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strace/syscall.c
Dmitry V. Levin e3dfc5901f Make sure that tcp->s_ent and tcp->s_prev_ent do not point to freed memory 
This complements commit v4.13-33-g60d7ec8.

* syscall.c (sysent_buf): New structure.
(free_sysent_buf): New function.
(get_scno): Use them.
2016-08-09 10:34:09 +00:00

1364 lines
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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.
*/
#include "defs.h"
#include "native_defs.h"
#include <sys/param.h>
#include <signal.h>
/* for struct iovec */
#include <sys/uio.h>
#include "regs.h"
#include "ptrace.h"
#if defined(SPARC64)
# undef PTRACE_GETREGS
# define PTRACE_GETREGS PTRACE_GETREGS64
# undef PTRACE_SETREGS
# define PTRACE_SETREGS PTRACE_SETREGS64
#endif
#if defined SPARC64
# include <asm/psrcompat.h>
#elif defined SPARC
# include <asm/psr.h>
#endif
#ifdef IA64
# include <asm/rse.h>
#endif
#ifndef NT_PRSTATUS
# define NT_PRSTATUS 1
#endif
#ifndef NSIG
# warning: NSIG is not defined, using 32
# define NSIG 32
#endif
#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
#define TM TRACE_MEMORY
#define NF SYSCALL_NEVER_FAILS
#define MA MAX_ARGS
#define SI STACKTRACE_INVALIDATE_CACHE
#define SE STACKTRACE_CAPTURE_ON_ENTER
#define SEN(syscall_name) SEN_ ## syscall_name, SYS_FUNC_NAME(sys_ ## syscall_name)
const struct_sysent sysent0[] = {
#include "syscallent.h"
};
#if SUPPORTED_PERSONALITIES > 1
# include PERSONALITY1_INCLUDE_FUNCS
static const struct_sysent sysent1[] = {
# include "syscallent1.h"
};
#endif
#if SUPPORTED_PERSONALITIES > 2
# include PERSONALITY2_INCLUDE_FUNCS
static const struct_sysent sysent2[] = {
# include "syscallent2.h"
};
#endif
/* Now undef them since short defines cause wicked namespace pollution. */
#undef SEN
#undef TD
#undef TF
#undef TI
#undef TN
#undef TP
#undef TS
#undef TM
#undef NF
#undef MA
#undef SI
#undef SE
/*
* `ioctlent[012].h' files are automatically generated by the auxiliary
* program `ioctlsort', such that the list is sorted by the `code' field.
* This has the side-effect of resolving the _IO.. macros into
* plain integers, eliminating the need to include here everything
* in "/usr/include".
*/
const char *const errnoent0[] = {
#include "errnoent.h"
};
const char *const signalent0[] = {
#include "signalent.h"
};
const struct_ioctlent ioctlent0[] = {
#include "ioctlent0.h"
};
#if SUPPORTED_PERSONALITIES > 1
static const char *const errnoent1[] = {
# include "errnoent1.h"
};
static const char *const signalent1[] = {
# include "signalent1.h"
};
static const struct_ioctlent ioctlent1[] = {
# include "ioctlent1.h"
};
# include PERSONALITY0_INCLUDE_PRINTERS_DECLS
static const struct_printers printers0 = {
# include PERSONALITY0_INCLUDE_PRINTERS_DEFS
};
# include PERSONALITY1_INCLUDE_PRINTERS_DECLS
static const struct_printers printers1 = {
# include PERSONALITY1_INCLUDE_PRINTERS_DEFS
};
#endif
#if SUPPORTED_PERSONALITIES > 2
static const char *const errnoent2[] = {
# include "errnoent2.h"
};
static const char *const signalent2[] = {
# include "signalent2.h"
};
static const struct_ioctlent ioctlent2[] = {
# include "ioctlent2.h"
};
# include PERSONALITY2_INCLUDE_PRINTERS_DECLS
static const struct_printers printers2 = {
# include PERSONALITY2_INCLUDE_PRINTERS_DEFS
};
#endif
enum {
nsyscalls0 = ARRAY_SIZE(sysent0)
#if SUPPORTED_PERSONALITIES > 1
, nsyscalls1 = ARRAY_SIZE(sysent1)
# if SUPPORTED_PERSONALITIES > 2
, nsyscalls2 = ARRAY_SIZE(sysent2)
# endif
#endif
};
enum {
nerrnos0 = ARRAY_SIZE(errnoent0)
