arm-freebsd.c revision 303975 
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: releng/11.0/usr.bin/truss/arm-freebsd.c 295056 2016-01-30 01:00:54Z jhb $");
34
35/* FreeBSD/arm-specific system call handling. */
36
37#include <sys/ptrace.h>
38#include <sys/syscall.h>
39
40#include <machine/reg.h>
41#include <machine/armreg.h>
42#include <machine/ucontext.h>
43
44#include <stdio.h>
45#include <sysdecode.h>
46
47#include "truss.h"
48
49static int
50arm_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, syscall_num;
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 the first argument.
72	 */
73#ifdef __ARM_EABI__
74	syscall_num = regs.r[7];
75#else
76	if ((syscall_num = ptrace(PT_READ_I, tid,
77	    (caddr_t)(regs.r[_REG_PC] - INSN_SIZE), 0)) == -1) {
78		fprintf(trussinfo->outfile, "-- CANNOT READ PC --\n");
79		return (-1);
80	}
81	syscall_num = syscall_num & 0x000fffff;
82#endif
83
84	reg = 0;
85	switch (syscall_num) {
86	case SYS_syscall:
87		reg = 1;
88		break;
89	case SYS___syscall:
90		reg = 2;
91		break;
92	}
93
94	for (i = 0; i < narg && reg < 4; i++, reg++)
95		cs->args[i] = regs.r[reg];
96	if (narg > i) {
97		iorequest.piod_op = PIOD_READ_D;
98		iorequest.piod_offs = (void *)(regs.r_sp +
99		    4 * sizeof(uint32_t));
100		iorequest.piod_addr = &cs->args[i];
101		iorequest.piod_len = (narg - i) * sizeof(cs->args[0]);
102		ptrace(PT_IO, tid, (caddr_t)&iorequest, 0);
103		if (iorequest.piod_len == 0)
104			return (-1);
105	}
106
107	return (0);
108}
109
110static int
111arm_fetch_retval(struct trussinfo *trussinfo, long *retval, int *errorp)
112{
113	struct reg regs;
114	lwpid_t tid;
115
116	tid = trussinfo->curthread->tid;
117	if (ptrace(PT_GETREGS, tid, (caddr_t)&regs, 0) < 0) {
118		fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
119		return (-1);
120	}
121
122	/* XXX: Does not have the __ARMEB__ handling for __syscall(). */
123	retval[0] = regs.r[0];
124	retval[1] = regs.r[1];
125	*errorp = !!(regs.r_cpsr & PSR_C);
126	return (0);
127}
128
129static struct procabi arm_freebsd = {
130	"FreeBSD ELF32",
131	SYSDECODE_ABI_FREEBSD,
132	arm_fetch_args,
133	arm_fetch_retval
134};
135
136PROCABI(arm_freebsd);
137