scripts/runqemu: Improve lockfile handling for python with close_fd=True

On python versions with close_fds=True (python 3.2 onwards), the tap
device lockfile isn't passed to the child process.

Since this guards against use of an active interface, we really want this
here, so pass it in pass_fds. This means if the parent exits early, the child
still holds the lock, avoiding messages like:

runqemu - ERROR - Failed to run qemu: qemu-system-x86_64: could not configure /dev/net/tun (tap0): Device or resource busy

(From OE-Core rev: 17a0a067d597c445c5892ff9914e91a2187f7e09)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

diff --git a/scripts/runqemu b/scripts/runqemu
index a83c8a6944d05df1127547d6fc6f284d00edbe95..c6b7580ddcb16980212ce8e26a1d9d5fe99519ff 100755 (executable)
--- a/scripts/runqemu
+++ b/scripts/runqemu
@@ -1215,7 +1215,10 @@ class BaseConfig(object):
         cmd = "%s %s" % (self.qemu_opt, kernel_opts)
         cmds = shlex.split(cmd)
         logger.info('Running %s\n' % cmd)
-        process = subprocess.Popen(cmds, stderr=subprocess.PIPE)
+        pass_fds = []
+        if self.lock_descriptor:
+            pass_fds = [self.lock_descriptor.fileno()]
+        process = subprocess.Popen(cmds, stderr=subprocess.PIPE, pass_fds=pass_fds)
         self.qemupid = process.pid
         retcode = process.wait()
         if retcode: