/
syscall.c
2861 lines (2686 loc) · 66.6 KB
/
syscall.c
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/*
* Copyright (c) 1991, 1992 Paul Kranenburg <pk@cs.few.eur.nl>
* Copyright (c) 1993 Branko Lankester <branko@hacktic.nl>
* Copyright (c) 1993, 1994, 1995, 1996 Rick Sladkey <jrs@world.std.com>
* Copyright (c) 1996-1999 Wichert Akkerman <wichert@cistron.nl>
* Copyright (c) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Linux for s390 port by D.J. Barrow
* <barrow_dj@mail.yahoo.com,djbarrow@de.ibm.com>
* All rights reserved.
*
* 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. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
*
* $Id$
*/
#include "defs.h"
#include <signal.h>
#include <time.h>
#include <errno.h>
#include <sys/user.h>
#include <sys/syscall.h>
#include <sys/param.h>
#ifdef HAVE_SYS_REG_H
#include <sys/reg.h>
#ifndef PTRACE_PEEKUSR
# define PTRACE_PEEKUSR PTRACE_PEEKUSER
#endif
#elif defined(HAVE_LINUX_PTRACE_H)
#undef PTRACE_SYSCALL
# ifdef HAVE_STRUCT_IA64_FPREG
# define ia64_fpreg XXX_ia64_fpreg
# endif
# ifdef HAVE_STRUCT_PT_ALL_USER_REGS
# define pt_all_user_regs XXX_pt_all_user_regs
# endif
#include <linux/ptrace.h>
# undef ia64_fpreg
# undef pt_all_user_regs
#endif
#if defined (LINUX) && defined (SPARC64)
# undef PTRACE_GETREGS
# define PTRACE_GETREGS PTRACE_GETREGS64
# undef PTRACE_SETREGS
# define PTRACE_SETREGS PTRACE_SETREGS64
#endif /* LINUX && SPARC64 */
#if defined(LINUX) && defined(IA64)
# include <asm/ptrace_offsets.h>
# include <asm/rse.h>
#endif
#define NR_SYSCALL_BASE 0
#ifdef LINUX
#ifndef ERESTARTSYS
#define ERESTARTSYS 512
#endif
#ifndef ERESTARTNOINTR
#define ERESTARTNOINTR 513
#endif
#ifndef ERESTARTNOHAND
#define ERESTARTNOHAND 514 /* restart if no handler.. */
#endif
#ifndef ENOIOCTLCMD
#define ENOIOCTLCMD 515 /* No ioctl command */
#endif
#ifndef ERESTART_RESTARTBLOCK
#define ERESTART_RESTARTBLOCK 516 /* restart by calling sys_restart_syscall */
#endif
#ifndef NSIG
#define NSIG 32
#endif
#ifdef ARM
#undef NSIG
#define NSIG 32
#undef NR_SYSCALL_BASE
#define NR_SYSCALL_BASE __NR_SYSCALL_BASE
#endif
#endif /* LINUX */
#include "syscall.h"
/* Define these shorthand notations to simplify the syscallent files. */
#define TD TRACE_DESC
#define TF TRACE_FILE
#define TI TRACE_IPC
#define TN TRACE_NETWORK
#define TP TRACE_PROCESS
#define TS TRACE_SIGNAL
static const struct sysent sysent0[] = {
#include "syscallent.h"
};
static const int nsyscalls0 = sizeof sysent0 / sizeof sysent0[0];
int qual_flags0[MAX_QUALS];
#if SUPPORTED_PERSONALITIES >= 2
static const struct sysent sysent1[] = {
#include "syscallent1.h"
};
static const int nsyscalls1 = sizeof sysent1 / sizeof sysent1[0];
int qual_flags1[MAX_QUALS];
#endif /* SUPPORTED_PERSONALITIES >= 2 */
#if SUPPORTED_PERSONALITIES >= 3
static const struct sysent sysent2[] = {
#include "syscallent2.h"
};
static const int nsyscalls2 = sizeof sysent2 / sizeof sysent2[0];
int qual_flags2[MAX_QUALS];
#endif /* SUPPORTED_PERSONALITIES >= 3 */
const struct sysent *sysent;
int *qual_flags;
int nsyscalls;
