Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!usc!elroy.jpl.nasa.gov!ames!dftsrv!iris613!stailey
From: stailey@iris613.gsfc.nasa.gov (Ken Stailey)
Newsgroups: comp.os.minix
Subject: ps fix
Summary: "portable" approach to seeing user proc names
Keywords: ST ps 1.5.X
Message-ID: <1057@dftsrv.gsfc.nasa.gov>
Date: 5 Mar 90 04:45:06 GMT
Sender: news@dftsrv.gsfc.nasa.gov
Reply-To: stailey@iris613.gsfc.nasa.gov (Ken Stailey)
Organization: Goddard Space Flight Center Climate and Radiation Branch
Lines: 204


This is a fix for ps.c, by Peter Valkenburg (valke@psy.vu.nl), january 1990.
This fix allows it to see the user process names under MINIX ST.  It may
even be portable to the PC too.  If you have PC MINIX I would appreciate
some feedback about this.  It works by looking at yet another system
variable, "aout", an array of proccess names generated for the PF1 key
dump by the system task routine, "do_exec()".  This hack does not allow
you to see path argv[0] too look at the command arguements, but future
enhancements will hopefully support this.

[climbing on soapbox]
Imagine if you had to locate and decode the inode table "by hand" in order
to find out basic information about files that the stat() call will tell you.
The program "ps" is just about as stupid.  Why isn't there a system call
to divulge process table entries?

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

*** ps.c.1.5.3	Sun Mar  4 20:26:32 1990
--- ps.c	Sun Mar  4 23:20:07 1990
***************
*** 85,96 ****
  #define	ID_MPROC	"_mproc"	/* from mm namelist */
  #define	ID_FPROC	"_fproc"	/* from fs namelist */
  #define	ID_TASKTAB	"_tasktab"	/* from kernel namelist */
  
  /*
   * Structure for system address info (also layout of ps's database).
   */
  typedef struct {
! 	struct nlist ke_proc[2], ke_tasktab[2];
  	struct nlist mm_mproc[2];
  	struct nlist fs_fproc[2];
  } sysinfo_t;
--- 85,97 ----
  #define	ID_MPROC	"_mproc"	/* from mm namelist */
  #define	ID_FPROC	"_fproc"	/* from fs namelist */
  #define	ID_TASKTAB	"_tasktab"	/* from kernel namelist */
+ #define	ID_AOUT		"_aout"		/* from kernel namelist */
  
  /*
   * Structure for system address info (also layout of ps's database).
   */
  typedef struct {
! 	struct nlist ke_proc[2], ke_tasktab[2], ke_aout[2];
  	struct nlist mm_mproc[2];
  	struct nlist fs_fproc[2];
  } sysinfo_t;
***************
*** 104,109 ****
--- 105,111 ----
  #define	MPROC	mproc
  #define	FPROC	fproc
  #define	TASKTAB	tasktab
+ #define AOUT	aout
  
  /* default paths for system binaries */
  #define KERNEL_PATH	"/usr/src/kernel/kernel.mix"
***************
*** 125,130 ****
--- 127,134 ----
  
