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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31 * $FreeBSD: src/usr.bin/truss/i386-fbsd.c,v 1.7.2.2 2001/10/29 20:12:56 des Exp $
32 * $DragonFly: src/usr.bin/truss/i386-fbsd.c,v 1.2 2003/06/17 04:29:33 dillon Exp $
36 * FreeBSD/386-specific system call handling. This is probably the most
37 * complex part of the entire truss program, although I've got lots of
38 * it handled relatively cleanly now. The system call names are generated
39 * automatically, thanks to /usr/src/sys/kern/syscalls.master. The
40 * names used for the various structures are confusing, I sadly admit.
43 #include <sys/types.h>
44 #include <sys/ioctl.h>
45 #include <sys/pioctl.h>
46 #include <sys/syscall.h>
48 #include <machine/reg.h>
49 #include <machine/psl.h>
68 static int nsyscalls = sizeof(syscallnames) / sizeof(syscallnames[0]);
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).
76 * 'struct syscall' describes the system call; it may be NULL, however,
77 * if we don't know about this particular system call yet.
79 static struct freebsd_syscall {
84 int nargs; /* number of arguments -- *not* number of words! */
85 char **s_args; /* the printable arguments */
88 /* Clear up and free parts of the fsc structure. */
96 for (i = 0; i < fsc.nargs; i++)
101 memset(&fsc, 0, sizeof(fsc));
105 * Called when a process has entered a system call. nargs is the
106 * number of words, not number of arguments (a necessary distinction
107 * in some cases). Note that if the STOPEVENT() code in i386/i386/trap.c
108 * is ever changed these functions need to keep up.
112 i386_syscall_entry(int pid, int nargs) {
114 struct reg regs = { 0 };
117 unsigned int parm_offset;
120 if (fd == -1 || pid != cpid) {
121 sprintf(buf, "/proc/%d/regs", pid);
122 fd = open(buf, O_RDWR);
124 fprintf(outfile, "-- CANNOT READ REGISTERS --\n");
132 i = read(fd, ®s, sizeof(regs));
133 parm_offset = regs.r_esp + sizeof(int);
136 * FreeBSD has two special kinds of system call redirctions --
137 * SYS_syscall, and SYS___syscall. The former is the old syscall()
138 * routine, basicly; the latter is for quad-aligned arguments.
140 syscall = regs.r_eax;
143 lseek(Procfd, parm_offset, SEEK_SET);
144 read(Procfd, &syscall, sizeof(int));
145 parm_offset += sizeof(int);
148 lseek(Procfd, parm_offset, SEEK_SET);
149 read(Procfd, &syscall, sizeof(int));
150 parm_offset += sizeof(quad_t);
154 fsc.number = syscall;
156 (syscall < 0 || syscall > nsyscalls) ? NULL : syscallnames[syscall];
158 fprintf(outfile, "-- UNKNOWN SYSCALL %d --\n", syscall);
164 fsc.args = malloc((1+nargs) * sizeof(unsigned long));
165 lseek(Procfd, parm_offset, SEEK_SET);
166 if (read(Procfd, fsc.args, nargs * sizeof(unsigned long)) == -1)
169 sc = get_syscall(fsc.name);
171 fsc.nargs = sc->nargs;
174 fprintf(outfile, "unknown syscall %s -- setting args to %d\n",
180 fsc.s_args = malloc((1+fsc.nargs) * sizeof(char*));
181 memset(fsc.s_args, 0, fsc.nargs * sizeof(char*));
185 * At this point, we set up the system call arguments.
186 * We ignore any OUT ones, however -- those are arguments that
187 * are set by the system call, and so are probably meaningless
188 * now. This doesn't currently support arguments that are
189 * passed in *and* out, however.
195 fprintf(stderr, "syscall %s(", fsc.name);
197 for (i = 0; i < fsc.nargs; i++) {
199 fprintf(stderr, "0x%x%s",
201 ? fsc.args[sc->args[i].offset]
203 i < (fsc.nargs -1) ? "," : "");
205 if (sc && !(sc->args[i].type & OUT)) {
206 fsc.s_args[i] = print_arg(Procfd, &sc->args[i], fsc.args);
210 fprintf(stderr, ")\n");
215 fprintf(outfile, "\n");
219 * Some system calls should be printed out before they are done --
220 * execve() and exit(), for example, never return. Possibly change
221 * this to work for any system call that doesn't have an OUT
225 if (!strcmp(fsc.name, "execve") || !strcmp(fsc.name, "exit")) {
226 print_syscall(outfile, fsc.name, fsc.nargs, fsc.s_args);
233 * And when the system call is done, we handle it here.
234 * Currently, no attempt is made to ensure that the system calls
235 * match -- this needs to be fixed (and is, in fact, why S_SCX includes
236 * the sytem call number instead of, say, an error status).
240 i386_syscall_exit(int pid, int syscall) {
248 if (fd == -1 || pid != cpid) {
249 sprintf(buf, "/proc/%d/regs", pid);
250 fd = open(buf, O_RDONLY);
252 fprintf(outfile, "-- CANNOT READ REGISTERS --\n");
259 if (read(fd, ®s, sizeof(regs)) != sizeof(regs))
262 errorp = !!(regs.r_eflags & PSL_C);
265 * This code, while simpler than the initial versions I used, could
266 * stand some significant cleaning.
271 for (i = 0; i < fsc.nargs; i++) {
272 fsc.s_args[i] = malloc(12);
273 sprintf(fsc.s_args[i], "0x%lx", fsc.args[i]);
277 * Here, we only look for arguments that have OUT masked in --
278 * otherwise, they were handled in the syscall_entry function.
280 for (i = 0; i < sc->nargs; i++) {
282 if (sc->args[i].type & OUT) {
284 * If an error occurred, than don't bothe getting the data;
285 * it may not be valid.
289 sprintf(temp, "0x%lx", fsc.args[sc->args[i].offset]);
291 temp = print_arg(Procfd, &sc->args[i], fsc.args);
293 fsc.s_args[i] = temp;
299 * It would probably be a good idea to merge the error handling,
300 * but that complicates things considerably.
303 print_syscall_ret(outfile, fsc.name, fsc.nargs, fsc.s_args, errorp, retval);