/* Now undef them since short defines cause wicked namespace pollution. */
#undef TD
#undef TF
#undef TI
#undef TN
#undef TP
#undef TS
static const char *const errnoent0[] = {
#include "errnoent.h"
};
static const int nerrnos0 = sizeof errnoent0 / sizeof errnoent0[0];
#if SUPPORTED_PERSONALITIES >= 2
static const char *const errnoent1[] = {
#include "errnoent1.h"
};
static const int nerrnos1 = sizeof errnoent1 / sizeof errnoent1[0];
#endif /* SUPPORTED_PERSONALITIES >= 2 */
#if SUPPORTED_PERSONALITIES >= 3
static const char *const errnoent2[] = {
#include "errnoent2.h"
};
static const int nerrnos2 = sizeof errnoent2 / sizeof errnoent2[0];
#endif /* SUPPORTED_PERSONALITIES >= 3 */
const char *const *errnoent;
int nerrnos;
int current_personality;
#ifndef PERSONALITY0_WORDSIZE
# define PERSONALITY0_WORDSIZE sizeof(long)
#endif
const int personality_wordsize[SUPPORTED_PERSONALITIES] = {
PERSONALITY0_WORDSIZE,
#if SUPPORTED_PERSONALITIES > 1
PERSONALITY1_WORDSIZE,
#endif
#if SUPPORTED_PERSONALITIES > 2
PERSONALITY2_WORDSIZE,
#endif
};;
int
set_personality(int personality)
{
switch (personality) {
case 0:
errnoent = errnoent0;
nerrnos = nerrnos0;
sysent = sysent0;
nsyscalls = nsyscalls0;
ioctlent = ioctlent0;
nioctlents = nioctlents0;
signalent = signalent0;
nsignals = nsignals0;
qual_flags = qual_flags0;
break;
#if SUPPORTED_PERSONALITIES >= 2
case 1:
errnoent = errnoent1;
nerrnos = nerrnos1;
sysent = sysent1;
nsyscalls = nsyscalls1;
ioctlent = ioctlent1;
nioctlents = nioctlents1;
signalent = signalent1;
nsignals = nsignals1;
qual_flags = qual_flags1;
break;
#endif /* SUPPORTED_PERSONALITIES >= 2 */
#if SUPPORTED_PERSONALITIES >= 3
case 2:
errnoent = errnoent2;
nerrnos = nerrnos2;
sysent = sysent2;
nsyscalls = nsyscalls2;
ioctlent = ioctlent2;
nioctlents = nioctlents2;
signalent = signalent2;
nsignals = nsignals2;
qual_flags = qual_flags2;
break;
#endif /* SUPPORTED_PERSONALITIES >= 3 */
default:
return -1;
}
current_personality = personality;
return 0;
}
static int qual_syscall(), qual_signal(), qual_fault(), qual_desc();
static const struct qual_options {
int bitflag;
const char *option_name;
int (*qualify)(const char *, const struct qual_options *, int);
const char *argument_name;
} qual_options[] = {
{ QUAL_TRACE, "trace", qual_syscall, "system call" },
{ QUAL_TRACE, "t", qual_syscall, "system call" },
{ QUAL_ABBREV, "abbrev", qual_syscall, "system call" },
{ QUAL_ABBREV, "a", qual_syscall, "system call" },
{ QUAL_VERBOSE, "verbose", qual_syscall, "system call" },
{ QUAL_VERBOSE, "v", qual_syscall, "system call" },
{ QUAL_RAW, "raw", qual_syscall, "system call" },
{ QUAL_RAW, "x", qual_syscall, "system call" },
{ QUAL_SIGNAL, "signal", qual_signal, "signal" },
{ QUAL_SIGNAL, "signals", qual_signal, "signal" },
{ QUAL_SIGNAL, "s", qual_signal, "signal" },
{ QUAL_FAULT, "fault", qual_fault, "fault" },
{ QUAL_FAULT, "faults", qual_fault, "fault" },
{ QUAL_FAULT, "m", qual_fault, "fault" },
{ QUAL_READ, "read", qual_desc, "descriptor" },
{ QUAL_READ, "reads", qual_desc, "descriptor" },
