Add pokeuser

Author: marmistrz

src/sys/ptrace.rs

@@ -204,6 +204,13 @@ pub fn peekuser(pid: Pid, reg: Register) -> Result<Word> {
     }
 } 
 
+/// Makes the `PTRACE_PEEKUSER` request to ptrace
+pub unsafe fn pokeuser(pid: Pid, reg: Register, val: Word) -> Result<()> {
+    let reg_arg = (reg as u64) as *mut c_void;
+    ptrace(ptrace::PTRACE_POKEUSER, pid, reg_arg, val as *mut c_void).map(|_| ()) // ignore the useless return value
+}
+
+
 /// Sets the process as traceable with `PTRACE_TRACEME`
 pub fn traceme() -> Result<()> {
     unsafe {