Add wrapper for mremap

Author: sporksmith

src/sys/mman.rs

@@ -315,6 +315,27 @@ pub unsafe fn mmap(addr: *mut c_void, length: size_t, prot: ProtFlags, flags: Ma
     }
 }
 
+/// Expands (or shrinks) an existing memory mapping, potentially moving it at the same time.
+///
+/// # Safety
+///
+/// See the `mremap(2)` man page for detailed requirements.
+pub unsafe fn mremap(
+    addr: *mut c_void,
+    old_size: size_t,
+    new_size: size_t,
+    flags: MapFlags,
+    new_address: size_t,
+) -> Result<*mut c_void> {
+    let ret = libc::mremap(addr, old_size, new_size, flags.bits(), new_address);
+
+    if ret == libc::MAP_FAILED {
+        Err(Error::Sys(Errno::last()))
+    } else {
+        Ok(ret)
+    }
+}
+
 /// remove a mapping
 ///
 /// # Safety