| From: Axel Rasmussen <axelrasmussen@google.com> |
| Subject: userfaultfd-update-documentation-to-describe-dev-userfaultfd-v7 |
| Date: Fri, 19 Aug 2022 13:52:00 -0700 |
| |
| improve wording in two spots in the documentation, per Mike |
| |
| Link: https://lkml.kernel.org/r/20220819205201.658693-5-axelrasmussen@google.com |
| Acked-by: Peter Xu <peterx@redhat.com> |
| Signed-off-by: Axel Rasmussen <axelrasmussen@google.com> |
| Reviewed-by: Shuah Khan <skhan@linuxfoundation.org> |
| Cc: Al Viro <viro@zeniv.linux.org.uk> |
| Cc: Dave Hansen <dave.hansen@linux.intel.com> |
| Cc: Dmitry V. Levin <ldv@altlinux.org> |
| Cc: Gleb Fotengauer-Malinovskiy <glebfm@altlinux.org> |
| Cc: Hugh Dickins <hughd@google.com> |
| Cc: Jan Kara <jack@suse.cz> |
| Cc: Jonathan Corbet <corbet@lwn.net> |
| Cc: Mel Gorman <mgorman@techsingularity.net> |
| Cc: Mike Kravetz <mike.kravetz@oracle.com> |
| Cc: Mike Rapoport <rppt@kernel.org> |
| Cc: Mike Rapoport <rppt@linux.ibm.com> |
| Cc: Nadav Amit <namit@vmware.com> |
| Cc: Suren Baghdasaryan <surenb@google.com> |
| Cc: Vlastimil Babka <vbabka@suse.cz> |
| Cc: Zhang Yi <yi.zhang@huawei.com> |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| --- |
| |
| Documentation/admin-guide/mm/userfaultfd.rst | 10 +++++----- |
| 1 file changed, 5 insertions(+), 5 deletions(-) |
| |
| --- a/Documentation/admin-guide/mm/userfaultfd.rst~userfaultfd-update-documentation-to-describe-dev-userfaultfd-v7 |
| +++ a/Documentation/admin-guide/mm/userfaultfd.rst |
| @@ -66,14 +66,14 @@ userfaultfd(2) syscall. Access to this i |
| only. Such a userfaultfd can be created using the userfaultfd(2) syscall |
| with the flag UFFD_USER_MODE_ONLY. |
| |
| -- In order to also trap kernel page faults for the address space, then either |
| - the process needs the CAP_SYS_PTRACE capability, or the system must have |
| +- In order to also trap kernel page faults for the address space, either the |
| + process needs the CAP_SYS_PTRACE capability, or the system must have |
| vm.unprivileged_userfaultfd set to 1. By default, vm.unprivileged_userfaultfd |
| is set to 0. |
| |
| -The second way, added to the kernel more recently, is by opening and issuing a |
| -USERFAULTFD_IOC_NEW ioctl to /dev/userfaultfd. This method yields equivalent |
| -userfaultfds to the userfaultfd(2) syscall. |
| +The second way, added to the kernel more recently, is by opening |
| +/dev/userfaultfd and issuing a USERFAULTFD_IOC_NEW ioctl to it. This method |
| +yields equivalent userfaultfds to the userfaultfd(2) syscall. |
| |
| Unlike userfaultfd(2), access to /dev/userfaultfd is controlled via normal |
| filesystem permissions (user/group/mode), which gives fine grained access to |
| _ |
