xref: /openbsd-src/sys/arch/arm/arm/db_trace.c (revision a4a50d9633ad5d32f291ac2e2a431b18d1120b73)
1 /*	$OpenBSD: db_trace.c,v 1.16 2021/03/25 04:12:00 jsg Exp $	*/
2 /*	$NetBSD: db_trace.c,v 1.8 2003/01/17 22:28:48 thorpej Exp $	*/
3 
4 /*
5  * Copyright (c) 2000, 2001 Ben Harris
6  * Copyright (c) 1996 Scott K. Stevens
7  *
8  * Mach Operating System
9  * Copyright (c) 1991,1990 Carnegie Mellon University
10  * All Rights Reserved.
11  *
12  * Permission to use, copy, modify and distribute this software and its
13  * documentation is hereby granted, provided that both the copyright
14  * notice and this permission notice appear in all copies of the
15  * software, derivative works or modified versions, and any portions
16  * thereof, and that both notices appear in supporting documentation.
17  *
18  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
19  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
20  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
21  *
22  * Carnegie Mellon requests users of this software to return to
23  *
24  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
25  *  School of Computer Science
26  *  Carnegie Mellon University
27  *  Pittsburgh PA 15213-3890
28  *
29  * any improvements or extensions that they make and grant Carnegie the
30  * rights to redistribute these changes.
31  */
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/proc.h>
36 #include <sys/user.h>
37 #include <machine/db_machdep.h>
38 
39 #include <ddb/db_interface.h>
40 #include <ddb/db_sym.h>
41 #include <ddb/db_output.h>
42 
43 db_regs_t ddb_regs;
44 
45 #define INKERNEL(va)	(((vaddr_t)(va)) >= VM_MIN_KERNEL_ADDRESS)
46 
47 /*
48  *          return link value       [fp, #+4]
49  *          return fp value         [fp]        <- fp points to here
50  */
51 #define FR_RFP	(0)
52 #define FR_RLV	(+1)
53 
54 void
db_stack_trace_print(db_expr_t addr,int have_addr,db_expr_t count,char * modif,int (* pr)(const char *,...))55 db_stack_trace_print(db_expr_t addr, int have_addr, db_expr_t count,
56     char *modif, int (*pr)(const char *, ...))
57 {
58 	u_int32_t	*frame, *lastframe;
59 	char		c, *cp = modif;
60 	int		kernel_only = 1;
61 	int		trace_thread = 0;
62 	vaddr_t		scp;
63 
64 	while ((c = *cp++) != 0) {
65 		if (c == 'u')
66 			kernel_only = 0;
67 		if (c == 't')
68 			trace_thread = 1;
69 	}
70 
71 	if (!have_addr) {
72 		frame = (u_int32_t *)(ddb_regs.tf_r11);
73 		scp = ddb_regs.tf_pc;
74 	} else {
75 		if (trace_thread) {
76 			struct proc *p;
77 			struct user *u;
78 			(*pr) ("trace: pid %d ", (int)addr);
79 			p = tfind(addr);
80 			if (p == NULL) {
81 				(*pr)("not found\n");
82 				return;
83 			}
84 			u = p->p_addr;
85 			frame = (u_int32_t *)(u->u_pcb.pcb_un.un_32.pcb32_r11);
86 			(*pr)("at %p\n", frame);
87 			scp = u->u_pcb.pcb_un.un_32.pcb32_pc;
88 		} else
89 			frame = (u_int32_t *)(addr);
90 	}
91 	lastframe = NULL;
92 
93 	while (count-- && frame != NULL) {
94 		db_printsym(scp, DB_STGY_PROC, pr);
95 		(*pr)("\n\trlv=0x%08x rfp=0x%08x\n", frame[FR_RLV], frame[FR_RFP]);
96 		scp = frame[FR_RLV];
97 
98 		/*
99 		 * Switch to next frame up
100 		 */
101 		if (frame[FR_RFP] == 0)
102 			break; /* Top of stack */
103 
104 		lastframe = frame;
105 		frame = (u_int32_t *)(frame[FR_RFP]);
106 
107 		if (INKERNEL((int)frame)) {
108 			/* staying in kernel */
109 			if (frame <= lastframe) {
110 				(*pr)("Bad frame pointer: %p\n", frame);
111 				break;
112 			}
113 		} else if (INKERNEL((int)lastframe)) {
114 			/* switch from user to kernel */
115 			if (kernel_only)
116 				break;	/* kernel stack only */
117 		} else {
118 			/* in user */
119 			if (frame <= lastframe) {
120 				(*pr)("Bad user frame pointer: %p\n",
121 					  frame);
122 				break;
123 			}
124 		}
125 	}
126 }
127