>Number:         5191
>Category:       kern
>Synopsis:       A feature to allow dumping core to "core" instead of "prog.core"
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    kern-bug-people (Kernel Bug People)
>State:          open
>Class:          change-request
>Submitter-Id:   net
>Arrival-Date:   Mon Mar 23 20:05:00 1998
>Last-Modified:
>Originator:     Nathan J. Williams
>Organization:
	Massachvsetts Institvte of Technology
>Release:        NetBSD-current of 1998/3/22
>Environment:
System: NetBSD road-runner.mit.edu 1.3E NetBSD 1.3E (ROAD-RUNNER) #98: Mon Mar 23 22:12:16 EST 1998 nathanw@road-runner.mit.edu:/u1/usr/src/sys/arch/i386/compile/ROAD-RUNNER i386

>Description:
	NetBSD, like other 4.4BSD derivitaves, dumps a program's core image
into a file named "progname.core" under various circumstances. At some sites
it may be prefereable for the core file to simply be named "core". There may
be non-NetBSD corefile expungers, or there may be a desire to have a 
"core -> /somewhere/core" symlink work for all programs and across different
platforms, or the administrator may simply be of a traditional frame of mind.
NetBSD is not currently adjustable in this regard. 
>How-To-Repeat:
	
>Fix:
	I have implemented this feature by way of a kernel variable
"shortcorename", adjustable by the sysctl variable kern.shortcorefile
and by a "options SHORTCOREFILE" kernel configuration option.
	This patch adds the variable, the option, and appropriate
documentation in sysctl(3), sysctl(8), options(4), and core(5). It also
adjusts /etc/daily to look for both foo.core and core, which is useful both
in the presence of this setting and when the partitions being searched are
exported to non-4.4BSD clients. It also fixes a minor bug in /etc/daily's
"Possible core dumps" display heuristic. 

	I'm not very attached to the name. The names "longcorename", 
"44bsdcorefilename", "kern_44bsdcorefilename", "bsd44corefilename", and 
"progdotcore" were considered but ultimately rejected.

*** sys/kern/kern_sig.c.orig	Sun Mar  1 07:21:14 1998
--- sys/kern/kern_sig.c	Mon Mar 23 21:34:51 1998
***************
*** 1043,1050 ****
  }
  
  /*
!  * Dump core, into a file named "progname.core", unless the process was
!  * setuid/setgid.
   */
  int
  coredump(p)
--- 1043,1050 ----
  }
  
  /*
!  * Dump core, into a file named "progname.core" or "core" (depending on the 
!  * value of shortcorename), unless the process was setuid/setgid.
   */
  int
  coredump(p)
***************
*** 1058,1063 ****
--- 1058,1064 ----
  	int error, error1;
  	char name[MAXCOMLEN+6];		/* progname.core */
  	struct core core;
+ 	extern int shortcorename;
  
  	/*
  	 * Make sure the process has not set-id, to prevent data leaks.
***************
*** 1081,1087 ****
  	if (p->p_fd->fd_cdir->v_mount->mnt_flag & MNT_NOCOREDUMP)
  		return (EPERM);
  
! 	sprintf(name, "%s.core", p->p_comm);
  	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, name, p);
  	error = vn_open(&nd, O_CREAT | FWRITE, S_IRUSR | S_IWUSR);
  	if (error)
--- 1082,1091 ----
  	if (p->p_fd->fd_cdir->v_mount->mnt_flag & MNT_NOCOREDUMP)
  		return (EPERM);
  
! 	if (shortcorename) 
! 		sprintf(name, "core");
! 	else
! 		sprintf(name, "%s.core", p->p_comm);
  	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, name, p);
  	error = vn_open(&nd, O_CREAT | FWRITE, S_IRUSR | S_IWUSR);
  	if (error)
*** sys/kern/kern_sysctl.c.orig	Sun Mar  1 07:21:16 1998
--- sys/kern/kern_sysctl.c	Mon Mar 23 22:31:39 1998
***************
*** 212,217 ****
--- 212,222 ----
  #else
  int securelevel = 0;
  #endif
+ #ifdef SHORTCORENAME
+ int shortcorename = 1;
+ #else
+ int shortcorename = 0;
+ #endif
  
