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
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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 * 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/ptrace.h>
46 #include <machine/reg.h>
47 #include <machine/psl.h>
62 #include "linux_syscalls.h"
64 static int nsyscalls = nitems(linux_syscallnames);
67 * This is what this particular file uses to keep track of a system call.
68 * It is probably not quite sufficient -- I can probably use the same
69 * structure for the various syscall personalities, and I also probably
70 * need to nest system calls (for signal handlers).
72 * 'struct syscall' describes the system call; it may be NULL, however,
73 * if we don't know about this particular system call yet.
75 struct linux_syscall {
79 unsigned long args[5];
80 int nargs; /* number of arguments -- *not* number of words! */
81 char **s_args; /* the printable arguments */
84 static struct linux_syscall *
88 return (malloc(sizeof(struct linux_syscall)));
91 /* Clear up and free parts of the fsc structure. */
93 free_fsc(struct linux_syscall *fsc)
98 for (i = 0; i < fsc->nargs; i++)
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 i386/i386/trap.c
109 * is ever changed these functions need to keep up.
113 i386_linux_syscall_entry(struct trussinfo *trussinfo, int nargs)
116 struct linux_syscall *fsc;
121 tid = trussinfo->curthread->tid;
123 if (ptrace(PT_GETREGS, tid, (caddr_t)®s, 0) < 0) {
124 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
128 syscall_num = regs.r_eax;
133 fsc->number = syscall_num;
134 fsc->name = (syscall_num < 0 || syscall_num >= nsyscalls) ?
135 NULL : linux_syscallnames[syscall_num];
137 fprintf(trussinfo->outfile, "-- UNKNOWN SYSCALL %d --\n",
141 if (fsc->name && (trussinfo->flags & FOLLOWFORKS) &&
142 (strcmp(fsc->name, "linux_fork") == 0 ||
143 strcmp(fsc->name, "linux_vfork") == 0))
144 trussinfo->curthread->in_fork = 1;
150 * Linux passes syscall arguments in registers, not
151 * on the stack. Fortunately, we've got access to the
152 * register set. Note that we don't bother checking the
153 * number of arguments. And what does linux do for syscalls
154 * that have more than five arguments?
157 fsc->args[0] = regs.r_ebx;
158 fsc->args[1] = regs.r_ecx;
159 fsc->args[2] = regs.r_edx;
160 fsc->args[3] = regs.r_esi;
161 fsc->args[4] = regs.r_edi;
163 sc = get_syscall(fsc->name);
165 fsc->nargs = sc->nargs;
168 fprintf(trussinfo->outfile, "unknown syscall %s -- setting "
169 "args to %d\n", fsc->name, nargs);
174 fsc->s_args = calloc(1, (1 + fsc->nargs) * sizeof(char *));
178 * At this point, we set up the system call arguments.
179 * We ignore any OUT ones, however -- those are arguments that
180 * are set by the system call, and so are probably meaningless
181 * now. This doesn't currently support arguments that are
182 * passed in *and* out, however.
187 fprintf(stderr, "syscall %s(", fsc->name);
189 for (i = 0; i < fsc->nargs; i++) {
191 fprintf(stderr, "0x%x%s", sc ?
192 fsc->args[sc->args[i].offset] : fsc->args[i],
193 i < (fsc->nargs - 1) ? "," : "");
195 if (sc && !(sc->args[i].type & OUT)) {
196 fsc->s_args[i] = print_arg(&sc->args[i],
197 fsc->args, 0, trussinfo);
201 fprintf(stderr, ")\n");
206 fprintf(trussinfo->outfile, "\n");
209 trussinfo->curthread->fsc = fsc;
213 * Linux syscalls return negative errno's, we do positive and map them
215 static const int bsd_to_linux_errno[] = {
216 -0, -1, -2, -3, -4, -5, -6, -7, -8, -9,
217 -10, -35, -12, -13, -14, -15, -16, -17, -18, -19,
218 -20, -21, -22, -23, -24, -25, -26, -27, -28, -29,
219 -30, -31, -32, -33, -34, -11,-115,-114, -88, -89,
220 -90, -91, -92, -93, -94, -95, -96, -97, -98, -99,
221 -100,-101,-102,-103,-104,-105,-106,-107,-108,-109,
222 -110,-111, -40, -36,-112,-113, -39, -11, -87,-122,
223 -116, -66, -6, -6, -6, -6, -6, -37, -38, -9,
228 i386_linux_syscall_exit(struct trussinfo *trussinfo, int syscall_num __unused)
231 struct linux_syscall *fsc;
237 if (trussinfo->curthread->fsc == NULL)
240 tid = trussinfo->curthread->tid;
242 if (ptrace(PT_GETREGS, tid, (caddr_t)®s, 0) < 0) {
243 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
248 errorp = !!(regs.r_eflags & PSL_C);
251 * This code, while simpler than the initial versions I used, could
252 * stand some significant cleaning.
255 fsc = trussinfo->curthread->fsc;
258 for (i = 0; i < fsc->nargs; i++)
259 asprintf(&fsc->s_args[i], "0x%lx", fsc->args[i]);
262 * Here, we only look for arguments that have OUT masked in --
263 * otherwise, they were handled in the syscall_entry function.
265 for (i = 0; i < sc->nargs; i++) {
268 if (sc->args[i].type & OUT) {
270 * If an error occurred, then don't bother
271 * getting the data; it may not be valid.
274 asprintf(&temp, "0x%lx",
275 fsc->args[sc->args[i].offset]);
277 temp = print_arg(&sc->args[i],
278 fsc->args, retval, trussinfo);
280 fsc->s_args[i] = temp;
286 * It would probably be a good idea to merge the error handling,
287 * but that complicates things considerably.
290 for (i = 0; (size_t)i < nitems(bsd_to_linux_errno); i++) {
291 if (retval == bsd_to_linux_errno[i])
296 if (fsc->name != NULL && (strcmp(fsc->name, "linux_execve") == 0 ||
297 strcmp(fsc->name, "exit") == 0))
298 trussinfo->curthread->in_syscall = 1;
300 print_syscall_ret(trussinfo, fsc->name, fsc->nargs, fsc->s_args, errorp,
301 errorp ? i : retval, fsc->sc);