From: Peter Xu <peterx@redhat.com>
To: linux-kernel@vger.kernel.org, linux-mm@kvack.org
Cc: Axel Rasmussen <axelrasmussen@google.com>,
Nadav Amit <nadav.amit@gmail.com>,
Jerome Glisse <jglisse@redhat.com>,
"Kirill A . Shutemov" <kirill@shutemov.name>,
Jason Gunthorpe <jgg@ziepe.ca>,
Alistair Popple <apopple@nvidia.com>,
Andrew Morton <akpm@linux-foundation.org>,
David Hildenbrand <david@redhat.com>,
peterx@redhat.com, Andrea Arcangeli <aarcange@redhat.com>,
Matthew Wilcox <willy@infradead.org>,
Mike Kravetz <mike.kravetz@oracle.com>,
Tiberiu Georgescu <tiberiu.georgescu@nutanix.com>,
Hugh Dickins <hughd@google.com>,
Miaohe Lin <linmiaohe@huawei.com>,
Mike Rapoport <rppt@linux.vnet.ibm.com>
Subject: [PATCH v5 25/26] mm/userfaultfd: Enable write protection for shmem & hugetlbfs
Date: Thu, 15 Jul 2021 16:16:55 -0400 [thread overview]
Message-ID: <20210715201655.212184-1-peterx@redhat.com> (raw)
In-Reply-To: <20210715201422.211004-1-peterx@redhat.com>
We've had all the necessary changes ready for both shmem and hugetlbfs. Turn
on all the shmem/hugetlbfs switches for userfaultfd-wp.
We can expand UFFD_API_RANGE_IOCTLS_BASIC with _UFFDIO_WRITEPROTECT too because
all existing types now support write protection mode.
Since vma_can_userfault() will be used elsewhere, move into userfaultfd_k.h.
Signed-off-by: Peter Xu <peterx@redhat.com>
---
fs/userfaultfd.c | 21 ++-------------------
include/linux/userfaultfd_k.h | 12 ++++++++++++
include/uapi/linux/userfaultfd.h | 10 ++++++++--
mm/userfaultfd.c | 9 +++------
4 files changed, 25 insertions(+), 27 deletions(-)
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 644df737fbb2..980879117110 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -1275,24 +1275,6 @@ static __always_inline int validate_range(struct mm_struct *mm,
return 0;
}
-static inline bool vma_can_userfault(struct vm_area_struct *vma,
- unsigned long vm_flags)
-{
- /* FIXME: add WP support to hugetlbfs and shmem */
- if (vm_flags & VM_UFFD_WP) {
- if (is_vm_hugetlb_page(vma) || vma_is_shmem(vma))
- return false;
- }
-
- if (vm_flags & VM_UFFD_MINOR) {
- if (!(is_vm_hugetlb_page(vma) || vma_is_shmem(vma)))
- return false;
- }
-
- return vma_is_anonymous(vma) || is_vm_hugetlb_page(vma) ||
- vma_is_shmem(vma);
-}
-
static int userfaultfd_register(struct userfaultfd_ctx *ctx,
unsigned long arg)
{
@@ -1966,7 +1948,8 @@ static int userfaultfd_api(struct userfaultfd_ctx *ctx,
~(UFFD_FEATURE_MINOR_HUGETLBFS | UFFD_FEATURE_MINOR_SHMEM);
#endif
#ifndef CONFIG_HAVE_ARCH_USERFAULTFD_WP
- uffdio_api.features &= ~UFFD_FEATURE_PAGEFAULT_FLAG_WP;
+ uffdio_api.features &=
+ ~(UFFD_FEATURE_PAGEFAULT_FLAG_WP | UFFD_FEATURE_WP_HUGETLBFS_SHMEM);
#endif
uffdio_api.ioctls = UFFD_API_IOCTLS;
ret = -EFAULT;
diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h
index 92606d95b005..4382240de7c3 100644
--- a/include/linux/userfaultfd_k.h
+++ b/include/linux/userfaultfd_k.h
@@ -16,6 +16,7 @@
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <asm-generic/pgtable_uffd.h>
+#include <linux/hugetlb_inline.h>
/* The set of all possible UFFD-related VM flags. */
#define __VM_UFFD_FLAGS (VM_UFFD_MISSING | VM_UFFD_WP | VM_UFFD_MINOR)
@@ -138,6 +139,17 @@ static inline bool userfaultfd_armed(struct vm_area_struct *vma)
return vma->vm_flags & __VM_UFFD_FLAGS;
}
+static inline bool vma_can_userfault(struct vm_area_struct *vma,
