From: Mike Rapoport <rppt@linux.ibm.com>
To: Peter Xu <peterx@redhat.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
David Hildenbrand <david@redhat.com>,
Hugh Dickins <hughd@google.com>, Maya Gokhale <gokhale2@llnl.gov>,
Jerome Glisse <jglisse@redhat.com>,
Pavel Emelyanov <xemul@virtuozzo.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Martin Cracauer <cracauer@cons.org>, Shaohua Li <shli@fb.com>,
Marty McFadden <mcfadden8@llnl.gov>,
Andrea Arcangeli <aarcange@redhat.com>,
Mike Kravetz <mike.kravetz@oracle.com>,
Denis Plotnikov <dplotnikov@virtuozzo.com>,
Mike Rapoport <rppt@linux.vnet.ibm.com>,
Mel Gorman <mgorman@suse.de>,
"Kirill A . Shutemov" <kirill@shutemov.name>,
"Dr . David Alan Gilbert" <dgilbert@redhat.com>
Subject: Re: [PATCH v2 19/26] userfaultfd: introduce helper vma_find_uffd
Date: Mon, 25 Feb 2019 22:48:15 +0200 [thread overview]
Message-ID: <20190225204815.GB10454@rapoport-lnx> (raw)
In-Reply-To: <20190212025632.28946-20-peterx@redhat.com>
On Tue, Feb 12, 2019 at 10:56:25AM +0800, Peter Xu wrote:
> We've have multiple (and more coming) places that would like to find a
> userfault enabled VMA from a mm struct that covers a specific memory
> range. This patch introduce the helper for it, meanwhile apply it to
> the code.
>
> Suggested-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
> Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
> ---
> mm/userfaultfd.c | 54 +++++++++++++++++++++++++++---------------------
> 1 file changed, 30 insertions(+), 24 deletions(-)
>
> diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
> index 80bcd642911d..fefa81c301b7 100644
> --- a/mm/userfaultfd.c
> +++ b/mm/userfaultfd.c
> @@ -20,6 +20,34 @@
> #include <asm/tlbflush.h>
> #include "internal.h"
>
> +/*
> + * Find a valid userfault enabled VMA region that covers the whole
> + * address range, or NULL on failure. Must be called with mmap_sem
> + * held.
> + */
> +static struct vm_area_struct *vma_find_uffd(struct mm_struct *mm,
> + unsigned long start,
> + unsigned long len)
> +{
> + struct vm_area_struct *vma = find_vma(mm, start);
> +
> + if (!vma)
> + return NULL;
> +
> + /*
> + * Check the vma is registered in uffd, this is required to
> + * enforce the VM_MAYWRITE check done at uffd registration
> + * time.
> + */
> + if (!vma->vm_userfaultfd_ctx.ctx)
> + return NULL;
> +
> + if (start < vma->vm_start || start + len > vma->vm_end)
> + return NULL;
> +
> + return vma;
> +}
> +
> static int mcopy_atomic_pte(struct mm_struct *dst_mm,
> pmd_t *dst_pmd,
> struct vm_area_struct *dst_vma,
> @@ -228,20 +256,9 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
> */
> if (!dst_vma) {
> err = -ENOENT;
> - dst_vma = find_vma(dst_mm, dst_start);
> + dst_vma = vma_find_uffd(dst_mm, dst_start, len);
> if (!dst_vma || !is_vm_hugetlb_page(dst_vma))
> goto out_unlock;
> - /*
> - * Check the vma is registered in uffd, this is
> - * required to enforce the VM_MAYWRITE check done at
> - * uffd registration time.
> - */
> - if (!dst_vma->vm_userfaultfd_ctx.ctx)
> - goto out_unlock;
> -
> - if (dst_start < dst_vma->vm_start ||
> - dst_start + len > dst_vma->vm_end)
> - goto out_unlock;
>
> err = -EINVAL;
> if (vma_hpagesize != vma_kernel_pagesize(dst_vma))
> @@ -488,20 +505,9 @@ static __always_inline ssize_t __mcopy_atomic(struct mm_struct *dst_mm,
> * both valid and fully within a single existing vma.
> */
> err = -ENOENT;
> - dst_vma = find_vma(dst_mm, dst_start);
> + dst_vma = vma_find_uffd(dst_mm, dst_start, len);
> if (!dst_vma)
> goto out_unlock;
> - /*
> - * Check the vma is registered in uffd, this is required to
> - * enforce the VM_MAYWRITE check done at uffd registration
> - * time.
