2 * Copryight 1997 Sean Eric Fagan
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5 * modification, are permitted provided that the following conditions
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14 * This product includes software developed by Sean Eric Fagan
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33 static const char rcsid[] =
38 * FreeBSD/amd64-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.
45 #include <sys/types.h>
46 #include <sys/ioctl.h>
47 #include <sys/pioctl.h>
48 #include <sys/syscall.h>
50 #include <machine/reg.h>
51 #include <machine/psl.h>
71 static int nsyscalls = sizeof(syscallnames) / sizeof(syscallnames[0]);
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).
79 * 'struct syscall' describes the system call; it may be NULL, however,
80 * if we don't know about this particular system call yet.
82 static struct freebsd_syscall {
87 int nargs; /* number of arguments -- *not* number of words! */
88 char **s_args; /* the printable arguments */
91 /* Clear up and free parts of the fsc structure. */
99 for (i = 0; i < fsc.nargs; i++)
104 memset(&fsc, 0, sizeof(fsc));
108 * Called when a process has entered a system call. nargs is the
109 * number of words, not number of arguments (a necessary distinction
110 * in some cases). Note that if the STOPEVENT() code in amd64/amd64/trap.c
111 * is ever changed these functions need to keep up.
115 amd64_syscall_entry(struct trussinfo *trussinfo, int nargs) {
122 if (fd == -1 || trussinfo->pid != cpid) {
123 sprintf(buf, "/proc/%d/regs", trussinfo->pid);
124 fd = open(buf, O_RDWR);
126 fprintf(trussinfo->outfile, "-- CANNOT OPEN REGISTERS --\n");
129 cpid = trussinfo->pid;
134 if (read(fd, ®s, sizeof(regs)) != sizeof(regs)) {
135 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
140 * FreeBSD has two special kinds of system call redirctions --
141 * SYS_syscall, and SYS___syscall. The former is the old syscall()
142 * routine, basicly; the latter is for quad-aligned arguments.
145 syscall_num = regs.r_rax;
146 switch (syscall_num) {
149 syscall_num = regs.r_rdi;
154 fsc.number = syscall_num;
156 (syscall_num < 0 || syscall_num > nsyscalls) ? NULL : syscallnames[syscall_num];
158 fprintf(trussinfo->outfile, "-- UNKNOWN SYSCALL %d --\n", syscall_num);
161 if (fsc.name && (trussinfo->flags & FOLLOWFORKS)
162 && ((!strcmp(fsc.name, "fork")
163 || !strcmp(fsc.name, "rfork")
164 || !strcmp(fsc.name, "vfork"))))
166 trussinfo->in_fork = 1;
172 fsc.args = malloc((1+nargs) * sizeof(unsigned long));
173 for (i = 0; i < nargs && reg < 6; i++, reg++) {
175 case 0: fsc.args[i] = regs.r_rdi; break;
176 case 1: fsc.args[i] = regs.r_rsi; break;
177 case 2: fsc.args[i] = regs.r_rdx; break;
178 case 3: fsc.args[i] = regs.r_rcx; break;
179 case 4: fsc.args[i] = regs.r_r8; break;
180 case 5: fsc.args[i] = regs.r_r9; break;
184 lseek(Procfd, regs.r_rsp + sizeof(register_t), SEEK_SET);
185 if (read(Procfd, &fsc.args[i], (nargs-i) * sizeof(register_t)) == -1)
189 sc = get_syscall(fsc.name);
191 fsc.nargs = sc->nargs;
194 fprintf(trussinfo->outfile, "unknown syscall %s -- setting args to %d\n",
200 fsc.s_args = malloc((1+fsc.nargs) * sizeof(char*));
201 memset(fsc.s_args, 0, fsc.nargs * sizeof(char*));
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.
215 fprintf(stderr, "syscall %s(", fsc.name);
217 for (i = 0; i < fsc.nargs; i++) {
219 fprintf(stderr, "0x%x%s",
221 ? fsc.args[sc->args[i].offset]
223 i < (fsc.nargs - 1) ? "," : "");
225 if (sc && !(sc->args[i].type & OUT)) {
226 fsc.s_args[i] = print_arg(Procfd, &sc->args[i], fsc.args, 0);
230 fprintf(stderr, ")\n");
235 fprintf(trussinfo->outfile, "\n");
239 * Some system calls should be printed out before they are done --
240 * execve() and exit(), for example, never return. Possibly change
241 * this to work for any system call that doesn't have an OUT
245 if (!strcmp(fsc.name, "execve") || !strcmp(fsc.name, "exit")) {
248 * This could be done in a more general
249 * manner but it still wouldn't be very pretty.
251 if (!strcmp(fsc.name, "execve")) {
252 if ((trussinfo->flags & EXECVEARGS) == 0)
255 fsc.s_args[1] = NULL;
257 if ((trussinfo->flags & EXECVEENVS) == 0)
260 fsc.s_args[2] = NULL;
264 print_syscall(trussinfo, fsc.name, fsc.nargs, fsc.s_args);
265 fprintf(trussinfo->outfile, "\n");
272 * And when the system call is done, we handle it here.
273 * Currently, no attempt is made to ensure that the system calls
274 * match -- this needs to be fixed (and is, in fact, why S_SCX includes
275 * the sytem call number instead of, say, an error status).
279 amd64_syscall_exit(struct trussinfo *trussinfo, int syscall_num __unused)
288 if (fd == -1 || trussinfo->pid != cpid) {
289 sprintf(buf, "/proc/%d/regs", trussinfo->pid);
290 fd = open(buf, O_RDONLY);
292 fprintf(trussinfo->outfile, "-- CANNOT OPEN REGISTERS --\n");
295 cpid = trussinfo->pid;
299 if (read(fd, ®s, sizeof(regs)) != sizeof(regs)) {
300 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
304 errorp = !!(regs.r_rflags & PSL_C);
307 * This code, while simpler than the initial versions I used, could
308 * stand some significant cleaning.
313 for (i = 0; i < fsc.nargs; i++)
314 asprintf(&fsc.s_args[i], "0x%lx", fsc.args[i]);
317 * Here, we only look for arguments that have OUT masked in --
318 * otherwise, they were handled in the syscall_entry function.
320 for (i = 0; i < sc->nargs; i++) {
322 if (sc->args[i].type & OUT) {
324 * If an error occurred, than don't bothe getting the data;
325 * it may not be valid.
328 asprintf(&temp, "0x%lx", fsc.args[sc->args[i].offset]);
330 temp = print_arg(Procfd, &sc->args[i], fsc.args, retval);
331 fsc.s_args[i] = temp;
337 * It would probably be a good idea to merge the error handling,
338 * but that complicates things considerably.
341 print_syscall_ret(trussinfo, fsc.name, fsc.nargs, fsc.s_args, errorp, retval);