{ QUAL_READ, "r", qual_desc, "descriptor" },
{ QUAL_WRITE, "write", qual_desc, "descriptor" },
{ QUAL_WRITE, "writes", qual_desc, "descriptor" },
{ QUAL_WRITE, "w", qual_desc, "descriptor" },
{ 0, NULL, NULL, NULL },
};
static void
qualify_one(n, opt, not, pers)
int n;
const struct qual_options *opt;
int not;
int pers;
{
if (pers == 0 || pers < 0) {
if (not)
qual_flags0[n] &= ~opt->bitflag;
else
qual_flags0[n] |= opt->bitflag;
}
#if SUPPORTED_PERSONALITIES >= 2
if (pers == 1 || pers < 0) {
if (not)
qual_flags1[n] &= ~opt->bitflag;
else
qual_flags1[n] |= opt->bitflag;
}
#endif /* SUPPORTED_PERSONALITIES >= 2 */
#if SUPPORTED_PERSONALITIES >= 3
if (pers == 2 || pers < 0) {
if (not)
qual_flags2[n] &= ~opt->bitflag;
else
qual_flags2[n] |= opt->bitflag;
}
#endif /* SUPPORTED_PERSONALITIES >= 3 */
}
static int
qual_syscall(const char *s, const struct qual_options *opt, int not)
{
int i;
int rc = -1;
if (isdigit((unsigned char)*s)) {
int i = atoi(s);
if (i < 0 || i >= MAX_QUALS)
return -1;
qualify_one(i, opt, not, -1);
return 0;
}
for (i = 0; i < nsyscalls0; i++)
if (strcmp(s, sysent0[i].sys_name) == 0) {
qualify_one(i, opt, not, 0);
rc = 0;
}
#if SUPPORTED_PERSONALITIES >= 2
for (i = 0; i < nsyscalls1; i++)
if (strcmp(s, sysent1[i].sys_name) == 0) {
qualify_one(i, opt, not, 1);
rc = 0;
}
#endif /* SUPPORTED_PERSONALITIES >= 2 */
#if SUPPORTED_PERSONALITIES >= 3
for (i = 0; i < nsyscalls2; i++)
if (strcmp(s, sysent2[i].sys_name) == 0) {
qualify_one(i, opt, not, 2);
rc = 0;
}
#endif /* SUPPORTED_PERSONALITIES >= 3 */
return rc;
}
static int
qual_signal(const char *s, const struct qual_options *opt, int not)
{
int i;
char buf[32];
if (isdigit((unsigned char)*s)) {
int signo = atoi(s);
if (signo < 0 || signo >= MAX_QUALS)
return -1;
qualify_one(signo, opt, not, -1);
return 0;
}
if (strlen(s) >= sizeof buf)
return -1;
strcpy(buf, s);
s = buf;
if (strncasecmp(s, "SIG", 3) == 0)
s += 3;
for (i = 0; i <= NSIG; i++)
if (strcasecmp(s, signame(i) + 3) == 0) {
qualify_one(i, opt, not, -1);
return 0;
}
return -1;
}
static int
qual_fault(const char *s, const struct qual_options *opt, int not)
{
return -1;
}
static int
qual_desc(const char *s, const struct qual_options *opt, int not)
{
if (isdigit((unsigned char)*s)) {
int desc = atoi(s);
if (desc < 0 || desc >= MAX_QUALS)
return -1;
qualify_one(desc, opt, not, -1);
return 0;
}
return -1;
}
static int
lookup_class(const char *s)
{
if (strcmp(s, "file") == 0)
return TRACE_FILE;
if (strcmp(s, "ipc") == 0)
return TRACE_IPC;
if (strcmp(s, "network") == 0)
return TRACE_NETWORK;
if (strcmp(s, "process") == 0)
return TRACE_PROCESS;
if (strcmp(s, "signal") == 0)
return TRACE_SIGNAL;
if (strcmp(s, "desc") == 0)
return TRACE_DESC;
return -1;
}
void
qualify(const char *s)
{
const struct qual_options *opt;
int not;
char *copy;
const char *p;
int i, n;
opt = &qual_options[0];
for (i = 0; (p = qual_options[i].option_name); i++) {
n = strlen(p);
if (strncmp(s, p, n) == 0 && s[n] == '=') {
opt = &qual_options[i];
s += n + 1;
break;
}
}
not = 0;
if (*s == '!') {
not = 1;
s++;
}
