xref: /dragonfly/sys/cpu/x86_64/misc/ktr.c (revision dcd37f7d)
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_ddb.h"
39 #include "opt_ktr.h"
40 
41 #include <sys/param.h>
42 #include <sys/cons.h>
43 #include <sys/kernel.h>
44 #include <sys/libkern.h>
45 #include <sys/proc.h>
46 #include <sys/sysctl.h>
47 #include <sys/ktr.h>
48 
49 /*
50  * This routine fills in the ktr_caller1 and ktr_caller2 fields by
51  * tracing back through the kernel stack to locate the stack frames
52  * and return addresses.
53  *
54  *
55  *	[first argument]
56  *	[retpc]
57  *	[frameptr]		-> points to caller's frame pointer
58  * sp ->[junk]
59  */
60 
61 static __inline
62 void **
63 FRAMEUP(void **frameptr)
64 {
65     void **newframeptr;
66 
67     newframeptr = (void **)frameptr[0];
68     if (((uintptr_t)newframeptr ^ (uintptr_t)frameptr) & ~16383)
69 	newframeptr = frameptr;
70     return(newframeptr);
71 }
72 
73 void
74 cpu_ktr_caller(struct ktr_entry *_ktr)
75 {
76     struct ktr_entry *ktr;
77     void **frameptr;
78 
79     frameptr = (void **)&_ktr - 2;	/* frame, retpc to ktr_log */
80     ktr = _ktr;
81     frameptr = FRAMEUP(frameptr);	/* frame, retpc to traced function */
82     frameptr = FRAMEUP(frameptr);	/* frame, caller1 of traced function */
83     ktr->ktr_caller1 = frameptr[1];
84     frameptr = FRAMEUP(frameptr);	/* frame, caller2 of caller1 */
85     ktr->ktr_caller2 = frameptr[1];
86 }
87