Add mlockall and munlockall

bytecodealliance · Oct 9, 2023 · eefd082 · eefd082
1 parent 1a9d129
commit eefd082
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Showing 5 changed files with 218 additions and 2 deletions.
diff --git a/src/backend/libc/mm/syscalls.rs b/src/backend/libc/mm/syscalls.rs
@@ -2,6 +2,15 @@
 
 #[cfg(not(target_os = "redox"))]
 use super::types::Advice;
+#[cfg(any(
+    linux_kernel,
+    target_os = "freebsd",
+    target_os = "netbsd",
+    target_os = "openbsd",
+    target_os = "dragonfly",
+    target_os = "illumos",
+))]
+use super::types::MlockFlags;
 #[cfg(any(target_os = "emscripten", target_os = "linux"))]
 use super::types::MremapFlags;
 use super::types::{MapFlags, MprotectFlags, MsyncFlags, ProtFlags};
@@ -220,3 +229,36 @@ pub(crate) unsafe fn userfaultfd(flags: UserfaultfdFlags) -> io::Result<OwnedFd>
     }
     ret_owned_fd(userfaultfd(bitflags_bits!(flags)))
 }
+
+/// Locks all pages mapped into the address space of the calling process.
+///
+/// This includes the pages of the code, data and stack segment, as well as shared libraries,
+/// user space kernel data, shared memory, and memory-mapped files. All mapped pages are
+/// guaranteed to be resident in RAM when the call returns successfully;
+/// the pages are guaranteed to stay in RAM until later unlocked.
+#[inline]
+#[cfg(any(
+    linux_kernel,
+    target_os = "freebsd",
+    target_os = "netbsd",
+    target_os = "openbsd",
+    target_os = "dragonfly",
+    target_os = "illumos",
+))]
+pub(crate) fn mlockall(flags: MlockFlags) -> io::Result<()> {
+    unsafe { ret(c::mlockall(bitflags_bits!(flags))) }
+}
+
+/// Unlocks all pages mapped into the address space of the calling process.
+#[inline]
+#[cfg(any(
+    linux_kernel,
+    target_os = "freebsd",
+    target_os = "netbsd",
+    target_os = "openbsd",
+    target_os = "dragonfly",
+    target_os = "illumos",
+))]
+pub(crate) fn munlockall() -> io::Result<()> {
+    unsafe { ret(c::munlockall()) }
+}
diff --git a/src/backend/libc/mm/types.rs b/src/backend/libc/mm/types.rs
@@ -442,3 +442,30 @@ bitflags! {
         const _ = !0;
     }
 }
+
+#[cfg(any(
+    linux_kernel,
+    target_os = "freebsd",
+    target_os = "netbsd",
+    target_os = "openbsd",
+    target_os = "dragonfly",
+    target_os = "illumos",
+))]
+bitflags! {
+    /// `MCL_*` flags for use with [`mlockall`].
+    ///
+    /// [`mlockall`]: crate::mm::mlockall
+    pub struct MlockallFlags: i32 {
+        // libc doesn't define `MCL_ONFAULT` yet.
+        // const ONFAULT = libc::MCL_ONFAULT;
+        /// Lock all pages which will become mapped into the address
+        /// space of the process in the future.  These could be, for
+        /// instance, new pages required by a growing heap and stack
+        /// as well as new memory-mapped files or shared memory
+        /// regions.
+        const FUTURE = libc::MCL_FUTURE;
+        /// Lock all pages which are currently mapped into the address
+        /// space of the process.
