From 5de5611c24e8b2d78c7e9437a5ec294e68cbca2e Mon Sep 17 00:00:00 2001
From: George Koehler <xkernigh@netscape.net>
Date: Fri, 15 Jun 2018 00:17:12 -0400
Subject: [PATCH 1/2] Use 2-byte alignment in pdpv7 to prevent SIGBUS.

Change the alignment in C structs (wa, pa, sa, and so on) from 1 to 2
bytes.  This prevents the SIGBUS when PDP-11 Unix V7 catches the
misalignment.  This fixes hilo_p.pdpv7 in simh-pdp11.

Change ALIGN to document that sections have 2-byte alignment.  This
change should have no effect, because the sections only contain 2-byte
values.
---
 plat/pdpv7/descr | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/plat/pdpv7/descr b/plat/pdpv7/descr
index ee69bf137..1fcc21161 100644
--- a/plat/pdpv7/descr
+++ b/plat/pdpv7/descr
@@ -1,24 +1,24 @@
 # $Revision$
 var w=2
-var wa=1
+var wa=2
 var p=2
-var pa=1
+var pa=2
 var s=2
-var sa=1
+var sa=2
 var l=4
-var la=1
+var la=2
 var f=4
-var fa=1
+var fa=2
 var d=8
-var da=1
+var da=2
 var x=8
-var xa=1
+var xa=2
 
 var ARCH=pdp
 var PLATFORM=pdpv7
 var PLATFORMDIR={EM}/share/ack/{PLATFORM}
 var CPP_F=-D__unix
-var ALIGN=-a0:1 -a1:1 -a2:1 -a3:1
+var ALIGN=-a0:2 -a1:2 -a2:2 -a3:2
 
 var C_INCLUDES=-I{PLATFORMDIR}/include -I{EM}/share/ack/include/ansi
 

From 5db312a1c0891f16d88fd3f187e0fda46044b4a5 Mon Sep 17 00:00:00 2001
From: George Koehler <xkernigh@netscape.net>
Date: Fri, 15 Jun 2018 00:48:29 -0400
Subject: [PATCH 2/2] Prevent crash in isatty()

The existing code allocated 2 bytes (char*), but gtty() needs 6 bytes
(struct sgttyb), so isatty() smashed the stack and corrupted its
return address, probably causing SIGBUS or SIGSEGV.

Fix by switching to TIOCGETD, which needs 2 bytes.  TIOCGETD isn't in
the manual for tty(4), but does appear in
https://minnie.tuhs.org//cgi-bin/utree.pl?file=V7/usr/sys/dev/tty.c

This fixes hilo_c.pdpv7 and hilo_mod.pdpv7 in simh-pdp11.
---
 plat/pdpv7/libsys/isatty.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/plat/pdpv7/libsys/isatty.c b/plat/pdpv7/libsys/isatty.c
index 9ff30e797..7bf22b914 100644
--- a/plat/pdpv7/libsys/isatty.c
+++ b/plat/pdpv7/libsys/isatty.c
@@ -1,8 +1,8 @@
 int isatty(int fd)
 {
-    char* p;
+    unsigned u;
 
-    if (gtty(fd, &p) < 0)
+    if (ioctl(fd, /*TIOCGETD*/(('t'<<8)|0), &u) < 0)
         return 0;
     return 1;
 }