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signal.c
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/*
* Emulation of Linux signals
*
* Copyright (c) 2003 Fabrice Bellard
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "qemu/bitops.h"
#include <sys/ucontext.h>
#include <sys/resource.h>
#include "qemu.h"
#include "qemu-common.h"
#include "target_signal.h"
#include "trace.h"
static struct target_sigaltstack target_sigaltstack_used = {
.ss_sp = 0,
.ss_size = 0,
.ss_flags = TARGET_SS_DISABLE,
};
static struct target_sigaction sigact_table[TARGET_NSIG];
static void host_signal_handler(int host_signum, siginfo_t *info,
void *puc);
static uint8_t host_to_target_signal_table[_NSIG] = {
[SIGHUP] = TARGET_SIGHUP,
[SIGINT] = TARGET_SIGINT,
[SIGQUIT] = TARGET_SIGQUIT,
[SIGILL] = TARGET_SIGILL,
[SIGTRAP] = TARGET_SIGTRAP,
[SIGABRT] = TARGET_SIGABRT,
/* [SIGIOT] = TARGET_SIGIOT,*/
[SIGBUS] = TARGET_SIGBUS,
[SIGFPE] = TARGET_SIGFPE,
[SIGKILL] = TARGET_SIGKILL,
[SIGUSR1] = TARGET_SIGUSR1,
[SIGSEGV] = TARGET_SIGSEGV,
[SIGUSR2] = TARGET_SIGUSR2,
[SIGPIPE] = TARGET_SIGPIPE,
[SIGALRM] = TARGET_SIGALRM,
[SIGTERM] = TARGET_SIGTERM,
#ifdef SIGSTKFLT
[SIGSTKFLT] = TARGET_SIGSTKFLT,
#endif
[SIGCHLD] = TARGET_SIGCHLD,
[SIGCONT] = TARGET_SIGCONT,
[SIGSTOP] = TARGET_SIGSTOP,
[SIGTSTP] = TARGET_SIGTSTP,
[SIGTTIN] = TARGET_SIGTTIN,
[SIGTTOU] = TARGET_SIGTTOU,
[SIGURG] = TARGET_SIGURG,
[SIGXCPU] = TARGET_SIGXCPU,
[SIGXFSZ] = TARGET_SIGXFSZ,
[SIGVTALRM] = TARGET_SIGVTALRM,
[SIGPROF] = TARGET_SIGPROF,
[SIGWINCH] = TARGET_SIGWINCH,
[SIGIO] = TARGET_SIGIO,
[SIGPWR] = TARGET_SIGPWR,
[SIGSYS] = TARGET_SIGSYS,
/* next signals stay the same */
/* Nasty hack: Reverse SIGRTMIN and SIGRTMAX to avoid overlap with
host libpthread signals. This assumes no one actually uses SIGRTMAX :-/
To fix this properly we need to do manual signal delivery multiplexed
over a single host signal. */
[__SIGRTMIN] = __SIGRTMAX,
[__SIGRTMAX] = __SIGRTMIN,
};
static uint8_t target_to_host_signal_table[_NSIG];
static inline int on_sig_stack(unsigned long sp)
{
return (sp - target_sigaltstack_used.ss_sp
< target_sigaltstack_used.ss_size);
}
static inline int sas_ss_flags(unsigned long sp)
{
return (target_sigaltstack_used.ss_size == 0 ? SS_DISABLE
: on_sig_stack(sp) ? SS_ONSTACK : 0);
}
int host_to_target_signal(int sig)
{
if (sig < 0 || sig >= _NSIG)
return sig;
return host_to_target_signal_table[sig];
}
int target_to_host_signal(int sig)
{
if (sig < 0 || sig >= _NSIG)
return sig;
return target_to_host_signal_table[sig];
}
static inline void target_sigemptyset(target_sigset_t *set)
{
memset(set, 0, sizeof(*set));
}
static inline void target_sigaddset(target_sigset_t *set, int signum)
{
signum--;
abi_ulong mask = (abi_ulong)1 << (signum % TARGET_NSIG_BPW);
set->sig[signum / TARGET_NSIG_BPW] |= mask;
}
static inline int target_sigismember(const target_sigset_t *set, int signum)
{
signum--;
abi_ulong mask = (abi_ulong)1 << (signum % TARGET_NSIG_BPW);
return ((set->sig[signum / TARGET_NSIG_BPW] & mask) != 0);
}
static void host_to_target_sigset_internal(target_sigset_t *d,
const sigset_t *s)
{
int i;
target_sigemptyset(d);
for (i = 1; i <= TARGET_NSIG; i++) {
if (sigismember(s, i)) {
target_sigaddset(d, host_to_target_signal(i));
}
}
}
