Fix UnsupportedOperation when using ptrace_* functions

Author: Susurrus

src/sys/ptrace.rs

@@ -91,15 +91,16 @@ fn ptrace_peek(request: ptrace::PtraceRequest, pid: Pid, addr: *mut c_void, data
     }
 }
 
-/// Function for ptrace requests that return values from the data field. 
+/// Function for ptrace requests that return values from the data field.
 /// Some ptrace get requests populate structs or larger elements than c_long
 /// and therefore use the data field to return values. This function handles these
 /// requests.
 fn ptrace_get_data<T>(request: ptrace::PtraceRequest, pid: Pid) -> Result<T> {
-    // Creates an uninitialized pointer to store result in 
+    // Creates an uninitialized pointer to store result in
     let data: Box<T> = Box::new(unsafe { mem::uninitialized() });
     let data: *mut c_void = unsafe { mem::transmute(data) };
-    ptrace(request, pid, ptr::null_mut(), data)?;
+    let res = unsafe { ffi::ptrace(request, pid.into(), ptr::null_mut(), data) };
+    Errno::result(res)?;
     // Convert back into the original data format and return unboxed value
     let data: Box<T> = unsafe { mem::transmute(data) };
     Ok(*data)
@@ -114,7 +115,8 @@ pub fn ptrace_setoptions(pid: Pid, options: ptrace::PtraceOptions) -> Result<()>
     use self::ptrace::*;
     use std::ptr;
 
-    ptrace(PTRACE_SETOPTIONS, pid, ptr::null_mut(), options as *mut c_void).map(drop)
+    let res = unsafe { ffi::ptrace(PTRACE_SETOPTIONS, pid.into(), ptr::null_mut(), options as *mut c_void) };
+    Errno::result(res).map(|_| ())
 }
 
 /// Gets a ptrace event as described by `ptrace(PTRACE_GETEVENTMSG,...)`

test/sys/test_ptrace.rs

@@ -3,7 +3,8 @@ use nix::errno::*;
 use nix::unistd::*;
 use nix::sys::ptrace::*;
 use nix::sys::ptrace::ptrace::*;
-use std::ptr;
+
+use std::{mem, ptr};
 
 #[test]
 fn test_ptrace() {
@@ -12,3 +13,36 @@ fn test_ptrace() {
     let err = ptrace(PTRACE_ATTACH, getpid(), ptr::null_mut(), ptr::null_mut()).unwrap_err();
     assert!(err == Error::Sys(Errno::EPERM) || err == Error::Sys(Errno::ENOSYS));
 }
+
+// Just make sure ptrace_setoptions can be called at all, for now.
+#[test]
+fn test_ptrace_setoptions() {
+    let err = ptrace_setoptions(getpid(), PTRACE_O_TRACESYSGOOD).unwrap_err();
+    assert!(err != Error::UnsupportedOperation);
+}
+
+// Just make sure ptrace_getevent can be called at all, for now.
+#[test]
+fn test_ptrace_getevent() {
+    let err = ptrace_getevent(getpid()).unwrap_err();
+    assert!(err != Error::UnsupportedOperation);
+}
+
+// Just make sure ptrace_getsiginfo can be called at all, for now.
+#[test]
+fn test_ptrace_getsiginfo() {
+    match ptrace_getsiginfo(getpid()) {
+        Err(Error::UnsupportedOperation) => panic!("ptrace_getsiginfo returns Error::UnsupportedOperation!"),
+        _ => (),
+    }
+}
+
+// Just make sure ptrace_setsiginfo can be called at all, for now.
+#[test]
+fn test_ptrace_setsiginfo() {
+    let siginfo = unsafe { mem::uninitialized() };
+    match ptrace_setsiginfo(getpid(), &siginfo) {
+        Err(Error::UnsupportedOperation) => panic!("ptrace_setsiginfo returns Error::UnsupportedOperation!"),
+        _ => (),
+    }
+}