#if SUPPORTED_PERSONALITIES > 1
, nerrnos1 = ARRAY_SIZE(errnoent1)
# if SUPPORTED_PERSONALITIES > 2
, nerrnos2 = ARRAY_SIZE(errnoent2)
# endif
#endif
};
enum {
nsignals0 = ARRAY_SIZE(signalent0)
#if SUPPORTED_PERSONALITIES > 1
, nsignals1 = ARRAY_SIZE(signalent1)
# if SUPPORTED_PERSONALITIES > 2
, nsignals2 = ARRAY_SIZE(signalent2)
# endif
#endif
};
enum {
nioctlents0 = ARRAY_SIZE(ioctlent0)
#if SUPPORTED_PERSONALITIES > 1
, nioctlents1 = ARRAY_SIZE(ioctlent1)
# if SUPPORTED_PERSONALITIES > 2
, nioctlents2 = ARRAY_SIZE(ioctlent2)
# endif
#endif
};
#if SUPPORTED_PERSONALITIES > 1
const struct_sysent *sysent = sysent0;
const char *const *errnoent = errnoent0;
const char *const *signalent = signalent0;
const struct_ioctlent *ioctlent = ioctlent0;
const struct_printers *printers = &printers0;
#endif
unsigned nsyscalls = nsyscalls0;
unsigned nerrnos = nerrnos0;
unsigned nsignals = nsignals0;
unsigned nioctlents = nioctlents0;
unsigned num_quals;
qualbits_t *qual_vec[SUPPORTED_PERSONALITIES];
static const unsigned nsyscall_vec[SUPPORTED_PERSONALITIES] = {
nsyscalls0,
#if SUPPORTED_PERSONALITIES > 1
nsyscalls1,
#endif
#if SUPPORTED_PERSONALITIES > 2
nsyscalls2,
#endif
};
static const struct_sysent *const sysent_vec[SUPPORTED_PERSONALITIES] = {
sysent0,
#if SUPPORTED_PERSONALITIES > 1
sysent1,
#endif
#if SUPPORTED_PERSONALITIES > 2
sysent2,
#endif
};
enum {
MAX_NSYSCALLS1 = (nsyscalls0
#if SUPPORTED_PERSONALITIES > 1
> nsyscalls1 ? nsyscalls0 : nsyscalls1
#endif
),
MAX_NSYSCALLS2 = (MAX_NSYSCALLS1
#if SUPPORTED_PERSONALITIES > 2
> nsyscalls2 ? MAX_NSYSCALLS1 : nsyscalls2
#endif
),
MAX_NSYSCALLS = MAX_NSYSCALLS2,
/* We are ready for arches with up to 255 signals,
* even though the largest known signo is on MIPS and it is 128.
* The number of existing syscalls on all arches is
* larger that 255 anyway, so it is just a pedantic matter.
*/
MIN_QUALS = MAX_NSYSCALLS > 255 ? MAX_NSYSCALLS : 255
};
#if SUPPORTED_PERSONALITIES > 1
unsigned current_personality;
# ifndef current_wordsize
unsigned current_wordsize;
static const int personality_wordsize[SUPPORTED_PERSONALITIES] = {
PERSONALITY0_WORDSIZE,
PERSONALITY1_WORDSIZE,
# if SUPPORTED_PERSONALITIES > 2
PERSONALITY2_WORDSIZE,
# endif
};
# endif
void
set_personality(int personality)
{
nsyscalls = nsyscall_vec[personality];
sysent = sysent_vec[personality];
switch (personality) {
case 0:
errnoent = errnoent0;
nerrnos = nerrnos0;
ioctlent = ioctlent0;
nioctlents = nioctlents0;
signalent = signalent0;
nsignals = nsignals0;
printers = &printers0;
break;
case 1:
errnoent = errnoent1;
nerrnos = nerrnos1;
ioctlent = ioctlent1;
nioctlents = nioctlents1;
signalent = signalent1;
nsignals = nsignals1;
printers = &printers1;
break;
# if SUPPORTED_PERSONALITIES > 2
case 2:
errnoent = errnoent2;
nerrnos = nerrnos2;
ioctlent = ioctlent2;
nioctlents = nioctlents2;
signalent = signalent2;
nsignals = nsignals2;
printers = &printers2;
break;
# endif
}
current_personality = personality;
# ifndef current_wordsize
current_wordsize = personality_wordsize[personality];
# endif
}
static void
update_personality(struct tcb *tcp, unsigned int personality)
{
if (personality == current_personality)
return;
set_personality(personality);
if (personality == tcp->currpers)
return;
tcp->currpers = personality;
# undef PERSONALITY_NAMES
# if defined POWERPC64
# define PERSONALITY_NAMES {"64 bit", "32 bit"}
# elif defined X86_64
# define PERSONALITY_NAMES {"64 bit", "32 bit", "x32"}
# elif defined X32
# define PERSONALITY_NAMES {"x32", "32 bit"}
# elif defined AARCH64
# define PERSONALITY_NAMES {"64 bit", "32 bit"}
# elif defined TILE
# define PERSONALITY_NAMES {"64-bit", "32-bit"}
# endif
# ifdef PERSONALITY_NAMES
if (!qflag) {