void host_to_target_sigset(target_sigset_t *d, const sigset_t *s)
{
target_sigset_t d1;
int i;
host_to_target_sigset_internal(&d1, s);
for(i = 0;i < TARGET_NSIG_WORDS; i++)
d->sig[i] = tswapal(d1.sig[i]);
}
static void target_to_host_sigset_internal(sigset_t *d,
const target_sigset_t *s)
{
int i;
sigemptyset(d);
for (i = 1; i <= TARGET_NSIG; i++) {
if (target_sigismember(s, i)) {
sigaddset(d, target_to_host_signal(i));
}
}
}
void target_to_host_sigset(sigset_t *d, const target_sigset_t *s)
{
target_sigset_t s1;
int i;
for(i = 0;i < TARGET_NSIG_WORDS; i++)
s1.sig[i] = tswapal(s->sig[i]);
target_to_host_sigset_internal(d, &s1);
}
void host_to_target_old_sigset(abi_ulong *old_sigset,
const sigset_t *sigset)
{
target_sigset_t d;
host_to_target_sigset(&d, sigset);
*old_sigset = d.sig[0];
}
void target_to_host_old_sigset(sigset_t *sigset,
const abi_ulong *old_sigset)
{
target_sigset_t d;
int i;
d.sig[0] = *old_sigset;
for(i = 1;i < TARGET_NSIG_WORDS; i++)
d.sig[i] = 0;
target_to_host_sigset(sigset, &d);
}
int block_signals(void)
{
TaskState *ts = (TaskState *)thread_cpu->opaque;
sigset_t set;
/* It's OK to block everything including SIGSEGV, because we won't
* run any further guest code before unblocking signals in
* process_pending_signals().
*/
sigfillset(&set);
sigprocmask(SIG_SETMASK, &set, 0);
return atomic_xchg(&ts->signal_pending, 1);
}
/* Wrapper for sigprocmask function
* Emulates a sigprocmask in a safe way for the guest. Note that set and oldset
* are host signal set, not guest ones. Returns -TARGET_ERESTARTSYS if
* a signal was already pending and the syscall must be restarted, or
* 0 on success.
* If set is NULL, this is guaranteed not to fail.
*/
int do_sigprocmask(int how, const sigset_t *set, sigset_t *oldset)
{
TaskState *ts = (TaskState *)thread_cpu->opaque;
if (oldset) {
*oldset = ts->signal_mask;
}
if (set) {
int i;
if (block_signals()) {
return -TARGET_ERESTARTSYS;
}
switch (how) {
case SIG_BLOCK:
sigorset(&ts->signal_mask, &ts->signal_mask, set);
break;
case SIG_UNBLOCK:
for (i = 1; i <= NSIG; ++i) {
if (sigismember(set, i)) {
sigdelset(&ts->signal_mask, i);
}
}
break;
case SIG_SETMASK:
ts->signal_mask = *set;
break;
default:
g_assert_not_reached();
}
/* Silently ignore attempts to change blocking status of KILL or STOP */
sigdelset(&ts->signal_mask, SIGKILL);
sigdelset(&ts->signal_mask, SIGSTOP);
}
return 0;
}
#if !defined(TARGET_OPENRISC) && !defined(TARGET_UNICORE32) && \
!defined(TARGET_X86_64) && !defined(TARGET_NIOS2)
/* Just set the guest's signal mask to the specified value; the
* caller is assumed to have called block_signals() already.
*/
static void set_sigmask(const sigset_t *set)
{
TaskState *ts = (TaskState *)thread_cpu->opaque;
ts->signal_mask = *set;
}
#endif
/* siginfo conversion */
static inline void host_to_target_siginfo_noswap(target_siginfo_t *tinfo,
const siginfo_t *info)
{
int sig = host_to_target_signal(info->si_signo);
int si_code = info->si_code;
int si_type;
tinfo->si_signo = sig;
tinfo->si_errno = 0;
tinfo->si_code = info->si_code;
/* This memset serves two purposes:
* (1) ensure we don't leak random junk to the guest later
* (2) placate false positives from gcc about fields
* being used uninitialized if it chooses to inline both this
* function and tswap_siginfo() into host_to_target_siginfo().