if (strcmp(s, "none") == 0) {
not = 1 - not;
s = "all";
}
if (strcmp(s, "all") == 0) {
for (i = 0; i < MAX_QUALS; i++) {
qualify_one(i, opt, not, -1);
}
return;
}
for (i = 0; i < MAX_QUALS; i++) {
qualify_one(i, opt, !not, -1);
}
if (!strchr(s, ','))
return;
if (!(copy = strdup(s))) {
fprintf(stderr, "out of memory\n");
exit(1);
}
for (p = strtok(copy, ","); p; p = strtok(NULL, ",")) {
if (opt->bitflag == QUAL_TRACE && (n = lookup_class(p)) > 0) {
for (i = 0; i < nsyscalls0; i++)
if (sysent0[i].sys_flags & n)
qualify_one(i, opt, not, 0);
#if SUPPORTED_PERSONALITIES >= 2
for (i = 0; i < nsyscalls1; i++)
if (sysent1[i].sys_flags & n)
qualify_one(i, opt, not, 1);
#endif /* SUPPORTED_PERSONALITIES >= 2 */
#if SUPPORTED_PERSONALITIES >= 3
for (i = 0; i < nsyscalls2; i++)
if (sysent2[i].sys_flags & n)
qualify_one(i, opt, not, 2);
#endif /* SUPPORTED_PERSONALITIES >= 3 */
continue;
}
if (opt->qualify(p, opt, not)) {
fprintf(stderr, "strace: invalid %s `%s'\n",
opt->argument_name, p);
exit(1);
}
}
free(copy);
return;
}
static void
dumpio(tcp)
struct tcb *tcp;
{
if (syserror(tcp))
return;
if (tcp->u_arg[0] < 0 || tcp->u_arg[0] >= MAX_QUALS)
return;
switch (known_scno(tcp)) {
case SYS_read:
#ifdef SYS_pread64
case SYS_pread64:
#endif
#if defined SYS_pread && SYS_pread64 != SYS_pread
case SYS_pread:
#endif
#ifdef SYS_recv
case SYS_recv:
#elif defined SYS_sub_recv
case SYS_sub_recv:
#endif
#ifdef SYS_recvfrom
case SYS_recvfrom:
#elif defined SYS_sub_recvfrom
case SYS_sub_recvfrom:
#endif
if (qual_flags[tcp->u_arg[0]] & QUAL_READ)
dumpstr(tcp, tcp->u_arg[1], tcp->u_rval);
break;
case SYS_write:
#ifdef SYS_pwrite64
case SYS_pwrite64:
#endif
#if defined SYS_pwrite && SYS_pwrite64 != SYS_pwrite
case SYS_pwrite:
#endif
#ifdef SYS_send
case SYS_send:
#elif defined SYS_sub_send
case SYS_sub_send:
#endif
#ifdef SYS_sendto
case SYS_sendto:
#elif defined SYS_sub_sendto
case SYS_sub_sendto:
#endif
if (qual_flags[tcp->u_arg[0]] & QUAL_WRITE)
dumpstr(tcp, tcp->u_arg[1], tcp->u_arg[2]);
break;
#ifdef SYS_readv
case SYS_readv:
if (qual_flags[tcp->u_arg[0]] & QUAL_READ)
dumpiov(tcp, tcp->u_arg[2], tcp->u_arg[1]);
break;
#endif
#ifdef SYS_writev
case SYS_writev:
if (qual_flags[tcp->u_arg[0]] & QUAL_WRITE)
dumpiov(tcp, tcp->u_arg[2], tcp->u_arg[1]);
break;
#endif
}
}
#ifndef FREEBSD
enum subcall_style { shift_style, deref_style, mask_style, door_style };
#else /* FREEBSD */
enum subcall_style { shift_style, deref_style, mask_style, door_style, table_style };
struct subcall {
int call;
int nsubcalls;
int subcalls[5];
};
static const struct subcall subcalls_table[] = {
{ SYS_shmsys, 5, { SYS_shmat, SYS_shmctl, SYS_shmdt, SYS_shmget, SYS_shmctl } },
#ifdef SYS_semconfig
{ SYS_semsys, 4, { SYS___semctl, SYS_semget, SYS_semop, SYS_semconfig } },
#else
{ SYS_semsys, 3, { SYS___semctl, SYS_semget, SYS_semop } },
#endif
{ SYS_msgsys, 4, { SYS_msgctl, SYS_msgget, SYS_msgsnd, SYS_msgrcv } },
};
#endif /* FREEBSD */
#if !(defined(LINUX) && ( defined(ALPHA) || defined(MIPS) || defined(__ARM_EABI__) ))
static void
decode_subcall(tcp, subcall, nsubcalls, style)
