2 * Copryight 1997 Sean Eric Fagan
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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/ptrace.h>
47 #include <sys/syscall.h>
49 #include <machine/reg.h>
50 #include <machine/psl.h>
69 static int nsyscalls = sizeof(syscallnames) / sizeof(syscallnames[0]);
72 * This is what this particular file uses to keep track of a system call.
73 * It is probably not quite sufficient -- I can probably use the same
74 * structure for the various syscall personalities, and I also probably
75 * need to nest system calls (for signal handlers).
77 * 'struct syscall' describes the system call; it may be NULL, however,
78 * if we don't know about this particular system call yet.
80 static struct freebsd_syscall {
85 int nargs; /* number of arguments -- *not* number of words! */
86 char **s_args; /* the printable arguments */
89 /* Clear up and free parts of the fsc structure. */
97 for (i = 0; i < fsc.nargs; i++)
102 memset(&fsc, 0, sizeof(fsc));
106 * Called when a process has entered a system call. nargs is the
107 * number of words, not number of arguments (a necessary distinction
108 * in some cases). Note that if the STOPEVENT() code in amd64/amd64/trap.c
109 * is ever changed these functions need to keep up.
113 amd64_syscall_entry(struct trussinfo *trussinfo, int nargs) {
119 cpid = trussinfo->curthread->tid;
122 if (ptrace(PT_GETREGS, cpid, (caddr_t)®s, 0) < 0)
124 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
129 * FreeBSD has two special kinds of system call redirctions --
130 * SYS_syscall, and SYS___syscall. The former is the old syscall()
131 * routine, basicly; the latter is for quad-aligned arguments.
134 syscall_num = regs.r_rax;
135 switch (syscall_num) {
138 syscall_num = regs.r_rdi;
143 fsc.number = syscall_num;
145 (syscall_num < 0 || syscall_num > nsyscalls) ? NULL : syscallnames[syscall_num];
147 fprintf(trussinfo->outfile, "-- UNKNOWN SYSCALL %d --\n", syscall_num);
150 if (fsc.name && (trussinfo->flags & FOLLOWFORKS)
151 && ((!strcmp(fsc.name, "fork")
152 || !strcmp(fsc.name, "rfork")
153 || !strcmp(fsc.name, "vfork"))))
155 trussinfo->curthread->in_fork = 1;
161 fsc.args = malloc((1+nargs) * sizeof(unsigned long));
162 for (i = 0; i < nargs && reg < 6; i++, reg++) {
164 case 0: fsc.args[i] = regs.r_rdi; break;
165 case 1: fsc.args[i] = regs.r_rsi; break;
166 case 2: fsc.args[i] = regs.r_rdx; break;
167 case 3: fsc.args[i] = regs.r_rcx; break;
168 case 4: fsc.args[i] = regs.r_r8; break;
169 case 5: fsc.args[i] = regs.r_r9; break;
173 struct ptrace_io_desc iorequest;
174 iorequest.piod_op = PIOD_READ_D;
175 iorequest.piod_offs = (void *)(regs.r_rsp + sizeof(register_t));
176 iorequest.piod_addr = &fsc.args[i];
177 iorequest.piod_len = (nargs - i) * sizeof(register_t);
178 ptrace(PT_IO, cpid, (caddr_t)&iorequest, 0);
179 if (iorequest.piod_len == 0)
183 sc = get_syscall(fsc.name);
185 fsc.nargs = sc->nargs;
188 fprintf(trussinfo->outfile, "unknown syscall %s -- setting args to %d\n",
194 fsc.s_args = malloc((1+fsc.nargs) * sizeof(char*));
195 memset(fsc.s_args, 0, fsc.nargs * sizeof(char*));
199 * At this point, we set up the system call arguments.
200 * We ignore any OUT ones, however -- those are arguments that
201 * are set by the system call, and so are probably meaningless
202 * now. This doesn't currently support arguments that are
203 * passed in *and* out, however.
209 fprintf(stderr, "syscall %s(", fsc.name);
211 for (i = 0; i < fsc.nargs; i++) {
213 fprintf(stderr, "0x%lx%s",
215 ? fsc.args[sc->args[i].offset]
217 i < (fsc.nargs - 1) ? "," : "");
219 if (sc && !(sc->args[i].type & OUT)) {
220 fsc.s_args[i] = print_arg(&sc->args[i], fsc.args, 0, trussinfo);
224 fprintf(stderr, ")\n");
229 fprintf(trussinfo->outfile, "\n");
232 if (fsc.name != NULL &&
233 (!strcmp(fsc.name, "execve") || !strcmp(fsc.name, "exit"))) {
236 * This could be done in a more general
237 * manner but it still wouldn't be very pretty.
239 if (!strcmp(fsc.name, "execve")) {
240 if ((trussinfo->flags & EXECVEARGS) == 0)
243 fsc.s_args[1] = NULL;
245 if ((trussinfo->flags & EXECVEENVS) == 0)
248 fsc.s_args[2] = NULL;
258 * And when the system call is done, we handle it here.
259 * Currently, no attempt is made to ensure that the system calls
260 * match -- this needs to be fixed (and is, in fact, why S_SCX includes
261 * the sytem call number instead of, say, an error status).
265 amd64_syscall_exit(struct trussinfo *trussinfo, int syscall_num __unused)
273 if (fsc.name == NULL)
276 cpid = trussinfo->curthread->tid;
278 if (ptrace(PT_GETREGS, cpid, (caddr_t)®s, 0) < 0)
280 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
284 errorp = !!(regs.r_rflags & PSL_C);
287 * This code, while simpler than the initial versions I used, could
288 * stand some significant cleaning.
293 for (i = 0; i < fsc.nargs; i++)
294 asprintf(&fsc.s_args[i], "0x%lx", fsc.args[i]);
297 * Here, we only look for arguments that have OUT masked in --
298 * otherwise, they were handled in the syscall_entry function.
300 for (i = 0; i < sc->nargs; i++) {
302 if (sc->args[i].type & OUT) {
304 * If an error occurred, than don't bothe getting the data;
305 * it may not be valid.
308 asprintf(&temp, "0x%lx", fsc.args[sc->args[i].offset]);
310 temp = print_arg(&sc->args[i], fsc.args, retval, trussinfo);
311 fsc.s_args[i] = temp;
316 if (fsc.name != NULL &&
317 (!strcmp(fsc.name, "execve") || !strcmp(fsc.name, "exit"))) {
318 trussinfo->curthread->in_syscall = 1;
322 * It would probably be a good idea to merge the error handling,
323 * but that complicates things considerably.
326 print_syscall_ret(trussinfo, fsc.name, fsc.nargs, fsc.s_args, errorp, retval);