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/usr.bin/truss/amd64-fbsd32.c

https://bitbucket.org/freebsd/freebsd-head/
C | 339 lines | 206 code | 41 blank | 92 comment | 53 complexity | e17b0c979e8ad332be169aa548cc0028 MD5 | raw file
  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
 33static const char rcsid[] =
 34  "$FreeBSD$";
 35#endif /* not lint */
 36
 37/*
 38 * FreeBSD/i386-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#include <machine/psl.h>
 51
 52#include <errno.h>
 53#include <fcntl.h>
 54#include <signal.h>
 55#include <stdio.h>
 56#include <stdlib.h>
 57#include <string.h>
 58#include <time.h>
 59#include <unistd.h>
 60
 61#include "truss.h"
 62#include "syscall.h"
 63#include "extern.h"
 64
 65#include "freebsd32_syscalls.h"
 66
 67static int nsyscalls = sizeof(freebsd32_syscallnames) /
 68    sizeof(freebsd32_syscallnames[0]);
 69
 70/*
 71 * This is what this particular file uses to keep track of a system call.
 72 * It is probably not quite sufficient -- I can probably use the same
 73 * structure for the various syscall personalities, and I also probably
 74 * need to nest system calls (for signal handlers).
 75 *
 76 * 'struct syscall' describes the system call; it may be NULL, however,
 77 * if we don't know about this particular system call yet.
 78 */
 79struct freebsd32_syscall {
 80	struct syscall *sc;
 81	const char *name;
 82	int number;
 83	unsigned long *args;
 84	unsigned int *args32;
 85	int nargs;	/* number of arguments -- *not* number of words! */
 86	char **s_args;	/* the printable arguments */
 87};
 88
 89static struct freebsd32_syscall *
 90alloc_fsc(void)
 91{
 92
 93	return (malloc(sizeof(struct freebsd32_syscall)));
 94}
 95
 96/* Clear up and free parts of the fsc structure. */
 97static void
 98free_fsc(struct freebsd32_syscall *fsc)
 99{
100	int i;
101
102	free(fsc->args);
103	free(fsc->args32);
104	if (fsc->s_args) {
105		for (i = 0; i < fsc->nargs; i++)
106			free(fsc->s_args[i]);
107		free(fsc->s_args);
108	}
109	free(fsc);
110}
111
112/*
113 * Called when a process has entered a system call.  nargs is the
114 * number of words, not number of arguments (a necessary distinction
115 * in some cases).  Note that if the STOPEVENT() code in i386/i386/trap.c
116 * is ever changed these functions need to keep up.
117 */
118
119void
120amd64_fbsd32_syscall_entry(struct trussinfo *trussinfo, int nargs)
121{
122	struct ptrace_io_desc iorequest;
123	struct reg regs;
124	struct freebsd32_syscall *fsc;
125	struct syscall *sc;
126	lwpid_t tid;
127	unsigned long parm_offset;
128	int i, syscall_num;
129
130	tid = trussinfo->curthread->tid;
131
132	if (ptrace(PT_GETREGS, tid, (caddr_t)&regs, 0) < 0) {
133		fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
134		return;
135	}
136	parm_offset = regs.r_rsp + sizeof(int);
137
138	/*
139	 * FreeBSD has two special kinds of system call redirctions --
140	 * SYS_syscall, and SYS___syscall.  The former is the old syscall()
141	 * routine, basically; the latter is for quad-aligned arguments.
142	 */
143	syscall_num = regs.r_rax;
144	switch (syscall_num) {
145	case SYS_syscall:
146		syscall_num = ptrace(PT_READ_D, tid, (caddr_t)parm_offset, 0);
147		parm_offset += sizeof(int);
148		break;
149	case SYS___syscall:
150		syscall_num = ptrace(PT_READ_D, tid, (caddr_t)parm_offset, 0);
151		parm_offset += sizeof(quad_t);
152		break;
153	}
154
155	fsc = alloc_fsc();
156	if (fsc == NULL)
157		return;
158	fsc->number = syscall_num;
159	fsc->name = (syscall_num < 0 || syscall_num >= nsyscalls) ?
160	    NULL : freebsd32_syscallnames[syscall_num];
161	if (!fsc->name) {
162		fprintf(trussinfo->outfile, "-- UNKNOWN SYSCALL %d --\n",
163		    syscall_num);
164	}
165
166	if (fsc->name && (trussinfo->flags & FOLLOWFORKS) &&
167	    (strcmp(fsc->name, "fork") == 0 ||
168	    strcmp(fsc->name, "rfork") == 0 ||
169	    strcmp(fsc->name, "vfork") == 0))
170		trussinfo->curthread->in_fork = 1;
171
172	if (nargs == 0)
173		return;
174
175	fsc->args32 = malloc((1 + nargs) * sizeof(unsigned int));
176	iorequest.piod_op = PIOD_READ_D;
177	iorequest.piod_offs = (void *)parm_offset;
178	iorequest.piod_addr = fsc->args32;
179	iorequest.piod_len = (1 + nargs) * sizeof(unsigned int);
180	ptrace(PT_IO, tid, (caddr_t)&iorequest, 0);
181	if (iorequest.piod_len == 0)
182		return;
183
184	fsc->args = malloc((1 + nargs) * sizeof(unsigned long));
185	for (i = 0; i < nargs + 1; i++)
186		 fsc->args[i] = fsc->args32[i];
187
188	sc = NULL;
189	if (fsc->name)
190		sc = get_syscall(fsc->name);
191	if (sc)
192		fsc->nargs = sc->nargs;
193	else {
194#if DEBUG
195		fprintf(trussinfo->outfile, "unknown syscall %s -- setting "
196		    "args to %d\n", fsc->name, nargs);
197#endif
198		fsc->nargs = nargs;
199	}
200
201	fsc->s_args = calloc(1, (1 + fsc->nargs) * sizeof(char *));
202	fsc->sc = sc;
203
204	/*
205	 * At this point, we set up the system call arguments.
