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.
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
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16 * products derived from this software without specific prior written
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33 static const char rcsid[] =
38 * Linux/i386-specific system call handling. Given how much of this code
39 * is taken from the freebsd equivalent, I can probably put even more of
40 * it in support routines that can be used by any personality support.
43 #include <sys/types.h>
44 #include <sys/ioctl.h>
45 #include <sys/pioctl.h>
47 #include <machine/reg.h>
48 #include <machine/psl.h>
66 #include "linux_syscalls.h"
68 static int nsyscalls =
69 sizeof(linux_syscallnames) / sizeof(linux_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 linux_syscall {
84 unsigned long args[5];
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. */
94 for (i = 0; i < fsc.nargs; i++)
99 memset(&fsc, 0, sizeof(fsc));
103 * Called when a process has entered a system call. nargs is the
104 * number of words, not number of arguments (a necessary distinction
105 * in some cases). Note that if the STOPEVENT() code in i386/i386/trap.c
106 * is ever changed these functions need to keep up.
110 i386_linux_syscall_entry(struct trussinfo *trussinfo, int nargs) {
117 if (fd == -1 || trussinfo->pid != cpid) {
118 sprintf(buf, "/proc/%d/regs", trussinfo->pid);
119 fd = open(buf, O_RDWR);
121 fprintf(trussinfo->outfile, "-- CANNOT OPEN REGISTERS --\n");
124 cpid = trussinfo->pid;
129 if (read(fd, ®s, sizeof(regs)) != sizeof(regs)) {
130 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
133 syscall_num = regs.r_eax;
135 fsc.number = syscall_num;
137 (syscall_num < 0 || syscall_num > nsyscalls) ? NULL : linux_syscallnames[syscall_num];
139 fprintf(trussinfo->outfile, "-- UNKNOWN SYSCALL %d --\n", syscall_num);
142 if (fsc.name && (trussinfo->flags & FOLLOWFORKS)
143 && ((!strcmp(fsc.name, "linux_fork")
144 || !strcmp(fsc.name, "linux_vfork"))))
146 trussinfo->in_fork = 1;
153 * Linux passes syscall arguments in registers, not
154 * on the stack. Fortunately, we've got access to the
155 * register set. Note that we don't bother checking the
156 * number of arguments. And what does linux do for syscalls
157 * that have more than five arguments?
160 fsc.args[0] = regs.r_ebx;
161 fsc.args[1] = regs.r_ecx;
162 fsc.args[2] = regs.r_edx;
163 fsc.args[3] = regs.r_esi;
164 fsc.args[4] = regs.r_edi;
166 sc = get_syscall(fsc.name);
168 fsc.nargs = sc->nargs;
171 fprintf(trussinfo->outfile, "unknown syscall %s -- setting args to %d\n",
177 fsc.s_args = malloc((1+fsc.nargs) * sizeof(char*));
178 memset(fsc.s_args, 0, fsc.nargs * sizeof(char*));
182 * At this point, we set up the system call arguments.
183 * We ignore any OUT ones, however -- those are arguments that
184 * are set by the system call, and so are probably meaningless
185 * now. This doesn't currently support arguments that are
186 * passed in *and* out, however.
192 fprintf(stderr, "syscall %s(", fsc.name);
194 for (i = 0; i < fsc.nargs; i++) {
196 fprintf(stderr, "0x%x%s",
198 ? fsc.args[sc->args[i].offset]
200 i < (fsc.nargs - 1) ? "," : "");
202 if (sc && !(sc->args[i].type & OUT)) {
203 fsc.s_args[i] = print_arg(Procfd, &sc->args[i], fsc.args, 0, trussinfo);
207 fprintf(stderr, ")\n");
212 fprintf(trussinfo->outfile, "\n");
216 * Some system calls should be printed out before they are done --
217 * execve() and exit(), for example, never return. Possibly change
218 * this to work for any system call that doesn't have an OUT
222 if (!strcmp(fsc.name, "linux_execve") || !strcmp(fsc.name, "exit")) {
225 * This could be done in a more general
226 * manner but it still wouldn't be very pretty.
228 if (!strcmp(fsc.name, "linux_execve")) {
229 if ((trussinfo->flags & EXECVEARGS) == 0)
232 fsc.s_args[1] = NULL;
234 if ((trussinfo->flags & EXECVEENVS) == 0)
237 fsc.s_args[2] = NULL;
241 print_syscall(trussinfo, fsc.name, fsc.nargs, fsc.s_args);
242 fprintf(trussinfo->outfile, "\n");
249 * Linux syscalls return negative errno's, we do positive and map them
251 const int bsd_to_linux_errno[] = {
252 -0, -1, -2, -3, -4, -5, -6, -7, -8, -9,
253 -10, -35, -12, -13, -14, -15, -16, -17, -18, -19,
254 -20, -21, -22, -23, -24, -25, -26, -27, -28, -29,
255 -30, -31, -32, -33, -34, -11,-115,-114, -88, -89,
256 -90, -91, -92, -93, -94, -95, -96, -97, -98, -99,
257 -100,-101,-102,-103,-104,-105,-106,-107,-108,-109,
258 -110,-111, -40, -36,-112,-113, -39, -11, -87,-122,
259 -116, -66, -6, -6, -6, -6, -6, -37, -38, -9,
264 i386_linux_syscall_exit(struct trussinfo *trussinfo, int syscall_num __unused)
273 if (fd == -1 || trussinfo->pid != cpid) {
274 sprintf(buf, "/proc/%d/regs", trussinfo->pid);
275 fd = open(buf, O_RDONLY);
277 fprintf(trussinfo->outfile, "-- CANNOT OPEN REGISTERS --\n");
280 cpid = trussinfo->pid;
284 if (read(fd, ®s, sizeof(regs)) != sizeof(regs)) {
285 fprintf(trussinfo->outfile, "\n");
289 errorp = !!(regs.r_eflags & PSL_C);
292 * This code, while simpler than the initial versions I used, could
293 * stand some significant cleaning.
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, than don't bothe getting the data;
310 * it may not be valid.
313 asprintf(&temp, "0x%lx", fsc.args[sc->args[i].offset]);
315 temp = print_arg(Procfd, &sc->args[i], fsc.args, retval, trussinfo);
316 fsc.s_args[i] = temp;
322 * It would probably be a good idea to merge the error handling,
323 * but that complicates things considerably.
326 for (i = 0; (size_t)i < sizeof(bsd_to_linux_errno) / sizeof(int); i++)
327 if (retval == bsd_to_linux_errno[i])
330 print_syscall_ret(trussinfo, fsc.name, fsc.nargs, fsc.s_args, errorp,
331 errorp ? i : retval);