/*
* 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>
* Copyright (c) 1999-2018 The strace developers.
* 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 "ptrace.h"
#include "nsig.h"
#include "number_set.h"
#include <limits.h>
/* for struct iovec */
#include <sys/uio.h>
/* for __X32_SYSCALL_BIT */
#include <asm/unistd.h>
#include "regs.h"
#if defined(SPARC64)
# undef PTRACE_GETREGS
# define PTRACE_GETREGS PTRACE_GETREGS64
# undef PTRACE_SETREGS
# define PTRACE_SETREGS PTRACE_SETREGS64
#endif
#ifndef NT_PRSTATUS
# define NT_PRSTATUS 1
#endif
#include "syscall.h"
#include "xstring.h"
/* Define these shorthand notations to simplify the syscallent files. */
#include "sysent_shorthand_defs.h"
#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. */
#include "sysent_shorthand_undefs.h"
/*
* `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;
const unsigned int nsyscall_vec[SUPPORTED_PERSONALITIES] = {
nsyscalls0,
#if SUPPORTED_PERSONALITIES > 1
nsyscalls1,
#endif
#if SUPPORTED_PERSONALITIES > 2
nsyscalls2,
#endif
};
const struct_sysent *const sysent_vec[SUPPORTED_PERSONALITIES] = {
sysent0,
#if SUPPORTED_PERSONALITIES > 1
sysent1,
#endif
#if SUPPORTED_PERSONALITIES > 2
sysent2,
#endif
};
const char *const personality_names[] =
# if defined X86_64
{"64 bit", "32 bit", "x32"}
# elif defined X32
{"x32", "32 bit"}
# elif SUPPORTED_PERSONALITIES == 2
{"64 bit", "32 bit"}
# else
{STRINGIFY_VAL(__WORDSIZE) " bit"}
# endif
;
#if SUPPORTED_PERSONALITIES > 1
unsigned current_personality;
# ifndef current_wordsize
unsigned current_wordsize = PERSONALITY0_WORDSIZE;
static const int personality_wordsize[SUPPORTED_PERSONALITIES] = {
PERSONALITY0_WORDSIZE,
PERSONALITY1_WORDSIZE,
# if SUPPORTED_PERSONALITIES > 2
PERSONALITY2_WORDSIZE,
# endif
};
# endif
# ifndef current_klongsize
unsigned current_klongsize = PERSONALITY0_KLONGSIZE;
static const int personality_klongsize[SUPPORTED_PERSONALITIES] = {
PERSONALITY0_KLONGSIZE,
PERSONALITY1_KLONGSIZE,
# if SUPPORTED_PERSONALITIES > 2
PERSONALITY2_KLONGSIZE,
# endif
};
# endif
void
set_personality(unsigned int personality)
{
if (personality == current_personality)
return;
if (personality >= SUPPORTED_PERSONALITIES)
error_msg_and_die("Requested switch to unsupported personality "
"%u", 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
# ifndef current_klongsize
current_klongsize = personality_klongsize[personality];
# endif
}
static void
update_personality(struct tcb *tcp, unsigned int personality)
{
static bool need_mpers_warning[] =
{ false, !HAVE_PERSONALITY_1_MPERS, !HAVE_PERSONALITY_2_MPERS };
set_personality(personality);
if (personality == tcp->currpers)
return;
tcp->currpers = personality;
if (!qflag) {
error_msg("[ Process PID=%d runs in %s mode. ]",
tcp->pid, personality_names[personality]);
}
if (need_mpers_warning[personality]) {
error_msg("WARNING: Proper structure decoding for this "
"personality is not supported, please consider "
"building strace with mpers support enabled.");
need_mpers_warning[personality] = false;
}
}
#endif
#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 kernel_ulong_t 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 /* SYS_socket_subcall */
#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 /* SYS_ipc_subcall */
#ifdef SYS_syscall_subcall
static void
decode_syscall_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]));
# ifdef LINUX_MIPSO32
/*
* Fetching the last arg of 7-arg syscalls (fadvise64_64
* and sync_file_range) requires additional code,
* see linux/mips/get_syscall_args.c
*/