> - */
> - if (!dst_vma->vm_userfaultfd_ctx.ctx)
> - goto out_unlock;
> -
> - if (dst_start < dst_vma->vm_start ||
> - dst_start + len > dst_vma->vm_end)
> - goto out_unlock;
>
> err = -EINVAL;
> /*
> --
> 2.17.1
>
--
Sincerely yours,
Mike.
next prev parent reply other threads:[~2019-02-25 20:48 UTC|newest]
Thread overview: 113+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-12 2:56 [PATCH v2 00/26] userfaultfd: write protection support Peter Xu
2019-02-12 2:56 ` [PATCH v2 01/26] mm: gup: rename "nonblocking" to "locked" where proper Peter Xu
2019-02-21 15:17 ` Jerome Glisse
2019-02-22 3:42 ` Peter Xu
2019-02-12 2:56 ` [PATCH v2 02/26] mm: userfault: return VM_FAULT_RETRY on signals Peter Xu
2019-02-21 15:29 ` Jerome Glisse
2019-02-22 3:51 ` Peter Xu
2019-02-12 2:56 ` [PATCH v2 03/26] userfaultfd: don't retake mmap_sem to emulate NOPAGE Peter Xu
2019-02-21 15:34 ` Jerome Glisse
2019-02-12 2:56 ` [PATCH v2 04/26] mm: allow VM_FAULT_RETRY for multiple times Peter Xu
2019-02-13 3:34 ` Peter Xu
2019-02-20 11:48 ` Peter Xu
2019-02-21 8:56 ` [PATCH v2.1 " Peter Xu
2019-02-21 15:53 ` Jerome Glisse
2019-02-22 4:25 ` Peter Xu
2019-02-22 15:11 ` Jerome Glisse
2019-02-25 6:19 ` Peter Xu
2019-02-12 2:56 ` [PATCH v2 05/26] mm: gup: " Peter Xu
2019-02-21 16:06 ` Jerome Glisse
2019-02-22 4:41 ` Peter Xu
2019-02-22 15:13 ` Jerome Glisse
2019-02-12 2:56 ` [PATCH v2 06/26] userfaultfd: wp: add helper for writeprotect check Peter Xu
2019-02-21 16:07 ` Jerome Glisse
2019-02-25 15:41 ` Mike Rapoport
2019-02-12 2:56 ` [PATCH v2 07/26] userfaultfd: wp: hook userfault handler to write protection fault Peter Xu
2019-02-21 16:25 ` Jerome Glisse
2019-02-25 15:43 ` Mike Rapoport
2019-02-12 2:56 ` [PATCH v2 08/26] userfaultfd: wp: add WP pagetable tracking to x86 Peter Xu
2019-02-21 17:20 ` Jerome Glisse
2019-02-25 15:48 ` Mike Rapoport
2019-02-12 2:56 ` [PATCH v2 09/26] userfaultfd: wp: userfaultfd_pte/huge_pmd_wp() helpers Peter Xu
2019-02-21 17:21 ` Jerome Glisse
2019-02-25 17:12 ` Mike Rapoport
2019-02-12 2:56 ` [PATCH v2 10/26] userfaultfd: wp: add UFFDIO_COPY_MODE_WP Peter Xu
2019-02-21 17:29 ` Jerome Glisse
2019-02-22 7:11 ` Peter Xu
2019-02-22 15:15 ` Jerome Glisse
2019-02-25 6:45 ` Peter Xu
2019-02-25 15:58 ` Mike Rapoport
2019-02-26 5:09 ` Peter Xu
2019-02-26 8:28 ` Mike Rapoport
2019-02-12 2:56 ` [PATCH v2 11/26] mm: merge parameters for change_protection() Peter Xu
2019-02-21 17:32 ` Jerome Glisse
2019-02-12 2:56 ` [PATCH v2 12/26] userfaultfd: wp: apply _PAGE_UFFD_WP bit Peter Xu
2019-02-21 17:44 ` Jerome Glisse
2019-02-22 7:31 ` Peter Xu
2019-02-22 15:17 ` Jerome Glisse
2019-02-25 18:00 ` Mike Rapoport
2019-02-12 2:56 ` [PATCH v2 13/26] mm: export wp_page_copy() Peter Xu
2019-02-21 17:44 ` Jerome Glisse
2019-02-12 2:56 ` [PATCH v2 14/26] userfaultfd: wp: handle COW properly for uffd-wp Peter Xu
