[OE-core] [PATCH 1/1] runqemu: fix handling of SIGTERM and the problem of line wrapping

[Chen Qi]

The current handling of SIGTERM is incorrect as the process pid returned
by Popen call with shell setting to True is actualy the shell instead of
the qemu binary. So fix to send SIGTERM to the process group of runqemu.
This ensures that all processes in the same process group, including the
shell and the qemu process, will receive SIGTERM.

Also, as we install a SIGTERM handler, we need handle the situation of
qemu terminated by SIGTERM, otherwise we will get ERROR message in such
case.

Besides, we have a problem that after running qemu, the terminal's behavior
is incorrect regarding long lines or long commands. Long commands or long
outputs should appear in multiple lines, but they appear in the same line,
overriding previous output. Use `tput smam' to fix this problem.

Signed-off-by: Chen Qi <Qi.Chen at windriver.com>
---
 scripts/runqemu | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/scripts/runqemu b/scripts/runqemu
index 409d17c..bc2aba5 100755
--- a/scripts/runqemu
+++ b/scripts/runqemu
@@ -1213,9 +1213,12 @@ class BaseConfig(object):
         cmd = "%s %s" % (self.qemu_opt, kernel_opts)
         logger.info('Running %s\n' % cmd)
         process = subprocess.Popen(cmd, shell=True, stderr=subprocess.PIPE)
-        self.qemupid = process.pid
-        if process.wait():
-            logger.error("Failed to run qemu: %s", process.stderr.read().decode())
+        retcode = process.wait()
+        if retcode:
+            if retcode == -signal.SIGTERM:
+                logger.info("Qemu terminated by SIGTERM")
+            else:
+                logger.error("Failed to run qemu: %s", process.stderr.read().decode())
 
     def cleanup(self):
         if self.cleaned:
@@ -1308,8 +1311,10 @@ def main():
 
         def sigterm_handler(signum, frame):
             logger.info("SIGTERM received")
-            os.kill(config.qemupid, signal.SIGTERM)
+            signal.signal(signal.SIGTERM, signal.SIG_IGN)
+            os.kill(0, signal.SIGTERM)
             config.cleanup()
+            subprocess.run(["tput", "smam"])
         signal.signal(signal.SIGTERM, sigterm_handler)
 
         config.check_args()
@@ -1331,6 +1336,7 @@ def main():
         return 1
     finally:
         config.cleanup()
+        subprocess.run(["tput", "smam"])
 
 if __name__ == "__main__":
     sys.exit(main())
-- 
1.9.1