*/
memset(tinfo->_sifields._pad, 0, sizeof(tinfo->_sifields._pad));
/* This is awkward, because we have to use a combination of
* the si_code and si_signo to figure out which of the union's
* members are valid. (Within the host kernel it is always possible
* to tell, but the kernel carefully avoids giving userspace the
* high 16 bits of si_code, so we don't have the information to
* do this the easy way...) We therefore make our best guess,
* bearing in mind that a guest can spoof most of the si_codes
* via rt_sigqueueinfo() if it likes.
*
* Once we have made our guess, we record it in the top 16 bits of
* the si_code, so that tswap_siginfo() later can use it.
* tswap_siginfo() will strip these top bits out before writing
* si_code to the guest (sign-extending the lower bits).
*/
switch (si_code) {
case SI_USER:
case SI_TKILL:
case SI_KERNEL:
/* Sent via kill(), tkill() or tgkill(), or direct from the kernel.
* These are the only unspoofable si_code values.
*/
tinfo->_sifields._kill._pid = info->si_pid;
tinfo->_sifields._kill._uid = info->si_uid;
si_type = QEMU_SI_KILL;
break;
default:
/* Everything else is spoofable. Make best guess based on signal */
switch (sig) {
case TARGET_SIGCHLD:
tinfo->_sifields._sigchld._pid = info->si_pid;
tinfo->_sifields._sigchld._uid = info->si_uid;
tinfo->_sifields._sigchld._status
= host_to_target_waitstatus(info->si_status);
tinfo->_sifields._sigchld._utime = info->si_utime;
tinfo->_sifields._sigchld._stime = info->si_stime;
si_type = QEMU_SI_CHLD;
break;
case TARGET_SIGIO:
tinfo->_sifields._sigpoll._band = info->si_band;
tinfo->_sifields._sigpoll._fd = info->si_fd;
si_type = QEMU_SI_POLL;
break;
default:
/* Assume a sigqueue()/mq_notify()/rt_sigqueueinfo() source. */
tinfo->_sifields._rt._pid = info->si_pid;
tinfo->_sifields._rt._uid = info->si_uid;
/* XXX: potential problem if 64 bit */
tinfo->_sifields._rt._sigval.sival_ptr
= (abi_ulong)(unsigned long)info->si_value.sival_ptr;
si_type = QEMU_SI_RT;
break;
}
break;
}
tinfo->si_code = deposit32(si_code, 16, 16, si_type);
}
static void tswap_siginfo(target_siginfo_t *tinfo,
const target_siginfo_t *info)
{
int si_type = extract32(info->si_code, 16, 16);
int si_code = sextract32(info->si_code, 0, 16);
__put_user(info->si_signo, &tinfo->si_signo);
__put_user(info->si_errno, &tinfo->si_errno);
__put_user(si_code, &tinfo->si_code);
/* We can use our internal marker of which fields in the structure
* are valid, rather than duplicating the guesswork of
* host_to_target_siginfo_noswap() here.
*/
switch (si_type) {
case QEMU_SI_KILL:
__put_user(info->_sifields._kill._pid, &tinfo->_sifields._kill._pid);
__put_user(info->_sifields._kill._uid, &tinfo->_sifields._kill._uid);
break;
case QEMU_SI_TIMER:
__put_user(info->_sifields._timer._timer1,
&tinfo->_sifields._timer._timer1);
__put_user(info->_sifields._timer._timer2,
&tinfo->_sifields._timer._timer2);
break;
case QEMU_SI_POLL:
__put_user(info->_sifields._sigpoll._band,
&tinfo->_sifields._sigpoll._band);
__put_user(info->_sifields._sigpoll._fd,
&tinfo->_sifields._sigpoll._fd);
break;
case QEMU_SI_FAULT:
__put_user(info->_sifields._sigfault._addr,
&tinfo->_sifields._sigfault._addr);
break;
case QEMU_SI_CHLD:
__put_user(info->_sifields._sigchld._pid,
&tinfo->_sifields._sigchld._pid);
__put_user(info->_sifields._sigchld._uid,
&tinfo->_sifields._sigchld._uid);
__put_user(info->_sifields._sigchld._status,
&tinfo->_sifields._sigchld._status);
__put_user(info->_sifields._sigchld._utime,
&tinfo->_sifields._sigchld._utime);
__put_user(info->_sifields._sigchld._stime,
&tinfo->_sifields._sigchld._stime);
break;
case QEMU_SI_RT:
__put_user(info->_sifields._rt._pid, &tinfo->_sifields._rt._pid);
__put_user(info->_sifields._rt._uid, &tinfo->_sifields._rt._uid);
__put_user(info->_sifields._rt._sigval.sival_ptr,
&tinfo->_sifields._rt._sigval.sival_ptr);
break;
default:
g_assert_not_reached();
}
}
void host_to_target_siginfo(target_siginfo_t *tinfo, const siginfo_t *info)
{
target_siginfo_t tgt_tmp;
host_to_target_siginfo_noswap(&tgt_tmp, info);
tswap_siginfo(tinfo, &tgt_tmp);
}
/* XXX: we support only POSIX RT signals are used. */
/* XXX: find a solution for 64 bit (additional malloced data is needed) */
void target_to_host_siginfo(siginfo_t *info, const target_siginfo_t *tinfo)
{
/* This conversion is used only for the rt_sigqueueinfo syscall,
* and so we know that the _rt fields are the valid ones.
