sys/cpu/x86_64/misc/ktr.c

   1 /*
   2  * Copyright (c) 2005 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@backplane.com>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34 /*
  35  * Kernel tracepoint facility.
  36  */
  37
  38 #include "opt_ktr.h"
  39
  40 #include <sys/param.h>
  41 #include <sys/cons.h>
  42 #include <sys/kernel.h>
  43 #include <sys/libkern.h>
  44 #include <sys/proc.h>
  45 #include <sys/sysctl.h>
  46 #include <sys/ktr.h>
  47
  48 /*
  49  * This routine fills in the ktr_caller1 and ktr_caller2 fields by
  50  * tracing back through the kernel stack to locate the stack frames
  51  * and return addresses.
  52  *
  53  *
  54  *      [first argument]
  55  *      [retpc]
  56  *      [frameptr]              -> points to caller's frame pointer
  57  * sp ->[junk]
  58  */
  59
  60 static __inline
  61 void **
  62 FRAMEUP(void **frameptr)
  63 {
  64     void **newframeptr;
  65
  66     newframeptr = (void **)frameptr[0];
  67     if (((uintptr_t)newframeptr ^ (uintptr_t)frameptr) & ~16383ULL)
  68         newframeptr = frameptr;
  69     return(newframeptr);
  70 }
  71
  72 struct x86_64_frame {
  73         struct x86_64_frame     *f_frame;
  74         long                    f_retaddr;
  75         long                    f_arg0;
  76 };
  77
  78 void
  79 cpu_ktr_caller(struct ktr_entry *_ktr)
  80 {
  81     struct x86_64_frame *frame;
  82     struct ktr_entry *ktr;
  83     void **frameptr;
  84     register_t  rbp;
  85
  86     __asm __volatile("movq %%rbp, %0" : "=r" (rbp));
  87     frame = (struct x86_64_frame *)rbp;
  88     frameptr = (void **)frame->f_frame;
  89     ktr = _ktr;
  90     frameptr = FRAMEUP(frameptr);       /* frame, retpc to traced function */
  91     frameptr = FRAMEUP(frameptr);       /* frame, caller1 of traced function */
  92     ktr->ktr_caller1 = frameptr[1];
  93     frameptr = FRAMEUP(frameptr);       /* frame, caller2 of caller1 */
  94     ktr->ktr_caller2 = frameptr[1];
  95 }