From 2c9fb90995c4e551d4f668f5a87309cea17c4f75 Mon Sep 17 00:00:00 2001 From: Dima Dorfman Date: Sat, 24 Nov 2001 15:34:18 +0000 Subject: [PATCH] Return EBUSY if we try to attach to a tty that is already being snooped on. This causes all kinds of Bad Things(tm) to happen since closing one session will clobber state that's needed for the other one. This could theoretically be supported if the code was careful, but until somebody implements that, preventing this will stop people from unknowingly shooting themselves in the foot. --- sys/dev/snp/snp.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/sys/dev/snp/snp.c b/sys/dev/snp/snp.c index e6cf7970e88..0b4504703d6 100644 --- a/sys/dev/snp/snp.c +++ b/sys/dev/snp/snp.c @@ -508,6 +508,8 @@ snpioctl(dev, cmd, data, flags, td) tp = snpdevtotty(tdev); if (!tp) return (EINVAL); + if (tp->t_state & TS_SNOOP) + return (EBUSY); s = spltty();