if (tcp->s_ent->nargs == MAX_ARGS) {
if (umoven(tcp,
mips_REG_SP + MAX_ARGS * sizeof(tcp->u_arg[0]),
sizeof(tcp->u_arg[0]),
&tcp->u_arg[MAX_ARGS - 1]) < 0)
tcp->u_arg[MAX_ARGS - 1] = 0;
}
# endif /* LINUX_MIPSO32 */
}
#endif /* SYS_syscall_subcall */
static void
dumpio(struct tcb *tcp)
{
if (syserror(tcp))
return;
int fd = tcp->u_arg[0];
if (fd < 0)
return;
if (is_number_in_set(fd, read_set)) {
switch (tcp->s_ent->sen) {
case SEN_read:
case SEN_pread:
case SEN_recv:
case SEN_recvfrom:
case SEN_mq_timedreceive:
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 (is_number_in_set(fd, write_set)) {
switch (tcp->s_ent->sen) {
case SEN_write:
case SEN_pwrite:
case SEN_send:
case SEN_sendto:
case SEN_mq_timedsend:
dumpstr(tcp, tcp->u_arg[1], tcp->u_arg[2]);
break;
case SEN_writev:
case SEN_pwritev:
case SEN_pwritev2:
case SEN_vmsplice:
dumpiov_upto(tcp, tcp->u_arg[2], tcp->u_arg[1], -1);
break;
case SEN_sendmsg:
dumpiov_in_msghdr(tcp, tcp->u_arg[1], -1);
break;
case SEN_sendmmsg:
dumpiov_in_mmsghdr(tcp, tcp->u_arg[1]);
break;
}
}
}
const char *
err_name(unsigned long err)
{
if ((err < nerrnos) && errnoent[err])
return errnoent[err];
return NULL;
}
static long get_regs(struct tcb *);
static int get_syscall_args(struct tcb *);
static int get_syscall_result(struct tcb *);
static int arch_get_scno(struct tcb *tcp);
static int arch_set_scno(struct tcb *, kernel_ulong_t);
static void get_error(struct tcb *, const bool);
static int arch_set_error(struct tcb *);
static int arch_set_success(struct tcb *);
struct inject_opts *inject_vec[SUPPORTED_PERSONALITIES];
static struct inject_opts *
tcb_inject_opts(struct tcb *tcp)
{
return (scno_in_range(tcp->scno) && tcp->inject_vec[current_personality])
? &tcp->inject_vec[current_personality][tcp->scno] : NULL;
}
static long
tamper_with_syscall_entering(struct tcb *tcp, unsigned int *signo)
{
if (!tcp->inject_vec[current_personality]) {
tcp->inject_vec[current_personality] =
xcalloc(nsyscalls, sizeof(**inject_vec));
memcpy(tcp->inject_vec[current_personality],
inject_vec[current_personality],
nsyscalls * sizeof(**inject_vec));
}
struct inject_opts *opts = tcb_inject_opts(tcp);
if (!opts || opts->first == 0)
return 0;
--opts->first;
if (opts->first != 0)
return 0;
opts->first = opts->step;
if (!recovering(tcp)) {
if (opts->data.flags & INJECT_F_SIGNAL)
*signo = opts->data.signo;
if (opts->data.flags & INJECT_F_RETVAL &&
!arch_set_scno(tcp, -1))
tcp->flags |= TCB_TAMPERED;
}
return 0;
}
static long
tamper_with_syscall_exiting(struct tcb *tcp)
{
if (!syserror(tcp)) {
error_msg("Failed to tamper with process %d: got no error "
"(return value %#" PRI_klx ")",
tcp->pid, tcp->u_rval);
return 1;
}
struct inject_opts *opts = tcb_inject_opts(tcp);
bool update_tcb = false;
if (!opts)
return 0;
if (opts->data.rval >= 0) {
kernel_long_t u_rval = tcp->u_rval;
tcp->u_rval = opts->data.rval;
if (arch_set_success(tcp)) {
tcp->u_rval = u_rval;
} else {
update_tcb = true;
tcp->u_error = 0;
}
} else {
unsigned long new_error = -opts->data.rval;
if (new_error != tcp->u_error && new_error <= MAX_ERRNO_VALUE) {
unsigned long u_error = tcp->u_error;
tcp->u_error = new_error;
if (arch_set_error(tcp)) {
tcp->u_error = u_error;
} else {
update_tcb = true;
}
}
}
if (update_tcb) {
tcp->u_error = 0;
get_error(tcp, !(tcp->s_ent->sys_flags & SYSCALL_NEVER_FAILS));
}
return 0;
}
/*
* Returns:
* 0: "ignore this ptrace stop", bail out silently.
* 1: ok, decoded; call
* syscall_entering_finish(tcp, syscall_entering_trace(tcp, ...)).
* other: error; call syscall_entering_finish(tcp, res), where res is the value
* returned.
