diff options
| author | Peter Xu <peterx@redhat.com> | 2021-06-30 18:49:06 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-06-30 20:47:27 -0700 |
| commit | 00b151f21f390f1e0b294720a3660506abaf49cd (patch) | |
| tree | e66aa23dd80c0e249d7646b1626dc7d5e0e46bc1 | |
| parent | 8f34f1eac3820fc2722e5159acceb22545b30b0d (diff) | |
mm/userfaultfd: fail uffd-wp registration if not supported
We should fail uffd-wp registration immediately if the arch does not even
have CONFIG_HAVE_ARCH_USERFAULTFD_WP defined. That'll block also relevant
ioctls on e.g. UFFDIO_WRITEPROTECT because that'll check against
VM_UFFD_WP, which can only be applied with a success registration.
Remove the WP feature bit too for those archs when handling UFFDIO_API
ioctl.
Link: https://lkml.kernel.org/r/20210428225030.9708-5-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Oliver Upton <oupton@google.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Wang Qing <wangqing@vivo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/userfaultfd.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index 14f92285d04f..5dd78238cc15 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -1304,8 +1304,12 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx, vm_flags = 0; if (uffdio_register.mode & UFFDIO_REGISTER_MODE_MISSING) vm_flags |= VM_UFFD_MISSING; - if (uffdio_register.mode & UFFDIO_REGISTER_MODE_WP) + if (uffdio_register.mode & UFFDIO_REGISTER_MODE_WP) { +#ifndef CONFIG_HAVE_ARCH_USERFAULTFD_WP + goto out; +#endif vm_flags |= VM_UFFD_WP; + } if (uffdio_register.mode & UFFDIO_REGISTER_MODE_MINOR) { #ifndef CONFIG_HAVE_ARCH_USERFAULTFD_MINOR goto out; @@ -1943,6 +1947,9 @@ static int userfaultfd_api(struct userfaultfd_ctx *ctx, #ifndef CONFIG_HAVE_ARCH_USERFAULTFD_MINOR uffdio_api.features &= ~UFFD_FEATURE_MINOR_HUGETLBFS; #endif +#ifndef CONFIG_HAVE_ARCH_USERFAULTFD_WP + uffdio_api.features &= ~UFFD_FEATURE_PAGEFAULT_FLAG_WP; +#endif uffdio_api.ioctls = UFFD_API_IOCTLS; ret = -EFAULT; if (copy_to_user(buf, &uffdio_api, sizeof(uffdio_api))) |