  /*
   * kernel related system variables.
***************
*** 229,234 ****
--- 234,240 ----
  	int error, level, inthostid;
  	int old_autonicetime;
  	int old_vnodes;
+ 	int old_shortcorename;
  	extern char ostype[], osrelease[], version[];
  
  	/* all sysctl names at this level are terminal */
***************
*** 348,353 ****
--- 354,369 ----
  			return (ENXIO);
  		}
  		return (sysctl_rdint(oldp, oldlenp, newp, msgbufp->msg_bufs));
+ 	case KERN_SHORTCORENAME:
+ 		/* Only allow values of zero or one. */
+ 		old_shortcorename = shortcorename;
+ 		error = sysctl_int(oldp, oldlenp, newp, newlen, 
+ 		    &shortcorename);
+ 		if (shortcorename != 0 && shortcorename != 1) {
+ 			shortcorename = old_shortcorename;
+ 			return (EINVAL);
+ 		}
+ 		return (error);
  	default:
  		return (EOPNOTSUPP);
  	}
*** sys/sys/sysctl.h.orig	Tue Mar  3 07:26:19 1998
--- sys/sys/sysctl.h	Mon Mar 23 22:31:14 1998
***************
*** 141,147 ****
  #define	KERN_RTC_OFFSET		29	/* int: offset of rtc from gmt */
  #define	KERN_ROOT_DEVICE	30	/* string: root device */
  #define	KERN_MSGBUFSIZE		31	/* int: max # of chars in msg buffer */
! #define	KERN_MAXID		32	/* number of valid kern ids */
  
  #define CTL_KERN_NAMES { \
  	{ 0, 0 }, \
--- 141,148 ----
  #define	KERN_RTC_OFFSET		29	/* int: offset of rtc from gmt */
  #define	KERN_ROOT_DEVICE	30	/* string: root device */
  #define	KERN_MSGBUFSIZE		31	/* int: max # of chars in msg buffer */
! #define	KERN_SHORTCORENAME	32	/* int: dump core as "core" */
! #define	KERN_MAXID		33	/* number of valid kern ids */
  
  #define CTL_KERN_NAMES { \
  	{ 0, 0 }, \
***************
*** 176,181 ****
--- 177,183 ----
  	{ "rtc_offset", CTLTYPE_INT }, \
  	{ "root_device", CTLTYPE_STRING }, \
  	{ "msgbufsize", CTLTYPE_INT }, \
+ 	{ "shortcorename", CTLTYPE_INT }, \
  }
  
  /*
*** etc/daily.orig	Mon Jan 26 07:43:53 1998
--- etc/daily	Mon Mar 23 22:05:22 1998
***************
*** 77,88 ****
  	find / \( ! -fstype local -o -fstype rdonly -o -fstype fdesc \
  		-o -fstype kernfs -o -fstype procfs \) -a -prune -o \
  		-name 'lost+found' -a -prune -o \
! 		-name '*.core' -a -print > $TMP
  #		\( -name '[#,]*' -o -name '.#*' -o -name a.out \
  #		   -o -name '*.CKP' -o -name '.emacs_[0-9]*' \) \
  #			-a -atime +3 -exec rm -f -- {} \; -a -print > $TMP
  
! 	egrep '\.core' $TMP > $TMP2
  	if [ -s $TMP2 ]; then
  		echo ""
  		echo "Possible core dumps:"
--- 77,88 ----
  	find / \( ! -fstype local -o -fstype rdonly -o -fstype fdesc \
  		-o -fstype kernfs -o -fstype procfs \) -a -prune -o \
  		-name 'lost+found' -a -prune -o \
! 		\( -name '*.core' -o -name 'core' \) -a -print > $TMP
  #		\( -name '[#,]*' -o -name '.#*' -o -name a.out \
  #		   -o -name '*.CKP' -o -name '.emacs_[0-9]*' \) \
  #			-a -atime +3 -exec rm -f -- {} \; -a -print > $TMP
  
