xref: /freebsd/lib/libproc/proc_regs.c (revision 4f1f4356f3012928b463f9ef1710fb908e48b1e2)
1 /*
2  * Copyright (c) 2010 The FreeBSD Foundation
3  * All rights reserved.
4  *
5  * This software was developed by Rui Paulo under sponsorship from the
6  * FreeBSD Foundation.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
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 the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/types.h>
34 #include <sys/ptrace.h>
35 
36 #include <err.h>
37 #include <stdio.h>
38 #include <string.h>
39 #include <errno.h>
40 #include "_libproc.h"
41 
42 int
43 proc_regget(struct proc_handle *phdl, proc_reg_t reg, unsigned long *regvalue)
44 {
45 	struct reg regs;
46 
47 	if (phdl->status == PS_DEAD || phdl->status == PS_UNDEAD ||
48 	    phdl->status == PS_IDLE) {
49 		errno = ENOENT;
50 		return (-1);
51 	}
52 	memset(&regs, 0, sizeof(regs));
53 	if (ptrace(PT_GETREGS, proc_getpid(phdl), (caddr_t)&regs, 0) < 0)
54 		return (-1);
55 	switch (reg) {
56 	case REG_PC:
57 #if defined(__amd64__)
58 		*regvalue = regs.r_rip;
59 #elif defined(__i386__)
60 		*regvalue = regs.r_eip;
61 #endif
62 		break;
63 	case REG_SP:
64 #if defined(__amd64__)
65 		*regvalue = regs.r_rsp;
66 #elif defined(__i386__)
67 		*regvalue = regs.r_esp;
68 #endif
69 		break;
70 	default:
71 		warn("ERROR: no support for reg number %d", reg);
72 		return (-1);
73 	}
74 
75 	return (0);
76 }
77 
78 int
79 proc_regset(struct proc_handle *phdl, proc_reg_t reg, unsigned long regvalue)
80 {
81 	struct reg regs;
82 
83 	if (phdl->status == PS_DEAD || phdl->status == PS_UNDEAD ||
84 	    phdl->status == PS_IDLE) {
85 		errno = ENOENT;
86 		return (-1);
87 	}
88 	if (ptrace(PT_GETREGS, proc_getpid(phdl), (caddr_t)&regs, 0) < 0)
89 		return (-1);
90 	switch (reg) {
91 	case REG_PC:
92 #if defined(__amd64__)
93 		regs.r_rip = regvalue;
94 #elif defined(__i386__)
95 		regs.r_eip = regvalue;
96 #endif
97 		break;
98 	case REG_SP:
99 #if defined(__amd64__)
100 		regs.r_rsp = regvalue;
101 #elif defined(__i386__)
102 		regs.r_esp = regvalue;
103 #endif
104 		break;
105 	default:
106 		warn("ERROR: no support for reg number %d", reg);
107 		return (-1);
108 	}
109 	if (ptrace(PT_SETREGS, proc_getpid(phdl), (caddr_t)&regs, 0) < 0)
110 		return (-1);
111 
112 	return (0);
113 }
114