1 files changed, 122 insertions, 0 deletions
diff --git a/third_party/rust/nix/test/sys/test_mman.rs b/third_party/rust/nix/test/sys/test_mman.rs
new file mode 100644
index 0000000000..e748427bcd
--- /dev/null
+++ b/third_party/rust/nix/test/sys/test_mman.rs
@@ -0,0 +1,122 @@
+use nix::sys::mman::{mmap, MapFlags, ProtFlags};
+use std::num::NonZeroUsize;
+
+#[test]
+fn test_mmap_anonymous() {
+    unsafe {
+        let ptr = mmap(
+            None,
+            NonZeroUsize::new(1).unwrap(),
+            ProtFlags::PROT_READ | ProtFlags::PROT_WRITE,
+            MapFlags::MAP_PRIVATE | MapFlags::MAP_ANONYMOUS,
+            -1,
+            0,
+        )
+        .unwrap() as *mut u8;
+        assert_eq!(*ptr, 0x00u8);
+        *ptr = 0xffu8;
+        assert_eq!(*ptr, 0xffu8);
+    }
+}
+
+#[test]
+#[cfg(any(target_os = "linux", target_os = "netbsd"))]
+fn test_mremap_grow() {
+    use nix::libc::{c_void, size_t};
+    use nix::sys::mman::{mremap, MRemapFlags};
+
+    const ONE_K: size_t = 1024;
+    let one_k_non_zero = NonZeroUsize::new(ONE_K).unwrap();
+
+    let slice: &mut [u8] = unsafe {
+        let mem = mmap(
+            None,
+            one_k_non_zero,
+            ProtFlags::PROT_READ | ProtFlags::PROT_WRITE,
+            MapFlags::MAP_ANONYMOUS | MapFlags::MAP_PRIVATE,
+            -1,
+            0,
+        )
+        .unwrap();
+        std::slice::from_raw_parts_mut(mem as *mut u8, ONE_K)
+    };
+    assert_eq!(slice[ONE_K - 1], 0x00);
+    slice[ONE_K - 1] = 0xFF;
+    assert_eq!(slice[ONE_K - 1], 0xFF);
+
+    let slice: &mut [u8] = unsafe {
+        #[cfg(target_os = "linux")]
+        let mem = mremap(
+            slice.as_mut_ptr() as *mut c_void,
+            ONE_K,
+            10 * ONE_K,
+            MRemapFlags::MREMAP_MAYMOVE,
+            None,
+        )
+        .unwrap();
+        #[cfg(target_os = "netbsd")]
+        let mem = mremap(
+            slice.as_mut_ptr() as *mut c_void,
+            ONE_K,
+            10 * ONE_K,
+            MRemapFlags::MAP_REMAPDUP,
+            None,
+        )
+        .unwrap();
+        std::slice::from_raw_parts_mut(mem as *mut u8, 10 * ONE_K)
+    };
+
+    // The first KB should still have the old data in it.
+    assert_eq!(slice[ONE_K - 1], 0xFF);
+
+    // The additional range should be zero-init'd and accessible.
+    assert_eq!(slice[10 * ONE_K - 1], 0x00);
+    slice[10 * ONE_K - 1] = 0xFF;
+    assert_eq!(slice[10 * ONE_K - 1], 0xFF);
+}
+
+#[test]
+#[cfg(any(target_os = "linux", target_os = "netbsd"))]
+// Segfaults for unknown reasons under QEMU for 32-bit targets
+#[cfg_attr(all(target_pointer_width = "32", qemu), ignore)]
+fn test_mremap_shrink() {
+    use nix::libc::{c_void, size_t};
+    use nix::sys::mman::{mremap, MRemapFlags};
+    use std::num::NonZeroUsize;
+
+    const ONE_K: size_t = 1024;
+    let ten_one_k = NonZeroUsize::new(10 * ONE_K).unwrap();
+    let slice: &mut [u8] = unsafe {
+        let mem = mmap(
+            None,
+            ten_one_k,
+            ProtFlags::PROT_READ | ProtFlags::PROT_WRITE,
+            MapFlags::MAP_ANONYMOUS | MapFlags::MAP_PRIVATE,
+            -1,
+            0,
+        )
+        .unwrap();
+        std::slice::from_raw_parts_mut(mem as *mut u8, ONE_K)
+    };
+    assert_eq!(slice[ONE_K - 1], 0x00);
+    slice[ONE_K - 1] = 0xFF;
+    assert_eq!(slice[ONE_K - 1], 0xFF);
+
+    let slice: &mut [u8] = unsafe {
+        let mem = mremap(
+            slice.as_mut_ptr() as *mut c_void,
+            ten_one_k.into(),
+            ONE_K,
+            MRemapFlags::empty(),
+            None,
+        )
+        .unwrap();
+        // Since we didn't supply MREMAP_MAYMOVE, the address should be the
+        // same.
+        assert_eq!(mem, slice.as_mut_ptr() as *mut c_void);
+        std::slice::from_raw_parts_mut(mem as *mut u8, ONE_K)
+    };
+
+    // The first KB should still be accessible and have the old data in it.
+    assert_eq!(slice[ONE_K - 1], 0xFF);
+}