Move anonymous mappings to server code

Signed-off-by: Alex Saveau <[email protected]>
SUPERCILEX · Jul 31, 2024 · c833ef8 · c833ef8
1 parent a4c4ca2
commit c833ef8
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Showing 3 changed files with 48 additions and 28 deletions.
diff --git a/core/api.golden b/core/api.golden
@@ -514,7 +514,6 @@ pub fn clipboard_history_core::ring::Mmap::from<Fd: std::os::fd::owned::AsFd>(fd
 pub const fn clipboard_history_core::ring::Mmap::is_empty(&self) -> bool
 pub const fn clipboard_history_core::ring::Mmap::len(&self) -> usize
 pub fn clipboard_history_core::ring::Mmap::new<Fd: std::os::fd::owned::AsFd>(fd: Fd, len: usize) -> rustix::io::errno::Result<Self>
-pub fn clipboard_history_core::ring::Mmap::new_anon(len: usize) -> rustix::io::errno::Result<Self>
 pub const fn clipboard_history_core::ring::Mmap::ptr(&self) -> core::ptr::non_null::NonNull<u8>
 pub fn clipboard_history_core::ring::Mmap::remap(&mut self, len: usize) -> rustix::io::errno::Result<()>
 impl core::convert::AsRef<[u8]> for clipboard_history_core::ring::Mmap

diff --git a/core/src/ring.rs b/core/src/ring.rs
@@ -12,7 +12,7 @@ use std::{
 
 use rustix::{
     fs::{openat, statx, AtFlags, Mode, OFlags, StatxFlags, CWD},
-    mm::{mmap, mmap_anonymous, mremap, munmap, MapFlags, MremapFlags, ProtFlags},
+    mm::{mmap, mremap, munmap, MapFlags, MremapFlags, ProtFlags},
     path::Arg,
 };
 
@@ -176,22 +176,6 @@ impl Mmap {
         })
     }
 
-    pub fn new_anon(len: usize) -> rustix::io::Result<Self> {
-        Ok(Self {
-            ptr: unsafe {
-                NonNull::new_unchecked(mmap_anonymous(
-                    ptr::null_mut(),
-                    len,
-                    ProtFlags::READ | ProtFlags::WRITE,
-                    MapFlags::PRIVATE,
-                )?)
-            }
-            .cast(),
-            requested_len: len,
-            backing_len: len,
-        })
-    }
-
     pub fn remap(&mut self, len: usize) -> rustix::io::Result<()> {
         if len >= self.requested_len && len <= self.backing_len {
             self.requested_len = len;

diff --git a/server/src/io_uring.rs b/server/src/io_uring.rs
@@ -1,8 +1,10 @@
-use std::io;
+use std::{io, ptr, ptr::NonNull};
 
 use io_uring::Submitter;
-use ringboard_core::ring::Mmap;
-use rustix::io_uring::io_uring_buf;
+use rustix::{
+    io_uring::io_uring_buf,
+    mm::{mmap_anonymous, munmap, MapFlags, ProtFlags},
+};
 
 use crate::io_uring::buf_ring::BufRing;
 
@@ -18,13 +20,42 @@ pub fn register_buf_ring(
         )
     };
 
-    let ring = Mmap::new_anon(bytes().ok_or(io::ErrorKind::InvalidInput)?)?;
+    let ring = MmapAnon::new(bytes().ok_or(io::ErrorKind::InvalidInput)?)?;
     unsafe {
-        submitter.register_buf_ring(ring.ptr().as_ptr() as u64, ring_entries, bgid)?;
+        submitter.register_buf_ring(ring.ptr.as_ptr() as u64, ring_entries, bgid)?;
     }
     Ok(BufRing::init(ring, ring_entries, entry_size, bgid))
 }
 
+#[derive(Debug)]
+pub struct MmapAnon {
+    ptr: NonNull<u8>,
+    len: usize,
+}
+
+impl MmapAnon {
+    pub fn new(len: usize) -> io::Result<Self> {
+        Ok(Self {
+            ptr: unsafe {
+                NonNull::new_unchecked(mmap_anonymous(
+                    ptr::null_mut(),
+                    len,
+                    ProtFlags::READ | ProtFlags::WRITE,
+                    MapFlags::PRIVATE,
+                )?)
+            }
+            .cast(),
+            len,
+        })
+    }
+}
+
+impl Drop for MmapAnon {
+    fn drop(&mut self) {
+        let _ = unsafe { munmap(self.ptr.as_ptr().cast(), self.len) };
+    }
+}
+
 pub mod types {
     use std::slice;
 
@@ -177,18 +208,24 @@ pub mod buf_ring {
     };
 
     use io_uring::Submitter;
-    use ringboard_core::ring::Mmap;
     use rustix::io_uring::{io_uring_buf, IORING_CQE_BUFFER_SHIFT};
 
+    use crate::io_uring::MmapAnon;
+
     pub struct BufRing {
-        ring: Mmap,
+        ring: MmapAnon,
         ring_entries: u16,
         entry_size: u32,
         group_id: u16,
     }
 
     impl BufRing {
-        pub(super) fn init(ring: Mmap, ring_entries: u16, entry_size: u32, group_id: u16) -> Self {
+        pub(super) fn init(
+            ring: MmapAnon,
+            ring_entries: u16,
+            entry_size: u32,
+            group_id: u16,
+        ) -> Self {
             let mut this = Self {
                 ring,
                 ring_entries,
@@ -209,8 +246,8 @@ pub mod buf_ring {
 
         #[allow(clippy::cast_ptr_alignment)]
         pub fn submissions(&mut self) -> BufRingSubmissions<'_> {
-            let ring_ptr = self.ring.ptr().as_ptr().cast::<io_uring_buf>();
-            let tail_ptr = unsafe { self.ring.ptr().as_ptr().add(8 + 4 + 2) };
+            let ring_ptr = self.ring.ptr.as_ptr().cast::<io_uring_buf>();
+            let tail_ptr = unsafe { self.ring.ptr.as_ptr().add(8 + 4 + 2) };
             let ring_entries = usize::from(self.ring_entries);
             BufRingSubmissions {
                 ring_ptr,