From bb1e4de95fd8a187cae29a5e12720cfce20b02da Mon Sep 17 00:00:00 2001
From: David Carlier <devnexen@gmail.com>
Date: Tue, 5 Dec 2023 20:37:51 +0000
Subject: [PATCH] sys::memfd additional flags related to the hugetlb filesystem
 support.

---
 changelog/2252.added.md |  1 +
 src/sys/memfd.rs        | 43 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+)
 create mode 100644 changelog/2252.added.md

diff --git a/changelog/2252.added.md b/changelog/2252.added.md
new file mode 100644
index 0000000000..8737adde79
--- /dev/null
+++ b/changelog/2252.added.md
@@ -0,0 +1 @@
+Added new `MemFdCreateFlag` constants to `sys::memfd` on Linux and Android related to hugetlbfs support.
diff --git a/src/sys/memfd.rs b/src/sys/memfd.rs
index 516ffd3262..22ee5fc5b7 100644
--- a/src/sys/memfd.rs
+++ b/src/sys/memfd.rs
@@ -29,6 +29,49 @@ libc_bitflags!(
         ///
         /// [`memfd_create(2)`]: https://man7.org/linux/man-pages/man2/memfd_create.2.html
         MFD_ALLOW_SEALING;
+        /// Anonymous file will be created using huge pages. It should be safe now to
+        /// combine with [`MFD_ALLOW_SEALING`] too.
+        /// However, despite its presence, on FreeBSD it is unimplemented for now (ENOSYS).
+        ///
+        /// See also the hugetlb filesystem in [`memfd_create(2)`].
+        ///
+        /// [`memfd_create(2)`]: https://man7.org/linux/man-pages/man2/memfd_create.2.html
+        #[cfg(linux_android)]
+        MFD_HUGETLB;
+        /// Following are to be used with [`MFD_HUGETLB`], indicating the desired hugetlb size.
+        ///
+        /// See also the hugetlb filesystem in [`memfd_create(2)`].
+        ///
+        /// [`memfd_create(2)`]: https://man7.org/linux/man-pages/man2/memfd_create.2.html
+        #[cfg(linux_android)]
+        MFD_HUGE_1MB;
+        /// hugetlb size of 2MB.
+        #[cfg(linux_android)]
+        MFD_HUGE_2MB;
+        /// hugetlb size of 8MB.
+        #[cfg(linux_android)]
+        MFD_HUGE_8MB;
+        /// hugetlb size of 16MB.
+        #[cfg(linux_android)]
+        MFD_HUGE_16MB;
+        /// hugetlb size of 32MB.
+        #[cfg(linux_android)]
+        MFD_HUGE_32MB;
+        /// hugetlb size of 256MB.
+        #[cfg(linux_android)]
+        MFD_HUGE_256MB;
+        /// hugetlb size of 512MB.
+        #[cfg(linux_android)]
+        MFD_HUGE_512MB;
+        /// hugetlb size of 1GB.
+        #[cfg(linux_android)]
+        MFD_HUGE_1GB;
+        /// hugetlb size of 2GB.
+        #[cfg(linux_android)]
+        MFD_HUGE_2GB;
+        /// hugetlb size of 16GB.
+        #[cfg(linux_android)]
+        MFD_HUGE_16GB;
     }
 );