Add ptrace::syscall test

test/sys/test_ptrace.rs

@@ -105,3 +105,76 @@ fn test_ptrace_cont() {
         },
     }
 }
+
+// ptrace::setoptions needed to trace syscalls is only available in these platforms
+#[cfg(any(target_os = "android", target_os = "linux"))]
+#[test]
+fn test_ptrace_syscall() {
+    use nix::sys::signal::kill;
+    use nix::sys::ptrace;
+    use nix::sys::signal::Signal;
+    use nix::sys::wait::{waitpid, WaitStatus};
+    use nix::unistd::fork;
+    use nix::unistd::getpid;
+    use nix::unistd::ForkResult::*;
+
+    let _m = ::FORK_MTX.lock().expect("Mutex got poisoned by another test");
+
+    // FIXME: qemu-user doesn't implement ptrace on all architectures
+    // and retunrs ENOSYS in this case.
+    // We (ab)use this behavior to detect the affected platforms
+    // and skip the test then.
+    // On valid platforms the ptrace call should return Errno::EPERM, this
+    // is already tested by `test_ptrace`.
+    let err = ptrace::attach(getpid()).unwrap_err();
+    if err == Error::Sys(Errno::ENOSYS) {
+        return;
+    }
+
+    match fork().expect("Error: Fork Failed") {
+        Child => {
+            ptrace::traceme().unwrap();
+            // first sigstop until parent is ready to continue
+            kill(getpid(), Signal::SIGSTOP).unwrap();
+            kill(getpid(), Signal::SIGTERM).unwrap();
+        },
+
+        Parent { child } => {
+            assert_eq!(waitpid(child, None), Ok(WaitStatus::Stopped(child, Signal::SIGSTOP)));
+
+            // set this option to recognize syscall-stops
+            ptrace::setoptions(child, ptrace::Options::PTRACE_O_TRACESYSGOOD).unwrap();
+
+            let get_syscall_id = || ptrace::getregs(child).unwrap().orig_rax as i64;
+
+
+            // getpid entry
+            ptrace::syscall(child, None).unwrap();
+            assert_eq!(waitpid(child, None), Ok(WaitStatus::PtraceSyscall(child)));
+            assert_eq!(get_syscall_id(), libc::SYS_getpid);
+
+            // getpid exit
+            ptrace::syscall(child, None).unwrap();
+            assert_eq!(waitpid(child, None), Ok(WaitStatus::PtraceSyscall(child)));
+            assert_eq!(get_syscall_id(), libc::SYS_getpid);
+
+            // kill entry
+            ptrace::syscall(child, None).unwrap();
+            assert_eq!(waitpid(child, None), Ok(WaitStatus::PtraceSyscall(child)));
+            assert_eq!(get_syscall_id(), libc::SYS_kill);
+
+            // kill exit
+            ptrace::syscall(child, None).unwrap();
+            assert_eq!(waitpid(child, None), Ok(WaitStatus::PtraceSyscall(child)));
+            assert_eq!(get_syscall_id(), libc::SYS_kill);
+
+            // receive signal
+            ptrace::syscall(child, None).unwrap();
+            assert_eq!(waitpid(child, None), Ok(WaitStatus::Stopped(child, Signal::SIGTERM)));
+
+            // inject signal
+            ptrace::syscall(child, Signal::SIGTERM).unwrap();
+            assert_eq!(waitpid(child, None), Ok(WaitStatus::Signaled(child, Signal::SIGTERM, false)));
+        },
+    }
+}