FreeBSD/Linux Kernel Cross Reference
sys/kern/xpr.c

     /* 
      * Mach Operating System
      * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
      * All Rights Reserved.
      * 
      * Permission to use, copy, modify and distribute this software and its
      * documentation is hereby granted, provided that both the copyright
      * notice and this permission notice appear in all copies of the
      * software, derivative works or modified versions, and any portions
     * thereof, and that both notices appear in supporting documentation.
     * 
     * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
     * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
     * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
     * 
     * Carnegie Mellon requests users of this software to return to
     * 
     *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
     *  School of Computer Science
     *  Carnegie Mellon University
     *  Pittsburgh PA 15213-3890
     * 
     * any improvements or extensions that they make and grant Carnegie Mellon
     * the rights to redistribute these changes.
     */
    /*
     * HISTORY
     * $Log:        xpr.c,v $
     * Revision 2.13  93/05/15  18:56:18  mrt
     *      machparam.h -> machspl.h
     * 
     * Revision 2.12  93/01/14  17:37:26  danner
     *      Proper spl typing.
     *      [92/12/01            af]
     * 
     * Revision 2.11  92/08/03  17:40:31  jfriedl
     *      removed silly prototypes
     *      [92/08/02            jfriedl]
     * 
     * Revision 2.10  92/05/21  17:17:12  jfriedl
     *      tried prototypes.
     *      [92/05/20            jfriedl]
     * 
     * 16-May-92  Jeffrey Friedl (jfriedl) at Carnegie-Mellon University
     *      Added void to fcns that still needed it.
     * Revision 2.9  91/10/09  16:11:50  af
     *      Removed xpr_save.  Modified xpr_dump to make it useful
     *      for dumping xpr buffers in user space tasks.
     *      [91/09/20            rpd]
     * 
     *      Turned on xprenable by default.  xprbootstrap now preserves
     *      the original contents of the buffer if xprenable is off.
     *      [91/09/18            rpd]
     * 
     * Revision 2.8  91/08/28  11:14:56  jsb
     *      Fixed xprbootstrap to zero the allocate memory.
     *      [91/08/18            rpd]
     * 
     * Revision 2.7  91/05/18  14:34:37  rpd
     *      Added xprenable and other minor changes so that the xpr buffer
     *      may be examined after a spontaneous reboot.
     *      [91/05/03            rpd]
     *      Fixed the initialization check in xpr.
     *      Fixed xpr_dump.
     *      [91/04/02            rpd]
     * 
     * Revision 2.6  91/05/14  16:50:09  mrt
     *      Correcting copyright
     * 
     * Revision 2.5  91/03/16  14:53:24  rpd
     *      Updated for new kmem_alloc interface.
     *      [91/03/03            rpd]
     * 
     * Revision 2.4  91/02/05  17:31:13  mrt
     *      Changed to new Mach copyright
     *      [91/02/01  16:21:17  mrt]
     * 
     * Revision 2.3  90/09/09  14:33:04  rpd
     *      Use decl_simple_lock_data.
     *      [90/08/30            rpd]
     * 
     * Revision 2.2  89/11/29  14:09:21  af
     *      Added xpr_dump() to print on console the content of the buffer,
     *      only valid for KDB usage.
     *      [89/11/12            af]
     * 
     *      MACH_KERNEL: include sys/cpu_number.h instead of machine/cpu.h.
     *      Clean up comments.
     *      [88/12/19            dbg]
     * 
     * Revision 2.1  89/08/03  15:49:11  rwd
     * Created.
     * 
     * Revision 2.2  88/12/19  02:48:30  mwyoung
     *      Fix include file references.
     *      [88/11/22  02:17:01  mwyoung]
     *      
     *      Separate initialization into two phases.
     *      [88/11/22  01:13:11  mwyoung]
    * 
    *  6-Jan-88  Michael Young (mwyoung) at Carnegie-Mellon University
    *      Eliminate use of arg6 in order to allow a more shapely event structure.
    *
    * 30-Dec-87  David Golub (dbg) at Carnegie-Mellon University
    *      Delinted.
    *
    *  7-Dec-87  Richard Sanzi (sanzi) at Carnegie-Mellon University
    *      Added xpr_save() routine.
    *
    */ 
   #include <mach_kdb.h>
   /*
    * xpr silent tracing circular buffer.
    */
   #include <kern/xpr.h>
   #include <kern/lock.h>
   #include <kern/cpu_number.h>
   #include <machine/machspl.h>
   #include <vm/vm_kern.h>
   