static const char *const names[] = PERSONALITY_NAMES;
error_msg("[ Process PID=%d runs in %s mode. ]",
tcp->pid, names[personality]);
}
# endif
}
#endif
static int qual_syscall(), qual_signal(), qual_desc();
static const struct qual_options {
unsigned int bitflag;
const char *option_name;
int (*qualify)(const char *, int, 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_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
reallocate_qual(const unsigned int n)
{
unsigned p;
qualbits_t *qp;
for (p = 0; p < SUPPORTED_PERSONALITIES; p++) {
qp = qual_vec[p] = xreallocarray(qual_vec[p], n,
sizeof(qualbits_t));
memset(&qp[num_quals], 0, (n - num_quals) * sizeof(qualbits_t));
}
num_quals = n;
}
static void
qualify_one(const unsigned int n, unsigned int bitflag, const int not, const int pers)
{
int p;
if (num_quals <= n)
reallocate_qual(n + 1);
for (p = 0; p < SUPPORTED_PERSONALITIES; p++) {
if (pers == p || pers < 0) {
if (not)
qual_vec[p][n] &= ~bitflag;
else
qual_vec[p][n] |= bitflag;
}
}
}
static int
qual_syscall(const char *s, const unsigned int bitflag, const int not)
{
int p;
unsigned int i;
int rc = -1;
if (*s >= '0' && *s <= '9') {
i = string_to_uint(s);
if (i >= MAX_NSYSCALLS)
return -1;
qualify_one(i, bitflag, not, -1);
return 0;
}
for (p = 0; p < SUPPORTED_PERSONALITIES; p++) {
for (i = 0; i < nsyscall_vec[p]; i++) {
if (sysent_vec[p][i].sys_name
&& strcmp(s, sysent_vec[p][i].sys_name) == 0
) {
qualify_one(i, bitflag, not, p);
rc = 0;
}
}
}
return rc;
}
static int
qual_signal(const char *s, const unsigned int bitflag, const int not)
{
unsigned int i;
if (*s >= '0' && *s <= '9') {
int signo = string_to_uint(s);
if (signo < 0 || signo > 255)
return -1;
qualify_one(signo, bitflag, not, -1);
return 0;
}
if (strncasecmp(s, "SIG", 3) == 0)
s += 3;
for (i = 0; i <= NSIG; i++) {
if (strcasecmp(s, signame(i) + 3) == 0) {
qualify_one(i, bitflag, not, -1);
return 0;
}
}
return -1;
}
static int
qual_desc(const char *s, const unsigned int bitflag, const int not)
{
if (*s >= '0' && *s <= '9') {
int desc = string_to_uint(s);
if (desc < 0 || desc > 0x7fff) /* paranoia */
return -1;
qualify_one(desc, bitflag, 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;
if (strcmp(s, "memory") == 0)
return TRACE_MEMORY;
return -1;
}
void
qualify(const char *s)
{
const struct qual_options *opt;
char *copy;
const char *p;
int not;
unsigned int i;
if (num_quals == 0)
reallocate_qual(MIN_QUALS);
opt = &qual_options[0];
for (i = 0; (p = qual_options[i].option_name); i++) {
unsigned int len = strlen(p);
if (strncmp(s, p, len) == 0 && s[len] == '=') {
opt = &qual_options[i];
s += len + 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 < num_quals; i++) {
qualify_one(i, opt->bitflag, not, -1);
}
return;
}
for (i = 0; i < num_quals; i++) {
qualify_one(i, opt->bitflag, !not, -1);
}
copy = xstrdup(s);
for (p = strtok(copy, ","); p; p = strtok(NULL, ",")) {
int n;
if (opt->bitflag == QUAL_TRACE && (n = lookup_class(p)) > 0) {
unsigned pers;
for (pers = 0; pers < SUPPORTED_PERSONALITIES; pers++) {
for (i = 0; i < nsyscall_vec[pers]; i++)
if (sysent_vec[pers][i].sys_flags & n)
qualify_one(i, opt->bitflag, not, pers);
}
continue;
}
if (opt->qualify(p, opt->bitflag, not)) {
error_msg_and_die("invalid %s '%s'",
opt->argument_name, p);
}
}
free(copy);
return;
}
#ifdef SYS_socket_subcall
static void
