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/* FreeBSD/amd64-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 <stdio.h>
44
45#include "truss.h"
46
47#include "syscalls.h"
48
49static int
50amd64_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	u_int i, reg;
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
65	/*
66	 * FreeBSD has two special kinds of system call redirections --
67	 * SYS_syscall, and SYS___syscall.  The former is the old syscall()
68	 * routine, basically; the latter is for quad-aligned arguments.
69	 *
70	 * The system call argument count and code from ptrace() already
71	 * account for these, but we need to skip over %rax if it contains
72	 * either of these values.
73	 */
74	reg = 0;
75	switch (regs.r_rax) {
76	case SYS_syscall:
77	case SYS___syscall:
78		reg++;
79		break;
80	}
81
82	for (i = 0; i < narg && reg < 6; i++, reg++) {
83		switch (reg) {
84		case 0: cs->args[i] = regs.r_rdi; break;
85		case 1: cs->args[i] = regs.r_rsi; break;
86		case 2: cs->args[i] = regs.r_rdx; break;
87		case 3: cs->args[i] = regs.r_rcx; break;
88		case 4: cs->args[i] = regs.r_r8; break;
89		case 5: cs->args[i] = regs.r_r9; break;
90		}
91	}
92	if (narg > i) {
93		iorequest.piod_op = PIOD_READ_D;
94		iorequest.piod_offs = (void *)(regs.r_rsp + sizeof(register_t));
95		iorequest.piod_addr = &cs->args[i];
96		iorequest.piod_len = (narg - i) * sizeof(register_t);
97		ptrace(PT_IO, tid, (caddr_t)&iorequest, 0);
98		if (iorequest.piod_len == 0)
99			return (-1);
100	}
101
102	return (0);
103}
104
105static int
106amd64_fetch_retval(struct trussinfo *trussinfo, long *retval, int *errorp)
107{
108	struct reg regs;
109	lwpid_t tid;
110
111	tid = trussinfo->curthread->tid;
112	if (ptrace(PT_GETREGS, tid, (caddr_t)&regs, 0) < 0) {
113		fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
114		return (-1);
115	}
116
117	retval[0] = regs.r_rax;
118	retval[1] = regs.r_rdx;
119	*errorp = !!(regs.r_rflags & PSL_C);
120	return (0);
121}
122
123static struct procabi amd64_fbsd = {
124	"FreeBSD ELF64",
125	syscallnames,
126	nitems(syscallnames),
127	amd64_fetch_args,
128	amd64_fetch_retval
129};
130
131PROCABI(amd64_fbsd);
132