ktest: Restore tty settings after closing console
When ktest runs the console program as a child process, the parent and
child share the same tty for stdin and stderr. This is problematic when
using a libvirt target. The "virsh console" program makes a lot of
changes to the tty settings, making ktest's output hard to read
(carriage returns don't work). After ktest exits, the terminal is
unusable (CRs broken, stdin isn't echoed).
I think the best way to fix this issue would be to create a
pseudoterminal (pty pair) so the child process would have a dedicated
tty, and then use pipes to connect the two ttys. I'm not sure if that's
overkill, but it's far beyond my current Perl abilities.
This patch is a much easier way to (partially) fix this issue. It saves
the tty settings before opening the console and restores them after
closing it. There are still a few places where ktest prints mangled
output while the console is open, but the output is much more legible
overall, and the terminal works just fine after ktest exits.
Link: http://lkml.kernel.org/r/1bb89abc0025cf1d6da657c7ba58bbeb4381a515.1422382008.git.jpoimboe@redhat.com
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/tools/testing/ktest/ktest.pl b/tools/testing/ktest/ktest.pl
index 27273c2..1dae000 100755
--- a/tools/testing/ktest/ktest.pl
+++ b/tools/testing/ktest/ktest.pl
@@ -178,6 +178,7 @@
my $localversion;
my $iteration = 0;
my $successes = 0;
+my $stty;
my $bisect_good;
my $bisect_bad;
@@ -1349,6 +1350,9 @@
my $flags;
+ # save terminal settings
+ $stty = `stty -g`;
+
my $pid = open($fp, "$console|") or
dodie "Can't open console $console";
@@ -1368,6 +1372,9 @@
print "closing!\n";
close($fp);
+
+ # restore terminal settings
+ system("stty $stty");
}
sub start_monitor {