0, 0, + 0, 0, PAGE_IS_PRESENT, PAGEMAP_OP_MASK); + ksft_test_result(ret == 0, "%s Don't get present pages\n", __func__); + + wp_free(mem, mem_size); + munmap(mem, mem_size); + + /* 8. Find dirty present pages with return mask */ + mem = mmap(NULL, mem_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0); + if (mem == MAP_FAILED) + ksft_exit_fail_msg("error nomem\n"); + wp_init(mem, mem_size); + + memset(mem, 0, mem_size); + + ret = pagemap_ioctl(mem, mem_size, vec, vec_size, 0, 0, + 0, PAGEMAP_OP_MASK, 0, PAGE_IS_WT); + ksft_test_result(ret >= 0 && vec[0].start == (uintptr_t)mem && vec[0].len == vec_size && + vec[0].bitmap == PAGE_IS_WT, + "%s Find dirty present pages with return mask\n", __func__); + wp_free(mem, mem_size); + munmap(mem, mem_size); + + /* 9. Memory mapped file */ + int fd; + struct stat sbuf; + + fd = open(__FILE__, O_RDONLY); + if (fd < 0) { + ksft_test_result_skip("%s Memory mapped file\n"); + goto free_vec_and_return; + } + + ret = stat(__FILE__, &sbuf); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + fmem = mmap(NULL, sbuf.st_size, PROT_READ, MAP_SHARED, fd, 0); + if (fmem == MAP_FAILED) + ksft_exit_fail_msg("error nomem\n"); + + ret = pagemap_ioctl(fmem, sbuf.st_size, vec, vec_size, 0, 0, + 0, PAGEMAP_NON_WT_MASK, 0, PAGEMAP_NON_WT_MASK); + + ksft_test_result(ret >= 0 && vec[0].start == (uintptr_t)fmem && + vec[0].len == ceilf((float)sbuf.st_size/page_size) && + vec[0].bitmap == PAGE_IS_FILE, + "%s Memory mapped file\n", __func__); + + munmap(fmem, sbuf.st_size); + close(fd); + +free_vec_and_return: + free(vec); + return 0; +} + +int mprotect_tests(void) +{ + int ret; + char *mem, *mem2; + struct page_region vec; + int pagemap_fd = open("/proc/self/pagemap", O_RDONLY); + + if (pagemap_fd < 0) { + fprintf(stderr, "open() failed\n"); + exit(1); + } + + /* 1. Map two pages */ + mem = mmap(0, 2 * page_size, PROT_READ|PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0); + if (mem == MAP_FAILED) + ksft_exit_fail_msg("error nomem\n"); + wp_init(mem, 2 * page_size); + + /* Populate both pages. */ + memset(mem, 1, 2 * page_size); + + ret = pagemap_ioctl(mem, 2 * page_size, &vec, 1, 0, 0, PAGE_IS_WT, + 0, 0, PAGE_IS_WT); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + ksft_test_result(ret == 1 && vec.len == 2, "%s Both pages dirty\n", __func__); + + /* 2. Start softdirty tracking. Clear VM_SOFTDIRTY and clear the softdirty PTE bit. */ + ret = pagemap_ioctl(mem, 2 * page_size, NULL, 0, PAGEMAP_WP_ENGAGE, 0, + 0, 0, 0, 0); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + ksft_test_result(pagemap_ioctl(mem, 2 * page_size, &vec, 1, 0, 0, PAGE_IS_WT, + 0, 0, PAGE_IS_WT) == 0, + "%s Both pages are not soft dirty\n", __func__); + + /* 3. Remap the second page */ + mem2 = mmap(mem + page_size, page_size, PROT_READ|PROT_WRITE, + MAP_PRIVATE|MAP_ANON|MAP_FIXED, -1, 0); + if (mem2 == MAP_FAILED) + ksft_exit_fail_msg("error nomem\n"); + wp_init(mem2, page_size); + + /* Protect + unprotect. */ + mprotect(mem, 2 * page_size, PROT_READ); + mprotect(mem, 2 * page_size, PROT_READ|PROT_WRITE); + + /* Modify both pages. */ + memset(mem, 2, 2 * page_size); + + ret = pagemap_ioctl(mem, 2 * page_size, &vec, 1, 0, 0, PAGE_IS_WT, + 0, 0, PAGE_IS_WT); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + ksft_test_result(ret == 1 && vec.len == 2, + "%s Both pages dirty after remap and mprotect\n", __func__); + + /* 4. Clear and make the pages dirty */ + ret = pagemap_ioctl(mem, 2 * page_size, NULL, 0, PAGEMAP_WP_ENGAGE, 0, + 0, 0, 0, 0); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + memset(mem, 'A', 2 * page_size); + + ret = pagemap_ioctl(mem, 2 * page_size, &vec, 1, 0, 0, PAGE_IS_WT, + 0, 0, PAGE_IS_WT); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + ksft_test_result(ret == 1 && vec.len == 2, + "%s Clear and make the pages dirty\n", __func__); + + wp_free(mem, 2 * page_size); + munmap(mem, 2 * page_size); + return 0; +} + +int main(void) +{ + char *mem, *map; + int mem_size; + + ksft_print_header(); + ksft_set_plan(54); + + page_size = getpagesize(); + hpage_size = read_pmd_pagesize(); + + pagemap_fd = open(PAGEMAP, O_RDWR); + if (pagemap_fd < 0) + return -EINVAL; + + if (init_uffd()) + ksft_exit_fail_msg("uffd init failed\n"); + + /* + * Soft-dirty PTE bit tests + */ + + /* 1. Sanity testing */ + sanity_tests_sd(); + + /* 2. Normal page testing */ + mem_size = 10 * page_size; + mem = mmap(NULL, mem_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0); + if (mem == MAP_FAILED) + ksft_exit_fail_msg("error nomem\n"); + wp_init(mem, mem_size); + + base_tests("Page testing:", mem, mem_size, 0); + + wp_free(mem, mem_size); + munmap(mem, mem_size); + + /* 3. Large page testing */ + mem_size = 512 * 10 * page_size; + mem = mmap(NULL, mem_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0); + if (mem == MAP_FAILED) + ksft_exit_fail_msg("error nomem\n"); + wp_init(mem, mem_size); + + base_tests("Large Page testing:", mem, mem_size, 0); + + wp_free(mem, mem_size); + munmap(mem, mem_size); + + /* 4. Huge page testing */ + map = gethugepage(hpage_size); + if (map) + base_tests("Huge page testing:", map, hpage_size, 0); + else + base_tests("Huge page testing:", NULL, 0, 1); + + wp_free(map, hpage_size); + free(map); + + /* 6. Huge page tests */ + hpage_unit_tests(); + + /* 7. Iterative test */ + test_simple(); + + /* 8. Mprotect test */ + mprotect_tests(); + + /* + * Other PTE bit tests + */ + + /* 1. Sanity testing */ + sanity_tests(); + + /* 2. Unmapped address test */ + unmapped_region_tests(); + + close(pagemap_fd); + return ksft_exit_pass(); +}