*/
int
syscall_entering_decode(struct tcb *tcp)
{
int res = get_scno(tcp);
if (res == 0)
return res;
int scno_good = res;
if (res != 1 || (res = get_syscall_args(tcp)) != 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.
*/
return res;
}
#if defined SYS_ipc_subcall \
|| defined SYS_socket_subcall \
|| defined SYS_syscall_subcall
for (;;) {
switch (tcp->s_ent->sen) {
# ifdef SYS_ipc_subcall
case SEN_ipc:
decode_ipc_subcall(tcp);
break;
# endif
# ifdef SYS_socket_subcall
case SEN_socketcall:
decode_socket_subcall(tcp);
break;
# endif
# ifdef SYS_syscall_subcall
case SEN_syscall:
decode_syscall_subcall(tcp);
if (tcp->s_ent->sen != SEN_syscall)
continue;
break;
# endif
}
break;
}
#endif
return 1;
}
int
syscall_entering_trace(struct tcb *tcp, unsigned int *sig)
{
/* Restrain from fault injection while the trace executes strace code. */
if (hide_log(tcp)) {
tcp->qual_flg &= ~QUAL_INJECT;
}
switch (tcp->s_ent->sen) {
case SEN_execve:
case SEN_execveat:
#if defined SPARC || defined SPARC64
case SEN_execv:
#endif
tcp->flags &= ~TCB_HIDE_LOG;
break;
}
if (!traced(tcp) || (tracing_paths && !pathtrace_match(tcp))) {
tcp->flags |= TCB_FILTERED;
return 0;
}
tcp->flags &= ~TCB_FILTERED;
if (hide_log(tcp)) {
return 0;
}
if (inject(tcp))
tamper_with_syscall_entering(tcp, sig);
if (cflag == CFLAG_ONLY_STATS) {
return 0;
}
#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);
int res = raw(tcp) ? printargs(tcp) : tcp->s_ent->sys_func(tcp);
fflush(tcp->outf);
return res;
}
void
syscall_entering_finish(struct tcb *tcp, int res)
{
tcp->flags |= TCB_INSYSCALL;
tcp->sys_func_rval = res;
/* Measure the entrance time as late as possible to avoid errors. */
if ((Tflag || cflag) && !filtered(tcp))
gettimeofday(&tcp->etime, NULL);
}
/* Returns:
* 0: "bail out".
* 1: ok.
* -1: error in one of ptrace ops.
*
* If not 0, call syscall_exiting_trace(tcp, res), where res is the return
* value. Anyway, call syscall_exiting_finish(tcp) then.
*/
int
syscall_exiting_decode(struct tcb *tcp, struct timeval *ptv)
{
/* Measure the exit time as early as possible to avoid errors. */
if ((Tflag || cflag) && !(filtered(tcp) || hide_log(tcp)))
gettimeofday(ptv, NULL);
#ifdef USE_LIBUNWIND
if (stack_trace_enabled) {
if (tcp->s_ent->sys_flags & STACKTRACE_INVALIDATE_CACHE)
unwind_cache_invalidate(tcp);
}
#endif
if (filtered(tcp) || hide_log(tcp))
return 0;
#if SUPPORTED_PERSONALITIES > 1
update_personality(tcp, tcp->currpers);
#endif
return get_syscall_result(tcp);
}
int
syscall_exiting_trace(struct tcb *tcp, struct timeval tv, int res)
{
if (syscall_tampered(tcp))
tamper_with_syscall_exiting(tcp);
if (cflag) {
count_syscall(tcp, &tv);
if (cflag == CFLAG_ONLY_STATS) {
return 0;
}
}
/* 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();
return res;
}
tcp->s_prev_ent = tcp->s_ent;
int sys_res = 0;
if (raw(tcp)) {
/* 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("does_not_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)
return 0; /* 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();
unsigned long u_error = tcp->u_error;
kernel_long_t u_rval;
if (raw(tcp)) {
if (u_error) {
tprintf("= -1 (errno %lu)", u_error);
} else {
tprintf("= %#" PRI_klx, tcp->u_rval);
}
if (syscall_tampered(tcp))
tprints(" (INJECTED)");
} else if (!(sys_res & RVAL_NONE) && u_error) {
const char *u_error_str;
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:
u_rval = sys_res & RVAL_PRINT_ERR_VAL ?
