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 #ifndef lint
33 static const char rcsid[] =
34 "$FreeBSD$";
35 #endif /* not lint */
36
37 /*
38 * FreeBSD/ia64-specific system call handling. This is probably the most
39 * complex part of the entire truss program, although I've got lots of
40 * it handled relatively cleanly now. The system call names are generated
41 * automatically, thanks to /usr/src/sys/kern/syscalls.master. The
42 * names used for the various structures are confusing, I sadly admit.
43 */
44
45 #include <sys/types.h>
46 #include <sys/ptrace.h>
47 #include <sys/syscall.h>
48
49 #include <machine/reg.h>
50
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 #include "syscalls.h"
65
66 static int nsyscalls = sizeof(syscallnames) / sizeof(syscallnames[0]);
67
68 /*
69 * This is what this particular file uses to keep track of a system call.
70 * It is probably not quite sufficient -- I can probably use the same
71 * structure for the various syscall personalities, and I also probably
72 * need to nest system calls (for signal handlers).
73 *
74 * 'struct syscall' describes the system call; it may be NULL, however,
75 * if we don't know about this particular system call yet.
76 */
77 struct freebsd_syscall {
78 struct syscall *sc;
79 const char *name;
80 int number;
81 unsigned long *args;
82 int nargs; /* number of arguments -- *not* number of words! */
83 char **s_args; /* the printable arguments */
84 };
85
86 static struct freebsd_syscall *
alloc_fsc(void)87 alloc_fsc(void)
88 {
89
90 return (malloc(sizeof(struct freebsd_syscall)));
91 }
92
93 /* Clear up and free parts of the fsc structure. */
94 static void
free_fsc(struct freebsd_syscall * fsc)95 free_fsc(struct freebsd_syscall *fsc)
96 {
97 int i;
98
99 free(fsc->args);
100 if (fsc->s_args) {
101 for (i = 0; i < fsc->nargs; i++)
102 free(fsc->s_args[i]);
103 free(fsc->s_args);
104 }
105 free(fsc);
106 }
107
108 /*
109 * Called when a process has entered a system call. nargs is the
110 * number of words, not number of arguments (a necessary distinction
111 * in some cases). Note that if the STOPEVENT() code in ia64/ia64/trap.c
112 * is ever changed these functions need to keep up.
113 */
114
115 void
ia64_syscall_entry(struct trussinfo * trussinfo,int nargs)116 ia64_syscall_entry(struct trussinfo *trussinfo, int nargs)
117 {
118 struct reg regs;
119 struct freebsd_syscall *fsc;
120 struct syscall *sc;
121 unsigned long *parm_offset;
122 lwpid_t tid;
123 int i, syscall_num;
124
125 tid = trussinfo->curthread->tid;
126
127 if (ptrace(PT_GETREGS, tid, (caddr_t)®s, 0) < 0) {
128 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
129 return;
130 }
131 parm_offset = ®s.r_scratch.gr16;
132
133 /*
134 * FreeBSD has two special kinds of system call redirctions --
135 * SYS_syscall, and SYS___syscall. The former is the old syscall()
136 * routine, basically; the latter is for quad-aligned arguments.
137 */
138 syscall_num = regs.r_scratch.gr15; /* XXX double-check. */
139 if (syscall_num == SYS_syscall || syscall_num == SYS___syscall)
140 syscall_num = (int)*parm_offset++;
141
142 fsc = alloc_fsc();
143 if (fsc == NULL)
144 return;
145 fsc->number = syscall_num;
146 fsc->name = (syscall_num < 0 || syscall_num >= nsyscalls) ?
147 NULL : syscallnames[syscall_num];
148 if (!fsc->name) {
149 fprintf(trussinfo->outfile, "-- UNKNOWN SYSCALL %d --\n",
150 syscall_num);
151 }
152
153 if (fsc->name && (trussinfo->flags & FOLLOWFORKS) &&
154 (strcmp(fsc->name, "fork") == 0 ||
155 strcmp(fsc->name, "rfork") == 0 ||
156 strcmp(fsc->name, "vfork") == 0))
157 trussinfo->curthread->in_fork = 1;
158
159 if (nargs == 0)
160 return;
161
162 fsc->args = malloc((1 + nargs) * sizeof(unsigned long));
163 memcpy(fsc->args, parm_offset, nargs * sizeof(long));
164
165 sc = get_syscall(fsc->name);
166 if (sc)
167 fsc->nargs = sc->nargs;
168 else {
169 #if DEBUG
170 fprintf(trussinfo->outfile, "unknown syscall %s -- setting "
171 "args to %d\n", fsc->name, nargs);
172 #endif
173 fsc->nargs = nargs;
174 }
175
176 fsc->s_args = calloc(1, (1 + fsc->nargs) * sizeof(char *));
177 fsc->sc = sc;
178
179 /*
180 * At this point, we set up the system call arguments.
