From patchwork Tue Jan 24 08:43:20 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: 13113657 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 2679CC38142 for ; Tue, 24 Jan 2023 08:44:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233129AbjAXIop (ORCPT ); Tue, 24 Jan 2023 03:44:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59648 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232896AbjAXIom (ORCPT ); Tue, 24 Jan 2023 03:44:42 -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 42C7532533; Tue, 24 Jan 2023 00:44:41 -0800 (PST) Received: from localhost.localdomain (unknown [39.45.186.163]) (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 B4E1D6602E2B; Tue, 24 Jan 2023 08:44:31 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1674549879; bh=m/++XbQn9BatMFvanRp2XUIOa0zCFwRYse69T8hHq3A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WBW0lX/oQGiGf6RmlizOjOfaR7O9XvMYK0Ybxo3oXOnEJr2A80AStD0iglUEUaiE9 h6TIqMPwPx0t0gL+dH18QDgZgBgAghyuEI+veHKt7sOKaKKgaAgNviYWQvmpMxbZHl wuddkQF1DzY+FA+zg3B1Qxw9sYPr3cLs2km9v/Q3EFnUCV2++W21yrxVy/sv4ZrHky 1tWRq0JlGBvfQMpTBkforZU4Fghyfn0eh6blchhWnyp++sK7SFAkLTXCYPZG8IdW2F K1HKDDhFoSKH7UBSXDAsczZ+Qiw9ioI5FcVOibaRLRwwDeh8JFr0Mu5pGVDyzF+ydK yzbVjt8eJK/mg== 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 v8 1/4] userfaultfd: Add UFFD WP Async support Date: Tue, 24 Jan 2023 13:43:20 +0500 Message-Id: <20230124084323.1363825-2-usama.anjum@collabora.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230124084323.1363825-1-usama.anjum@collabora.com> References: <20230124084323.1363825-1-usama.anjum@collabora.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Add new WP Async mode (UFFD_FEATURE_WP_ASYNC) 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 synchronous 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 asynchronous 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. Suggested-by: Peter Xu Signed-off-by: Muhammad Usama Anjum --- Changes in v7: - Remove UFFDIO_WRITEPROTECT_MODE_ASYNC_WP and add UFFD_FEATURE_WP_ASYNC - Handle automatic page fault resolution in better way (thanks to Peter) --- fs/userfaultfd.c | 11 +++++++++++ include/linux/userfaultfd_k.h | 6 ++++++ include/uapi/linux/userfaultfd.h | 8 +++++++- mm/memory.c | 29 +++++++++++++++++++++++++++-- 4 files changed, 51 insertions(+), 3 deletions(-) diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index 15a5bf765d43..b82af02092ce 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -1867,6 +1867,10 @@ static int userfaultfd_writeprotect(struct userfaultfd_ctx *ctx, mode_wp = uffdio_wp.mode & UFFDIO_WRITEPROTECT_MODE_WP; mode_dontwake = uffdio_wp.mode & UFFDIO_WRITEPROTECT_MODE_DONTWAKE; + /* Write protection cannot be disabled in case of aync WP */ + if (!mode_wp && (ctx->features & UFFD_FEATURE_WP_ASYNC)) + return -EINVAL; + if (mode_wp && mode_dontwake) return -EINVAL; @@ -1950,6 +1954,13 @@ static int userfaultfd_continue(struct userfaultfd_ctx *ctx, unsigned long arg) return ret; } +int userfaultfd_wp_async(struct vm_area_struct *vma) +{ + struct userfaultfd_ctx *ctx = vma->vm_userfaultfd_ctx.ctx; + + return (ctx && (ctx->features & UFFD_FEATURE_WP_ASYNC)); +} + 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..5db51fccae1d 100644 --- a/include/linux/userfaultfd_k.h +++ b/include/linux/userfaultfd_k.h @@ -179,6 +179,7 @@ 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 userfaultfd_wp_async(struct vm_area_struct *vma); #else /* CONFIG_USERFAULTFD */ @@ -274,6 +275,11 @@ static inline bool uffd_disable_fault_around(struct vm_area_struct *vma) return false; } +int userfaultfd_wp_async(struct vm_area_struct *vma) +{ + return false; +} + #endif /* CONFIG_USERFAULTFD */ static inline bool pte_marker_entry_uffd_wp(swp_entry_t entry) diff --git a/include/uapi/linux/userfaultfd.h b/include/uapi/linux/userfaultfd.h index 005e5e306266..f4252ef40071 100644 --- a/include/uapi/linux/userfaultfd.h +++ b/include/uapi/linux/userfaultfd.h @@ -38,7 +38,8 @@ UFFD_FEATURE_MINOR_HUGETLBFS | \ UFFD_FEATURE_MINOR_SHMEM | \ UFFD_FEATURE_EXACT_ADDRESS | \ - UFFD_FEATURE_WP_HUGETLBFS_SHMEM) + UFFD_FEATURE_WP_HUGETLBFS_SHMEM | \ + UFFD_FEATURE_WP_ASYNC) #define UFFD_API_IOCTLS \ ((__u64)1 << _UFFDIO_REGISTER | \ (__u64)1 << _UFFDIO_UNREGISTER | \ @@ -203,6 +204,10 @@ struct uffdio_api { * * UFFD_FEATURE_WP_HUGETLBFS_SHMEM indicates that userfaultfd * write-protection mode is supported on both shmem and hugetlbfs. + * + * UFFD_FEATURE_WP_ASYNC indicates that userfaultfd write-protection + * asynchronous mode is supported in which the write fault is automatically + * resolved and write-protection is un-set. */ #define UFFD_FEATURE_PAGEFAULT_FLAG_WP (1<<0) #define UFFD_FEATURE_EVENT_FORK (1<<1) @@ -217,6 +222,7 @@ struct uffdio_api { #define UFFD_FEATURE_MINOR_SHMEM (1<<10) #define UFFD_FEATURE_EXACT_ADDRESS (1<<11) #define UFFD_FEATURE_WP_HUGETLBFS_SHMEM (1<<12) +#define UFFD_FEATURE_WP_ASYNC (1<<13) __u64 features; __u64 ioctls; diff --git a/mm/memory.c b/mm/memory.c index 4000e9f017e0..8c03b133d483 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3351,6 +3351,18 @@ static vm_fault_t do_wp_page(struct vm_fault *vmf) if (likely(!unshare)) { if (userfaultfd_pte_wp(vma, *vmf->pte)) { + if (userfaultfd_wp_async(vma)) { + /* + * Nothing needed (cache flush, TLB invalidations, + * etc.) because we're only removing the uffd-wp bit, + * which is completely invisible to the user. This + * falls through to possible CoW. + */ + pte_unmap_unlock(vmf->pte, vmf->ptl); + set_pte_at(vma->vm_mm, vmf->address, vmf->pte, + pte_clear_uffd_wp(*vmf->pte)); + return 0; + } pte_unmap_unlock(vmf->pte, vmf->ptl); return handle_userfault(vmf, VM_UFFD_WP); } @@ -4812,8 +4824,21 @@ static inline vm_fault_t wp_huge_pmd(struct vm_fault *vmf) if (vma_is_anonymous(vmf->vma)) { if (likely(!unshare) && - userfaultfd_huge_pmd_wp(vmf->vma, vmf->orig_pmd)) - return handle_userfault(vmf, VM_UFFD_WP); + userfaultfd_huge_pmd_wp(vmf->vma, vmf->orig_pmd)) { + if (userfaultfd_wp_async(vmf->vma)) { + /* + * Nothing needed (cache flush, TLB invalidations, + * etc.) because we're only removing the uffd-wp bit, + * which is completely invisible to the user. This + * falls through to possible CoW. + */ + set_pmd_at(vmf->vma->vm_mm, vmf->address, vmf->pmd, + pmd_clear_uffd_wp(*vmf->pmd)); + return 0; + } else { + return handle_userfault(vmf, VM_UFFD_WP); + } + } return do_huge_pmd_wp_page(vmf); } From patchwork Tue Jan 24 08:43:21 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: 13113658 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 8FCC8C38142 for ; Tue, 24 Jan 2023 08:44:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233174AbjAXIo4 (ORCPT ); Tue, 24 Jan 2023 03:44:56 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59810 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233165AbjAXIot (ORCPT ); Tue, 24 Jan 2023 03:44:49 -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 B3D5432536; Tue, 24 Jan 2023 00:44:47 -0800 (PST) Received: from localhost.localdomain (unknown [39.45.186.163]) (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 7B4876602E2C; Tue, 24 Jan 2023 08:44:39 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1674549886; bh=RhznnELLur/OFCYFz9nqeAiw2g/ULL6wGU1+TD5rlvc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bUm+6PNenlG1HTsei/j6rwysWnI8TegYAR6iAvi9zzJwK6VPMMr+FplOGi/L1HfUa r3Ll8oFgrop7lH0ZC3hz82Yt7dgmbpgU3SHB6LbQ6Nn13bC5vOs/tYeQ3eJjSxy/UL 2Lk/jmcy1sxNNMrKJbiUjDSGXaLeIQHCZuieQZwZpXivOBPp4FL/YB69rofnMAB0F8 opwMmSz2c6XWhw9SkuJD+GJoN9zUdGWBBlbDpz2dxAExQrB1XT16iZudardQesIqQV ltsLSpi+vDXhWc+g7NihNtxOqQn7gp6UoaljbWkIzyLMuotx5aXbAnXXBQNyxQOGaY SaDJV/V9WQkHw== 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 v8 2/4] userfaultfd: split mwriteprotect_range() Date: Tue, 24 Jan 2023 13:43:21 +0500 Message-Id: <20230124084323.1363825-3-usama.anjum@collabora.