fix pty_test error by releasing tty received from test

The test Truncate set ControllingTTY without releasing
it on VFS2. This leads test ReleaseTTYSignals and ReleaseTTY
fail when setting ControllingTTY.

Skip the test on VFS1 and native, as setting Controlling TTY
when open replica only happens on VFS2.

Signed-off-by: Howard Zhang <howard.zhang@arm.com>

2 files changed, 18 insertions, 0 deletions

diff --git a/test/syscalls/linux/BUILD b/test/syscalls/linux/BUILD
index 94a582256..1ff001426 100644
--- a/test/syscalls/linux/BUILD
+++ b/test/syscalls/linux/BUILD
@@ -1471,6 +1471,7 @@ cc_binary(
         "//test/util:cleanup",
         "//test/util:posix_error",
         "//test/util:pty_util",
+        "//test/util:signal_util",
         "//test/util:test_main",
         "//test/util:test_util",
         "//test/util:thread_util",
diff --git a/test/syscalls/linux/pty.cc b/test/syscalls/linux/pty.cc
index 8d15c491e..541b2744c 100644
--- a/test/syscalls/linux/pty.cc
+++ b/test/syscalls/linux/pty.cc
@@ -40,6 +40,7 @@
 #include "test/util/file_descriptor.h"
 #include "test/util/posix_error.h"
 #include "test/util/pty_util.h"
+#include "test/util/signal_util.h"
 #include "test/util/test_util.h"
 #include "test/util/thread_util.h"
 
@@ -387,6 +388,21 @@ PosixErrorOr<size_t> PollAndReadFd(int fd, void* buf, size_t count,
 }
 
 TEST(PtyTrunc, Truncate) {
+  SKIP_IF(IsRunningWithVFS1());
+
+  // setsid either puts us in a new session or fails because we're already the
+  // session leader. Either way, this ensures we're the session leader and have
+  // no controlling terminal.
+  setsid();
+
+  // Make sure we're ignoring SIGHUP, which will be sent to this process once we
+  // disconnect they TTY.
+  struct sigaction sa = {};
+  sa.sa_handler = SIG_IGN;
+  sa.sa_flags = 0;
+  sigemptyset(&sa.sa_mask);
+  auto const cleanup = ASSERT_NO_ERRNO_AND_VALUE(ScopedSigaction(SIGHUP, sa));
+
   // Opening PTYs with O_TRUNC shouldn't cause an error, but calls to
   // (f)truncate should.
   FileDescriptor master =
@@ -395,6 +411,7 @@ TEST(PtyTrunc, Truncate) {
   std::string spath = absl::StrCat("/dev/pts/", n);
   FileDescriptor replica =
       ASSERT_NO_ERRNO_AND_VALUE(Open(spath, O_RDWR | O_NONBLOCK | O_TRUNC));
+  ASSERT_THAT(ioctl(replica.get(), TIOCNOTTY), SyscallSucceeds());
 
   EXPECT_THAT(truncate(kMasterPath, 0), SyscallFailsWithErrno(EINVAL));
   EXPECT_THAT(truncate(spath.c_str(), 0), SyscallFailsWithErrno(EINVAL));