206	 * We ignore any OUT ones, however -- those are arguments that
207	 * are set by the system call, and so are probably meaningless
208	 * now.	This doesn't currently support arguments that are
209	 * passed in *and* out, however.
210	 */
211
212	if (fsc->name) {
213#if DEBUG
214		fprintf(stderr, "syscall %s(", fsc->name);
215#endif
216		for (i = 0; i < fsc->nargs; i++) {
217#if DEBUG
218			fprintf(stderr, "0x%x%s", sc ?
219			    fsc->args[sc->args[i].offset] : fsc->args[i],
220			    i < (fsc->nargs - 1) ? "," : "");
221#endif
222			if (sc && !(sc->args[i].type & OUT)) {
223				fsc->s_args[i] = print_arg(&sc->args[i],
224				    fsc->args, 0, trussinfo);
225			}
226		}
227#if DEBUG
228		fprintf(stderr, ")\n");
229#endif
230	}
231
232#if DEBUG
233	fprintf(trussinfo->outfile, "\n");
234#endif
235
236	if (fsc->name != NULL && (strcmp(fsc->name, "freebsd32_execve") == 0 ||
237	    strcmp(fsc->name, "exit") == 0)) {
238		/*
239		 * XXX
240		 * This could be done in a more general
241		 * manner but it still wouldn't be very pretty.
242		 */
243		if (strcmp(fsc->name, "freebsd32_execve") == 0) {
244			if ((trussinfo->flags & EXECVEARGS) == 0) {
245				if (fsc->s_args[1]) {
246					free(fsc->s_args[1]);
247					fsc->s_args[1] = NULL;
248				}
249			}
250			if ((trussinfo->flags & EXECVEENVS) == 0) {
251				if (fsc->s_args[2]) {
252					free(fsc->s_args[2]);
253					fsc->s_args[2] = NULL;
254				}
255			}
256		}
257	}
258	trussinfo->curthread->fsc = fsc;
259}
260
261/*
262 * And when the system call is done, we handle it here.
263 * Currently, no attempt is made to ensure that the system calls
264 * match -- this needs to be fixed (and is, in fact, why S_SCX includes
265 * the system call number instead of, say, an error status).
266 */
267
268long
269amd64_fbsd32_syscall_exit(struct trussinfo *trussinfo, int syscall_num __unused)
270{
271	struct reg regs;
272	struct freebsd32_syscall *fsc;
273	struct syscall *sc;
274	lwpid_t tid;
275	long retval;
276	int errorp, i;
277
278	if (trussinfo->curthread->fsc == NULL)
279		return (-1);
280
281	tid = trussinfo->curthread->tid;
282
283	if (ptrace(PT_GETREGS, tid, (caddr_t)&regs, 0) < 0) {
284		fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
285		return (-1);
286	}
287
288	retval = regs.r_rax;
289	errorp = !!(regs.r_rflags & PSL_C);
290
291	/*
292	 * This code, while simpler than the initial versions I used, could
293	 * stand some significant cleaning.
294	 */
295
296	fsc = trussinfo->curthread->fsc;
297	sc = fsc->sc;
298	if (!sc) {
299		for (i = 0; i < fsc->nargs; i++)
300			asprintf(&fsc->s_args[i], "0x%lx", fsc->args[i]);
301	} else {
302		/*
303		 * Here, we only look for arguments that have OUT masked in --
304		 * otherwise, they were handled in the syscall_entry function.
305		 */
306		for (i = 0; i < sc->nargs; i++) {
307			char *temp;
308			if (sc->args[i].type & OUT) {
309				/*
310				 * If an error occurred, then don't bother
311				 * getting the data; it may not be valid.
312				 */
313				if (errorp) {
314					asprintf(&temp, "0x%lx",
315					    fsc->args[sc->args[i].offset]);
316				} else {
317					temp = print_arg(&sc->args[i],
318					    fsc->args, retval, trussinfo);
319				}
320				fsc->s_args[i] = temp;
321			}
322		}
323	}
324
325	if (fsc->name != NULL && (strcmp(fsc->name, "freebsd32_execve") == 0 ||
326	    strcmp(fsc->name, "exit") == 0))
327		trussinfo->curthread->in_syscall = 1;
328
329	/*
330	 * It would probably be a good idea to merge the error handling,
331	 * but that complicates things considerably.
332	 */
333
334	print_syscall_ret(trussinfo, fsc->name, fsc->nargs, fsc->s_args, errorp,
335	    retval, fsc->sc);
336	free_fsc(fsc);
337
338	return (retval);
339}