181 * We ignore any OUT ones, however -- those are arguments that
182 * are set by the system call, and so are probably meaningless
183 * now. This doesn't currently support arguments that are
184 * passed in *and* out, however.
185 */
186
187 if (fsc->name) {
188 #if DEBUG
189 fprintf(stderr, "syscall %s(", fsc->name);
190 #endif
191 for (i = 0; i < fsc->nargs; i++) {
192 #if DEBUG
193 fprintf(stderr, "0x%x%s", sc ?
194 fsc->args[sc->args[i].offset] : fsc->args[i],
195 i < (fsc->nargs - 1) ? "," : "");
196 #endif
197 if (sc && !(sc->args[i].type & OUT)) {
198 fsc->s_args[i] = print_arg(&sc->args[i],
199 fsc->args, 0, trussinfo);
200 }
201 }
202 #if DEBUG
203 fprintf(stderr, ")\n");
204 #endif
205 }
206
207 #if DEBUG
208 fprintf(trussinfo->outfile, "\n");
209 #endif
210
211 if (fsc->name != NULL && (strcmp(fsc->name, "execve") == 0 ||
212 strcmp(fsc->name, "exit") == 0)) {
213 /*
214 * XXX
215 * This could be done in a more general
216 * manner but it still wouldn't be very pretty.
217 */
218 if (strcmp(fsc->name, "execve") == 0) {
219 if ((trussinfo->flags & EXECVEARGS) == 0) {
220 if (fsc->s_args[1]) {
221 free(fsc->s_args[1]);
222 fsc->s_args[1] = NULL;
223 }
224 }
225 if ((trussinfo->flags & EXECVEENVS) == 0) {
226 if (fsc->s_args[2]) {
227 free(fsc->s_args[2]);
228 fsc->s_args[2] = NULL;
229 }
230 }
231 }
232 }
233 trussinfo->curthread->fsc = fsc;
234 }
235
236 /*
237 * And when the system call is done, we handle it here.
238 * Currently, no attempt is made to ensure that the system calls
239 * match -- this needs to be fixed (and is, in fact, why S_SCX includes
240 * the system call number instead of, say, an error status).
241 */
242
243 long
ia64_syscall_exit(struct trussinfo * trussinfo,int syscall_num __unused)244 ia64_syscall_exit(struct trussinfo *trussinfo, int syscall_num __unused)
245 {
246 struct reg regs;
247 struct freebsd_syscall *fsc;
248 struct syscall *sc;
249 lwpid_t tid;
250 long retval;
251 int errorp, i;
252
253 if (trussinfo->curthread->fsc == NULL)
254 return (-1);
255
256 tid = trussinfo->curthread->tid;
257
258 if (ptrace(PT_GETREGS, tid, (caddr_t)®s, 0) < 0) {
259 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
260 return (-1);
261 }
262
263 retval = regs.r_scratch.gr8;
264 errorp = (regs.r_scratch.gr10 != 0) ? 1 : 0;
265
266 /*
267 * This code, while simpler than the initial versions I used, could
268 * stand some significant cleaning.
269 */
270
271 fsc = trussinfo->curthread->fsc;
272 sc = fsc->sc;
273 if (!sc) {
274 for (i = 0; i < fsc->nargs; i++)
275 asprintf(&fsc->s_args[i], "0x%lx", fsc->args[i]);
276 } else {
277 /*
278 * Here, we only look for arguments that have OUT masked in --
279 * otherwise, they were handled in the syscall_entry function.
280 */
281 for (i = 0; i < sc->nargs; i++) {
282 char *temp;
283 if (sc->args[i].type & OUT) {
284 /*
285 * If an error occurred, then don't bother
286 * getting the data; it may not be valid.
287 */
288 if (errorp) {
289 asprintf(&temp, "0x%lx",
290 fsc->args[sc->args[i].offset]);
291 } else {
292 temp = print_arg(&sc->args[i],
293 fsc->args, retval, trussinfo);
294 }
295 fsc->s_args[i] = temp;
296 }
297 }
298 }
299
300 if (fsc->name != NULL && (strcmp(fsc->name, "execve") == 0 ||
301 strcmp(fsc->name, "exit") == 0))
302 trussinfo->curthread->in_syscall = 1;
303
304 /*
305 * It would probably be a good idea to merge the error handling,
306 * but that complicates things considerably.
307 */
308
309 print_syscall_ret(trussinfo, fsc->name, fsc->nargs, fsc->s_args, errorp,
310 retval, fsc->sc);
311 free_fsc(fsc);
312
313 return (retval);
314 }
315