   
   /*
    *      After a spontaneous reboot, it is desirable to look
    *      at the old xpr buffer.  Assuming xprbootstrap allocates
    *      the buffer in the same place in physical memory and
    *      the reboot doesn't clear memory, this should work.
    *      xprptr will be reset, but the saved value should be OK.
    *      Just set xprenable false so the buffer isn't overwritten.
    */
   
   decl_simple_lock_data(, xprlock)
   
   boolean_t xprenable = TRUE;     /* Enable xpr tracing */
   int nxprbufs = 0;       /* Number of contiguous xprbufs allocated */
   int xprflags = 0;       /* Bit mask of xpr flags enabled */
   struct xprbuf *xprbase; /* Pointer to circular buffer nxprbufs*sizeof(xprbuf)*/
   struct xprbuf *xprptr;  /* Currently allocated xprbuf */
   struct xprbuf *xprlast; /* Pointer to end of circular buffer */
   
   /*VARARGS1*/
   void xpr(msg, arg1, arg2, arg3, arg4, arg5)
   char *msg;
   int arg1, arg2, arg3, arg4, arg5;
   {
           register spl_t s;
           register struct xprbuf *x;
   
           /* If we aren't initialized, ignore trace request */
           if (!xprenable || (xprptr == 0))
                   return;
           /* Guard against all interrupts and allocate next buffer. */
           s = splhigh();
           simple_lock(&xprlock);
           x = xprptr++;
           if (xprptr >= xprlast) {
                   /* wrap around */
                   xprptr = xprbase;
           }
           /* Save xprptr in allocated memory. */
           *(struct xprbuf **)xprlast = xprptr;
           simple_unlock(&xprlock);
           splx(s);
           x->msg = msg;
           x->arg1 = arg1;
           x->arg2 = arg2;
           x->arg3 = arg3;
           x->arg4 = arg4;
           x->arg5 = arg5;
           x->timestamp = XPR_TIMESTAMP;
           x->cpuinfo = cpu_number();
   }
   
   void xprbootstrap()
   {
           vm_offset_t addr;
           vm_size_t size;
           kern_return_t kr;
   
           simple_lock_init(&xprlock);
           if (nxprbufs == 0)
                   return; /* assume XPR support not desired */
   
           /* leave room at the end for a saved copy of xprptr */
           size = nxprbufs * sizeof(struct xprbuf) + sizeof xprptr;
   
           kr = kmem_alloc_wired(kernel_map, &addr, size);
           if (kr != KERN_SUCCESS)
                   panic("xprbootstrap");
   
           if (xprenable) {
                   /*
                    *      If xprenable is set (the default) then we zero
                    *      the buffer so xpr_dump doesn't encounter bad pointers.
                    *      If xprenable isn't set, then we preserve
                    *      the original contents of the buffer.  This is useful
                    *      if memory survives reboots, so xpr_dump can show
                    *      the previous buffer contents.
                    */
   
                   bzero((char *) addr, size);
           }
   
           xprbase = (struct xprbuf *) addr;
           xprlast = &xprbase[nxprbufs];
           xprptr = xprbase;       /* setting xprptr enables tracing */
   }
   
   int             xprinitial = 0;
   
   void xprinit()
   {
           xprflags |= xprinitial;
   }
   
   #if     MACH_KDB
   #include <machine/setjmp.h>
   
   
   extern void db_printf();
   extern jmp_buf_t *db_recover;
   
   /*
    *      Print current content of xpr buffers (KDB's sake)
    *      Use stack order to make it understandable.
    *
    *      Called as "!xpr_dump" this dumps the kernel's xpr buffer.
    *      Called with arguments, it can dump xpr buffers in user tasks,
    *      assuming they use the same format as the kernel.
    */
   void xpr_dump(base, nbufs)
           struct xprbuf *base;
           int nbufs;
   {
           jmp_buf_t db_jmpbuf;
           jmp_buf_t *prev;
           struct xprbuf *last, *ptr;
           register struct xprbuf *x;
           int i;
           spl_t s;
   
           if (base == 0) {
                   base = xprbase;
                   nbufs = nxprbufs;
           }
   
           if (nbufs == 0)
                   return;
   
           if (base == xprbase) {
                   s = splhigh();
                   simple_lock(&xprlock);
           }
   
           last = base + nbufs;
           ptr = * (struct xprbuf **) last;
   
           prev = db_recover;
           if (_setjmp(db_recover = &db_jmpbuf) == 0)
               for (x = ptr, i = 0; i < nbufs; i++) {
                   if (--x < base)
                           x = last - 1;
   
                   if (x->msg == 0)
                           break;
   
                   db_printf("<%d:%x:%x> ", x - base, x->cpuinfo, x->timestamp);
                   db_printf(x->msg, x->arg1,x->arg2,x->arg3,x->arg4,x->arg5);
               }
           db_recover = prev;
   
           if (base == xprbase) {
                   simple_unlock(&xprlock);
                   (void) splx(s);
           }
   }
   #endif  MACH_KDB

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