decode_socket_subcall(struct tcb *tcp)
{
const int call = tcp->u_arg[0];
if (call < 1 || call >= SYS_socket_nsubcalls)
return;
const unsigned long scno = SYS_socket_subcall + call;
const unsigned int nargs = sysent[scno].nargs;
uint64_t buf[nargs];
if (umoven(tcp, tcp->u_arg[1], nargs * current_wordsize, buf) < 0)
return;
tcp->scno = scno;
tcp->qual_flg = qual_flags[scno];
tcp->s_ent = &sysent[scno];
unsigned int i;
for (i = 0; i < nargs; ++i)
tcp->u_arg[i] = (sizeof(uint32_t) == current_wordsize)
? ((uint32_t *) (void *) buf)[i] : buf[i];
}
#endif
#ifdef SYS_ipc_subcall
static void
decode_ipc_subcall(struct tcb *tcp)
{
unsigned int call = tcp->u_arg[0];
const unsigned int version = call >> 16;
if (version) {
# if defined S390 || defined S390X
return;
# else
# ifdef SPARC64
if (current_wordsize == 8)
return;
# endif
set_tcb_priv_ulong(tcp, version);
call &= 0xffff;
# endif
}
switch (call) {
case 1: case 2: case 3: case 4:
case 11: case 12: case 13: case 14:
case 21: case 22: case 23: case 24:
break;
default:
return;
}
tcp->scno = SYS_ipc_subcall + call;
tcp->qual_flg = qual_flags[tcp->scno];
tcp->s_ent = &sysent[tcp->scno];
const unsigned int n = tcp->s_ent->nargs;
unsigned int i;
for (i = 0; i < n; i++)
tcp->u_arg[i] = tcp->u_arg[i + 1];
}
#endif
#ifdef LINUX_MIPSO32
static void
decode_mips_subcall(struct tcb *tcp)
{
if (!SCNO_IS_VALID(tcp->u_arg[0]))
return;
tcp->scno = tcp->u_arg[0];
tcp->qual_flg = qual_flags[tcp->scno];
tcp->s_ent = &sysent[tcp->scno];
memmove(&tcp->u_arg[0], &tcp->u_arg[1],
sizeof(tcp->u_arg) - sizeof(tcp->u_arg[0]));
/*
* Fetching the last arg of 7-arg syscalls (fadvise64_64
* and sync_file_range) would require additional code,
* see linux/mips/get_syscall_args.c
*/
}
#endif
static void
dumpio(struct tcb *tcp)
{
int sen;
if (syserror(tcp))
return;
if ((unsigned long) tcp->u_arg[0] >= num_quals)
return;
sen = tcp->s_ent->sen;
if (SEN_printargs == sen)
return;
if (qual_flags[tcp->u_arg[0]] & QUAL_READ) {
switch (sen) {
case SEN_read:
case SEN_pread:
case SEN_recv:
case SEN_recvfrom:
dumpstr(tcp, tcp->u_arg[1], tcp->u_rval);
return;
case SEN_readv:
case SEN_preadv:
case SEN_preadv2:
dumpiov_upto(tcp, tcp->u_arg[2], tcp->u_arg[1],
tcp->u_rval);
return;
case SEN_recvmsg:
dumpiov_in_msghdr(tcp, tcp->u_arg[1], tcp->u_rval);
return;
case SEN_recvmmsg:
dumpiov_in_mmsghdr(tcp, tcp->u_arg[1]);
return;
}
}
if (qual_flags[tcp->u_arg[0]] & QUAL_WRITE) {
switch (sen) {
case SEN_write:
case SEN_pwrite:
case SEN_send:
case SEN_sendto:
dumpstr(tcp, tcp->u_arg[1], tcp->u_arg[2]);
break;
case SEN_writev:
case SEN_pwritev:
case SEN_pwritev2:
case SEN_vmsplice:
dumpiov(tcp, tcp->u_arg[2], tcp->u_arg[1]);
break;
case SEN_sendmsg:
dumpiov_in_msghdr(tcp, tcp->u_arg[1],
(unsigned long) -1L);
break;
case SEN_sendmmsg:
dumpiov_in_mmsghdr(tcp, tcp->u_arg[1]);
break;
}
}
}
/*
* Shuffle syscall numbers so that we don't have huge gaps in syscall table.
* The shuffling should be an involution: shuffle_scno(shuffle_scno(n)) == n.
*/
#if defined(ARM) || defined(AARCH64) /* So far only 32-bit ARM needs this */
static long
shuffle_scno(unsigned long scno)
{
if (scno < ARM_FIRST_SHUFFLED_SYSCALL)
return scno;
/* __ARM_NR_cmpxchg? Swap with LAST_ORDINARY+1 */
if (scno == ARM_FIRST_SHUFFLED_SYSCALL)
return 0x000ffff0;
if (scno == 0x000ffff0)
return ARM_FIRST_SHUFFLED_SYSCALL;
#define ARM_SECOND_SHUFFLED_SYSCALL (ARM_FIRST_SHUFFLED_SYSCALL + 1)
/*
* Is it ARM specific syscall?
* Swap [0x000f0000, 0x000f0000 + LAST_SPECIAL] range
* with [SECOND_SHUFFLED, SECOND_SHUFFLED + LAST_SPECIAL] range.
