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/*
* Copryight 1997 Sean Eric Fagan
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Sean Eric Fagan
* 4. Neither the name of the author may be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static const char rcsid[] =
"$FreeBSD$";
#endif /* not lint */
/*
* FreeBSD/i386-specific system call handling. This is probably the most
* complex part of the entire truss program, although I've got lots of
* it handled relatively cleanly now. The system call names are generated
* automatically, thanks to /usr/src/sys/kern/syscalls.master. The
* names used for the various structures are confusing, I sadly admit.
*/
#include <sys/types.h>
#include <sys/syscall.h>
#include <sys/ptrace.h>
#include <machine/reg.h>
#include <machine/psl.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include "truss.h"
#include "syscall.h"
#include "extern.h"
static int cpid = -1;
#include "syscalls.h"
static int nsyscalls = sizeof(syscallnames) / sizeof(syscallnames[0]);
/*
* This is what this particular file uses to keep track of a system call.
* It is probably not quite sufficient -- I can probably use the same
* structure for the various syscall personalities, and I also probably
* need to nest system calls (for signal handlers).
*
* 'struct syscall' describes the system call; it may be NULL, however,
* if we don't know about this particular system call yet.
*/
static struct freebsd_syscall {
struct syscall *sc;
const char *name;
int number;
unsigned long *args;
int nargs; /* number of arguments -- *not* number of words! */
char **s_args; /* the printable arguments */
} fsc;
/* Clear up and free parts of the fsc structure. */
static __inline void
clear_fsc(void) {
if (fsc.args) {
free(fsc.args);
}
if (fsc.s_args) {
int i;
for (i = 0; i < fsc.nargs; i++)
if (fsc.s_args[i])
free(fsc.s_args[i]);
free(fsc.s_args);
}
memset(&fsc, 0, sizeof(fsc));
}
/*
* Called when a process has entered a system call. nargs is the
* number of words, not number of arguments (a necessary distinction
* in some cases). Note that if the STOPEVENT() code in i386/i386/trap.c
* is ever changed these functions need to keep up.
*/
void
i386_syscall_entry(struct trussinfo *trussinfo, int nargs) {
struct reg regs;
int syscall_num;
int i;
unsigned int parm_offset;
struct syscall *sc = NULL;
struct ptrace_io_desc iorequest;
cpid = trussinfo->curthread->tid;
clear_fsc();
if (ptrace(PT_GETREGS, cpid, (caddr_t)®s, 0) < 0)
{
fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
return;
}
parm_offset = regs.r_esp + sizeof(int);
/*
* FreeBSD has two special kinds of system call redirctions --
* SYS_syscall, and SYS___syscall. The former is the old syscall()
* routine, basicly; the latter is for quad-aligned arguments.
*/
syscall_num = regs.r_eax;
switch (syscall_num) {
case SYS_syscall:
syscall_num = ptrace(PT_READ_D, cpid, (caddr_t)parm_offset, 0);
parm_offset += sizeof(int);
break;
case SYS___syscall:
syscall_num = ptrace(PT_READ_D, cpid, (caddr_t)parm_offset, 0);
parm_offset += sizeof(quad_t);
break;
}
fsc.number = syscall_num;
fsc.name =
(syscall_num < 0 || syscall_num > nsyscalls) ? NULL : syscallnames[syscall_num];
if (!fsc.name) {
fprintf(trussinfo->outfile, "-- UNKNOWN SYSCALL %d --\n", syscall_num);
}
if (fsc.name && (trussinfo->flags & FOLLOWFORKS)
&& ((!strcmp(fsc.name, "fork")
|| !strcmp(fsc.name, "rfork")
|| !strcmp(fsc.name, "vfork"))))
{
trussinfo->curthread->in_fork = 1;
}
if (nargs == 0)
return;
fsc.args = malloc((1+nargs) * sizeof(unsigned long));
iorequest.piod_op = PIOD_READ_D;
iorequest.piod_offs = (void *)parm_offset;
iorequest.piod_addr = fsc.args;
iorequest.piod_len = nargs * sizeof(unsigned long);
ptrace(PT_IO, cpid, (caddr_t)&iorequest, 0);
if (iorequest.piod_len == 0)
return;
if (fsc.name)
sc = get_syscall(fsc.name);
if (sc) {
fsc.nargs = sc->nargs;
} else {
#if DEBUG
fprintf(trussinfo->outfile, "unknown syscall %s -- setting args to %d\n",
fsc.name, nargs);
#endif
fsc.nargs = nargs;
}
fsc.s_args = malloc((1+fsc.nargs) * sizeof(char*));
memset(fsc.s_args, 0, fsc.nargs * sizeof(char*));
fsc.sc = sc;
/*
* At this point, we set up the system call arguments.