+ unsigned long vm_flags)
+{
+ if (vm_flags & VM_UFFD_MINOR)
+ return is_vm_hugetlb_page(vma) || vma_is_shmem(vma);
+
+ return vma_is_anonymous(vma) || is_vm_hugetlb_page(vma) ||
+ vma_is_shmem(vma);
+}
+
+
extern int dup_userfaultfd(struct vm_area_struct *, struct list_head *);
extern void dup_userfaultfd_complete(struct list_head *);
diff --git a/include/uapi/linux/userfaultfd.h b/include/uapi/linux/userfaultfd.h
index 05b31d60acf6..a67b5185a7a9 100644
--- a/include/uapi/linux/userfaultfd.h
+++ b/include/uapi/linux/userfaultfd.h
@@ -32,7 +32,8 @@
UFFD_FEATURE_SIGBUS | \
UFFD_FEATURE_THREAD_ID | \
UFFD_FEATURE_MINOR_HUGETLBFS | \
- UFFD_FEATURE_MINOR_SHMEM)
+ UFFD_FEATURE_MINOR_SHMEM | \
+ UFFD_FEATURE_WP_HUGETLBFS_SHMEM)
#define UFFD_API_IOCTLS \
((__u64)1 << _UFFDIO_REGISTER | \
(__u64)1 << _UFFDIO_UNREGISTER | \
@@ -46,7 +47,8 @@
#define UFFD_API_RANGE_IOCTLS_BASIC \
((__u64)1 << _UFFDIO_WAKE | \
(__u64)1 << _UFFDIO_COPY | \
- (__u64)1 << _UFFDIO_CONTINUE)
+ (__u64)1 << _UFFDIO_CONTINUE | \
+ (__u64)1 << _UFFDIO_WRITEPROTECT)
/*
* Valid ioctl command number range with this API is from 0x00 to
@@ -189,6 +191,9 @@ struct uffdio_api {
*
* UFFD_FEATURE_MINOR_SHMEM indicates the same support as
* UFFD_FEATURE_MINOR_HUGETLBFS, but for shmem-backed pages instead.
+ *
+ * UFFD_FEATURE_WP_HUGETLBFS_SHMEM indicates that userfaultfd
+ * write-protection mode is supported on both shmem and hugetlbfs.
*/
#define UFFD_FEATURE_PAGEFAULT_FLAG_WP (1<<0)
#define UFFD_FEATURE_EVENT_FORK (1<<1)
@@ -201,6 +206,7 @@ struct uffdio_api {
#define UFFD_FEATURE_THREAD_ID (1<<8)
#define UFFD_FEATURE_MINOR_HUGETLBFS (1<<9)
#define UFFD_FEATURE_MINOR_SHMEM (1<<10)
+#define UFFD_FEATURE_WP_HUGETLBFS_SHMEM (1<<11)
__u64 features;
__u64 ioctls;
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index a8038903effd..6587ed787707 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -724,15 +724,12 @@ int mwriteprotect_range(struct mm_struct *dst_mm, unsigned long start,
err = -ENOENT;
dst_vma = find_dst_vma(dst_mm, start, len);
- /*
- * Make sure the vma is not shared, that the dst range is
- * both valid and fully within a single existing vma.
- */
- if (!dst_vma || (dst_vma->vm_flags & VM_SHARED))
+
+ if (!dst_vma)
goto out_unlock;
if (!userfaultfd_wp(dst_vma))
goto out_unlock;
- if (!vma_is_anonymous(dst_vma))
+ if (!vma_can_userfault(dst_vma, dst_vma->vm_flags))
goto out_unlock;
if (is_vm_hugetlb_page(dst_vma)) {
--
2.31.1
next prev parent reply other threads:[~2021-07-15 20:17 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-15 20:13 [PATCH v5 00/26] userfaultfd-wp: Support shmem and hugetlbfs Peter Xu
2021-07-15 20:13 ` [PATCH v5 01/26] mm/shmem: Unconditionally set pte dirty in mfill_atomic_install_pte Peter Xu
2021-07-15 20:13 ` [PATCH v5 02/26] shmem/userfaultfd: Take care of UFFDIO_COPY_MODE_WP Peter Xu
2021-07-15 20:13 ` [PATCH v5 03/26] mm: Clear vmf->pte after pte_unmap_same() returns Peter Xu
2021-07-15 20:14 ` [PATCH v5 04/26] mm/userfaultfd: Introduce special pte for unmapped file-backed mem Peter Xu
2021-07-15 20:14 ` [PATCH v5 05/26] mm/swap: Introduce the idea of special swap ptes Peter Xu
2021-07-16 5:50 ` Alistair Popple
2021-07-16 19:11 ` Peter Xu
2021-07-21 11:28 ` Alistair Popple
2021-07-21 21:35 ` Peter Xu
2021-07-22 1:08 ` Alistair Popple
2021-07-22 15:21 ` Peter Xu
