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.
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
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
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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
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>
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 amd64/amd64/trap.c
113 * is ever changed these functions need to keep up.
117 amd64_syscall_entry(struct trussinfo *trussinfo, int nargs)
119 struct ptrace_io_desc iorequest;
121 struct freebsd_syscall *fsc;
124 int i, reg, syscall_num;
126 tid = trussinfo->curthread->tid;
128 if (ptrace(PT_GETREGS, tid, (caddr_t)®s, 0) < 0) {
129 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
134 * FreeBSD has two special kinds of system call redirctions --
135 * SYS_syscall, and SYS___syscall. The former is the old syscall()
136 * routine, basically; the latter is for quad-aligned arguments.
139 syscall_num = regs.r_rax;
140 switch (syscall_num) {
143 syscall_num = regs.r_rdi;
151 fsc->number = syscall_num;
152 fsc->name = (syscall_num < 0 || syscall_num >= nsyscalls) ?
153 NULL : syscallnames[syscall_num];
155 fprintf(trussinfo->outfile, "-- UNKNOWN SYSCALL %d --\n",
159 if (fsc->name && (trussinfo->flags & FOLLOWFORKS) &&
160 (strcmp(fsc->name, "fork") == 0 ||
161 strcmp(fsc->name, "rfork") == 0 ||
162 strcmp(fsc->name, "vfork") == 0))
163 trussinfo->curthread->in_fork = 1;
168 fsc->args = malloc((1 + nargs) * sizeof(unsigned long));
169 for (i = 0; i < nargs && reg < 6; i++, reg++) {
171 case 0: fsc->args[i] = regs.r_rdi; break;
172 case 1: fsc->args[i] = regs.r_rsi; break;
173 case 2: fsc->args[i] = regs.r_rdx; break;
174 case 3: fsc->args[i] = regs.r_rcx; break;
175 case 4: fsc->args[i] = regs.r_r8; break;
176 case 5: fsc->args[i] = regs.r_r9; break;
180 iorequest.piod_op = PIOD_READ_D;
181 iorequest.piod_offs = (void *)(regs.r_rsp + sizeof(register_t));
182 iorequest.piod_addr = &fsc->args[i];
183 iorequest.piod_len = (nargs - i) * sizeof(register_t);
184 ptrace(PT_IO, tid, (caddr_t)&iorequest, 0);
185 if (iorequest.piod_len == 0)
189 sc = get_syscall(fsc->name);
191 fsc->nargs = sc->nargs;
194 fprintf(trussinfo->outfile, "unknown syscall %s -- setting "
195 "args to %d\n", fsc->name, nargs);
200 fsc->s_args = calloc(1, (1 + fsc->nargs) * sizeof(char *));
204 * At this point, we set up the system call arguments.
205 * We ignore any OUT ones, however -- those are arguments that
206 * are set by the system call, and so are probably meaningless
207 * now. This doesn't currently support arguments that are
208 * passed in *and* out, however.
213 fprintf(stderr, "syscall %s(", fsc->name);
215 for (i = 0; i < fsc->nargs; i++) {
217 fprintf(stderr, "0x%lx%s", sc ?
218 fsc->args[sc->args[i].offset] : fsc->args[i],
219 i < (fsc->nargs - 1) ? "," : "");
221 if (sc && !(sc->args[i].type & OUT)) {
222 fsc->s_args[i] = print_arg(&sc->args[i],
223 fsc->args, 0, trussinfo);
227 fprintf(stderr, ")\n");
232 fprintf(trussinfo->outfile, "\n");
235 if (fsc->name != NULL && (strcmp(fsc->name, "execve") == 0 ||
236 strcmp(fsc->name, "exit") == 0)) {
239 * This could be done in a more general
240 * manner but it still wouldn't be very pretty.
242 if (strcmp(fsc->name, "execve") == 0) {
243 if ((trussinfo->flags & EXECVEARGS) == 0) {
244 if (fsc->s_args[1]) {
245 free(fsc->s_args[1]);
246 fsc->s_args[1] = NULL;
249 if ((trussinfo->flags & EXECVEENVS) == 0) {
250 if (fsc->s_args[2]) {
251 free(fsc->s_args[2]);
252 fsc->s_args[2] = NULL;
257 trussinfo->curthread->fsc = fsc;
261 * And when the system call is done, we handle it here.
262 * Currently, no attempt is made to ensure that the system calls
263 * match -- this needs to be fixed (and is, in fact, why S_SCX includes
264 * the system call number instead of, say, an error status).
268 amd64_syscall_exit(struct trussinfo *trussinfo, int syscall_num __unused)
271 struct freebsd_syscall *fsc;
277 if (trussinfo->curthread->fsc == NULL)
280 tid = trussinfo->curthread->tid;
282 if (ptrace(PT_GETREGS, tid, (caddr_t)®s, 0) < 0) {
283 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
288 errorp = !!(regs.r_rflags & PSL_C);
291 * This code, while simpler than the initial versions I used, could
292 * stand some significant cleaning.
295 fsc = trussinfo->curthread->fsc;
298 for (i = 0; i < fsc->nargs; i++)
299 asprintf(&fsc->s_args[i], "0x%lx", fsc->args[i]);
302 * Here, we only look for arguments that have OUT masked in --
303 * otherwise, they were handled in the syscall_entry function.
305 for (i = 0; i < sc->nargs; i++) {
307 if (sc->args[i].type & OUT) {
309 * If an error occurred, then don't bother
310 * getting the data; it may not be valid.
313 asprintf(&temp, "0x%lx",
314 fsc->args[sc->args[i].offset]);
316 temp = print_arg(&sc->args[i],
317 fsc->args, retval, trussinfo);
319 fsc->s_args[i] = temp;
324 if (fsc->name != NULL && (strcmp(fsc->name, "execve") == 0 ||
325 strcmp(fsc->name, "exit") == 0))
326 trussinfo->curthread->in_syscall = 1;
329 * It would probably be a good idea to merge the error handling,
330 * but that complicates things considerably.
333 print_syscall_ret(trussinfo, fsc->name, fsc->nargs, fsc->s_args, errorp,