2 * Copyright 1997 Sean Eric Fagan
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
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.
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13 * must display the following acknowledgement:
14 * This product includes software developed by Sean Eric Fagan
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16 * products derived from this software without specific prior written
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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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
33 * FreeBSD/arm-specific system call handling. This is probably the most
34 * complex part of the entire truss program, although I've got lots of
35 * it handled relatively cleanly now. The system call names are generated
36 * automatically, thanks to /usr/src/sys/kern/syscalls.master. The
37 * names used for the various structures are confusing, I sadly admit.
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
42 #include <sys/types.h>
43 #include <sys/ptrace.h>
44 #include <sys/syscall.h>
46 #include <machine/reg.h>
47 #include <machine/armreg.h>
48 #include <machine/ucontext.h>
67 static int nsyscalls = sizeof(syscallnames) / sizeof(syscallnames[0]);
70 * This is what this particular file uses to keep track of a system call.
71 * It is probably not quite sufficient -- I can probably use the same
72 * structure for the various syscall personalities, and I also probably
73 * need to nest system calls (for signal handlers).
75 * 'struct syscall' describes the system call; it may be NULL, however,
76 * if we don't know about this particular system call yet.
78 struct freebsd_syscall {
83 int nargs; /* number of arguments -- *not* number of words! */
84 char **s_args; /* the printable arguments */
87 static struct freebsd_syscall *
91 return (malloc(sizeof(struct freebsd_syscall)));
94 /* Clear up and free parts of the fsc structure. */
96 free_fsc(struct freebsd_syscall *fsc)
102 for (i = 0; i < fsc->nargs; i++)
103 free(fsc->s_args[i]);
110 * Called when a process has entered a system call. nargs is the
111 * number of words, not number of arguments (a necessary distinction
112 * in some cases). Note that if the STOPEVENT() code in i386/i386/trap.c
113 * is ever changed these functions need to keep up.
117 arm_syscall_entry(struct trussinfo *trussinfo, int nargs)
119 struct ptrace_io_desc iorequest;
121 struct freebsd_syscall *fsc;
127 tid = trussinfo->curthread->tid;
129 if (ptrace(PT_GETREGS, tid, (caddr_t)®s, 0) < 0) {
130 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
136 * FreeBSD has two special kinds of system call redirctions --
137 * SYS_syscall, and SYS___syscall. The former is the old syscall()
138 * routine, basically; the latter is for quad-aligned arguments.
141 syscall_num = regs.r[7];
143 if ((syscall_num = ptrace(PT_READ_I, tid,
144 (caddr_t)(regs.r[_REG_PC] - INSN_SIZE), 0)) == -1) {
145 fprintf(trussinfo->outfile, "-- CANNOT READ PC --\n");
148 syscall_num = syscall_num & 0x000fffff;
150 switch (syscall_num) {
156 syscall_num = ap[_QUAD_LOWWORD];
165 fsc->number = syscall_num;
166 fsc->name = (syscall_num < 0 || syscall_num >= nsyscalls) ?
167 NULL : syscallnames[syscall_num];
169 fprintf(trussinfo->outfile, "-- UNKNOWN SYSCALL %d --\n",
173 if (fsc->name && (trussinfo->flags & FOLLOWFORKS) &&
174 (strcmp(fsc->name, "fork") == 0 ||
175 strcmp(fsc->name, "rfork") == 0 ||
176 strcmp(fsc->name, "vfork") == 0))
177 trussinfo->curthread->in_fork = 1;
182 fsc->args = malloc((1 + nargs) * sizeof(unsigned long));
186 * The OS doesn't seem to allow more than 10 words of
187 * parameters (yay!). So we shouldn't be here.
189 warn("More than 10 words (%d) of arguments!\n", nargs);
198 * If there are 7-10 words of arguments, they are placed
199 * on the stack, as is normal for other processors.
200 * The fall-through for all of these is deliberate!!!