*/
if (scno >= 0x000f0000 &&
scno <= 0x000f0000 + ARM_LAST_SPECIAL_SYSCALL) {
return scno - 0x000f0000 + ARM_SECOND_SHUFFLED_SYSCALL;
}
if (scno <= ARM_SECOND_SHUFFLED_SYSCALL + ARM_LAST_SPECIAL_SYSCALL) {
return scno + 0x000f0000 - ARM_SECOND_SHUFFLED_SYSCALL;
}
return scno;
}
#else
# define shuffle_scno(scno) ((long)(scno))
#endif
const char *
syscall_name(long scno)
{
static char buf[sizeof("syscall_%lu") + sizeof(long)*3];
if (SCNO_IS_VALID(scno))
return sysent[scno].sys_name;
else {
sprintf(buf, "syscall_%lu", scno);
return buf;
}
}
static long get_regs_error;
void
clear_regs(void)
{
get_regs_error = -1;
}
static int get_syscall_args(struct tcb *);
static int get_syscall_result(struct tcb *);
static int arch_get_scno(struct tcb *tcp);
static void get_error(struct tcb *, const bool);
#if defined X86_64 || defined POWERPC
static int getregs_old(pid_t);
#endif
static int
trace_syscall_entering(struct tcb *tcp)
{
int res, scno_good;
scno_good = res = get_scno(tcp);
if (res == 0)
return res;
if (res == 1)
res = get_syscall_args(tcp);
if (res != 1) {
printleader(tcp);
tprintf("%s(", scno_good == 1 ? tcp->s_ent->sys_name : "????");
/*
* " <unavailable>" will be added later by the code which
* detects ptrace errors.
*/
goto ret;
}
#ifdef LINUX_MIPSO32
if (SEN_syscall == tcp->s_ent->sen)
decode_mips_subcall(tcp);
#endif
if ( SEN_execve == tcp->s_ent->sen
# if defined(SPARC) || defined(SPARC64)
|| SEN_execv == tcp->s_ent->sen
# endif
) {
hide_log_until_execve = 0;
}
#if defined(SYS_socket_subcall) || defined(SYS_ipc_subcall)
switch (tcp->s_ent->sen) {
# ifdef SYS_socket_subcall
case SEN_socketcall:
decode_socket_subcall(tcp);
break;
# endif
# ifdef SYS_ipc_subcall
case SEN_ipc:
decode_ipc_subcall(tcp);
break;
# endif
}
#endif
if (!(tcp->qual_flg & QUAL_TRACE)
|| (tracing_paths && !pathtrace_match(tcp))
) {
tcp->flags |= TCB_INSYSCALL | TCB_FILTERED;
tcp->sys_func_rval = 0;
return 0;
}
tcp->flags &= ~TCB_FILTERED;
if (cflag == CFLAG_ONLY_STATS || hide_log_until_execve) {
res = 0;
goto ret;
}
#ifdef USE_LIBUNWIND
if (stack_trace_enabled) {
if (tcp->s_ent->sys_flags & STACKTRACE_CAPTURE_ON_ENTER)
unwind_capture_stacktrace(tcp);
}
#endif
printleader(tcp);
tprintf("%s(", tcp->s_ent->sys_name);
if ((tcp->qual_flg & QUAL_RAW) && SEN_exit != tcp->s_ent->sen)
res = printargs(tcp);
else
res = tcp->s_ent->sys_func(tcp);
fflush(tcp->outf);
ret:
tcp->flags |= TCB_INSYSCALL;
tcp->sys_func_rval = res;
/* Measure the entrance time as late as possible to avoid errors. */
if (Tflag || cflag)
gettimeofday(&tcp->etime, NULL);
return res;
}
static int
trace_syscall_exiting(struct tcb *tcp)
{
int sys_res;
struct timeval tv;
int res;
long u_error;
/* Measure the exit time as early as possible to avoid errors. */
if (Tflag || cflag)
gettimeofday(&tv, NULL);
#ifdef USE_LIBUNWIND
if (stack_trace_enabled) {
if (tcp->s_ent->sys_flags & STACKTRACE_INVALIDATE_CACHE)
unwind_cache_invalidate(tcp);
}
#endif
#if SUPPORTED_PERSONALITIES > 1
update_personality(tcp, tcp->currpers);
#endif
res = (get_regs_error ? -1 : get_syscall_result(tcp));
if (filtered(tcp) || hide_log_until_execve)
goto ret;
if (cflag) {
count_syscall(tcp, &tv);
if (cflag == CFLAG_ONLY_STATS) {
goto ret;
}
}
/* If not in -ff mode, and printing_tcp != tcp,
* then the log currently does not end with output
* of _our syscall entry_, but with something else.
* We need to say which syscall's return is this.
*
* Forced reprinting via TCB_REPRINT is used only by
* "strace -ff -oLOG test/threaded_execve" corner case.
* It's the only case when -ff mode needs reprinting.