*/
abi_ulong sival_ptr;
__get_user(info->si_signo, &tinfo->si_signo);
__get_user(info->si_errno, &tinfo->si_errno);
__get_user(info->si_code, &tinfo->si_code);
__get_user(info->si_pid, &tinfo->_sifields._rt._pid);
__get_user(info->si_uid, &tinfo->_sifields._rt._uid);
__get_user(sival_ptr, &tinfo->_sifields._rt._sigval.sival_ptr);
info->si_value.sival_ptr = (void *)(long)sival_ptr;
}
static int fatal_signal (int sig)
{
switch (sig) {
case TARGET_SIGCHLD:
case TARGET_SIGURG:
case TARGET_SIGWINCH:
/* Ignored by default. */
return 0;
case TARGET_SIGCONT:
case TARGET_SIGSTOP:
case TARGET_SIGTSTP:
case TARGET_SIGTTIN:
case TARGET_SIGTTOU:
/* Job control signals. */
return 0;
default:
return 1;
}
}
/* returns 1 if given signal should dump core if not handled */
static int core_dump_signal(int sig)
{
switch (sig) {
case TARGET_SIGABRT:
case TARGET_SIGFPE:
case TARGET_SIGILL:
case TARGET_SIGQUIT:
case TARGET_SIGSEGV:
case TARGET_SIGTRAP:
case TARGET_SIGBUS:
return (1);
default:
return (0);
}
}
void signal_init(void)
{
TaskState *ts = (TaskState *)thread_cpu->opaque;
struct sigaction act;
struct sigaction oact;
int i, j;
int host_sig;
/* generate signal conversion tables */
for(i = 1; i < _NSIG; i++) {
if (host_to_target_signal_table[i] == 0)
host_to_target_signal_table[i] = i;
}
for(i = 1; i < _NSIG; i++) {
j = host_to_target_signal_table[i];
target_to_host_signal_table[j] = i;
}
/* Set the signal mask from the host mask. */
sigprocmask(0, 0, &ts->signal_mask);
/* set all host signal handlers. ALL signals are blocked during
the handlers to serialize them. */
memset(sigact_table, 0, sizeof(sigact_table));
sigfillset(&act.sa_mask);
act.sa_flags = SA_SIGINFO;
act.sa_sigaction = host_signal_handler;
for(i = 1; i <= TARGET_NSIG; i++) {
host_sig = target_to_host_signal(i);
sigaction(host_sig, NULL, &oact);
if (oact.sa_sigaction == (void *)SIG_IGN) {
sigact_table[i - 1]._sa_handler = TARGET_SIG_IGN;
} else if (oact.sa_sigaction == (void *)SIG_DFL) {
sigact_table[i - 1]._sa_handler = TARGET_SIG_DFL;
}
/* If there's already a handler installed then something has
gone horribly wrong, so don't even try to handle that case. */
/* Install some handlers for our own use. We need at least
SIGSEGV and SIGBUS, to detect exceptions. We can not just
trap all signals because it affects syscall interrupt
behavior. But do trap all default-fatal signals. */
if (fatal_signal (i))
sigaction(host_sig, &act, NULL);
}
}
#if !(defined(TARGET_X86_64) || defined(TARGET_UNICORE32))
/* Force a synchronously taken signal. The kernel force_sig() function
* also forces the signal to "not blocked, not ignored", but for QEMU
* that work is done in process_pending_signals().
