/usr.bin/truss/mips-fbsd.c

  1/*
  2 * Copyright 1998 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
 33static const char rcsid[] =
 34  "$FreeBSD$";
 35#endif /* not lint */
 36
 37/*
 38 * FreeBSD/sparc64-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 * This file is almost nothing more than a slightly-edited i386-fbsd.c.
 45 */
 46
 47#include <sys/types.h>
 48#include <sys/ptrace.h>
 49#include <sys/syscall.h>
 50
 51#include <machine/frame.h>
 52#include <machine/reg.h>
 53
 54#include <err.h>
 55#include <errno.h>
 56#include <fcntl.h>
 57#include <signal.h>
 58#include <stddef.h>
 59#include <stdio.h>
 60#include <stdlib.h>
 61#include <string.h>
 62#include <time.h>
 63#include <unistd.h>
 64
 65#include "truss.h"
 66#include "syscall.h"
 67#include "extern.h"
 68
 69#include "syscalls.h"
 70
 71static int nsyscalls = sizeof(syscallnames) / sizeof(syscallnames[0]);
 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 sparc64/sparc64/trap.c
117 * is ever changed these functions need to keep up.
118 */
119
120void
121mips_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	lwpid_t tid;
128	int i, syscall_num;
129	int indir;	/* indirect system call */
130
131	tid = trussinfo->curthread->tid;
132
133	if (ptrace(PT_GETREGS, tid, (caddr_t)&regs, 0) < 0) {
134		fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
135		return;
136	}
137
138	indir = 0;
139	syscall_num = regs.r_regs[V0];
140	if (syscall_num == SYS_syscall) {
141		indir = 1;
142		syscall_num = regs.r_regs[A0];
143	}
144
145	fsc = alloc_fsc();
146	if (fsc == NULL)
147		return;
148	fsc->number = syscall_num;
149	fsc->name = (syscall_num < 0 || syscall_num >= nsyscalls) ?
150	    NULL : syscallnames[syscall_num];
151	if (!fsc->name) {
152		fprintf(trussinfo->outfile, "-- UNKNOWN SYSCALL %d --\n",
153		    syscall_num);
154	}
155
156	if (fsc->name && (trussinfo->flags & FOLLOWFORKS) &&
157	    (strcmp(fsc->name, "fork") == 0 ||
158	    strcmp(fsc->name, "rfork") == 0 ||
159	    strcmp(fsc->name, "vfork") == 0))
160		trussinfo->curthread->in_fork = 1;
161
162	if (nargs == 0)
163		return;
164
165	fsc->args = malloc((1 + nargs) * sizeof(unsigned long));
166#if 0 // XXX
167	iorequest.piod_op = PIOD_READ_D;
168	iorequest.piod_offs = (void *)parm_offset;
169	iorequest.piod_addr = fsc->args;
170	iorequest.piod_len = (1 + nargs) * sizeof(unsigned long);
171	ptrace(PT_IO, tid, (caddr_t)&iorequest, 0);
172	if (iorequest.piod_len == 0)
173		return;
174#else
175	iorequest.piod_op = PIOD_READ_D;
176#endif
177
178	switch (nargs) {
179	default:
180		/*
181		 * The OS doesn't seem to allow more than 10 words of
182		 * parameters (yay!).	So we shouldn't be here.
183		 */
184		warn("More than 10 words (%d) of arguments!\n", nargs);
185		break;
186	case 10:
187	case 9:
188	case 8:
189	case 7:
190	case 6:
191	case 5:
192		/*
193		 * If there are 7-10 words of arguments, they are placed
194		 * on the stack, as is normal for other processors.
195		 * The fall-through for all of these is deliberate!!!
196		 */
197		// XXX BAD constant used here
198		iorequest.piod_op = PIOD_READ_D;
199		iorequest.piod_offs = (void *)(regs.r_regs[SP] +
200		    4 * sizeof(uint32_t));
201		iorequest.piod_addr = &fsc->args[4];
202		iorequest.piod_len = (nargs - 4) * sizeof(fsc->args[0]);
203		ptrace(PT_IO, tid, (caddr_t)&iorequest, 0);
204		if (iorequest.piod_len == 0)
205			return;
206	case 4:	fsc->args[3] = regs.r_regs[A3];
207	case 3:	fsc->args[2] = regs.r_regs[A2];
208	case 2:	fsc->args[1] = regs.r_regs[A1];
209	case 1:	fsc->args[0] = regs.r_regs[A0];
210	case 0: break;
211	}
212	if (indir) {
213		memmove(&fsc->args[0], &fsc->args[1],
214		    (nargs - 1) * sizeof(fsc->args[0]));
215	}
216
217	sc = get_syscall(fsc->name);
218	if (sc)
219		fsc->nargs = sc->nargs;
220	else {
221#if DEBUG
222		fprintf(trussinfo->outfile, "unknown syscall %s -- setting "
223		    "args to %d\n", fsc->name, nargs);
224#endif
225		fsc->nargs = nargs;
226	}
227
228	fsc->s_args = calloc(1, (1 + fsc->nargs) * sizeof(char *));
229	fsc->sc = sc;
230
231	/*
232	 * At this point, we set up the system call arguments.
