From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f199.google.com (mail-qk0-f199.google.com [209.85.220.199]) by kanga.kvack.org (Postfix) with ESMTP id 7D0F16B02BA for ; Wed, 2 Nov 2016 15:34:13 -0400 (EDT) Received: by mail-qk0-f199.google.com with SMTP id g193so23147516qke.2 for ; Wed, 02 Nov 2016 12:34:13 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id q65si102814qkb.299.2016.11.02.12.34.12 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 02 Nov 2016 12:34:12 -0700 (PDT) From: Andrea Arcangeli Subject: [PATCH 26/33] userfaultfd: shmem: allow registration of shared memory ranges Date: Wed, 2 Nov 2016 20:33:58 +0100 Message-Id: <1478115245-32090-27-git-send-email-aarcange@redhat.com> In-Reply-To: <1478115245-32090-1-git-send-email-aarcange@redhat.com> References: <1478115245-32090-1-git-send-email-aarcange@redhat.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: linux-mm@kvack.org, Michael Rapoport , "Dr. David Alan Gilbert"@v2.random, " , Mike Kravetz , Shaohua Li , Pavel Emelyanov "@v2.random From: Mike Rapoport Expand the userfaultfd_register/unregister routines to allow shared memory VMAs. Currently, there is no UFFDIO_ZEROPAGE and write-protection support for shared memory VMAs, which is reflected in ioctl methods supported by uffdio_register. Signed-off-by: Mike Rapoport Signed-off-by: Andrea Arcangeli --- fs/userfaultfd.c | 21 +++++++-------------- include/uapi/linux/userfaultfd.h | 2 +- tools/testing/selftests/vm/userfaultfd.c | 2 +- 3 files changed, 9 insertions(+), 16 deletions(-) diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index 387fe77..53de9e7 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -1062,7 +1062,8 @@ static __always_inline int validate_range(struct mm_struct *mm, static inline bool vma_can_userfault(struct vm_area_struct *vma) { - return vma_is_anonymous(vma) || is_vm_hugetlb_page(vma); + return vma_is_anonymous(vma) || is_vm_hugetlb_page(vma) || + vma_is_shmem(vma); } static int userfaultfd_register(struct userfaultfd_ctx *ctx, @@ -1075,7 +1076,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx, struct uffdio_register __user *user_uffdio_register; unsigned long vm_flags, new_flags; bool found; - bool huge_pages; + bool non_anon_pages; unsigned long start, end, vma_end; user_uffdio_register = (struct uffdio_register __user *) arg; @@ -1139,13 +1140,9 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx, /* * Search for not compatible vmas. - * - * FIXME: this shall be relaxed later so that it doesn't fail - * on tmpfs backed vmas (in addition to the current allowance - * on anonymous vmas). */ found = false; - huge_pages = false; + non_anon_pages = false; for (cur = vma; cur && cur->vm_start < end; cur = cur->vm_next) { cond_resched(); @@ -1184,8 +1181,8 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx, /* * Note vmas containing huge pages */ - if (is_vm_hugetlb_page(cur)) - huge_pages = true; + if (is_vm_hugetlb_page(cur) || vma_is_shmem(cur)) + non_anon_pages = true; found = true; } @@ -1256,7 +1253,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx, * userland which ioctls methods are guaranteed to * succeed on this range. */ - if (put_user(huge_pages ? UFFD_API_RANGE_IOCTLS_HPAGE : + if (put_user(non_anon_pages ? UFFD_API_RANGE_IOCTLS_BASIC : UFFD_API_RANGE_IOCTLS, &user_uffdio_register->ioctls)) ret = -EFAULT; @@ -1316,10 +1313,6 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx, /* * Search for not compatible vmas. - * - * FIXME: this shall be relaxed later so that it doesn't fail - * on tmpfs backed vmas (in addition to the current allowance - * on anonymous vmas). */ found = false; ret = -EINVAL; diff --git a/include/uapi/linux/userfaultfd.h b/include/uapi/linux/userfaultfd.h index a3828a9..378dd27 100644 --- a/include/uapi/linux/userfaultfd.h +++ b/include/uapi/linux/userfaultfd.h @@ -29,7 +29,7 @@ ((__u64)1 << _UFFDIO_WAKE | \ (__u64)1 << _UFFDIO_COPY | \ (__u64)1 << _UFFDIO_ZEROPAGE) -#define UFFD_API_RANGE_IOCTLS_HPAGE \ +#define UFFD_API_RANGE_IOCTLS_BASIC \ ((__u64)1 << _UFFDIO_WAKE | \ (__u64)1 << _UFFDIO_COPY) diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c index 3011711..d753a91 100644 --- a/tools/testing/selftests/vm/userfaultfd.c +++ b/tools/testing/selftests/vm/userfaultfd.c @@ -129,7 +129,7 @@ static void allocate_area(void **alloc_area) #else /* HUGETLB_TEST */ -#define EXPECTED_IOCTLS UFFD_API_RANGE_IOCTLS_HPAGE +#define EXPECTED_IOCTLS UFFD_API_RANGE_IOCTLS_BASIC static int release_pages(char *rel_area) { -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org