Subject: Disabling Ctrl-Alt-Del
From: [email-masked] (Gerhard Wesp)
Date: Mon, 21 Jun 93 13:25:39 GMT
Newsgroups: comp.os.linux.announce

Hi!

Just in case somebody is interested, here are my diffs against the .99pl10
kernel sources to add a confuguration option for disabling the Ctrl-Alt-Del
reboot.

To apply them, cd to /usr/src/linux or whereever your kernel sources live
and type 'patch < patchfile', where 'patchfile' of course should contain
the diffs in this posting.

After that, type 'make config' and run through the normal configuration
procedure. There should be a new question, 'Ctrl-Alt-Del reboots the   
machine?' Answering yes will result in the usual kernel behaviour, ans-
wering no will #ifdef out all code related to detecting and reacting
to a Ctrl-Alt-Del combination.

Greetings, 
-Gerhard

============================= CUT HERE =================================
diff --context --recursive ../linux/config.in ./config.in
*** ../linux/config.in	Sat Jun 19 16:27:17 1993
--- ./config.in	Sat Jun 19 18:02:54 1993
***************
*** 69,74 ****
--- 69,76 ----
  .
  Keyboard meta-key sends ESC-prefix
  CONFIG_KBD_META y/n y
+ Ctrl-Alt-Del reboots the machine
+ CONFIG_KBD_CAD y/n y
  Logitech busmouse support
  CONFIG_BUSMOUSE y/n n
  PS/2 mouse (aka 'auxiliary device') support
diff --context --recursive ../linux/kernel/chr_drv/keyboard.c ./kernel/chr_drv/keyboard.c
*** ../linux/kernel/chr_drv/keyboard.c	Sat Jun  5 14:36:21 1993
--- ./kernel/chr_drv/keyboard.c	Sat Jun 19 18:02:25 1993
***************
*** 47,53 ****
--- 47,55 ----
  #include <asm/system.h>
  
  extern void do_keyboard_interrupt(void);
+ #ifdef CONFIG_KBD_CAD
  extern void ctrl_alt_del(void);
+ #endif
  extern void change_console(unsigned int new_console);
  extern void scrollback(int);
  extern void scrollfront(int);
***************
*** 502,512 ****
--- 504,516 ----
  	if (up_flag)
  		return;		/* no action, if this is a key release */
  
+ #ifdef CONFIG_KBD_CAD
  	if ((value == KVAL(K_PCOMMA) || value == KVAL(K_PDOT)) &&
  	    (kbd_flags & CTRL_KEYS) && (kbd_flags & (ALT_KEYS | ALTGR_KEYS))) {
  		ctrl_alt_del();
  		return;
  	}
+ #endif
  
  	if ((kbd_flags & ALT_KEYS) && value <= 9) {	/* Alt-numpad */
  		npadch = (npadch * 10 + value) % 1000;
diff --context --recursive ../linux/kernel/sys.c ./kernel/sys.c
*** ../linux/kernel/sys.c	Wed May 26 19:21:22 1993
--- ./kernel/sys.c	Sat Jun 19 18:02:24 1993
***************
*** 23,29 ****
--- 23,31 ----
  /*
   * this indicates wether you can reboot with ctrl-alt-del: the default is yes
   */
+ #ifdef CONFIG_KBD_CAD
  static int C_A_D = 1;
+ #endif
  
  /* 
   * The timezone where the local system is located.  Used as a default by some
***************
*** 220,229 ****
--- 222,233 ----
  		return -EINVAL;
  	if (flag == 0x01234567)
  		hard_reset_now();
+ #ifdef CONFIG_KBD_CAD
  	else if (flag == 0x89ABCDEF)
  		C_A_D = 1;
  	else if (!flag)
  		C_A_D = 0;
+ #endif
  	else
  		return -EINVAL;
  	return (0);
***************
*** 234,239 ****
--- 238,245 ----
   * As it's called within an interrupt, it may NOT sync: the only choice
   * is wether to reboot at once, or just ignore the ctrl-alt-del.
   */
+ 
+ #ifdef CONFIG_KBD_CAD
  void ctrl_alt_del(void)
  {
  	if (C_A_D)
***************
*** 241,247 ****
  	else
  		send_sig(SIGINT,task[1],1);
  }
! 	
  
  /*
   * This is done BSD-style, with no consideration of the saved gid, except
--- 247,253 ----
  	else
  		send_sig(SIGINT,task[1],1);
  }
! #endif 	
  
  /*
   * This is done BSD-style, with no consideration of the saved gid, except

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