Subject: fp simulator kernel crash, tcsh here doc crash, welcome y2k bug
Index:	 src/sys/pdp/mch_fpsim.s, src/bin/tcsh/(sh.glob.c,sh.dol.c,sh.decls.h), src/local/welcome/welcome.c

Description:
	Using the Floating Point simulation will crash the kernel when a
	signal (SIGTRAP, SIGILL, SIGFPE) needs to be generated.

	tcsh will crash when using a 'here document'.

	There is a year 2000 (y2k) bug in the 'welcome' program.

Repeat-By:
	1. Have a PDP-11 without floating point harware (but otherwise still
	capable of running 2.11BSD) and execute a floating point instruction
	with an invalid opcode (SIGILL), invalid / inaccessible data (SIGSEGV),
	or (SIGTRAP)
	
	The problem is that the signal names created during the kernel
	build process (by the 'genassym' helper program) have a '.' appended.
	So the signal name SIGILL (which has the value of 4) is given the 
	value of 4. 
	
	In mch_fpsim.s 

	   This analysis is courtesy of Dr. Walter F.J. Mueller:

	   mov $SIGILL.,r0

	   becomes

	   mov $4..,r0

	the assembler https://wolfram.schneider.org/bsd/7thEdManVol2/assembler/assembler.pdf

	   6.1  Expression  operators. The operators are:

		(blank) when there  is  no  operand  between  operands,
		the effect is exactly the same as if a + had appeared.

		So the lexer sees two tokens

		$4. --> number
		.   --> symbol for location counter

		and because the default operator is '+' interprets this as

		mov $4. + . , r0

		which ends up being a number in the 160000 to 177777 range.

		And that causes a crash.

	2. Use a 'here document' and tcsh will crash:

cat <<EOF
foobar
EOF

	3. Run the /usr/local/bin/welcome program and see that the year is
	   malformed

Fix:
	1. removing the extra '.' at the end of the signal names.

	2. fix was to move the rscan()' function to the same overlay as its
	   only use.  Since rscan is only used in one place make the function 
	   'static'.  Also the function Dtestq() was inlined because it was
	   only used in one place (in rscan).
	
	3. Remove the hardcoded '19' in the format string and add 1900 to the
	   year value.


	To apply this patch cut where indicated and save to a file (/tmp/453).

	Then:

	cd /
	patch -p0 < /tmp/453

	cd /usr/src/bin/tcsh
	make 
	make install
	make clean

	cd /usr/src/local/welcome
	make
	make install
	make clean

	It is only necessary to rebuild the kernel if the system does not
	have floating point hardware.

	This and previous updates to 2.11BSD are available at the following
	locations:
	
	ftp://ftp.update.uu.se/pub/pdp11/2.11BSD
	https://www.tuhs.org/Archive/Distributions/UCB/2.11BSD/Patches/
	ftp://ftp.2bsd.com/2.11BSD

---------------------------cut here--------------------
*** usr/src/sys/pdp/mch_fpsim.s.old	Tue Dec 26 16:56:08 2006
--- usr/src/sys/pdp/mch_fpsim.s	Fri Oct 11 12:32:49 2019
***************
*** 17,23 ****
   *	RIGHTS, APPROPRIATE COPYRIGHT LEGENDS MAY BE PLACED ON THE
   *	DERIVATIVE WORK IN ADDITION TO THAT SET FORTH ABOVE.
   *
!  *	@(#)mch_fpsim.s	1.3 (2.11BSD) 2006/12/26
   */
  #include "DEFS.h"
  
--- 17,23 ----
   *	RIGHTS, APPROPRIATE COPYRIGHT LEGENDS MAY BE PLACED ON THE
   *	DERIVATIVE WORK IN ADDITION TO THAT SET FORTH ABOVE.
   *
!  *	@(#)mch_fpsim.s	1.4 (2.11BSD) 2019/10/11
   */
  #include "DEFS.h"
  
