1/*
2 * Copyright 2006 Peter Grehan <grehan@freebsd.org>
3 * Copyright 2005 Orlando Bassotto <orlando@break.net>
4 * Copyright 1998 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 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28#ifndef lint
29static const char rcsid[] =
30 "$FreeBSD: head/usr.bin/truss/powerpc-fbsd.c 286937 2015-08-19 19:59:42Z jhb $";
31#endif /* not lint */
32
33/*
34 * FreeBSD/powerpc-specific system call handling. This is probably the most
35 * complex part of the entire truss program, although I've got lots of
36 * it handled relatively cleanly now. The system call names are generated
37 * automatically, thanks to /usr/src/sys/kern/syscalls.master. The
38 * names used for the various structures are confusing, I sadly admit.
39 *
40 * This file is almost nothing more than a slightly-edited i386-fbsd.c.
41 */
42
43#include <sys/types.h>
44#include <sys/ptrace.h>
45#include <sys/syscall.h>
46
47#include <machine/reg.h>
48#include <machine/frame.h>
49
50#include <err.h>
51#include <errno.h>
52#include <fcntl.h>
53#include <signal.h>
54#include <stdio.h>
55#include <stdlib.h>
56#include <string.h>
57#include <time.h>
58#include <unistd.h>
59
60#include "truss.h"
61#include "syscall.h"
62#include "extern.h"
63
64#ifdef __powerpc64__ /* 32-bit compatibility */
65#include "freebsd32_syscalls.h"
66#define syscallnames freebsd32_syscallnames
67#else /* native 32-bit */
68#include "syscalls.h"
69#endif
70
71static int nsyscalls = nitems(syscallnames);
72
73/*
74 * This is what this particular file uses to keep track of a system call.
75 * It is probably not quite sufficient -- I can probably use the same
76 * structure for the various syscall personalities, and I also probably
77 * need to nest system calls (for signal handlers).
78 *
79 * 'struct syscall' describes the system call; it may be NULL, however,
80 * if we don't know about this particular system call yet.
81 */
82struct freebsd_syscall {
83 struct syscall *sc;
84 const char *name;
85 int number;
86 unsigned long *args;
87 int nargs; /* number of arguments -- *not* number of words! */
88 char **s_args; /* the printable arguments */
89};
90
91static struct freebsd_syscall *
92alloc_fsc(void)
93{
94
95 return (malloc(sizeof(struct freebsd_syscall)));
96}
97
98/* Clear up and free parts of the fsc structure. */
99static void
100free_fsc(struct freebsd_syscall *fsc)
101{
102 int i;
103
104 free(fsc->args);
105 if (fsc->s_args) {
106 for (i = 0; i < fsc->nargs; i++)
107 free(fsc->s_args[i]);
108 free(fsc->s_args);
109 }
110 free(fsc);
111}
112
113/*
114 * Called when a process has entered a system call. nargs is the
115 * number of words, not number of arguments (a necessary distinction
116 * in some cases). Note that if the STOPEVENT() code in powerpc/powerpc/trap.c
117 * is ever changed these functions need to keep up.
118 */
119
120void
121powerpc_syscall_entry(struct trussinfo *trussinfo, int nargs)
122{
123 struct ptrace_io_desc iorequest;
124 struct reg regs;
125 struct freebsd_syscall *fsc;
126 struct syscall *sc;
127 void *args;
128 lwpid_t tid;
129 int i, regargs, syscall_num;
130
131 /* Account for a 64-bit argument with corresponding alignment. */
132 nargs += 2;
133
134 tid = trussinfo->curthread->tid;
135
136 if (ptrace(PT_GETREGS, tid, (caddr_t)&regs, 0) < 0) {
137 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
138 return;
139 }
140
141 /*
142 * FreeBSD has two special kinds of system call redirctions --
143 * SYS_syscall, and SYS___syscall. The former is the old syscall()
144 * routine, basically; the latter is for quad-aligned arguments.
145 */
146 regargs = NARGREG;
147 syscall_num = regs.fixreg[0];
148 args = &regs.fixreg[3];
149 if (syscall_num == SYS_syscall) {
150 args = &regs.fixreg[4];
151 regargs -= 1;
152 syscall_num = regs.fixreg[3];
153 } else if (syscall_num == SYS___syscall) {
154 args = &regs.fixreg[5];
155 regargs -= 2;
156 syscall_num = regs.fixreg[4];
157 }
158
159 fsc = alloc_fsc();
160 if (fsc == NULL)
161 return;
162 fsc->number = syscall_num;
163 fsc->name = (syscall_num < 0 || syscall_num >= nsyscalls) ?
164 NULL : syscallnames[syscall_num];
165 if (!fsc->name) {
166 fprintf(trussinfo->outfile, "-- UNKNOWN SYSCALL %d --\n",
167 syscall_num);
168 }
169
170 if (fsc->name && (trussinfo->flags & FOLLOWFORKS) &&
171 (strcmp(fsc->name, "fork") == 0 ||
172 strcmp(fsc->name, "pdfork") == 0 ||
173 strcmp(fsc->name, "rfork") == 0 ||
174 strcmp(fsc->name, "vfork") == 0))
175 trussinfo->curthread->in_fork = 1;
176
177 if (nargs == 0)
178 return;
179
180 fsc->args = malloc((1 + nargs) * sizeof(unsigned long));
181
182 if (nargs > regargs) {
183 memmove(&fsc->args[0], args, regargs * sizeof(fsc->args[0]));
184
185 iorequest.piod_op = PIOD_READ_D;
186 iorequest.piod_offs = (void *)(regs.fixreg[1] + 8);
187 iorequest.piod_addr = &fsc->args[regargs];
188 iorequest.piod_len = (nargs - regargs) * sizeof(fsc->args[0]);
189 ptrace(PT_IO, tid, (caddr_t)&iorequest, 0);
190 if (iorequest.piod_len == 0)
191 return;
192 } else
193 memmove(&fsc->args[0], args, nargs * sizeof(fsc->args[0]));
194
195 sc = get_syscall(fsc->name);
196 if (sc)
197 fsc->nargs = sc->nargs;
198 else {
199#if DEBUG
200 fprintf(trussinfo->outfile, "unknown syscall %s -- setting "
201 "args to %d\n", fsc->name, nargs);
202#endif
203 fsc->nargs = nargs;
204 }
205
206 fsc->s_args = calloc(1, (1 + fsc->nargs) * sizeof(char *));
207 fsc->sc = sc;
208
209 /*
210 * At this point, we set up the system call arguments.
