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("$FreeBSD$");
34
35/* Linux/i386-specific system call handling. */
36
37#include <sys/ptrace.h>
38
39#include <machine/reg.h>
40#include <machine/psl.h>
41
42#include <stdio.h>
43
44#include "truss.h"
45
46#include "linux_syscalls.h"
47
48static int
49i386_linux_fetch_args(struct trussinfo *trussinfo, u_int narg)
50{
51	struct reg regs;
52	struct current_syscall *cs;
53	lwpid_t tid;
54
55	tid = trussinfo->curthread->tid;
56	cs = &trussinfo->curthread->cs;
57	if (ptrace(PT_GETREGS, tid, (caddr_t)&regs, 0) < 0) {
58		fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
59		return (-1);
60	}
61
62	/*
63	 * Linux passes syscall arguments in registers, not
64	 * on the stack.  Fortunately, we've got access to the
65	 * register set.  Note that we don't bother checking the
66	 * number of arguments.	And what does linux do for syscalls
67	 * that have more than five arguments?
68	 */
69	switch (narg) {
70	default:
71		cs->args[5] = regs.r_ebp;	/* Unconfirmed */
72	case 5:
73		cs->args[4] = regs.r_edi;
74	case 4:
75		cs->args[3] = regs.r_esi;
76	case 3:
77		cs->args[2] = regs.r_edx;
78	case 2:
79		cs->args[1] = regs.r_ecx;
80	case 1:
81		cs->args[0] = regs.r_ebx;
82	}
83
84	return (0);
85}
86
87/*
88 * Linux syscalls return negative errno's, we do positive and map them
89 */
90static const int bsd_to_linux_errno[] = {
91	-0,  -1,  -2,  -3,  -4,  -5,  -6,  -7,  -8,  -9,
92	-10, -35, -12, -13, -14, -15, -16, -17, -18, -19,
93	-20, -21, -22, -23, -24, -25, -26, -27, -28, -29,
94	-30, -31, -32, -33, -34, -11,-115,-114, -88, -89,
95	-90, -91, -92, -93, -94, -95, -96, -97, -98, -99,
96	-100,-101,-102,-103,-104,-105,-106,-107,-108,-109,
97	-110,-111, -40, -36,-112,-113, -39, -11, -87,-122,
98	-116, -66,  -6,  -6,  -6,  -6,  -6, -37, -38,  -9,
99	-6,
100};
101
102static int
103i386_linux_fetch_retval(struct trussinfo *trussinfo, long *retval, int *errorp)
104{
105	struct reg regs;
106	lwpid_t tid;
107	size_t i;
108
109	tid = trussinfo->curthread->tid;
110	if (ptrace(PT_GETREGS, tid, (caddr_t)&regs, 0) < 0) {
111		fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
112		return (-1);
113	}
114
115	retval[0] = regs.r_eax;
116	retval[1] = regs.r_edx;
117	*errorp = !!(regs.r_eflags & PSL_C);
118
119	if (*errorp) {
120		for (i = 0; i < nitems(bsd_to_linux_errno); i++) {
121			if (retval[0] == bsd_to_linux_errno[i]) {
122				retval[0] = i;
123				return (0);
124			}
125		}
126
127		/* XXX: How to handle unknown errors? */
128	}
129	return (0);
130}
131
132static struct procabi i386_linux = {
133	"Linux ELF",
134	linux_syscallnames,
135	nitems(linux_syscallnames),
136	i386_linux_fetch_args,
137	i386_linux_fetch_retval
138};
139
140PROCABI(i386_linux);
141