* We ignore any OUT ones, however -- those are arguments that
* are set by the system call, and so are probably meaningless
* now. This doesn't currently support arguments that are
* passed in *and* out, however.
*/
if (fsc.name) {
#if DEBUG
fprintf(stderr, "syscall %s(", fsc.name);
#endif
for (i = 0; i < fsc.nargs; i++) {
#if DEBUG
fprintf(stderr, "0x%x%s",
sc
? fsc.args[sc->args[i].offset]
: fsc.args[i],
i < (fsc.nargs - 1) ? "," : "");
#endif
if (sc && !(sc->args[i].type & OUT)) {
fsc.s_args[i] = print_arg(&sc->args[i], fsc.args, 0, trussinfo);
}
}
#if DEBUG
fprintf(stderr, ")\n");
#endif
}
#if DEBUG
fprintf(trussinfo->outfile, "\n");
#endif
/*
* Some system calls should be printed out before they are done --
* execve() and exit(), for example, never return. Possibly change
* this to work for any system call that doesn't have an OUT
* parameter?
*/
if (fsc.name != NULL &&
(!strcmp(fsc.name, "execve") || !strcmp(fsc.name, "exit"))) {
/* XXX
* This could be done in a more general
* manner but it still wouldn't be very pretty.
*/
if (!strcmp(fsc.name, "execve")) {
if ((trussinfo->flags & EXECVEARGS) == 0)
if (fsc.s_args[1]) {
free(fsc.s_args[1]);
fsc.s_args[1] = NULL;
}
if ((trussinfo->flags & EXECVEENVS) == 0)
if (fsc.s_args[2]) {
free(fsc.s_args[2]);
fsc.s_args[2] = NULL;
}
}
print_syscall(trussinfo, fsc.name, fsc.nargs, fsc.s_args);
fprintf(trussinfo->outfile, "\n");
}
return;
}
/*
* And when the system call is done, we handle it here.
* Currently, no attempt is made to ensure that the system calls
* match -- this needs to be fixed (and is, in fact, why S_SCX includes
* the sytem call number instead of, say, an error status).
*/
long
i386_syscall_exit(struct trussinfo *trussinfo, int syscall_num __unused)
{
struct reg regs;
long retval;
int i;
int errorp;
struct syscall *sc;
cpid = trussinfo->curthread->tid;
if (ptrace(PT_GETREGS, cpid, (caddr_t)®s, 0) < 0)
{
fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
return (-1);
}
retval = regs.r_eax;
errorp = !!(regs.r_eflags & PSL_C);
/*
* This code, while simpler than the initial versions I used, could
* stand some significant cleaning.
*/
sc = fsc.sc;
if (!sc) {
for (i = 0; i < fsc.nargs; i++)
asprintf(&fsc.s_args[i], "0x%lx", fsc.args[i]);
} else {
/*
* Here, we only look for arguments that have OUT masked in --
* otherwise, they were handled in the syscall_entry function.
*/
for (i = 0; i < sc->nargs; i++) {
char *temp;
if (sc->args[i].type & OUT) {
/*
* If an error occurred, then don't bother getting the data;
* it may not be valid.
*/
if (errorp)
asprintf(&temp, "0x%lx", fsc.args[sc->args[i].offset]);
else
temp = print_arg(&sc->args[i], fsc.args, retval, trussinfo);
fsc.s_args[i] = temp;
}
}
}
/*
* The pipe syscall returns its fds in two registers and has assembly glue
* to provide the libc API, so it cannot be handled like regular syscalls.
* The nargs check is so we don't have to do yet another strcmp on every
* syscall.
*/
if (!errorp && fsc.nargs == 0 && fsc.name && strcmp(fsc.name, "pipe") == 0) {
fsc.nargs = 1;
fsc.s_args = malloc((1+fsc.nargs) * sizeof(char*));
asprintf(&fsc.s_args[0], "[%d,%d]", (int)retval, regs.r_edx);
retval = 0;
}
/*
* It would probably be a good idea to merge the error handling,
* but that complicates things considerably.
*/
print_syscall_ret(trussinfo, fsc.name, fsc.nargs, fsc.s_args, errorp, retval);
clear_fsc();
return (retval);
}
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