*/
if ((followfork < 2 && printing_tcp != tcp) || (tcp->flags & TCB_REPRINT)) {
tcp->flags &= ~TCB_REPRINT;
printleader(tcp);
tprintf("<... %s resumed> ", tcp->s_ent->sys_name);
}
printing_tcp = tcp;
tcp->s_prev_ent = NULL;
if (res != 1) {
/* There was error in one of prior ptrace ops */
tprints(") ");
tabto();
tprints("= ? <unavailable>\n");
line_ended();
tcp->flags &= ~TCB_INSYSCALL;
tcp->sys_func_rval = 0;
free_tcb_priv_data(tcp);
return res;
}
tcp->s_prev_ent = tcp->s_ent;
sys_res = 0;
if (tcp->qual_flg & QUAL_RAW) {
/* sys_res = printargs(tcp); - but it's nop on sysexit */
} else {
/* FIXME: not_failing_only (IOW, option -z) is broken:
* failure of syscall is known only after syscall return.
* Thus we end up with something like this on, say, ENOENT:
* open("doesnt_exist", O_RDONLY <unfinished ...>
* {next syscall decode}
* whereas the intended result is that open(...) line
* is not shown at all.
*/
if (not_failing_only && tcp->u_error)
goto ret; /* ignore failed syscalls */
if (tcp->sys_func_rval & RVAL_DECODED)
sys_res = tcp->sys_func_rval;
else
sys_res = tcp->s_ent->sys_func(tcp);
}
tprints(") ");
tabto();
u_error = tcp->u_error;
if (tcp->qual_flg & QUAL_RAW) {
if (u_error)
tprintf("= -1 (errno %ld)", u_error);
else
tprintf("= %#lx", tcp->u_rval);
}
else if (!(sys_res & RVAL_NONE) && u_error) {
switch (u_error) {
/* Blocked signals do not interrupt any syscalls.
* In this case syscalls don't return ERESTARTfoo codes.
*
* Deadly signals set to SIG_DFL interrupt syscalls
* and kill the process regardless of which of the codes below
* is returned by the interrupted syscall.
* In some cases, kernel forces a kernel-generated deadly
* signal to be unblocked and set to SIG_DFL (and thus cause
* death) if it is blocked or SIG_IGNed: for example, SIGSEGV
* or SIGILL. (The alternative is to leave process spinning
* forever on the faulty instruction - not useful).
*
* SIG_IGNed signals and non-deadly signals set to SIG_DFL
* (for example, SIGCHLD, SIGWINCH) interrupt syscalls,
* but kernel will always restart them.
*/
case ERESTARTSYS:
/* Most common type of signal-interrupted syscall exit code.
* The system call will be restarted with the same arguments
* if SA_RESTART is set; otherwise, it will fail with EINTR.
*/
tprints("= ? ERESTARTSYS (To be restarted if SA_RESTART is set)");
break;
case ERESTARTNOINTR:
/* Rare. For example, fork() returns this if interrupted.
* SA_RESTART is ignored (assumed set): the restart is unconditional.
*/
tprints("= ? ERESTARTNOINTR (To be restarted)");
break;
case ERESTARTNOHAND:
/* pause(), rt_sigsuspend() etc use this code.
* SA_RESTART is ignored (assumed not set):
* syscall won't restart (will return EINTR instead)
* even after signal with SA_RESTART set. However,
* after SIG_IGN or SIG_DFL signal it will restart
* (thus the name "restart only if has no handler").
*/
tprints("= ? ERESTARTNOHAND (To be restarted if no handler)");
break;
case ERESTART_RESTARTBLOCK:
/* Syscalls like nanosleep(), poll() which can't be
* restarted with their original arguments use this
* code. Kernel will execute restart_syscall() instead,
* which changes arguments before restarting syscall.
