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/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 <stdbool.h>
45 #include <stdio.h>
46 #include <sysdecode.h>
47
48 #include "truss.h"
49
50 static int
arm_fetch_args(struct trussinfo * trussinfo,u_int narg)51 arm_fetch_args(struct trussinfo *trussinfo, u_int narg)
52 {
53 struct ptrace_io_desc iorequest;
54 struct reg regs;
55 struct current_syscall *cs;
56 lwpid_t tid;
57 u_int i, reg, syscall_num;
58
59 tid = trussinfo->curthread->tid;
60 cs = &trussinfo->curthread->cs;
61 if (ptrace(PT_GETREGS, tid, (caddr_t)®s, 0) < 0) {
62 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
63 return (-1);
64 }
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 #ifdef __ARM_EABI__
75 syscall_num = regs.r[7];
76 #else
77 if ((syscall_num = ptrace(PT_READ_I, tid,
78 (caddr_t)(regs.r[_REG_PC] - INSN_SIZE), 0)) == -1) {
79 fprintf(trussinfo->outfile, "-- CANNOT READ PC --\n");
80 return (-1);
81 }
82 syscall_num = syscall_num & 0x000fffff;
83 #endif
84
85 reg = 0;
86 switch (syscall_num) {
87 case SYS_syscall:
88 reg = 1;
89 break;
90 case SYS___syscall:
91 reg = 2;
92 break;
93 }
94
95 for (i = 0; i < narg && reg < 4; i++, reg++)
96 cs->args[i] = regs.r[reg];
97 if (narg > i) {
98 iorequest.piod_op = PIOD_READ_D;
99 iorequest.piod_offs = (void *)(regs.r_sp +
100 4 * sizeof(uint32_t));
101 iorequest.piod_addr = &cs->args[i];
102 iorequest.piod_len = (narg - i) * sizeof(cs->args[0]);
103 ptrace(PT_IO, tid, (caddr_t)&iorequest, 0);
104 if (iorequest.piod_len == 0)
105 return (-1);
106 }
107
108 return (0);
109 }
110
111 static int
arm_fetch_retval(struct trussinfo * trussinfo,long * retval,int * errorp)112 arm_fetch_retval(struct trussinfo *trussinfo, long *retval, int *errorp)
113 {
114 struct reg regs;
115 lwpid_t tid;
116
117 tid = trussinfo->curthread->tid;
118 if (ptrace(PT_GETREGS, tid, (caddr_t)®s, 0) < 0) {
119 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
120 return (-1);
121 }
122
123 /* XXX: Does not have the __ARMEB__ handling for __syscall(). */
124 retval[0] = regs.r[0];
125 retval[1] = regs.r[1];
126 *errorp = !!(regs.r_cpsr & PSR_C);
127 return (0);
128 }
129
130 static struct procabi arm_freebsd = {
131 "FreeBSD ELF32",
132 SYSDECODE_ABI_FREEBSD,
133 arm_fetch_args,
134 arm_fetch_retval,
135 STAILQ_HEAD_INITIALIZER(arm_freebsd.extra_syscalls),
136 { NULL }
137 };
138
139 PROCABI(arm_freebsd);
140