Add msync function and stub for Redox

src/platform/linux/mod.rs

@@ -310,6 +310,10 @@ impl Pal for Sys {
         e(syscall!(MPROTECT, addr, len, prot)) as c_int
     }
 
+    unsafe fn msync(addr: *mut c_void, len: usize, flags: c_int) -> c_int {
+        e(syscall!(MSYNC, addr, len, flags)) as c_int
+    }
+
     unsafe fn munmap(addr: *mut c_void, len: usize) -> c_int {
         e(syscall!(MUNMAP, addr, len)) as c_int
     }

src/platform/pal/mod.rs

@@ -118,6 +118,8 @@ pub trait Pal {
 
     unsafe fn mprotect(addr: *mut c_void, len: usize, prot: c_int) -> c_int;
 
+    unsafe fn msync(addr: *mut c_void, len: usize, flags: c_int) -> c_int;
+
     unsafe fn munmap(addr: *mut c_void, len: usize) -> c_int;
 
     fn nanosleep(rqtp: *const timespec, rmtp: *mut timespec) -> c_int;

src/platform/redox/mod.rs

@@ -675,6 +675,18 @@ impl Pal for Sys {
         )) as c_int
     }
 
+    unsafe fn msync(addr: *mut c_void, len: usize, flags: c_int) -> c_int {
+        eprintln!("msync {:p} {:x} {:x}", addr, len, flags);
+        e(Err(syscall::Error::new(syscall::ENOSYS))) as c_int
+        /* TODO
+        e(syscall::msync(
+            addr as usize,
+            len,
+            flags
+        )) as c_int
+        */
+    }
+
     unsafe fn munmap(addr: *mut c_void, _len: usize) -> c_int {
         if e(syscall::funmap(addr as usize)) == !0 {
             return !0;