***************
*** 246,260 ****
  2:
  	jmp	cret
  1:
! 	mov	$SIGTRAP.,r0
  	br	2b
  badins:				/ Illegal Instruction
! 	mov	$SIGILL.,r0
  	br	2b
  segfault:			/ Segmentation Violation
  	mov	uar0,r0		/ Don't update any registers, but
  	sub	$2,2.(r0)	/ back up the pc to point to the instruction.
! 	mov	$SIGSEGV.,r0
  	br	2b
  fpexcept:			/ Floating Point Exception
  	/ restore all the new register values, and then
--- 246,260 ----
  2:
  	jmp	cret
  1:
! 	mov	$SIGTRAP,r0
  	br	2b
  badins:				/ Illegal Instruction
! 	mov	$SIGILL,r0
  	br	2b
  segfault:			/ Segmentation Violation
  	mov	uar0,r0		/ Don't update any registers, but
  	sub	$2,2.(r0)	/ back up the pc to point to the instruction.
! 	mov	$SIGSEGV,r0
  	br	2b
  fpexcept:			/ Floating Point Exception
  	/ restore all the new register values, and then
***************
*** 270,276 ****
  	mov	(r1)+,-6.(r0)	/ sp (r6)
  	mov	(r1)+,2.(r0)	/ pc (r7)
  	mov	(r1)+,4.(r0)	/ psw
! 	mov	$SIGFPE.,r0
  	jmp	cret
  
  freg:
--- 270,276 ----
  	mov	(r1)+,-6.(r0)	/ sp (r6)
  	mov	(r1)+,2.(r0)	/ pc (r7)
  	mov	(r1)+,4.(r0)	/ psw
! 	mov	$SIGFPE,r0
  	jmp	cret
  
  freg:
*** usr/src/bin/tcsh/sh.glob.c.old	Sun Oct  6 17:41:53 1991
--- usr/src/bin/tcsh/sh.glob.c	Fri Oct 11 13:07:08 2019
***************
*** 1,4 ****
- /* $Header: /home/hyperion/mu/christos/src/sys/tcsh-6.00/RCS/sh.glob.c,v 3.0 1991/07/04 21:49:28 christos Exp $ */
  /*
   * sh.glob.c: Regular expression expansion
   */
--- 1,3 ----
***************
*** 37,43 ****
  #include "config.h"
  #if !defined(lint) && !defined(pdp11)
  static char *rcsid() 
!     { return "$Id: sh.glob.c,v 3.0 1991/07/04 21:49:28 christos Exp $"; }
  #endif
  
  #include "sh.h"
--- 36,42 ----
  #include "config.h"
  #if !defined(lint) && !defined(pdp11)
  static char *rcsid() 
!     { return "$Id: sh.glob.c,v 3.1 2019/10/11 13:06:28 sms Exp $"; }
  #endif
  
  #include "sh.h"
***************
*** 530,547 ****
      gargv = (Char **) xmalloc((size_t) sizeof(Char *) * gargsiz);
      gargv[0] = 0;
      gargc = 0;
- }
- 
- void
- rscan(t, f)
-     register Char **t;
-     void    (*f) ();
- {
-     register Char *p;
- 
-     while (p = *t++)
- 	while (*p)
- 	    (*f) (*p++);
  }
  
  void
--- 529,534 ----
*** usr/src/bin/tcsh/sh.dol.c.old	Tue Aug 20 14:12:55 1991
--- usr/src/bin/tcsh/sh.dol.c	Fri Oct 11 12:56:41 2019
***************
*** 1,4 ****
- /* $Header: /home/hyperion/mu/christos/src/sys/tcsh-6.00/RCS/sh.dol.c,v 3.0 1991/07/04 21:49:28 christos Exp $ */
  /*
   * sh.dol.c: Variable substitutions
   */
--- 1,3 ----
***************
*** 37,43 ****
  #include "config.h"
  #if !defined(lint) && !defined(pdp11)
  static char *rcsid() 
!     { return "$Id: sh.dol.c,v 3.0 1991/07/04 21:49:28 christos Exp $"; }
  #endif
  
  #include "sh.h"
--- 36,42 ----
  #include "config.h"
  #if !defined(lint) && !defined(pdp11)
  static char *rcsid() 
!     { return "$Id: sh.dol.c,v 3.1 2019/10/11 12:37:28 sms Exp $"; }
  #endif
  
  #include "sh.h"
***************
*** 86,92 ****
  static	void	 setDolp	__P((Char *));
  static	void	 unDredc	__P((int));
  static	int	 Dredc		__P((void));
- static	void	 Dtestq		__P((int));
  