  struct tasktab tasktab[NR_TASKS + INIT_PROC_NR + 1];	/* task table */
  
+ phys_bytes aout[NR_TASKS];
+ 
  /*
   * Short and long listing formats:
   *
***************
*** 299,306 ****
  	if (opt_update || (db_fd = open(DBASE_PATH, O_RDONLY)) == -1) {
  		strncpy(sysinfo.ke_proc[0].n_name, ID_PROC, NAME_SIZ);
  		strncpy(sysinfo.ke_tasktab[0].n_name, ID_TASKTAB, NAME_SIZ);
! 		if (nlist(kpath, sysinfo.ke_proc) != 0 ||
! 		    nlist(kpath, sysinfo.ke_tasktab) != 0)
  			err("Can't read kernel namelist");
  		strncpy(sysinfo.mm_mproc[0].n_name, ID_MPROC, NAME_SIZ);
  		if (nlist(mpath, sysinfo.mm_mproc) != 0)
--- 303,312 ----
  	if (opt_update || (db_fd = open(DBASE_PATH, O_RDONLY)) == -1) {
  		strncpy(sysinfo.ke_proc[0].n_name, ID_PROC, NAME_SIZ);
  		strncpy(sysinfo.ke_tasktab[0].n_name, ID_TASKTAB, NAME_SIZ);
! 		strncpy(sysinfo.ke_aout[0].n_name, ID_AOUT, NAME_SIZ);
! 		if (nlist(kpath, sysinfo.ke_proc) != 0 ||
! 		    nlist(kpath, sysinfo.ke_tasktab) != 0 ||
! 		    nlist(kpath, sysinfo.ke_aout))
  			err("Can't read kernel namelist");
  		strncpy(sysinfo.mm_mproc[0].n_name, ID_MPROC, NAME_SIZ);
  		if (nlist(mpath, sysinfo.mm_mproc) != 0)
***************
*** 322,328 ****
  			err("Can't read psdatabase");	 
  	}
  	(void) close (db_fd);
! 	    	
  	/* get kernel tables */    	
  	if ((kmemfd = open(KMEM_PATH, O_RDONLY)) == -1)
  		err(KMEM_PATH);
--- 328,334 ----
  			err("Can't read psdatabase");	 
  	}
  	(void) close (db_fd);
! 
  	/* get kernel tables */    	
  	if ((kmemfd = open(KMEM_PATH, O_RDONLY)) == -1)
  		err(KMEM_PATH);
***************
*** 334,339 ****
--- 340,349 ----
  		     (vir_bytes) sysinfo.ke_tasktab[0].n_value,
  		     (char *) TASKTAB, sizeof(TASKTAB)) != sizeof(TASKTAB))
  		err("Can't get kernel task table from /dev/kmem");
+ 	if (addrread(kmemfd, (phys_clicks) 0,
+ 		     (vir_bytes) sysinfo.ke_aout[0].n_value,
+ 		     (char *) AOUT, sizeof(AOUT)) != sizeof(AOUT))
+ 		err("Can't get kernel aout table from /dev/kmem");
  
  	/* get mm/fs tables */
  	if ((memfd = open(MEM_PATH, O_RDONLY)) == -1)
***************
*** 346,352 ****
  		     (vir_bytes) sysinfo.fs_fproc[0].n_value,
  		     (char *) FPROC, sizeof(FPROC)) != sizeof(FPROC))
  		err("Can't get fs proc table from /dev/mem");
! 		
  	/* now loop through process table and handle each entry */
  	printf("%s", opt_long ? L_HEADER : S_HEADER);
  	for (i = -NR_TASKS; i < NR_PROCS; i++) {
--- 356,362 ----
  		     (vir_bytes) sysinfo.fs_fproc[0].n_value,
  		     (char *) FPROC, sizeof(FPROC)) != sizeof(FPROC))
  		err("Can't get fs proc table from /dev/mem");
! 
  	/* now loop through process table and handle each entry */
  	printf("%s", opt_long ? L_HEADER : S_HEADER);
  	for (i = -NR_TASKS; i < NR_PROCS; i++) {
***************
*** 477,489 ****
  	}
  	
  	if (state != DONE)
! 		return NULL;
  
  	/* get a local version of argv[0]; l is offset back from end of stack */
  	l = (bufp->ps_stack + bufp->ps_ssize) -
  		(bufp->ps_data + (vir_bytes) sp[1].stk_cp);
  	if (l < 0 || l > cnt)
! 		return NULL;
  	args = &((char *) stk)[cnt - (int) l];
  	neos = 0;
  	for (cp = args; cp < &((char *) stk)[cnt]; cp++)
--- 487,499 ----
  	}
  	
  	if (state != DONE)
! 		return (char *) NULL;
  
  	/* get a local version of argv[0]; l is offset back from end of stack */
  	l = (bufp->ps_stack + bufp->ps_ssize) -
  		(bufp->ps_data + (vir_bytes) sp[1].stk_cp);
  	if (l < 0 || l > cnt)
! 		return (char *) NULL;
  	args = &((char *) stk)[cnt - (int) l];
  	neos = 0;
  	for (cp = args; cp < &((char *) stk)[cnt]; cp++)
***************
*** 493,499 ****
  			else
  				*cp = ' ';	
  	if (neos != sp[0].stk_i)
! 		return NULL;			
  
  	return args;
  }
--- 503,509 ----
  			else
  				*cp = ' ';	
  	if (neos != sp[0].stk_i)
! 		return (char *) NULL;			
  
  	return args;
  }
***************
*** 576,582 ****
  	if (bufp->ps_state == Z_STATE)
  		bufp->ps_args = "<defunct>";
  	else if (p_nr > INIT_PROC_NR)
! 		bufp->ps_args = get_args(bufp);
  	
  	return 0;
  }
--- 586,593 ----
  	if (bufp->ps_state == Z_STATE)
  		bufp->ps_args = "<defunct>";
  	else if (p_nr > INIT_PROC_NR)
! /*		bufp->ps_args = get_args(bufp); */
! 		bufp->ps_args = (off_t) AOUT[p_nr];
  	
  	return 0;
  }

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