struct tcb *tcp;
int subcall;
int nsubcalls;
enum subcall_style style;
{
unsigned long addr, mask;
int i;
int size = personality_wordsize[current_personality];
switch (style) {
case shift_style:
if (tcp->u_arg[0] < 0 || tcp->u_arg[0] >= nsubcalls)
return;
tcp->scno = subcall + tcp->u_arg[0];
if (sysent[tcp->scno].nargs != -1)
tcp->u_nargs = sysent[tcp->scno].nargs;
else
tcp->u_nargs--;
for (i = 0; i < tcp->u_nargs; i++)
tcp->u_arg[i] = tcp->u_arg[i + 1];
break;
case deref_style:
if (tcp->u_arg[0] < 0 || tcp->u_arg[0] >= nsubcalls)
return;
tcp->scno = subcall + tcp->u_arg[0];
addr = tcp->u_arg[1];
for (i = 0; i < sysent[tcp->scno].nargs; i++) {
if (size == sizeof(int)) {
unsigned int arg;
if (umove(tcp, addr, &arg) < 0)
arg = 0;
tcp->u_arg[i] = arg;
}
else if (size == sizeof(long)) {
unsigned long arg;
if (umove(tcp, addr, &arg) < 0)
arg = 0;
tcp->u_arg[i] = arg;
}
else
abort();
addr += size;
}
tcp->u_nargs = sysent[tcp->scno].nargs;
break;
case mask_style:
mask = (tcp->u_arg[0] >> 8) & 0xff;
for (i = 0; mask; i++)
mask >>= 1;
if (i >= nsubcalls)
return;
tcp->u_arg[0] &= 0xff;
tcp->scno = subcall + i;
if (sysent[tcp->scno].nargs != -1)
tcp->u_nargs = sysent[tcp->scno].nargs;
break;
case door_style:
/*
* Oh, yuck. The call code is the *sixth* argument.
* (don't you mean the *last* argument? - JH)
*/
if (tcp->u_arg[5] < 0 || tcp->u_arg[5] >= nsubcalls)
return;
tcp->scno = subcall + tcp->u_arg[5];
if (sysent[tcp->scno].nargs != -1)
tcp->u_nargs = sysent[tcp->scno].nargs;
else
tcp->u_nargs--;
break;
#ifdef FREEBSD
case table_style:
for (i = 0; i < sizeof(subcalls_table) / sizeof(struct subcall); i++)
if (subcalls_table[i].call == tcp->scno) break;
if (i < sizeof(subcalls_table) / sizeof(struct subcall) &&
tcp->u_arg[0] >= 0 && tcp->u_arg[0] < subcalls_table[i].nsubcalls) {
tcp->scno = subcalls_table[i].subcalls[tcp->u_arg[0]];
for (i = 0; i < tcp->u_nargs; i++)
tcp->u_arg[i] = tcp->u_arg[i + 1];
}
break;
#endif /* FREEBSD */
}
}
#endif
struct tcb *tcp_last = NULL;
static int
internal_syscall(struct tcb *tcp)
{
/*
* We must always trace a few critical system calls in order to
* correctly support following forks in the presence of tracing
* qualifiers.
*/
int (*func)();
if (tcp->scno < 0 || tcp->scno >= nsyscalls)
return 0;
func = sysent[tcp->scno].sys_func;
if (sys_exit == func)
return internal_exit(tcp);
if ( sys_fork == func
#if defined(FREEBSD) || defined(LINUX) || defined(SUNOS4)
|| sys_vfork == func
#endif
#ifdef LINUX
|| sys_clone == func
#endif
#if UNIXWARE > 2
|| sys_rfork == func
#endif
)
return internal_fork(tcp);
if ( sys_execve == func
#if defined(SPARC) || defined(SPARC64) || defined(SUNOS4)
|| sys_execv == func
#endif
#if UNIXWARE > 2
|| sys_rexecve == func
#endif
)
return internal_exec(tcp);
if ( sys_waitpid == func
|| sys_wait4 == func
#if defined(SVR4) || defined(FREEBSD) || defined(SUNOS4)
|| sys_wait == func
#endif
#ifdef ALPHA
|| sys_osf_wait4 == func
#endif
)
return internal_wait(tcp, 2);
#if defined(LINUX) || defined(SVR4)
if (sys_waitid == func)
return internal_wait(tcp, 3);
#endif
return 0;
}
#ifdef LINUX
#if defined (I386)
static long eax;
#elif defined (IA64)
long r8, r10, psr;
long ia32 = 0;
#elif defined (POWERPC)
static long result,flags;
#elif defined (M68K)
static long d0;
#elif defined(BFIN)
static long r0;
#elif defined (ARM)
static struct pt_regs regs;
#elif defined (ALPHA)
static long r0;
static long a3;
#elif defined(AVR32)
static struct pt_regs regs;
#elif defined (SPARC) || defined (SPARC64)
static struct pt_regs regs;
static unsigned long trap;
#elif defined(LINUX_MIPSN32)
static long long a3;
static long long r2;
#elif defined(MIPS)
static long a3;
static long r2;
#elif defined(S390) || defined(S390X)
static long gpr2;
static long pc;
static long syscall_mode;
#elif defined(HPPA)
static long r28;
#elif defined(SH)
static long r0;
#elif defined(SH64)
static long r9;
#elif defined(X86_64)
static long rax;
#elif defined(CRISV10) || defined(CRISV32)
static long r10;
#elif defined(MICROBLAZE)
static long r3;
#endif
#endif /* LINUX */
#ifdef FREEBSD
struct reg regs;
#endif /* FREEBSD */
int
get_scno(struct tcb *tcp)
{
long scno = 0;
#ifdef LINUX
# if defined(S390) || defined(S390X)
if (tcp->flags & TCB_WAITEXECVE) {
/*
* When the execve system call completes successfully, the
* new process still has -ENOSYS (old style) or __NR_execve
* (new style) in gpr2. We cannot recover the scno again
* by disassembly, because the image that executed the
* syscall is gone now. Fortunately, we don't want it. We
* leave the flag set so that syscall_fixup can fake the
* result.
*/
if (tcp->flags & TCB_INSYSCALL)
return 1;
/*
* This is the SIGTRAP after execve. We cannot try to read
* the system call here either.
*/
tcp->flags &= ~TCB_WAITEXECVE;
return 0;
}
if (upeek(tcp, PT_GPR2, &syscall_mode) < 0)
return -1;
if (syscall_mode != -ENOSYS) {
/*
* Since kernel version 2.5.44 the scno gets passed in gpr2.
*/
scno = syscall_mode;
} else {
/*
* Old style of "passing" the scno via the SVC instruction.
*/
long opcode, offset_reg, tmp;
void * svc_addr;
int gpr_offset[16] = {PT_GPR0, PT_GPR1, PT_ORIGGPR2, PT_GPR3,
PT_GPR4, PT_GPR5, PT_GPR6, PT_GPR7,
PT_GPR8, PT_GPR9, PT_GPR10, PT_GPR11,
PT_GPR12, PT_GPR13, PT_GPR14, PT_GPR15};
if (upeek(tcp, PT_PSWADDR, &pc) < 0)
return -1;
errno = 0;
opcode = ptrace(PTRACE_PEEKTEXT, tcp->pid, (char *)(pc-sizeof(long)), 0);
if (errno) {
perror("peektext(pc-oneword)");
return -1;
}
/*
* We have to check if the SVC got executed directly or via an
* EXECUTE instruction. In case of EXECUTE it is necessary to do
* instruction decoding to derive the system call number.
* Unfortunately the opcode sizes of EXECUTE and SVC are differently,
* so that this doesn't work if a SVC opcode is part of an EXECUTE
* opcode. Since there is no way to find out the opcode size this
* is the best we can do...
*/
if ((opcode & 0xff00) == 0x0a00) {
/* SVC opcode */
scno = opcode & 0xff;
}
else {
/* SVC got executed by EXECUTE instruction */
/*
* Do instruction decoding of EXECUTE. If you really want to
* understand this, read the Principles of Operations.
