/*
* Copyright 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 */
/*
* Linux/i386-specific system call handling. Given how much of this code
* is taken from the freebsd equivalent, I can probably put even more of
* it in support routines that can be used by any personality support.
*/
#include <sys/types.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"
#include "linux32_syscalls.h"
static int nsyscalls =
sizeof(linux32_syscallnames) / sizeof(linux32_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.
*/
struct linux_syscall {
struct syscall *sc;
const char *name;
int number;
unsigned long args[5];
int nargs; /* number of arguments -- *not* number of words! */
char **s_args; /* the printable arguments */
};
static struct linux_syscall *
alloc_fsc(void)
{
return (malloc(sizeof(struct linux_syscall)));
}
/* Clear up and free parts of the fsc structure. */
static void
free_fsc(struct linux_syscall *fsc)
{
int i;
if (fsc->s_args) {
for (i = 0; i < fsc->nargs; i++)
free(fsc->s_args[i]);
free(fsc->s_args);
}
free(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
amd64_linux32_syscall_entry(struct trussinfo *trussinfo, int nargs)
{
struct reg regs;
struct linux_syscall *fsc;
struct syscall *sc;
lwpid_t tid;
int i, syscall_num;
tid = trussinfo->curthread->tid;
if (ptrace(PT_GETREGS, tid, (caddr_t)®s, 0) < 0) {
fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
return;
}
syscall_num = regs.r_rax;
fsc = alloc_fsc();
if (fsc == NULL)
return;
fsc->number = syscall_num;
fsc->name = (syscall_num < 0 || syscall_num >= nsyscalls) ?
NULL : linux32_syscallnames[syscall_num];
if (!fsc->name) {
fprintf(trussinfo->outfile, "-- UNKNOWN SYSCALL %d --\n",
syscall_num);
}
if (fsc->name && (trussinfo->flags & FOLLOWFORKS) &&
(strcmp(fsc->name, "linux_fork") == 0 ||
strcmp(fsc->name, "linux_vfork") == 0))
trussinfo->curthread->in_fork = 1;
if (nargs == 0)
return;
/*
* Linux passes syscall arguments in registers, not
* on the stack. Fortunately, we've got access to the
* register set. Note that we don't bother checking the
* number of arguments. And what does linux do for syscalls
* that have more than five arguments?
*/
fsc->args[0] = regs.r_rbx;
fsc->args[1] = regs.r_rcx;
fsc->args[2] = regs.r_rdx;
fsc->args[3] = regs.r_rsi;
fsc->args[4] = regs.r_rdi;
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 = calloc(1, (1 + 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
if (fsc->name != NULL && (strcmp(fsc->name, "linux_execve") == 0 ||
strcmp(fsc->name, "exit") == 0)) {
/*
* XXX
* This could be done in a more general
* manner but it still wouldn't be very pretty.
*/
if (strcmp(fsc->name, "linux_execve") == 0) {
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;
}
}
}
}
trussinfo->curthread->fsc = fsc;
}
/*
* Linux syscalls return negative errno's, we do positive and map them
*/
static const int bsd_to_linux_errno[] = {
-0, -1, -2, -3, -4, -5, -6, -7, -8, -9,
-10, -35, -12, -13, -14, -15, -16, -17, -18, -19,
-20, -21, -22, -23, -24, -25, -26, -27, -28, -29,
-30, -31, -32, -33, -34, -11,-115,-114, -88, -89,
-90, -91, -92, -93, -94, -95, -96, -97, -98, -99,
-100,-101,-102,-103,-104,-105,-106,-107,-108,-109,
-110,-111, -40, -36,-112,-113, -39, -11, -87,-122,
-116, -66, -6, -6, -6, -6, -6, -37, -38, -9,
-6,
};
long
amd64_linux32_syscall_exit(struct trussinfo *trussinfo,
int syscall_num __unused)
{
struct reg regs;
struct linux_syscall *fsc;
struct syscall *sc;
lwpid_t tid;
long retval;
int errorp, i;
if (trussinfo->curthread->fsc == NULL)
return (-1);
tid = trussinfo->curthread->tid;
if (ptrace(PT_GETREGS, tid, (caddr_t)®s, 0) < 0) {
fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
return (-1);
}
retval = regs.r_rax;
errorp = !!(regs.r_rflags & PSL_C);
/*
* This code, while simpler than the initial versions I used, could
* stand some significant cleaning.
*/
fsc = trussinfo->curthread->fsc;
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;
}
}
}
/*
* It would probably be a good idea to merge the error handling,
* but that complicates things considerably.
*/
if (errorp) {
for (i = 0;
(size_t)i < sizeof(bsd_to_linux_errno) / sizeof(int); i++) {
if (retval == bsd_to_linux_errno[i])
break;
}
}
if (fsc->name != NULL && (strcmp(fsc->name, "linux_execve") == 0 ||
strcmp(fsc->name, "exit") == 0))
trussinfo->curthread->in_syscall = 1;
print_syscall_ret(trussinfo, fsc->name, fsc->nargs, fsc->s_args, errorp,
errorp ? i : retval, fsc->sc);
free_fsc(fsc);
return (retval);
}