2019-02-21 18:04 ` Jerome Glisse
2019-02-22 8:46 ` Peter Xu
2019-02-22 15:35 ` Jerome Glisse
2019-02-25 7:13 ` Peter Xu
2019-02-25 15:32 ` Jerome Glisse
2019-02-12 2:56 ` [PATCH v2 15/26] userfaultfd: wp: drop _PAGE_UFFD_WP properly when fork Peter Xu
2019-02-21 18:06 ` Jerome Glisse
2019-02-22 9:09 ` Peter Xu
2019-02-22 15:36 ` Jerome Glisse
2019-02-25 18:19 ` Mike Rapoport
2019-02-12 2:56 ` [PATCH v2 16/26] userfaultfd: wp: add pmd_swp_*uffd_wp() helpers Peter Xu
2019-02-21 18:07 ` Jerome Glisse
2019-02-25 18:20 ` Mike Rapoport
2019-02-12 2:56 ` [PATCH v2 17/26] userfaultfd: wp: support swap and page migration Peter Xu
2019-02-21 18:16 ` Jerome Glisse
2019-02-25 7:48 ` Peter Xu
2019-02-25 18:28 ` Mike Rapoport
2019-02-12 2:56 ` [PATCH v2 18/26] khugepaged: skip collapse if uffd-wp detected Peter Xu
2019-02-21 18:17 ` Jerome Glisse
2019-02-25 18:50 ` Mike Rapoport
2019-02-12 2:56 ` [PATCH v2 19/26] userfaultfd: introduce helper vma_find_uffd Peter Xu
2019-02-21 18:19 ` Jerome Glisse
2019-02-25 20:48 ` Mike Rapoport [this message]
2019-02-12 2:56 ` [PATCH v2 20/26] userfaultfd: wp: support write protection for userfault vma range Peter Xu
2019-02-21 18:23 ` Jerome Glisse
2019-02-25 8:16 ` Peter Xu
2019-02-25 20:52 ` Mike Rapoport
2019-02-26 6:06 ` Peter Xu
2019-02-26 6:43 ` Mike Rapoport
2019-02-26 7:20 ` Peter Xu
2019-02-26 7:46 ` Mike Rapoport
2019-02-26 7:54 ` Peter Xu
2019-02-12 2:56 ` [PATCH v2 21/26] userfaultfd: wp: add the writeprotect API to userfaultfd ioctl Peter Xu
2019-02-21 18:28 ` Jerome Glisse
2019-02-25 8:31 ` Peter Xu
2019-02-25 21:03 ` Mike Rapoport
2019-02-26 6:30 ` Peter Xu
2019-02-12 2:56 ` [PATCH v2 22/26] userfaultfd: wp: enabled write protection in userfaultfd API Peter Xu
2019-02-21 18:29 ` Jerome Glisse
2019-02-25 8:34 ` Peter Xu
2019-02-12 2:56 ` [PATCH v2 23/26] userfaultfd: wp: don't wake up when doing write protect Peter Xu
2019-02-21 18:36 ` Jerome Glisse
2019-02-25 8:58 ` Peter Xu
2019-02-25 21:15 ` Mike Rapoport
2019-02-25 21:09 ` Mike Rapoport
2019-02-26 6:24 ` Peter Xu
2019-02-26 7:29 ` Mike Rapoport
2019-02-26 7:41 ` Peter Xu
2019-02-26 8:00 ` Mike Rapoport
2019-02-28 2:47 ` Peter Xu
2019-02-26 8:00 ` Mike Rapoport
2019-02-12 2:56 ` [PATCH v2 24/26] userfaultfd: wp: UFFDIO_REGISTER_MODE_WP documentation update Peter Xu
2019-02-21 18:38 ` Jerome Glisse
2019-02-25 21:19 ` Mike Rapoport
2019-02-26 6:53 ` Peter Xu
2019-02-26 7:04 ` Mike Rapoport
2019-02-26 7:42 ` Peter Xu
2019-02-12 2:56 ` [PATCH v2 25/26] userfaultfd: selftests: refactor statistics Peter Xu
2019-02-26 6:50 ` Mike Rapoport
2019-02-12 2:56 ` [PATCH v2 26/26] userfaultfd: selftests: add write-protect test Peter Xu
2019-02-26 6:58 ` Mike Rapoport
2019-02-26 7:52 ` Peter Xu
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