From 99c014a87979c9244806685f3c3fc7767f79f645 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Wed, 8 Mar 2017 10:16:17 -0500 Subject: [PATCH 1/2] ktest: Fix while loop in wait_for_input The run_command function was changed to use the wait_for_input function to allow having a timeout if the command to run takes too much time. There was a bug in the wait_for_input where it could end up going into an infinite loop. There's two issues here. One is that the return value of the sysread wasn't used for the write (to write a proper size), and that it should continue processing the passed in file descriptor too even if there was input. There was no check for error, if for some reason STDIN returned an error, the function would go into an infinite loop and never exit. Reported-by: Greg Kroah-Hartman Tested-by: Greg Kroah-Hartman Fixes: 6e98d1b4415f ("ktest: Add timeout to ssh command") Signed-off-by: Steven Rostedt (VMware) --- tools/testing/ktest/ktest.pl | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/tools/testing/ktest/ktest.pl b/tools/testing/ktest/ktest.pl index 29470b554711..0c006a2f165d 100755 --- a/tools/testing/ktest/ktest.pl +++ b/tools/testing/ktest/ktest.pl @@ -1904,11 +1904,12 @@ sub wait_for_input # copy data from stdin to the console if (vec($rout, fileno(\*STDIN), 1) == 1) { - sysread(\*STDIN, $buf, 1000); - syswrite($fp, $buf, 1000); - next; + $nr = sysread(\*STDIN, $buf, 1000); + syswrite($fp, $buf, $nr) if ($nr > 0); } + next if (vec($rout, fileno($fp), 1) != 1); + $line = ""; # try to read one char at a time From f7c6401ff84ab8ffffc281a29aa0a787f7eb346e Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Wed, 8 Mar 2017 10:36:59 -0500 Subject: [PATCH 2/2] ktest: Make sure wait_for_input does honor the timeout The function wait_for_input takes in a timeout, and even has a default timeout. But if for some reason the STDIN descriptor keeps sending in data, the function will never time out. The timout is to wait for the data from the passed in file descriptor, not for STDIN. Adding a test in the case where there's no data from the passed in file descriptor that checks to see if the timeout passed, will ensure that it will timeout properly even if there's input in STDIN. Signed-off-by: Steven Rostedt (VMware) --- tools/testing/ktest/ktest.pl | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/tools/testing/ktest/ktest.pl b/tools/testing/ktest/ktest.pl index 0c006a2f165d..49f7c8b9d9c4 100755 --- a/tools/testing/ktest/ktest.pl +++ b/tools/testing/ktest/ktest.pl @@ -1880,6 +1880,7 @@ sub get_grub_index { sub wait_for_input { my ($fp, $time) = @_; + my $start_time; my $rin; my $rout; my $nr; @@ -1895,12 +1896,12 @@ sub wait_for_input vec($rin, fileno($fp), 1) = 1; vec($rin, fileno(\*STDIN), 1) = 1; + $start_time = time; + while (1) { $nr = select($rout=$rin, undef, undef, $time); - if ($nr <= 0) { - return undef; - } + last if ($nr <= 0); # copy data from stdin to the console if (vec($rout, fileno(\*STDIN), 1) == 1) { @@ -1908,7 +1909,11 @@ sub wait_for_input syswrite($fp, $buf, $nr) if ($nr > 0); } - next if (vec($rout, fileno($fp), 1) != 1); + # The timeout is based on time waiting for the fp data + if (vec($rout, fileno($fp), 1) != 1) { + last if (defined($time) && (time - $start_time > $time)); + next; + } $line = ""; @@ -1918,12 +1923,11 @@ sub wait_for_input last if ($ch eq "\n"); } - if (!length($line)) { - return undef; - } + last if (!length($line)); return $line; } + return undef; } sub reboot_to {