* SA_RESTART is ignored (assumed not set) similarly
* to ERESTARTNOHAND. (Kernel can't honor SA_RESTART
* since restart data is saved in "restart block"
* in task struct, and if signal handler uses a syscall
* which in turn saves another such restart block,
* old data is lost and restart becomes impossible)
*/
tprints("= ? ERESTART_RESTARTBLOCK (Interrupted by signal)");
break;
default:
if ((unsigned long) u_error < nerrnos
&& errnoent[u_error])
tprintf("= -1 %s (%s)", errnoent[u_error],
strerror(u_error));
else
tprintf("= -1 ERRNO_%lu (%s)", u_error,
strerror(u_error));
break;
}
if ((sys_res & RVAL_STR) && tcp->auxstr)
tprintf(" (%s)", tcp->auxstr);
}
else {
if (sys_res & RVAL_NONE)
tprints("= ?");
else {
switch (sys_res & RVAL_MASK) {
case RVAL_HEX:
#if SUPPORTED_PERSONALITIES > 1
if (current_wordsize < sizeof(long))
tprintf("= %#x",
(unsigned int) tcp->u_rval);
else
#endif
tprintf("= %#lx", tcp->u_rval);
break;
case RVAL_OCTAL:
tprints("= ");
print_numeric_long_umask(tcp->u_rval);
break;
case RVAL_UDECIMAL:
#if SUPPORTED_PERSONALITIES > 1
if (current_wordsize < sizeof(long))
tprintf("= %u",
(unsigned int) tcp->u_rval);
else
#endif
tprintf("= %lu", tcp->u_rval);
break;
case RVAL_DECIMAL:
tprintf("= %ld", tcp->u_rval);
break;
case RVAL_FD:
if (show_fd_path) {
tprints("= ");
printfd(tcp, tcp->u_rval);
}
else
tprintf("= %ld", tcp->u_rval);
break;
#if HAVE_STRUCT_TCB_EXT_ARG
/*
case RVAL_LHEX:
tprintf("= %#llx", tcp->u_lrval);
break;
case RVAL_LOCTAL:
tprintf("= %#llo", tcp->u_lrval);
break;
*/
case RVAL_LUDECIMAL:
tprintf("= %llu", tcp->u_lrval);
break;
/*
case RVAL_LDECIMAL:
tprintf("= %lld", tcp->u_lrval);
break;
*/
#endif /* HAVE_STRUCT_TCB_EXT_ARG */
default:
error_msg("invalid rval format");
break;
}
}
if ((sys_res & RVAL_STR) && tcp->auxstr)
tprintf(" (%s)", tcp->auxstr);
}
if (Tflag) {
tv_sub(&tv, &tv, &tcp->etime);
tprintf(" <%ld.%06ld>",
(long) tv.tv_sec, (long) tv.tv_usec);
}
tprints("\n");
dumpio(tcp);
line_ended();
#ifdef USE_LIBUNWIND
if (stack_trace_enabled)
unwind_print_stacktrace(tcp);
#endif
ret:
tcp->flags &= ~TCB_INSYSCALL;
tcp->sys_func_rval = 0;
free_tcb_priv_data(tcp);
return 0;
}
int
trace_syscall(struct tcb *tcp)
{
return exiting(tcp) ?
trace_syscall_exiting(tcp) : trace_syscall_entering(tcp);
}
bool
is_erestart(struct tcb *tcp)
{
switch (tcp->u_error) {
case ERESTARTSYS:
case ERESTARTNOINTR:
case ERESTARTNOHAND:
case ERESTART_RESTARTBLOCK:
return true;
default:
return false;
}
}
static int saved_u_error;
void
temporarily_clear_syserror(struct tcb *tcp)
{
saved_u_error = tcp->u_error;
tcp->u_error = 0;
}
void
restore_cleared_syserror(struct tcb *tcp)
{
tcp->u_error = saved_u_error;
}
#include "kernel_types.h"
/*
* Check the syscall return value register value for whether it is
* a negated errno code indicating an error, or a success return value.
*/
static inline bool
is_negated_errno(kernel_ulong_t val)
{
/* Linux kernel defines MAX_ERRNO to 4095. */
kernel_ulong_t max = -(kernel_long_t) 4095;
#if SUPPORTED_PERSONALITIES > 1 && SIZEOF_LONG > 4
if (current_wordsize < sizeof(val)) {
val = (uint32_t) val;
max = (uint32_t) max;
}
#elif defined X32
/*
* current_wordsize is 4 even in personality 0 (native X32)
* but truncation _must not_ be done in it.
* can't check current_wordsize here!
