[PATCH v6 8/8] memfd_create.2: Describe MFD_INACCESSIBLE flag

Chao Peng
2022-05-19T15:44:29Z

Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
---
man2/memfd_create.2 | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/man2/memfd_create.2 b/man2/memfd_create.2
index 89e9c4136..2698222ae 100644
--- a/man2/memfd_create.2
+++ b/man2/memfd_create.2
@@ -101,6 +101,19 @@ meaning that no other seals can be set on the file.
.\" FIXME Why is the MFD_ALLOW_SEALING behavior not simply the default?
.\" Is it worth adding some text explaining this?
.TP
+.BR MFD_INACCESSIBLE
+Disallow userspace access through ordinary MMU accesses via
+.BR read (2),
+.BR write (2)
+and
+.BR mmap (2).
+The file size cannot be changed once initialized.
+This flag cannot coexist with
+.B MFD_ALLOW_SEALING
+and when this flag is set, the initial set of seals will be
+.B F_SEAL_SEAL,
+meaning that no other seals can be set on the file.
+.TP
.BR MFD_HUGETLB " (since Linux 4.14)"
.\" commit 749df87bd7bee5a79cef073f5d032ddb2b211de8
The anonymous file will be created in the hugetlbfs filesystem using
--
2.17.1