233	 * We ignore any OUT ones, however -- those are arguments that
234	 * are set by the system call, and so are probably meaningless
235	 * now.	This doesn't currently support arguments that are
236	 * passed in *and* out, however.
237	 */
238
239	if (fsc->name) {
240#if DEBUG
241		fprintf(stderr, "syscall %s(", fsc->name);
242#endif
243		for (i = 0; i < fsc->nargs; i++) {
244#if DEBUG
245			fprintf(stderr, "0x%x%s", sc ?
246			    fsc->args[sc->args[i].offset] : fsc->args[i],
247			    i < (fsc->nargs - 1) ? "," : "");
248#endif
249			if (sc && !(sc->args[i].type & OUT)) {
250				fsc->s_args[i] = print_arg(&sc->args[i],
251				    fsc->args, 0, trussinfo);
252			}
253		}
254#if DEBUG
255		fprintf(stderr, ")\n");
256#endif
257	}
258
259#if DEBUG
260	fprintf(trussinfo->outfile, "\n");
261#endif
262
263	if (fsc->name != NULL && (strcmp(fsc->name, "execve") == 0 ||
264	    strcmp(fsc->name, "exit") == 0)) {
265		/*
266		 * XXX
267		 * This could be done in a more general
268		 * manner but it still wouldn't be very pretty.
269		 */
270		if (strcmp(fsc->name, "execve") == 0) {
271			if ((trussinfo->flags & EXECVEARGS) == 0) {
272				if (fsc->s_args[1]) {
273					free(fsc->s_args[1]);
274					fsc->s_args[1] = NULL;
275				}
276			}
277			if ((trussinfo->flags & EXECVEENVS) == 0) {
278				if (fsc->s_args[2]) {
279					free(fsc->s_args[2]);
280					fsc->s_args[2] = NULL;
281				}
282			}
283		}
284	}
285	trussinfo->curthread->fsc = fsc;
286}
287
288/*
289 * And when the system call is done, we handle it here.
290 * Currently, no attempt is made to ensure that the system calls
291 * match -- this needs to be fixed (and is, in fact, why S_SCX includes
292 * the system call number instead of, say, an error status).
293 */
294
295long
296mips_syscall_exit(struct trussinfo *trussinfo, int syscall_num __unused)
297{
298	struct reg regs;
299	struct freebsd_syscall *fsc;
300	struct syscall *sc;
301	lwpid_t tid;
302	long retval;
303	int errorp, i;
304
305	if (trussinfo->curthread->fsc == NULL)
306		return (-1);
307
308	tid = trussinfo->curthread->tid;
309
310	if (ptrace(PT_GETREGS, tid, (caddr_t)&regs, 0) < 0) {
311		fprintf(trussinfo->outfile, "\n");
312		return (-1);
313	}
314
315	retval = regs.r_regs[V0];
316	errorp = !!regs.r_regs[A3];
317
318	/*
319	 * This code, while simpler than the initial versions I used, could
320	 * stand some significant cleaning.
321	 */
322
323	fsc = trussinfo->curthread->fsc;
324	sc = fsc->sc;
325	if (!sc) {
326		for (i = 0; i < fsc->nargs; i++)
327			asprintf(&fsc->s_args[i], "0x%lx", fsc->args[i]);
328	} else {
329		/*
330		 * Here, we only look for arguments that have OUT masked in --
331		 * otherwise, they were handled in the syscall_entry function.
332		 */
333		for (i = 0; i < sc->nargs; i++) {
334			char *temp;
335			if (sc->args[i].type & OUT) {
336				/*
337				 * If an error occurred, then don't bother
338				 * getting the data; it may not be valid.
339				 */
340				if (errorp) {
341					asprintf(&temp, "0x%lx",
342					    fsc->args[sc->args[i].offset]);
343				} else {
344					temp = print_arg(&sc->args[i],
345					    fsc->args, retval, trussinfo);
346				}
347				fsc->s_args[i] = temp;
348			}
349		}
350	}
351
352	if (fsc->name != NULL && (strcmp(fsc->name, "execve") == 0 ||
353	    strcmp(fsc->name, "exit") == 0))
354		trussinfo->curthread->in_syscall = 1;
355
356	/*
357	 * It would probably be a good idea to merge the error handling,
358	 * but that complicates things considerably.
359	 */
360
361	print_syscall_ret(trussinfo, fsc->name, fsc->nargs, fsc->s_args, errorp,
362	    retval, fsc->sc);
363	free_fsc(fsc);
364
365	return (retval);
366}