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230124084323.1363825-1-usama.anjum@collabora.com> References: <20230124084323.1363825-1-usama.anjum@collabora.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@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 --- Changes in v7: - Remove async being set in the PAGEMAP_IOCTL --- fs/userfaultfd.c | 10 +++++++++ include/linux/userfaultfd_k.h | 10 +++++++++ mm/userfaultfd.c | 40 ++++++++++++++++++++++------------- 3 files changed, 45 insertions(+), 15 deletions(-) diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index b82af02092ce..cd52c9ee8db9 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -1961,6 +1961,16 @@ int userfaultfd_wp_async(struct vm_area_struct *vma) return (ctx && (ctx->features & UFFD_FEATURE_WP_ASYNC)); } +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; + + 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 5db51fccae1d..40d1d9e8f34d 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); @@ -180,6 +183,8 @@ extern int userfaultfd_unmap_prep(struct mm_struct *mm, unsigned long start, extern void userfaultfd_unmap_complete(struct mm_struct *mm, struct list_head *uf); extern int userfaultfd_wp_async(struct vm_area_struct *vma); +extern int wp_range_async(struct vm_area_struct *vma, unsigned long start, + unsigned long len); #else /* CONFIG_USERFAULTFD */ @@ -280,6 +285,11 @@ int userfaultfd_wp_async(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 Tue Jan 24 08:43:22 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: 13113659 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 F2D1EC25B4E for ; Tue, 24 Jan 2023 08:45:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233220AbjAXIpP (ORCPT ); Tue, 24 Jan 2023 03:45:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59948 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233206AbjAXIpM (ORCPT ); Tue, 24 Jan 2023 03:45:12 -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 1FA9A3526B; Tue, 24 Jan 2023 00:44:55 -0800 (PST) Received: from localhost.localdomain (unknown [39.45.186.163]) (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 048456602E29; Tue, 24 Jan 2023 08:44:46 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1674549893; bh=zvQOHS4OemOKK7s48q0sdRpUgCuoq0sXZit8P7U09v4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CT6Qcs3PFg1hQgBAjLmZpL5L8hUr+0JqmM4ZAb7UMef59QT/cKbAU4cw0yk/01BzY G1L4Obs7KFMX9tbQIwpkN2nkjIRka4qjaX97nYAsItgeEbjWVmIpf1dpV8a3mPRx4y 2054pvdSp6g9x6kF4PI4oN6wyx2HcpWeCSy8dbx9IXVHYhA+rWqH09RGqL7P7+sBTh p9pmaNuool/lSNj/8E+XjZOBUMxUH5/WjwMlO5LEcdAaHTZJ17LiGsmtIrswkti7v2 ncSjA+cKp8/H7qPjp26wr4VrJIS8++i+DbfpCth2NqZQ+eZSUd/Dl5taOoN4/DeNkJ LbJwhEw1O0DVQ== 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 v8 3/4] fs/proc/task_mmu: Implement IOCTL to get and/or the clear info about PTEs Date: Tue, 24 Jan 2023 13:43:22 +0500 Message-Id: <20230124084323.1363825-4-usama.anjum@collabora.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230124084323.1363825-1-usama.anjum@collabora.com> References: <20230124084323.1363825-1-usama.anjum@collabora.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@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_WT + 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 of struct page_region array 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 IOCTL doesn't support hugetlbs at the moment. No information about hugetlb can be obtained. This patch has evolved from a basic patch from Gabriel Krisman Bertazi. Signed-off-by: Muhammad Usama Anjum --- Change in v8: - Correct is_pte_uffd_wp() - Improve readability and error checks - Remove some un-needed code 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 | 294 ++++++++++++++++++++++++++++++++++ include/uapi/linux/fs.h | 50 ++++++ tools/include/uapi/linux/fs.h | 50 ++++++ 3 files changed, 394 insertions(+) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index e35a0398db63..f9fbda00eb5c 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_any(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 +1780,288 @@ 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)) +#define HAS_NO_SPACE(p) (p->max_pages && (p->found_pages == p->max_pages)) + +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) && !userfaultfd_wp(vma) && !userfaultfd_wp_async(vma)) + return -EPERM; + if (IS_GET_OP(p) && HAS_NO_SPACE(p)) + 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 (HAS_NO_SPACE(p)) + return -ENOSPC; + + 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 start, + unsigned long end, struct mm_walk *walk) +{ + struct pagemap_scan_private *p = walk->private; + struct vm_area_struct *vma = walk->vma; + unsigned long addr = end; + unsigned int len; + spinlock_t *ptl; + int ret = 0; + pte_t *pte; + bool pmd_wt; + +#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 - start < HPAGE_SIZE))) { + spin_unlock(ptl); + split_huge_pmd(vma, pmd, start); + goto process_smaller_pages; + } + if (IS_GET_OP(p)) { + len = (end - start)/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, start, len); + if (ret) { + spin_unlock(ptl); + return ret; + } + } + spin_unlock(ptl); + if (IS_WP_ENGAGE_OP(p) && pmd_wt) + ret = wp_range_async(vma, start, 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, start, &ptl); + if (IS_GET_OP(p)) { + for (addr = start; + addr < end && !ret && (!p->max_pages || (p->found_pages < p->max_pages)); + pte++, addr += PAGE_SIZE) { + 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 (!ret && IS_WP_ENGAGE_OP(p)) + 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; +} + +/* No hugetlb support is present. */ +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 Tue Jan 24 08:43:23 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: 13113660 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 7F898C25B4E for ; Tue, 24 Jan 2023 08:45:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233252AbjAXIpS (ORCPT ); Tue, 24 Jan 2023 03:45:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59946 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233237AbjAXIpN (ORCPT ); Tue, 24 Jan 2023 03:45:13 -0500 Received: from madras.collabora.co.uk (madras.collabora.co.uk [46.235.227.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F3F623FF0C; Tue, 24 Jan 2023 00:45:01 -0800 (PST) Received: from localhost.localdomain (unknown [39.45.186.163]) (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 5E8B26602E28; Tue, 24 Jan 2023 08:44:54 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1674549900; bh=ejccu2em39toVwMusC76QVJdShtJJ6+g63BL8VMgQEY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZJ9+MZr7N9C1rGzGhoxx1cljMRgBVraHeLmM5iGoWA0oO7jvRHC0uSqPIhnBIIYXG BguAlSR0+hFW8PjbuxAXApgmDz7BfUdEEDP3nXNFgWuYVgvsjfY+sLo2vZnIayjrLg huSuJdOKQcahvrXbYH2ur62kmw4TrXIfXFVRtALSNMIe87I6ss1svikVVrCOpG76Uw C1ZNy9pFRKe1D4FeZ17saEXExiA0hejHe+EdnA2JskiXIQ6T7vKMbygmtsUtTLrN7c IqRsOiPDfdtxppzMcxL2NZjyOWHEmpZya1tJrqB3gIh3Ud6jiRIEWU8GZhKXfF1O/J Yf/0GjUH+iHPA== 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 v8 4/4] selftests: vm: add pagemap ioctl tests Date: Tue, 24 Jan 2023 13:43:23 +0500 Message-Id: <20230124084323.1363825-5-usama.anjum@collabora.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230124084323.1363825-1-usama.anjum@collabora.com> References: <20230124084323.1363825-1-usama.anjum@collabora.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@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 | 880 +++++++++++++++++++++ 3 files changed, 884 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..d192c20deb48 --- /dev/null +++ b/tools/testing/selftests/vm/pagemap_ioctl.c @@ -0,0 +1,880 @@ +// 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 = UFFD_FEATURE_WP_ASYNC; + 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_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_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)); + + ksft_test_result(dirty == 1 && vec[0].len >= 1, + "%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(); +}