  /*
   * Fix up the $ expansions and quotations in the
--- 85,90 ----
***************
*** 672,684 ****
  }
  
  static void
! Dtestq(c)
!     register int c;
  {
  
!     if (cmap(c, QUOTES))
! 	gflag = 1;
! }
  
  /*
   * Form a shell temporary file (in unit 0) from the words
--- 670,689 ----
  }
  
  static void
! rscan(t)
!     register Char **t;
  {
+     register Char *p, c;
  
!     while (p = *t++)
!           {
! 	  while (c = *p++)
!                 {
!                 if (cmap(c, QUOTES))
! 	           gflag = 1;
!                 }
!           }
! }
  
  /*
   * Form a shell temporary file (in unit 0) from the words
***************
*** 713,719 ****
      Dv[1] = NOSTR;
      gflag = 0;
      trim(Dv);
!     rscan(Dv, Dtestq);
      quoted = gflag;
      ocnt = BUFSIZ;
      obp = obuf;
--- 718,724 ----
      Dv[1] = NOSTR;
      gflag = 0;
      trim(Dv);
!     rscan(Dv);
      quoted = gflag;
      ocnt = BUFSIZ;
      obp = obuf;
*** usr/src/bin/tcsh/sh.decls.h.old	Tue Aug 20 14:12:53 1991
--- usr/src/bin/tcsh/sh.decls.h	Fri Oct 11 12:40:56 2019
***************
*** 1,5 ****
- /* $Header: /home/hyperion/mu/christos/src/sys/tcsh-6.00/RCS/sh.decls.h,v 3.0 1991/07/04 23:34:26 christos Exp $ */
  /*
   * sh.decls	 External declarations from sh*.c
   */
  /*-
--- 1,7 ----
  /*
+  *      @(#)sh.decls.h 2.0 (2.11BSD) 2019/10/11
+ */
+ /*
   * sh.decls	 External declarations from sh*.c
   */
  /*-
***************
*** 169,175 ****
  extern	int		  Gmatch	__P((Char *, Char *));
  extern	void		  ginit		__P((void));
  extern	Char		**globall	__P((Char **));
- extern	void		  rscan		__P((Char **, void (*)()));
  extern	void		  tglob		__P((Char **));
  extern	void		  trim		__P((Char **));
  #ifdef FILEC
--- 171,176 ----
*** usr/src/local/welcome/welcome.c.old	Sun Feb  5 02:46:27 1995
--- usr/src/local/welcome/welcome.c	Fri Oct 11 13:04:26 2019
***************
*** 1,3 ****
--- 1,9 ----
+ /*
+  *       welcome program
+  *
+  *      @(#) welcome.c 3.1 (2.11BSD) 2019/10/11
+  */
+ 
  #include <stdio.h>
  #include <sys/param.h>
  #include <sys/sysctl.h>
***************
*** 123,130 ****
  	x = 40 - (strlen(days[det->tm_wday]) / 2);
  	y = (69 - x);
  	printf("\033[8;%dH%s", y, days[det->tm_wday]);
! 	sprintf(bot, "%s %d, 19%d %d:%02d %cM", mons[det->tm_mon],
! 	        det->tm_mday, det->tm_year, det->tm_hour,
  		det->tm_min, ap);
  	a = 40 -(strlen(bot) / 2);
  	b = (54 - a);
--- 129,136 ----
  	x = 40 - (strlen(days[det->tm_wday]) / 2);
  	y = (69 - x);
  	printf("\033[8;%dH%s", y, days[det->tm_wday]);
! 	sprintf(bot, "%s %d, %d %d:%02d %cM", mons[det->tm_mon],
! 	        det->tm_mday, det->tm_year+1900, det->tm_hour,
  		det->tm_min, ap);
  	a = 40 -(strlen(bot) / 2);
  	b = (54 - a);
*** VERSION.old	Sat Apr 27 08:42:59 2019
--- VERSION	Fri Oct 11 12:34:04 2019
***************
*** 1,5 ****
! Current Patch Level: 452
! Date: April 27, 2019
  
  2.11 BSD
  ============
--- 1,5 ----
! Current Patch Level: 453
! Date: October 11, 2019
  
  2.11 BSD
  ============