amd64-linux32.c revision 330897 
1/*-
2 * SPDX-License-Identifier: BSD-4-Clause
3 *
4 * Copyright 1997 Sean Eric Fagan
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 *    must display the following acknowledgement:
16 *	This product includes software developed by Sean Eric Fagan
17 * 4. Neither the name of the author may be used to endorse or promote
18 *    products derived from this software without specific prior written
19 *    permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include <sys/cdefs.h>
35__FBSDID("$FreeBSD: stable/11/usr.bin/truss/amd64-linux32.c 330897 2018-03-14 03:19:51Z eadler $");
36
37/* Linux/i386-specific system call handling. */
38
39#include <sys/ptrace.h>
40
41#include <machine/reg.h>
42#include <machine/psl.h>
43
44#include <stdbool.h>
45#include <stdio.h>
46#include <sysdecode.h>
47
48#include "truss.h"
49
50static int
51amd64_linux32_fetch_args(struct trussinfo *trussinfo, u_int narg)
52{
53	struct reg regs;
54	struct current_syscall *cs;
55	lwpid_t tid;
56
57	tid = trussinfo->curthread->tid;
58	cs = &trussinfo->curthread->cs;
59	if (ptrace(PT_GETREGS, tid, (caddr_t)&regs, 0) < 0) {
60		fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
61		return (-1);
62	}
63
64	/*
65	 * Linux passes syscall arguments in registers, not
66	 * on the stack.  Fortunately, we've got access to the
67	 * register set.  Note that we don't bother checking the
68	 * number of arguments.	And what does linux do for syscalls
69	 * that have more than five arguments?
70	 */
71	switch (narg) {
72	default:
73		cs->args[5] = regs.r_rbp;	/* Unconfirmed */
74	case 5:
75		cs->args[4] = regs.r_rdi;
76	case 4:
77		cs->args[3] = regs.r_rsi;
78	case 3:
79		cs->args[2] = regs.r_rdx;
80	case 2:
81		cs->args[1] = regs.r_rcx;
82	case 1:
83		cs->args[0] = regs.r_rbx;
84	}
85
86	return (0);
87}
88
89static int
90amd64_linux32_fetch_retval(struct trussinfo *trussinfo, long *retval,
91    int *errorp)
92{
93	struct reg regs;
94	lwpid_t tid;
95
96	tid = trussinfo->curthread->tid;
97	if (ptrace(PT_GETREGS, tid, (caddr_t)&regs, 0) < 0) {
98		fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
99		return (-1);
100	}
101
102	retval[0] = regs.r_rax & 0xffffffff;
103	retval[1] = regs.r_rdx & 0xffffffff;
104	*errorp = !!(regs.r_rflags & PSL_C);
105	if (*errorp)
106		retval[0] = (int)retval[0];
107	return (0);
108}
109
110static struct procabi amd64_linux32 = {
111	"Linux ELF32",
112	SYSDECODE_ABI_LINUX32,
113	amd64_linux32_fetch_args,
114	amd64_linux32_fetch_retval,
115	STAILQ_HEAD_INITIALIZER(amd64_linux32.extra_syscalls),
116	{ NULL }
117};
118
119PROCABI(amd64_linux32);
120