211 * We ignore any OUT ones, however -- those are arguments that
212 * are set by the system call, and so are probably meaningless
213 * now. This doesn't currently support arguments that are
214 * passed in *and* out, however.
215 */
216
217 if (fsc->name) {
218#if DEBUG
219 fprintf(stderr, "syscall %s(", fsc->name);
220#endif
221 for (i = 0; i < fsc->nargs; i++) {
222#if DEBUG
223 fprintf(stderr, "0x%x%s", sc ?
224 fsc->args[sc->args[i].offset] : fsc->args[i],
225 i < (fsc->nargs - 1) ? "," : "");
226#endif
227 if (sc && !(sc->args[i].type & OUT)) {
228 fsc->s_args[i] = print_arg(&sc->args[i],
229 fsc->args, 0, trussinfo);
230 }
231 }
232#if DEBUG
233 fprintf(stderr, ")\n");
234#endif
235 }
236
237#if DEBUG
238 fprintf(trussinfo->outfile, "\n");
239#endif
240
241 if (fsc->name != NULL && (strcmp(fsc->name, "execve") == 0 ||
242 strcmp(fsc->name, "exit") == 0)) {
243 /*
244 * XXX
245 * This could be done in a more general
246 * manner but it still wouldn't be very pretty.
247 */
248 if (strcmp(fsc->name, "execve") == 0) {
249 if ((trussinfo->flags & EXECVEARGS) == 0) {
250 if (fsc->s_args[1]) {
251 free(fsc->s_args[1]);
252 fsc->s_args[1] = NULL;
253 }
254 }
255 if ((trussinfo->flags & EXECVEENVS) == 0) {
256 if (fsc->s_args[2]) {
257 free(fsc->s_args[2]);
258 fsc->s_args[2] = NULL;
259 }
260 }
261 }
262 }
263 trussinfo->curthread->fsc = fsc;
264}
265
266/*
267 * And when the system call is done, we handle it here.
268 * Currently, no attempt is made to ensure that the system calls
269 * match -- this needs to be fixed (and is, in fact, why S_SCX includes
270 * the system call number instead of, say, an error status).
271 */
272
273long
274powerpc_syscall_exit(struct trussinfo *trussinfo, int syscall_num __unused)
275{
276 struct reg regs;
277 struct freebsd_syscall *fsc;
278 struct syscall *sc;
279 lwpid_t tid;
280 long retval;
281 int errorp, i;
282
283 if (trussinfo->curthread->fsc == NULL)
284 return (-1);
285
286 tid = trussinfo->curthread->tid;
287
288 if (ptrace(PT_GETREGS, tid, (caddr_t)&regs, 0) < 0) {
289 fprintf(trussinfo->outfile, "\n");
290 return (-1);
291 }
292
293 retval = regs.fixreg[3];
294 errorp = !!(regs.cr & 0x10000000);
295
296 /*
297 * This code, while simpler than the initial versions I used, could
298 * stand some significant cleaning.
299 */
300
301 fsc = trussinfo->curthread->fsc;
302 sc = fsc->sc;
303 if (!sc) {
304 for (i = 0; i < fsc->nargs; i++)
305 asprintf(&fsc->s_args[i], "0x%lx", fsc->args[i]);
306 } else {
307 /*
308 * On 32-bit big-endian, the low word of a 64-bit return is
309 * in the greater address. Switch to this. XXX note that
310 * print_syscall_ret can't handle 64-bit return values (llseek)
311 */
312 if (sc->ret_type == 2)
313 retval = regs.fixreg[4];
314
315 /*
316 * Here, we only look for arguments that have OUT masked in --
317 * otherwise, they were handled in the syscall_entry function.
318 */
319 for (i = 0; i < sc->nargs; i++) {
320 char *temp;
321 if (sc->args[i].type & OUT) {
322 /*
323 * If an error occurred, then don't bother
324 * getting the data; it may not be valid.
325 */
326 if (errorp) {
327 asprintf(&temp, "0x%lx",
328 fsc->args[sc->args[i].offset]);
329 } else {
330 temp = print_arg(&sc->args[i],
331 fsc->args, retval, trussinfo);
332 }
333 fsc->s_args[i] = temp;
334 }
335 }
336 }
337
338 if (fsc->name != NULL && (strcmp(fsc->name, "execve") == 0 ||
339 strcmp(fsc->name, "exit") == 0))
340 trussinfo->curthread->in_syscall = 1;
341
342 /*
343 * It would probably be a good idea to merge the error handling,
344 * but that complicates things considerably.
345 */
346
347 print_syscall_ret(trussinfo, fsc->name, fsc->nargs, fsc->s_args, errorp,
348 retval, fsc->sc);
349 free_fsc(fsc);
350
351 return (retval);
352}