tcp->u_rval : -1;
u_error_str = err_name(u_error);
if (u_error_str)
tprintf("= %" PRI_kld " %s (%s)",
u_rval, u_error_str, strerror(u_error));
else
tprintf("= %" PRI_kld " %lu (%s)",
u_rval, u_error, strerror(u_error));
break;
}
if (syscall_tampered(tcp))
tprints(" (INJECTED)");
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 ANY_WORDSIZE_LESS_THAN_KERNEL_LONG
if (current_klongsize < sizeof(tcp->u_rval)) {
tprintf("= %#x",
(unsigned int) tcp->u_rval);
} else
#endif
{
tprintf("= %#" PRI_klx, tcp->u_rval);
}
break;
case RVAL_OCTAL:
tprints("= ");
print_numeric_long_umask(tcp->u_rval);
break;
case RVAL_UDECIMAL:
#if ANY_WORDSIZE_LESS_THAN_KERNEL_LONG
if (current_klongsize < sizeof(tcp->u_rval)) {
tprintf("= %u",
(unsigned int) tcp->u_rval);
} else
#endif
{
tprintf("= %" PRI_klu, tcp->u_rval);
}
break;
case RVAL_DECIMAL:
tprintf("= %" PRI_kld, tcp->u_rval);
break;
case RVAL_FD:
if (show_fd_path) {
tprints("= ");
printfd(tcp, tcp->u_rval);
} else
tprintf("= %" PRI_kld, tcp->u_rval);
break;
default:
error_msg("invalid rval format");
break;
}
}
if ((sys_res & RVAL_STR) && tcp->auxstr)
tprintf(" (%s)", tcp->auxstr);
if (syscall_tampered(tcp))
tprints(" (INJECTED)");
}
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
return 0;
}
void
syscall_exiting_finish(struct tcb *tcp)
{
tcp->flags &= ~(TCB_INSYSCALL | TCB_TAMPERED);
tcp->sys_func_rval = 0;
free_tcb_priv_data(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 unsigned long 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 "arch_regs.c"
#if HAVE_ARCH_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
kernel_ulong_t pc;
# define ARCH_PC_REG pc
# define ARCH_GET_PC upeek(tcp, ARCH_PC_PEEK_ADDR, &pc)
#else
# error Neither ARCH_PC_REG nor ARCH_PC_PEEK_ADDR is defined
#endif
if (get_regs(tcp) < 0 || ARCH_GET_PC)
tprints(current_wordsize == 4 ? "[????????] "
: "[????????????????] ");
else
tprintf(current_wordsize == 4
? "[%08" PRI_klx "] " : "[%016" PRI_klx "] ",
(kernel_ulong_t) ARCH_PC_REG);
}
#include "getregs_old.h"
#undef ptrace_getregset_or_getregs
#undef ptrace_setregset_or_setregs
#ifdef ARCH_REGS_FOR_GETREGSET
# define ptrace_getregset_or_getregs ptrace_getregset
static long
ptrace_getregset(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
}
# ifndef HAVE_GETREGS_OLD
# define ptrace_setregset_or_setregs ptrace_setregset
static int
ptrace_setregset(pid_t pid)
{
# ifdef ARCH_IOVEC_FOR_GETREGSET
/* variable iovec */
return ptrace(PTRACE_SETREGSET, 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_SETREGSET, pid, NT_PRSTATUS, &io);
# endif
}
# endif /* !HAVE_GETREGS_OLD */
#elif defined ARCH_REGS_FOR_GETREGS
# define ptrace_getregset_or_getregs ptrace_getregs
static long
ptrace_getregs(pid_t pid)
{
# if defined SPARC || defined SPARC64
/* SPARC systems have the meaning of data and addr reversed */
return ptrace(PTRACE_GETREGS, pid, (void *) &ARCH_REGS_FOR_GETREGS, 0);
# else
return ptrace(PTRACE_GETREGS, pid, NULL, &ARCH_REGS_FOR_GETREGS);
# endif
}
# ifndef HAVE_GETREGS_OLD
# define ptrace_setregset_or_setregs ptrace_setregs
static int
ptrace_setregs(pid_t pid)
{
# if defined SPARC || defined SPARC64
/* SPARC systems have the meaning of data and addr reversed */
return ptrace(PTRACE_SETREGS, pid, (void *) &ARCH_REGS_FOR_GETREGS, 0);
# else
return ptrace(PTRACE_SETREGS, pid, NULL, &ARCH_REGS_FOR_GETREGS);
# endif
}
# endif /* !HAVE_GETREGS_OLD */
#endif /* ARCH_REGS_FOR_GETREGSET || ARCH_REGS_FOR_GETREGS */
#ifdef ptrace_getregset_or_getregs
static long get_regs_error;
#endif
void
clear_regs(struct tcb *tcp)
{
#ifdef ptrace_getregset_or_getregs
get_regs_error = -1;
#endif
}
static long
get_regs(struct tcb *const tcp)
{
#ifdef ptrace_getregset_or_getregs
if (get_regs_error != -1)
return get_regs_error;
# ifdef HAVE_GETREGS_OLD
/*
* Try PTRACE_GETREGSET/PTRACE_GETREGS first,
* fallback to getregs_old.
