1/*
2 * Copyright 1997 Sean Eric Fagan
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 * 3. All advertising materials mentioning features or use of this software
13 *    must display the following acknowledgement:
14 *	This product includes software developed by Sean Eric Fagan
15 * 4. Neither the name of the author may be used to endorse or promote
16 *    products derived from this software without specific prior written
17 *    permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33__FBSDID("$FreeBSD: stable/11/usr.bin/truss/i386-freebsd.c 312084 2017-01-13 21:30:18Z jhb $");
34
35/* FreeBSD/i386-specific system call handling. */
36
37#include <sys/ptrace.h>
38#include <sys/syscall.h>
39
40#include <machine/reg.h>
41#include <machine/psl.h>
42
43#include <stdbool.h>
44#include <stdio.h>
45#include <sysdecode.h>
46
47#include "truss.h"
48
49static int
50i386_fetch_args(struct trussinfo *trussinfo, u_int narg)
51{
52	struct ptrace_io_desc iorequest;
53	struct reg regs;
54	struct current_syscall *cs;
55	lwpid_t tid;
56	unsigned int parm_offset;
57
58	tid = trussinfo->curthread->tid;
59	cs = &trussinfo->curthread->cs;
60	if (ptrace(PT_GETREGS, tid, (caddr_t)&regs, 0) < 0) {
61		fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
62		return (-1);
63	}
64	parm_offset = regs.r_esp + sizeof(int);
65
66	/*
67	 * FreeBSD has two special kinds of system call redirections --
68	 * SYS_syscall, and SYS___syscall.  The former is the old syscall()
69	 * routine, basically; the latter is for quad-aligned arguments.
70	 *
71	 * The system call argument count and code from ptrace() already
72	 * account for these, but we need to skip over the first argument.
73	 */
74	switch (regs.r_eax) {
75	case SYS_syscall:
76		parm_offset += sizeof(int);
77		break;
78	case SYS___syscall:
79		parm_offset += sizeof(quad_t);
80		break;
81	}
82
83	iorequest.piod_op = PIOD_READ_D;
84	iorequest.piod_offs = (void *)parm_offset;
85	iorequest.piod_addr = cs->args;
86	iorequest.piod_len = narg * sizeof(unsigned long);
87	ptrace(PT_IO, tid, (caddr_t)&iorequest, 0);
88	if (iorequest.piod_len == 0)
89		return (-1);
90
91	return (0);
92}
93
94static int
95i386_fetch_retval(struct trussinfo *trussinfo, long *retval, int *errorp)
96{
97	struct reg regs;
98	lwpid_t tid;
99
100	tid = trussinfo->curthread->tid;
101	if (ptrace(PT_GETREGS, tid, (caddr_t)&regs, 0) < 0) {
102		fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
103		return (-1);
104	}
105
106	retval[0] = regs.r_eax;
107	retval[1] = regs.r_edx;
108	*errorp = !!(regs.r_eflags & PSL_C);
109	return (0);
110}
111
112static struct procabi i386_freebsd = {
113	"FreeBSD ELF32",
114	SYSDECODE_ABI_FREEBSD,
115	i386_fetch_args,
116	i386_fetch_retval,
117	STAILQ_HEAD_INITIALIZER(i386_freebsd.extra_syscalls),
118	{ NULL }
119};
120
121PROCABI(i386_freebsd);
122
123static struct procabi i386_freebsd_aout = {
124	"FreeBSD a.out",
125	SYSDECODE_ABI_FREEBSD,
126	i386_fetch_args,
127	i386_fetch_retval,
128	STAILQ_HEAD_INITIALIZER(i386_freebsd_aout.extra_syscalls),
129	{ NULL }
130};
131
132PROCABI(i386_freebsd_aout);
133
134