*/
if (current_personality != 0) {
val = (uint32_t) val;
max = (uint32_t) max;
}
#endif
return val >= max;
}
#include "arch_regs.c"
#ifdef HAVE_GETRVAL2
# include "arch_getrval2.c"
#endif
void
print_pc(struct tcb *tcp)
{
#if defined ARCH_PC_REG
# define ARCH_GET_PC 0
#elif defined ARCH_PC_PEEK_ADDR
long pc;
# define ARCH_PC_REG pc
# define ARCH_GET_PC upeek(tcp->pid, ARCH_PC_PEEK_ADDR, &pc)
#else
# error Neither ARCH_PC_REG nor ARCH_PC_PEEK_ADDR is defined
#endif
if (get_regs_error || ARCH_GET_PC)
tprints(current_wordsize == 4 ? "[????????] "
: "[????????????????] ");
else
tprintf(current_wordsize == 4 ? "[%08lx] " : "[%016lx] ",
(unsigned long) ARCH_PC_REG);
}
#if defined ARCH_REGS_FOR_GETREGSET
static long
get_regset(pid_t pid)
{
# ifdef ARCH_IOVEC_FOR_GETREGSET
/* variable iovec */
ARCH_IOVEC_FOR_GETREGSET.iov_len = sizeof(ARCH_REGS_FOR_GETREGSET);
return ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS,
&ARCH_IOVEC_FOR_GETREGSET);
# else
/* constant iovec */
static struct iovec io = {
.iov_base = &ARCH_REGS_FOR_GETREGSET,
.iov_len = sizeof(ARCH_REGS_FOR_GETREGSET)
};
return ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS, &io);
# endif
}
#endif /* ARCH_REGS_FOR_GETREGSET */
void
get_regs(pid_t pid)
{
#undef USE_GET_SYSCALL_RESULT_REGS
#ifdef ARCH_REGS_FOR_GETREGSET
# ifdef X86_64
/* Try PTRACE_GETREGSET first, fallback to PTRACE_GETREGS. */
static int getregset_support;
if (getregset_support >= 0) {
get_regs_error = get_regset(pid);
if (getregset_support > 0)
return;
if (get_regs_error >= 0) {
getregset_support = 1;
return;
}
if (errno == EPERM || errno == ESRCH)
return;
getregset_support = -1;
}
get_regs_error = getregs_old(pid);
# else /* !X86_64 */
/* Assume that PTRACE_GETREGSET works. */
get_regs_error = get_regset(pid);
# endif
#elif defined ARCH_REGS_FOR_GETREGS
# if defined SPARC || defined SPARC64
/* SPARC systems have the meaning of data and addr reversed */
get_regs_error =
ptrace(PTRACE_GETREGS, pid, (void *) &ARCH_REGS_FOR_GETREGS, 0);
# elif defined POWERPC
static bool old_kernel = 0;
if (old_kernel)
goto old;
get_regs_error = ptrace(PTRACE_GETREGS, pid, NULL, &ARCH_REGS_FOR_GETREGS);
if (get_regs_error && errno == EIO) {
old_kernel = 1;
old:
get_regs_error = getregs_old(pid);
}
# else
/* Assume that PTRACE_GETREGS works. */
get_regs_error = ptrace(PTRACE_GETREGS, pid, NULL, &ARCH_REGS_FOR_GETREGS);
# endif
#else /* !ARCH_REGS_FOR_GETREGSET && !ARCH_REGS_FOR_GETREGS */
# define USE_GET_SYSCALL_RESULT_REGS 1
# warning get_regs is not implemented for this architecture yet
get_regs_error = 0;
#endif
}
struct sysent_buf {
struct tcb *tcp;
struct_sysent ent;
char buf[sizeof("syscall_%lu") + sizeof(long) * 3];
};
static void
free_sysent_buf(void *ptr)
{
struct sysent_buf *s = ptr;
s->tcp->s_prev_ent = s->tcp->s_ent = NULL;
free(ptr);
}
/*
* Returns:
* 0: "ignore this ptrace stop", bail out of trace_syscall_entering() silently.
* 1: ok, continue in trace_syscall_entering().
* other: error, trace_syscall_entering() should print error indicator
* ("????" etc) and bail out.
*/
int
get_scno(struct tcb *tcp)
{
if (get_regs_error)
return -1;
int rc = arch_get_scno(tcp);
if (rc != 1)
return rc;
if (SCNO_IS_VALID(tcp->scno)) {
tcp->s_ent = &sysent[tcp->scno];
tcp->qual_flg = qual_flags[tcp->scno];
} else {
struct sysent_buf *s = xcalloc(1, sizeof(*s));
s->tcp = tcp;
s->ent.nargs = MAX_ARGS;
s->ent.sen = SEN_printargs;
s->ent.sys_func = printargs;
s->ent.sys_name = s->buf;
sprintf(s->buf, "syscall_%lu", shuffle_scno(tcp->scno));
tcp->s_ent = &s->ent;
tcp->qual_flg = QUAL_RAW | DEFAULT_QUAL_FLAGS;
set_tcb_priv_data(tcp, s, free_sysent_buf);
if (debug_flag)
error_msg("pid %d invalid syscall %ld", tcp->pid, tcp->scno);
}
return 1;
}
#ifdef USE_GET_SYSCALL_RESULT_REGS
static int get_syscall_result_regs(struct tcb *);
#endif
/* Returns:
* 1: ok, continue in trace_syscall_exiting().
* -1: error, trace_syscall_exiting() should print error indicator
* ("????" etc) and bail out.
*/
static int
get_syscall_result(struct tcb *tcp)
{
#ifdef USE_GET_SYSCALL_RESULT_REGS
if (get_syscall_result_regs(tcp))
return -1;
#endif
tcp->u_error = 0;
get_error(tcp, !(tcp->s_ent->sys_flags & SYSCALL_NEVER_FAILS));
return 1;
}
#include "get_scno.c"
#include "get_syscall_args.c"
#ifdef USE_GET_SYSCALL_RESULT_REGS
# include "get_syscall_result.c"
#endif
#include "get_error.c"
#if defined X86_64 || defined POWERPC
# include "getregs_old.c"
#endif
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