+        const CURRENT = libc::MCL_CURRENT;
+    }
+}
diff --git a/src/backend/linux_raw/mm/syscalls.rs b/src/backend/linux_raw/mm/syscalls.rs
@@ -6,9 +6,17 @@
 #![allow(unsafe_code)]
 #![allow(clippy::undocumented_unsafe_blocks)]
 
+#[cfg(any(
+    linux_kernel,
+    target_os = "freebsd",
+    target_os = "netbsd",
+    target_os = "openbsd",
+    target_os = "dragonfly",
+    target_os = "illumos",
+))]
+use super::types::MlockFlags;
 use super::types::{
-    Advice, MapFlags, MlockFlags, MprotectFlags, MremapFlags, MsyncFlags, ProtFlags,
-    UserfaultfdFlags,
+    Advice, MapFlags, MprotectFlags, MremapFlags, MsyncFlags, ProtFlags, UserfaultfdFlags,
 };
 use crate::backend::c;
 #[cfg(target_pointer_width = "64")]
@@ -210,3 +218,36 @@ pub(crate) unsafe fn munlock(addr: *mut c::c_void, length: usize) -> io::Result<
 pub(crate) unsafe fn userfaultfd(flags: UserfaultfdFlags) -> io::Result<OwnedFd> {
     ret_owned_fd(syscall_readonly!(__NR_userfaultfd, flags))
 }
+
+/// Locks all pages mapped into the address space of the calling process.
+///
+/// This includes the pages of the code, data and stack segment, as well as shared libraries,
+/// user space kernel data, shared memory, and memory-mapped files. All mapped pages are
+/// guaranteed to be resident in RAM when the call returns successfully;
+/// the pages are guaranteed to stay in RAM until later unlocked.
+#[inline]
+#[cfg(any(
+    linux_kernel,
+    target_os = "freebsd",
+    target_os = "netbsd",
+    target_os = "openbsd",
+    target_os = "dragonfly",
+    target_os = "illumos",
+))]
+pub(crate) fn mlockall(flags: MlockFlags) -> io::Result<()> {
+    unsafe { ret(syscall_readonly!(__NR_mlockall, flags)) }
+}
+
+/// Unlocks all pages mapped into the address space of the calling process.
+#[inline]
+#[cfg(any(
+    linux_kernel,
+    target_os = "freebsd",
+    target_os = "netbsd",
+    target_os = "openbsd",
+    target_os = "dragonfly",
+    target_os = "illumos",
+))]
+pub(crate) fn munlockall() -> io::Result<()> {
+    unsafe { ret(syscall_readonly!(__NR_munlockall)) }
+}
diff --git a/src/backend/linux_raw/mm/types.rs b/src/backend/linux_raw/mm/types.rs
@@ -262,3 +262,39 @@ bitflags! {
         const _ = !0;
     }
 }
+
+#[cfg(any(
+    linux_kernel,
+    target_os = "freebsd",
+    target_os = "netbsd",
+    target_os = "openbsd",
+    target_os = "dragonfly",
+    target_os = "illumos",
+))]
+bitflags! {
+    /// `MCL_*` flags for use with [`mlockall`].
+    ///
+    /// [`mlockall`]: crate::mm::mlockall
+    pub struct MlockallFlags: u32 {
+        /// Used together with `MCL_CURRENT`, `MCL_FUTURE`, or both.  Mark
+        /// all current (with `MCL_CURRENT`) or future (with `MCL_FUTURE`)
+        /// mappings to lock pages when they are faulted in.  When
+        /// used with `MCL_CURRENT`, all present pages are locked, but
+        /// `mlockall()` will not fault in non-present pages.  When used
+        /// with `MCL_FUTURE`, all future mappings will be marked to
+        /// lock pages when they are faulted in, but they will not be
+        /// populated by the lock when the mapping is created.
+        /// `MCL_ONFAULT` must be used with either `MCL_CURRENT` or
+        /// `MCL_FUTURE` or both.
+        const ONFAULT = linux_raw_sys::general::MCL_ONFAULT;
+        /// Lock all pages which will become mapped into the address
+        /// space of the process in the future.  These could be, for
+        /// instance, new pages required by a growing heap and stack
+        /// as well as new memory-mapped files or shared memory
+        /// regions.
