2 * Copryight 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.
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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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33 static const char rcsid[] =
34 "$FreeBSD: src/usr.bin/truss/i386-fbsd.c,v 1.7.2.2 2001/10/29 20:12:56 des Exp $";
38 * FreeBSD/386-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>
70 static int nsyscalls = sizeof(syscallnames) / sizeof(syscallnames[0]);
73 * This is what this particular file uses to keep track of a system call.
74 * It is probably not quite sufficient -- I can probably use the same
75 * structure for the various syscall personalities, and I also probably
76 * need to nest system calls (for signal handlers).
78 * 'struct syscall' describes the system call; it may be NULL, however,
79 * if we don't know about this particular system call yet.
81 static struct freebsd_syscall {
86 int nargs; /* number of arguments -- *not* number of words! */
87 char **s_args; /* the printable arguments */
90 /* Clear up and free parts of the fsc structure. */
98 for (i = 0; i < fsc.nargs; i++)
103 memset(&fsc, 0, sizeof(fsc));
107 * Called when a process has entered a system call. nargs is the
108 * number of words, not number of arguments (a necessary distinction
109 * in some cases). Note that if the STOPEVENT() code in i386/i386/trap.c
110 * is ever changed these functions need to keep up.
114 i386_syscall_entry(int pid, int nargs) {
116 struct reg regs = { 0 };
119 unsigned int parm_offset;
122 if (fd == -1 || pid != cpid) {
123 sprintf(buf, "/proc/%d/regs", pid);
124 fd = open(buf, O_RDWR);
126 fprintf(outfile, "-- CANNOT READ REGISTERS --\n");
134 i = read(fd, ®s, sizeof(regs));
135 parm_offset = regs.r_esp + sizeof(int);
138 * FreeBSD has two special kinds of system call redirctions --
139 * SYS_syscall, and SYS___syscall. The former is the old syscall()
140 * routine, basicly; the latter is for quad-aligned arguments.
142 syscall = regs.r_eax;
145 lseek(Procfd, parm_offset, SEEK_SET);
146 read(Procfd, &syscall, sizeof(int));
147 parm_offset += sizeof(int);
150 lseek(Procfd, parm_offset, SEEK_SET);
151 read(Procfd, &syscall, sizeof(int));
152 parm_offset += sizeof(quad_t);
156 fsc.number = syscall;
158 (syscall < 0 || syscall > nsyscalls) ? NULL : syscallnames[syscall];
160 fprintf(outfile, "-- UNKNOWN SYSCALL %d --\n", syscall);
166 fsc.args = malloc((1+nargs) * sizeof(unsigned long));
167 lseek(Procfd, parm_offset, SEEK_SET);
168 if (read(Procfd, fsc.args, nargs * sizeof(unsigned long)) == -1)
171 sc = get_syscall(fsc.name);
173 fsc.nargs = sc->nargs;
176 fprintf(outfile, "unknown syscall %s -- setting args to %d\n",
182 fsc.s_args = malloc((1+fsc.nargs) * sizeof(char*));
183 memset(fsc.s_args, 0, fsc.nargs * sizeof(char*));
187 * At this point, we set up the system call arguments.
188 * We ignore any OUT ones, however -- those are arguments that
189 * are set by the system call, and so are probably meaningless
190 * now. This doesn't currently support arguments that are
191 * passed in *and* out, however.
197 fprintf(stderr, "syscall %s(", fsc.name);
199 for (i = 0; i < fsc.nargs; i++) {
201 fprintf(stderr, "0x%x%s",
203 ? fsc.args[sc->args[i].offset]
205 i < (fsc.nargs -1) ? "," : "");
207 if (sc && !(sc->args[i].type & OUT)) {
208 fsc.s_args[i] = print_arg(Procfd, &sc->args[i], fsc.args);
212 fprintf(stderr, ")\n");
217 fprintf(outfile, "\n");
221 * Some system calls should be printed out before they are done --
222 * execve() and exit(), for example, never return. Possibly change
223 * this to work for any system call that doesn't have an OUT
227 if (!strcmp(fsc.name, "execve") || !strcmp(fsc.name, "exit")) {
228 print_syscall(outfile, fsc.name, fsc.nargs, fsc.s_args);
235 * And when the system call is done, we handle it here.
236 * Currently, no attempt is made to ensure that the system calls
237 * match -- this needs to be fixed (and is, in fact, why S_SCX includes
238 * the sytem call number instead of, say, an error status).
242 i386_syscall_exit(int pid, int syscall) {
250 if (fd == -1 || pid != cpid) {
251 sprintf(buf, "/proc/%d/regs", pid);
252 fd = open(buf, O_RDONLY);
254 fprintf(outfile, "-- CANNOT READ REGISTERS --\n");
261 if (read(fd, ®s, sizeof(regs)) != sizeof(regs))
264 errorp = !!(regs.r_eflags & PSL_C);
267 * This code, while simpler than the initial versions I used, could
268 * stand some significant cleaning.
273 for (i = 0; i < fsc.nargs; i++) {
274 fsc.s_args[i] = malloc(12);
275 sprintf(fsc.s_args[i], "0x%lx", fsc.args[i]);
279 * Here, we only look for arguments that have OUT masked in --
280 * otherwise, they were handled in the syscall_entry function.
282 for (i = 0; i < sc->nargs; i++) {
284 if (sc->args[i].type & OUT) {
286 * If an error occurred, than don't bothe getting the data;
287 * it may not be valid.
291 sprintf(temp, "0x%lx", fsc.args[sc->args[i].offset]);
293 temp = print_arg(Procfd, &sc->args[i], fsc.args);
295 fsc.s_args[i] = temp;
301 * It would probably be a good idea to merge the error handling,
302 * but that complicates things considerably.
305 print_syscall_ret(outfile, fsc.name, fsc.nargs, fsc.s_args, errorp, retval);