! 	egrep '\.core$|^core$' $TMP > $TMP2
  	if [ -s $TMP2 ]; then
  		echo ""
  		echo "Possible core dumps:"
*** usr.sbin/sysctl/sysctl.8.orig	Fri Feb  6 08:07:50 1998
--- usr.sbin/sysctl/sysctl.8	Mon Mar 23 21:36:54 1998
***************
*** 133,138 ****
--- 133,139 ----
  .It kern.boottime	struct	no
  .It kern.autonicetime	integer	yes
  .It kern.autoniceval	integer	yes
+ .It kern.shortcorename	integer	yes
  .It vm.loadavg	struct	no
  .It machdep.console_device	dev_t	no
  .It net.inet.ip.forwarding	integer	yes
*** lib/libc/gen/sysctl.3.orig	Fri Feb  6 07:41:35 1998
--- lib/libc/gen/sysctl.3	Mon Mar 23 22:34:15 1998
***************
*** 282,287 ****
--- 282,288 ----
  .It KERN\_RAWPARTITION	integer	no
  .It KERN\_SAVED\_IDS	integer	no
  .It KERN\_SECURELVL	integer	raise only
+ .It KERN\_SHORTCORENAME	integer	yes
  .It KERN\_VDISABLE	integer	no
  .It KERN\_VERSION	string	no
  .It KERN\_VNODE	struct vnode	no
***************
*** 424,429 ****
--- 425,441 ----
  The system security level.
  This level may be raised by processes with appropriate privilege.
  It may only be lowered by process 1.
+ .It Li KERN_SHORTCORENAME
+ Whether core dumps are named 
+ .Nm programname.core
+ (default, value 0) or 
+ .Nm core
+ (value 1).
+ The default value can be changed to 1 with the kernel configuration option
+ .Cd options SHORTCORENAME
+ (see 
+ .Xr options 4 ,
+ .Xr core 5 ).
  .It Li KERN_VDISABLE
  Returns the terminal character disabling value.
  .It Li KERN_VERSION
*** share/man/man4/options.4.orig	Thu Mar 19 07:18:26 1998
--- share/man/man4/options.4	Mon Mar 23 21:49:55 1998
***************
*** 697,702 ****
--- 697,714 ----
  .Em CHILD_MAX
  is not permitted, as this would result in a violation of the semantics of
  .St -p1003.1-90 .
+ .It Cd options SHORTCORENAME
+ If set, process core dumps are named 
+ .Nm core .
+ If not specified, they are named
+ .Nm programname.core 
+ (the default in 4.4BSD). Note that this changes the value of the 
+ .Em kern.shortcorename 
+ sysctl variable which may be changed at run time. See
+ .Xr sysctl 8
+ and
+ .Xr sysctl 3
+ for details. 
  .El
  .Ss Networking Options
  .Bl -ohang
*** share/man/man5/core.5.orig	Thu Jul 10 07:15:47 1997
--- share/man/man5/core.5	Mon Mar 23 21:52:35 1998
***************
*** 47,60 ****
  to disk for later examination by one of the available debuggers.
  (See
  .Xr sigaction 2 . )
! This memory image is written to a file named
! .Nm programname.core
  in the working directory;
  provided the terminated process had write permission in the directory,
  and provided the abnormality did not cause
  a system crash.
  (In this event, the decision to save the core file is arbitrary, see
  .Xr savecore 8 . )
  .Pp
  The maximum size of a
  .Nm programname.core
--- 47,69 ----
  to disk for later examination by one of the available debuggers.
  (See
  .Xr sigaction 2 . )
! This memory image is written to a file 
  in the working directory;
  provided the terminated process had write permission in the directory,
  and provided the abnormality did not cause
  a system crash.
  (In this event, the decision to save the core file is arbitrary, see
  .Xr savecore 8 . )
+ The file is normally named 
+ .Nm programname.core ,
+ but is called
+ .Nm core
+ if the 
+ kernel configuration option 
+ .Cd options SHORTCORENAME
+ is defined or the sysctl variable
+ .Em kern.shortcorename
+ is set to 1.
  .Pp
  The maximum size of a
  .Nm programname.core
>Audit-Trail:
>Unformatted: