Job control fix

[Nicholas S Castellano <entropy@terminator.rs.itd.umich.edu>]

Here's a patch to fix job control handling.  Don't be surprised if
you get some offsets while applying the patch,

tty.c: ++entropy@terminator.rs.itd.umich.edu
	Fix SIGTTIN/SIGTTOU job control.

--- 1.10.1.3	1994/02/27 04:03:08
+++ tty.c	1994/02/27 04:14:34
@@ -658,8 +658,16 @@
 	}
 
 /* job control check */
-
-	if (tty->pgrp && tty->pgrp != curproc->pgrp) {
+/*
+entropy: only do the job control if SIGTTIN is neither blocked nor ignored,
+and only for the controlling tty (IEEE 1003.1-1990 7.1.1.4 70-78).
+BUG:  if the process group is orphaned or SIGTTIN *is* blocked or ignored,
+we should return EIO instead of signalling.
+*/
+
+	if ((tty->pgrp && tty->pgrp != curproc->pgrp) &&
+            (f->fc.dev == curproc->control->fc.dev) &&
+            (f->fc.index == curproc->control->fc.index)) {
 		TRACE(("job control: tty pgrp is %d proc pgrp is %d",
 			tty->pgrp, curproc->pgrp));
 		killgroup(curproc->pgrp, SIGTTIN);
@@ -787,8 +795,18 @@
 	}
 /* job control checks */
 /* AKP: added T_TOSTOP; don't stop BG output if T_TOSTOP is clear */
+/*
+entropy: only do the job control if SIGTTOU is neither blocked nor ignored,
+and only for the controlling tty (IEEE 1003.1-1990 7.1.1.4 79-87).
+BUG:  if the process group is orphaned and SIGTTOU *is not* blocked
+or ignored, we should return EIO instead of signalling.
+*/
 	if (tty->pgrp && tty->pgrp != curproc->pgrp &&
-	         (tty->sg.sg_flags & T_TOSTOP)) {
+	         (tty->sg.sg_flags & T_TOSTOP) &&
+                 (curproc->sighandle[SIGTTOU] != SIG_IGN) &&
+                 ((curproc->sigmask & (1L << SIGTTOU)) == 0L) &&
+                 (f->fc.dev == curproc->control->fc.dev) &&
+                 (f->fc.index == curproc->control->fc.index)) {
 		TRACE(("job control: tty pgrp is %d proc pgrp is %d",
 			tty->pgrp, curproc->pgrp));
 		killgroup(curproc->pgrp, SIGTTOU);

--
entropy -- it's not just a good idea, it's the second law.
Personal mail:      entropy@gnu.ai.mit.edu
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