*/
static int use_getregs_old;
if (use_getregs_old < 0) {
return get_regs_error = ptrace_getregset_or_getregs(tcp->pid);
} else if (use_getregs_old == 0) {
get_regs_error = ptrace_getregset_or_getregs(tcp->pid);
if (get_regs_error >= 0) {
use_getregs_old = -1;
return get_regs_error;
}
if (errno == EPERM || errno == ESRCH)
return get_regs_error;
use_getregs_old = 1;
}
return get_regs_error = getregs_old(tcp);
# else /* !HAVE_GETREGS_OLD */
/* Assume that PTRACE_GETREGSET/PTRACE_GETREGS works. */
get_regs_error = ptrace_getregset_or_getregs(tcp->pid);
# if defined ARCH_PERSONALITY_0_IOV_SIZE
if (get_regs_error)
return get_regs_error;
switch (ARCH_IOVEC_FOR_GETREGSET.iov_len) {
case ARCH_PERSONALITY_0_IOV_SIZE:
update_personality(tcp, 0);
break;
case ARCH_PERSONALITY_1_IOV_SIZE:
update_personality(tcp, 1);
break;
default: {
static bool printed = false;
if (!printed) {
error_msg("Unsupported regset size returned by "
"PTRACE_GETREGSET: %zu",
ARCH_IOVEC_FOR_GETREGSET.iov_len);
printed = true;
}
update_personality(tcp, 0);
}
}
# endif /* ARCH_PERSONALITY_0_IOV_SIZE */
return get_regs_error;
# endif /* !HAVE_GETREGS_OLD */
#else /* !ptrace_getregset_or_getregs */
# warning get_regs is not implemented for this architecture yet
return 0;
#endif /* !ptrace_getregset_or_getregs */
}
#ifdef ptrace_setregset_or_setregs
static int
set_regs(pid_t pid)
{
return ptrace_setregset_or_setregs(pid);
}
#endif /* ptrace_setregset_or_setregs */
struct sysent_buf {
struct tcb *tcp;
struct_sysent ent;
char buf[sizeof("syscall_0x") + sizeof(kernel_ulong_t) * 2];
};
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", syscall_entering_decode() should return a "bail
* out silently" code.
* 1: ok, continue in syscall_entering_decode().
* other: error, syscall_entering_decode() should print error indicator
* ("????" etc) and return an appropriate code.
*/
int
get_scno(struct tcb *tcp)
{
if (get_regs(tcp) < 0)
return -1;
int rc = arch_get_scno(tcp);
if (rc != 1)
return rc;
tcp->scno = shuffle_scno(tcp->scno);
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;
xsprintf(s->buf, "syscall_%#" PRI_klx, 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);
debug_msg("pid %d invalid syscall %#" PRI_klx,
tcp->pid, shuffle_scno(tcp->scno));
}
/*
* We refrain from argument decoding during recovering
* as tracee memory mappings has changed and the registers
* are very likely pointing to garbage already.
*/
if (recovering(tcp))
tcp->qual_flg |= QUAL_RAW;
return 1;
}
#ifdef ptrace_getregset_or_getregs
# define get_syscall_result_regs get_regs
#else
static int get_syscall_result_regs(struct tcb *);
#endif
/* Returns:
* 1: ok, continue in syscall_exiting_trace().
* -1: error, syscall_exiting_trace() should print error indicator
* ("????" etc) and bail out.
*/
static int
get_syscall_result(struct tcb *tcp)
{
if (get_syscall_result_regs(tcp) < 0)
return -1;
tcp->u_error = 0;
get_error(tcp,
!(tcp->s_ent->sys_flags & SYSCALL_NEVER_FAILS)
|| syscall_tampered(tcp));
return 1;
}
#include "get_scno.c"
#include "set_scno.c"
#include "get_syscall_args.c"
#ifndef ptrace_getregset_or_getregs
# include "get_syscall_result.c"
#endif
#include "get_error.c"
#include "set_error.c"
#ifdef HAVE_GETREGS_OLD
# include "getregs_old.c"
#endif
#include "shuffle_scno.c"
const char *
syscall_name(kernel_ulong_t scno)
{
return scno_is_valid(scno) ? sysent[scno].sys_name : NULL;
}