2021-07-15 20:14 ` [PATCH v5 06/26] shmem/userfaultfd: Handle uffd-wp special pte in page fault handler Peter Xu
2021-07-15 20:14 ` [PATCH v5 07/26] mm: Drop first_index/last_index in zap_details Peter Xu
2021-07-15 20:14 ` [PATCH v5 08/26] mm: Introduce zap_details.zap_flags Peter Xu
2021-07-15 20:14 ` [PATCH v5 09/26] mm: Introduce ZAP_FLAG_SKIP_SWAP Peter Xu
2021-07-15 20:14 ` [PATCH v5 10/26] shmem/userfaultfd: Persist uffd-wp bit across zapping for file-backed Peter Xu
2021-07-15 20:15 ` [PATCH v5 11/26] shmem/userfaultfd: Allow wr-protect none pte for file-backed mem Peter Xu
2021-07-15 20:16 ` [PATCH v5 12/26] shmem/userfaultfd: Allows file-back mem to be uffd wr-protected on thps Peter Xu
2021-07-15 20:16 ` [PATCH v5 13/26] shmem/userfaultfd: Handle the left-overed special swap ptes Peter Xu
2021-07-15 20:16 ` [PATCH v5 14/26] shmem/userfaultfd: Pass over uffd-wp special swap pte when fork() Peter Xu
2021-07-15 20:16 ` [PATCH v5 15/26] mm/hugetlb: Drop __unmap_hugepage_range definition from hugetlb.h Peter Xu
2021-07-15 20:16 ` [PATCH v5 16/26] mm/hugetlb: Introduce huge pte version of uffd-wp helpers Peter Xu
2021-07-15 20:16 ` [PATCH v5 17/26] hugetlb/userfaultfd: Hook page faults for uffd write protection Peter Xu
2021-07-20 15:37 ` kernel test robot
2021-07-21 21:50 ` Peter Xu
2021-07-15 20:16 ` [PATCH v5 18/26] hugetlb/userfaultfd: Take care of UFFDIO_COPY_MODE_WP Peter Xu
2021-07-20 23:59 ` kernel test robot
2021-07-15 20:16 ` [PATCH v5 19/26] hugetlb/userfaultfd: Handle UFFDIO_WRITEPROTECT Peter Xu
2021-07-21 8:24 ` kernel test robot
2021-07-15 20:16 ` [PATCH v5 20/26] mm/hugetlb: Introduce huge version of special swap pte helpers Peter Xu
2021-07-15 20:16 ` [PATCH v5 21/26] hugetlb/userfaultfd: Handle uffd-wp special pte in hugetlb pf handler Peter Xu
2021-07-15 20:16 ` [PATCH v5 22/26] hugetlb/userfaultfd: Allow wr-protect none ptes Peter Xu
2021-07-15 20:16 ` [PATCH v5 23/26] hugetlb/userfaultfd: Only drop uffd-wp special pte if required Peter Xu
2021-07-15 20:16 ` [PATCH v5 24/26] mm/pagemap: Recognize uffd-wp bit for shmem/hugetlbfs Peter Xu
2021-07-19 9:53 ` Tiberiu Georgescu
2021-07-19 16:03 ` Peter Xu
2021-07-19 17:23 ` Tiberiu Georgescu
2021-07-19 17:56 ` Peter Xu
2021-07-21 14:38 ` Ivan Teterevkov
2021-07-21 16:19 ` David Hildenbrand
2021-07-21 19:54 ` Ivan Teterevkov
2021-07-21 22:28 ` Peter Xu
2021-07-21 22:57 ` Peter Xu
2021-07-22 6:27 ` David Hildenbrand
2021-07-22 16:08 ` Peter Xu
2021-07-15 20:16 ` Peter Xu [this message]
2021-07-15 20:16 ` [PATCH v5 26/26] userfaultfd/selftests: Enable uffd-wp " Peter Xu
2021-07-19 19:21 ` [PATCH v5 00/26] userfaultfd-wp: Support shmem and hugetlbfs David Hildenbrand
2021-07-19 20:12 ` Peter Xu
2021-07-22 18:30 ` Peter Xu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210715201655.212184-1-peterx@redhat.com \
--to=peterx@redhat.com \
--cc=aarcange@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=apopple@nvidia.com \
--cc=axelrasmussen@google.com \
--cc=david@redhat.com \
--cc=hughd@google.com \
--cc=jgg@ziepe.ca \
--cc=jglisse@redhat.com \
--cc=kirill@shutemov.name \
--cc=linmiaohe@huawei.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mike.kravetz@oracle.com \
--cc=nadav.amit@gmail.com \
--cc=rppt@linux.vnet.ibm.com \
--cc=tiberiu.georgescu@nutanix.com \
--cc=willy@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).