*/
svc_addr = (void *) (opcode & 0xfff);
tmp = 0;
offset_reg = (opcode & 0x000f0000) >> 16;
if (offset_reg && (upeek(tcp, gpr_offset[offset_reg], &tmp) < 0))
return -1;
svc_addr += tmp;
tmp = 0;
offset_reg = (opcode & 0x0000f000) >> 12;
if (offset_reg && (upeek(tcp, gpr_offset[offset_reg], &tmp) < 0))
return -1;
svc_addr += tmp;
scno = ptrace(PTRACE_PEEKTEXT, tcp->pid, svc_addr, 0);
if (errno)
return -1;
# if defined(S390X)
scno >>= 48;
# else
scno >>= 16;
# endif
tmp = 0;
offset_reg = (opcode & 0x00f00000) >> 20;
if (offset_reg && (upeek(tcp, gpr_offset[offset_reg], &tmp) < 0))
return -1;
scno = (scno | tmp) & 0xff;
}
}
# elif defined (POWERPC)
if (upeek(tcp, sizeof(unsigned long)*PT_R0, &scno) < 0)
return -1;
if (!(tcp->flags & TCB_INSYSCALL)) {
/* Check if we return from execve. */
if (scno == 0 && (tcp->flags & TCB_WAITEXECVE)) {
tcp->flags &= ~TCB_WAITEXECVE;
return 0;
}
}
# ifdef POWERPC64
if (!(tcp->flags & TCB_INSYSCALL)) {
static int currpers = -1;
long val;
int pid = tcp->pid;
/* Check for 64/32 bit mode. */
if (upeek(tcp, sizeof (unsigned long)*PT_MSR, &val) < 0)
return -1;
/* SF is bit 0 of MSR */
if (val < 0)
currpers = 0;
else
currpers = 1;
if (currpers != current_personality) {
static const char *const names[] = {"64 bit", "32 bit"};
set_personality(currpers);
printf("[ Process PID=%d runs in %s mode. ]\n",
pid, names[current_personality]);
}
}
# endif
# elif defined(AVR32)
/*
* Read complete register set in one go.
*/
if (ptrace(PTRACE_GETREGS, tcp->pid, NULL, ®s) < 0)
return -1;
/*
* We only need to grab the syscall number on syscall entry.
*/
if (!(tcp->flags & TCB_INSYSCALL)) {
scno = regs.r8;
/* Check if we return from execve. */
if (tcp->flags & TCB_WAITEXECVE) {
tcp->flags &= ~TCB_WAITEXECVE;
return 0;
}
}
# elif defined(BFIN)
if (upeek(tcp, PT_ORIG_P0, &scno))
return -1;
# elif defined (I386)
if (upeek(tcp, 4*ORIG_EAX, &scno) < 0)
return -1;
# elif defined (X86_64)
if (upeek(tcp, 8*ORIG_RAX, &scno) < 0)
return -1;
if (!(tcp->flags & TCB_INSYSCALL)) {
static int currpers = -1;
long val;
int pid = tcp->pid;
/* Check CS register value. On x86-64 linux it is:
* 0x33 for long mode (64 bit)
* 0x23 for compatibility mode (32 bit)
* It takes only one ptrace and thus doesn't need
* to be cached.
*/
if (upeek(tcp, 8*CS, &val) < 0)
return -1;
switch (val) {
case 0x23: currpers = 1; break;
case 0x33: currpers = 0; break;
default:
fprintf(stderr, "Unknown value CS=0x%02X while "
"detecting personality of process "
"PID=%d\n", (int)val, pid);
currpers = current_personality;
break;
}
# if 0
/* This version analyzes the opcode of a syscall instruction.
* (int 0x80 on i386 vs. syscall on x86-64)
* It works, but is too complicated.
*/
unsigned long val, rip, i;
if (upeek(tcp, 8*RIP, &rip) < 0)
perror("upeek(RIP)");
/* sizeof(syscall) == sizeof(int 0x80) == 2 */
rip -= 2;
errno = 0;
call = ptrace(PTRACE_PEEKTEXT, pid, (char *)rip, (char *)0);
if (errno)
printf("ptrace_peektext failed: %s\n",
strerror(errno));
switch (call & 0xffff) {
/* x86-64: syscall = 0x0f 0x05 */
case 0x050f: currpers = 0; break;
/* i386: int 0x80 = 0xcd 0x80 */
case 0x80cd: currpers = 1; break;
default:
currpers = current_personality;
fprintf(stderr,
"Unknown syscall opcode (0x%04X) while "
"detecting personality of process "
"PID=%d\n", (int)call, pid);
break;
}
# endif
if (currpers != current_personality) {
static const char *const names[] = {"64 bit", "32 bit"};
set_personality(currpers);
printf("[ Process PID=%d runs in %s mode. ]\n",
pid, names[current_personality]);
}
}
# elif defined(IA64)
# define IA64_PSR_IS ((long)1 << 34)
if (upeek (tcp, PT_CR_IPSR, &psr) >= 0)
ia32 = (psr & IA64_PSR_IS) != 0;
if (!(tcp->flags & TCB_INSYSCALL)) {
if (ia32) {
if (upeek(tcp, PT_R1, &scno) < 0) /* orig eax */