xref: /illumos-gate/usr/src/boot/i386/loader/panic_action.c (revision 0da5724dc692b82c860b028aa33d5a924507194a)
1*0da5724dSToomas Soome /*
2*0da5724dSToomas Soome  * Copyright 2026 Edgecast Cloud LLC.
3*0da5724dSToomas Soome  * Copyright (c) 2016 The FreeBSD Foundation
4*0da5724dSToomas Soome  * All rights reserved.
5*0da5724dSToomas Soome  * Copyright (c) 1996
6*0da5724dSToomas Soome  *	Matthias Drochner.  All rights reserved.
7*0da5724dSToomas Soome  *
8*0da5724dSToomas Soome  * This software was developed by Konstantin Belousov under sponsorship
9*0da5724dSToomas Soome  * from the FreeBSD Foundation.
10*0da5724dSToomas Soome  *
11*0da5724dSToomas Soome  * Redistribution and use in source and binary forms, with or without
12*0da5724dSToomas Soome  * modification, are permitted provided that the following conditions
13*0da5724dSToomas Soome  * are met:
14*0da5724dSToomas Soome  * 1. Redistributions of source code must retain the above copyright
15*0da5724dSToomas Soome  *    notice, this list of conditions and the following disclaimer.
16*0da5724dSToomas Soome  * 2. Redistributions in binary form must reproduce the above copyright
17*0da5724dSToomas Soome  *    notice, this list of conditions and the following disclaimer in the
18*0da5724dSToomas Soome  *    documentation and/or other materials provided with the distribution.
19*0da5724dSToomas Soome  *
20*0da5724dSToomas Soome  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21*0da5724dSToomas Soome  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22*0da5724dSToomas Soome  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23*0da5724dSToomas Soome  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24*0da5724dSToomas Soome  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25*0da5724dSToomas Soome  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26*0da5724dSToomas Soome  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27*0da5724dSToomas Soome  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28*0da5724dSToomas Soome  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29*0da5724dSToomas Soome  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30*0da5724dSToomas Soome  * SUCH DAMAGE.
31*0da5724dSToomas Soome  */
32*0da5724dSToomas Soome 
33*0da5724dSToomas Soome #include <sys/cdefs.h>
34*0da5724dSToomas Soome 
35*0da5724dSToomas Soome #include <stand.h>
36*0da5724dSToomas Soome #include <btxv86.h>
37*0da5724dSToomas Soome #include <common/bootargs.h>
38*0da5724dSToomas Soome 
39*0da5724dSToomas Soome /*
40*0da5724dSToomas Soome  * loader is laid out as:
41*0da5724dSToomas Soome  * physical address 0xa000
42*0da5724dSToomas Soome  *   text data bss _end stack space <free mem from 0x413>
43*0da5724dSToomas Soome  */
44*0da5724dSToomas Soome extern char _end[];
45*0da5724dSToomas Soome 
46*0da5724dSToomas Soome struct frame {
47*0da5724dSToomas Soome 	struct frame	*fr_savfp;
48*0da5724dSToomas Soome 	uintptr_t	fr_savpc;
49*0da5724dSToomas Soome };
50*0da5724dSToomas Soome 
51*0da5724dSToomas Soome static void
52*0da5724dSToomas Soome stack_trace(struct frame *fp, uintptr_t pc)
53*0da5724dSToomas Soome {
54*0da5724dSToomas Soome 	char buf[80];
55*0da5724dSToomas Soome 	uintptr_t freemem = *(uint16_t *)PTOV(0x413) << 10;
56*0da5724dSToomas Soome 	uintptr_t stack_start;
57*0da5724dSToomas Soome 
58*0da5724dSToomas Soome 	/*
59*0da5724dSToomas Soome 	 * stack start is at freemem - __base - ARGSPACE.
60*0da5724dSToomas Soome 	 */
61*0da5724dSToomas Soome 	stack_start = (uintptr_t)PTOV(freemem - ARGSPACE);
62*0da5724dSToomas Soome 
63*0da5724dSToomas Soome 	printf("Stack trace:\n");
64*0da5724dSToomas Soome 	pager_open();
65*0da5724dSToomas Soome 	while (fp != NULL || pc != 0) {
66*0da5724dSToomas Soome 		struct frame *nfp;
67*0da5724dSToomas Soome 
68*0da5724dSToomas Soome 		(void) snprintf(buf, sizeof (buf),
69*0da5724dSToomas Soome 		    "FP 0x%08x: loader PC 0x%08x\n",
70*0da5724dSToomas Soome 		    (uintptr_t)fp, pc);
71*0da5724dSToomas Soome 		if (pager_output(buf))
72*0da5724dSToomas Soome 			break;
73*0da5724dSToomas Soome 
74*0da5724dSToomas Soome 		if (fp == NULL)
75*0da5724dSToomas Soome 			break;
76*0da5724dSToomas Soome 
77*0da5724dSToomas Soome 		nfp = fp->fr_savfp;
78*0da5724dSToomas Soome 		if (nfp != NULL && nfp <= fp) {
79*0da5724dSToomas Soome 			printf("FP 0x%08x: loop detected, stopping trace\n",
80*0da5724dSToomas Soome 			    (uintptr_t)nfp);
81*0da5724dSToomas Soome 			break;
82*0da5724dSToomas Soome 		}
83*0da5724dSToomas Soome 		fp = nfp;
84*0da5724dSToomas Soome 		if ((char *)fp < _end ||
85*0da5724dSToomas Soome 		    (uintptr_t)fp + sizeof (*fp) > stack_start)
86*0da5724dSToomas Soome 			break;
87*0da5724dSToomas Soome 
88*0da5724dSToomas Soome 		pc = fp->fr_savpc;
89*0da5724dSToomas Soome 	}
90*0da5724dSToomas Soome 	pager_close();
91*0da5724dSToomas Soome }
92*0da5724dSToomas Soome 
93*0da5724dSToomas Soome void
94*0da5724dSToomas Soome panic_action(void)
95*0da5724dSToomas Soome {
96*0da5724dSToomas Soome 	struct frame *fp;
97*0da5724dSToomas Soome 	uintptr_t eip;
98*0da5724dSToomas Soome 
99*0da5724dSToomas Soome 	__asm __volatile("movl %%ebp,%0" : "=r" (fp));
100*0da5724dSToomas Soome 
101*0da5724dSToomas Soome 	if (fp != NULL) {
102*0da5724dSToomas Soome 		eip = fp->fr_savpc;
103*0da5724dSToomas Soome 		stack_trace(fp, eip);
104*0da5724dSToomas Soome 	}
105*0da5724dSToomas Soome 	printf("--> Press a key on the console to reboot <--\n");
106*0da5724dSToomas Soome 	getchar();
107*0da5724dSToomas Soome 	printf("Rebooting...\n");
108*0da5724dSToomas Soome 	exit(1);
109*0da5724dSToomas Soome }
110