+        const FUTURE = linux_raw_sys::general::MCL_FUTURE;
+        /// Lock all pages which are currently mapped into the address
+        /// space of the process.
+        const CURRENT = linux_raw_sys::general::MCL_CURRENT;
+    }
+}
diff --git a/src/mm/mmap.rs b/src/mm/mmap.rs
@@ -340,3 +340,73 @@ pub unsafe fn mlock_with(ptr: *mut c_void, len: usize, flags: MlockFlags) -> io:
 pub unsafe fn munlock(ptr: *mut c_void, len: usize) -> io::Result<()> {
     backend::mm::syscalls::munlock(ptr, len)
 }
+
+/// Locks all pages mapped into the address space of the calling process.
+///
+/// This includes the pages of the code, data and stack segment, as well as shared libraries,
+/// user space kernel data, shared memory, and memory-mapped files. All mapped pages are
+/// guaranteed to be resident in RAM when the call returns successfully;
+/// the pages are guaranteed to stay in RAM until later unlocked.
+///
+/// # References
+///  - [POSIX]
+///  - [Linux]
+///  - [FreeBSD]
+///  - [NetBSD]
+///  - [OpenBSD]
+///  - [DragonFly BSD]
+///  - [illumos]
+///  - [glibc]
+///
+/// [POSIX]: https://pubs.opengroup.org/onlinepubs/9699919799/functions/mlockall.html
+/// [Linux]: https://man7.org/linux/man-pages/man2/mlockall.2.html
+/// [FreeBSD]: https://man.freebsd.org/cgi/man.cgi?query=mlockall&sektion=2
+/// [NetBSD]: https://man.netbsd.org/mlockall.2
+/// [OpenBSD]: https://man.openbsd.org/mlockall.2
+/// [DragonFly BSD]: https://man.dragonflybsd.org/?command=mlockall&section=2
+/// [illumos]: https://illumos.org/man/3C/mlockall
+/// [glibc]: https://www.gnu.org/software/libc/manual/html_node/Page-Lock-Functions.html#index-mlockall
+#[cfg(any(
+    linux_kernel,
+    target_os = "freebsd",
+    target_os = "netbsd",
+    target_os = "openbsd",
+    target_os = "dragonfly",
+    target_os = "illumos",
+))]
+pub fn mlockall(flags: MlockFlags) -> io::Result<()> {
+    backend::mm::syscalls::mlockall(flags)
+}
+
+/// Unlocks all pages mapped into the address space of the calling process.
+///
+/// # References
+///  - [POSIX]
+///  - [Linux]
+///  - [FreeBSD]
+///  - [NetBSD]
+///  - [OpenBSD]
+///  - [DragonFly BSD]
+///  - [illumos]
+///  - [glibc]
+///
+/// [POSIX]: https://pubs.opengroup.org/onlinepubs/9699919799/functions/munlockall.html
+/// [Linux]: https://man7.org/linux/man-pages/man2/munlockall.2.html
+/// [FreeBSD]: https://man.freebsd.org/cgi/man.cgi?query=munlockall&sektion=2
+/// [NetBSD]: https://man.netbsd.org/munlockall.2
+/// [OpenBSD]: https://man.openbsd.org/munlockall.2
+/// [DragonFly BSD]: https://man.dragonflybsd.org/?command=munlockall&section=2
+/// [illumos]: https://illumos.org/man/3C/munlockall
+/// [glibc]: https://www.gnu.org/software/libc/manual/html_node/Page-Lock-Functions.html#index-munlockall
+#[inline]
+#[cfg(any(
+    linux_kernel,
+    target_os = "freebsd",
+    target_os = "netbsd",
+    target_os = "openbsd",
+    target_os = "dragonfly",
+    target_os = "illumos",
+))]
+pub fn munlockall() -> io::Result<()> {
+    backend::mm::syscalls::munlockall()
+}