202 // XXX BAD constant used here
203 iorequest.piod_op = PIOD_READ_D;
204 iorequest.piod_offs = (void *)(regs.r[_REG_SP] +
205 4 * sizeof(uint32_t));
206 iorequest.piod_addr = &fsc->args[4];
207 iorequest.piod_len = (nargs - 4) * sizeof(fsc->args[0]);
208 ptrace(PT_IO, tid, (caddr_t)&iorequest, 0);
209 if (iorequest.piod_len == 0)
211 case 4: fsc->args[3] = ap[3];
212 case 3: fsc->args[2] = ap[2];
213 case 2: fsc->args[1] = ap[1];
214 case 1: fsc->args[0] = ap[0];
220 sc = get_syscall(fsc->name);
222 fsc->nargs = sc->nargs;
225 fprintf(trussinfo->outfile, "unknown syscall %s -- setting "
226 "args to %d\n", fsc->name, nargs);
231 fsc->s_args = calloc(1, (1 + fsc->nargs) * sizeof(char *));
235 * At this point, we set up the system call arguments.
236 * We ignore any OUT ones, however -- those are arguments that
237 * are set by the system call, and so are probably meaningless
238 * now. This doesn't currently support arguments that are
239 * passed in *and* out, however.
244 fprintf(stderr, "syscall %s(", fsc->name);
246 for (i = 0; i < fsc->nargs; i++) {
248 fprintf(stderr, "0x%x%s", sc ?
249 fsc->args[sc->args[i].offset] : fsc->args[i],
250 i < (fsc->nargs - 1) ? "," : "");
252 if (sc && !(sc->args[i].type & OUT)) {
253 fsc->s_args[i] = print_arg(&sc->args[i],
254 fsc->args, 0, trussinfo);
258 fprintf(stderr, ")\n");
263 fprintf(trussinfo->outfile, "\n");
266 if (fsc->name != NULL && (strcmp(fsc->name, "execve") == 0 ||
267 strcmp(fsc->name, "exit") == 0)) {
270 * This could be done in a more general
271 * manner but it still wouldn't be very pretty.
273 if (strcmp(fsc->name, "execve") == 0) {
274 if ((trussinfo->flags & EXECVEARGS) == 0) {
275 if (fsc->s_args[1]) {
276 free(fsc->s_args[1]);
277 fsc->s_args[1] = NULL;
280 if ((trussinfo->flags & EXECVEENVS) == 0) {
281 if (fsc->s_args[2]) {
282 free(fsc->s_args[2]);
283 fsc->s_args[2] = NULL;
288 trussinfo->curthread->fsc = fsc;
292 * And when the system call is done, we handle it here.
293 * Currently, no attempt is made to ensure that the system calls
294 * match -- this needs to be fixed (and is, in fact, why S_SCX includes
295 * the system call number instead of, say, an error status).
299 arm_syscall_exit(struct trussinfo *trussinfo, int syscall_num __unused)
302 struct freebsd_syscall *fsc;
308 if (trussinfo->curthread->fsc == NULL)
311 tid = trussinfo->curthread->tid;
313 if (ptrace(PT_GETREGS, tid, (caddr_t)®s, 0) < 0) {
314 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
319 errorp = !!(regs.r_cpsr & PSR_C_bit);
322 * This code, while simpler than the initial versions I used, could
323 * stand some significant cleaning.
326 fsc = trussinfo->curthread->fsc;
329 for (i = 0; i < fsc->nargs; i++)
330 asprintf(&fsc->s_args[i], "0x%lx", fsc->args[i]);
333 * Here, we only look for arguments that have OUT masked in --
334 * otherwise, they were handled in the syscall_entry function.
336 for (i = 0; i < sc->nargs; i++) {
338 if (sc->args[i].type & OUT) {
340 * If an error occurred, then don't bother
341 * getting the data; it may not be valid.
344 asprintf(&temp, "0x%lx",
345 fsc->args[sc->args[i].offset]);
347 temp = print_arg(&sc->args[i],
348 fsc->args, retval, trussinfo);
350 fsc->s_args[i] = temp;
355 if (fsc->name != NULL && (strcmp(fsc->name, "execve") == 0 ||
356 strcmp(fsc->name, "exit") == 0))
357 trussinfo->curthread->in_syscall = 1;
360 * It would probably be a good idea to merge the error handling,
361 * but that complicates things considerably.
364 print_syscall_ret(trussinfo, fsc->name, fsc->nargs, fsc->s_args, errorp,