*/
static void force_sig(int sig)
{
CPUState *cpu = thread_cpu;
CPUArchState *env = cpu->env_ptr;
target_siginfo_t info;
info.si_signo = sig;
info.si_errno = 0;
info.si_code = TARGET_SI_KERNEL;
info._sifields._kill._pid = 0;
info._sifields._kill._uid = 0;
queue_signal(env, info.si_signo, QEMU_SI_KILL, &info);
}
/* Force a SIGSEGV if we couldn't write to memory trying to set
* up the signal frame. oldsig is the signal we were trying to handle
* at the point of failure.
*/
static void force_sigsegv(int oldsig)
{
if (oldsig == SIGSEGV) {
/* Make sure we don't try to deliver the signal again; this will
* end up with handle_pending_signal() calling dump_core_and_abort().
*/
sigact_table[oldsig - 1]._sa_handler = TARGET_SIG_DFL;
}
force_sig(TARGET_SIGSEGV);
}
#endif
/* abort execution with signal */
static void QEMU_NORETURN dump_core_and_abort(int target_sig)
{
CPUState *cpu = thread_cpu;
CPUArchState *env = cpu->env_ptr;
TaskState *ts = (TaskState *)cpu->opaque;
int host_sig, core_dumped = 0;
struct sigaction act;
host_sig = target_to_host_signal(target_sig);
trace_user_force_sig(env, target_sig, host_sig);
gdb_signalled(env, target_sig);
/* dump core if supported by target binary format */
if (core_dump_signal(target_sig) && (ts->bprm->core_dump != NULL)) {
stop_all_tasks();
core_dumped =
((*ts->bprm->core_dump)(target_sig, env) == 0);
}
if (core_dumped) {
/* we already dumped the core of target process, we don't want
* a coredump of qemu itself */
struct rlimit nodump;
getrlimit(RLIMIT_CORE, &nodump);
nodump.rlim_cur=0;
setrlimit(RLIMIT_CORE, &nodump);
(void) fprintf(stderr, "qemu: uncaught target signal %d (%s) - %s\n",
target_sig, strsignal(host_sig), "core dumped" );
}
/* The proper exit code for dying from an uncaught signal is
* -<signal>. The kernel doesn't allow exit() or _exit() to pass
* a negative value. To get the proper exit code we need to
* actually die from an uncaught signal. Here the default signal
* handler is installed, we send ourself a signal and we wait for
* it to arrive. */
sigfillset(&act.sa_mask);
act.sa_handler = SIG_DFL;
act.sa_flags = 0;
sigaction(host_sig, &act, NULL);
/* For some reason raise(host_sig) doesn't send the signal when
* statically linked on x86-64. */
kill(getpid(), host_sig);
/* Make sure the signal isn't masked (just reuse the mask inside
of act) */
sigdelset(&act.sa_mask, host_sig);
sigsuspend(&act.sa_mask);
/* unreachable */
abort();
}
/* queue a signal so that it will be send to the virtual CPU as soon
as possible */
int queue_signal(CPUArchState *env, int sig, int si_type,
target_siginfo_t *info)
{
CPUState *cpu = ENV_GET_CPU(env);
TaskState *ts = cpu->opaque;
trace_user_queue_signal(env, sig);
info->si_code = deposit32(info->si_code, 16, 16, si_type);
ts->sync_signal.info = *info;
ts->sync_signal.pending = sig;
/* signal that a new signal is pending */
atomic_set(&ts->signal_pending, 1);
return 1; /* indicates that the signal was queued */
}
#ifndef HAVE_SAFE_SYSCALL
static inline void rewind_if_in_safe_syscall(void *puc)
{
/* Default version: never rewind */
}
#endif
static void host_signal_handler(int host_signum, siginfo_t *info,
void *puc)
{
CPUArchState *env = thread_cpu->env_ptr;
CPUState *cpu = ENV_GET_CPU(env);
TaskState *ts = cpu->opaque;
int sig;
target_siginfo_t tinfo;
ucontext_t *uc = puc;
struct emulated_sigtable *k;
/* the CPU emulator uses some host signals to detect exceptions,
we forward to it some signals */
if ((host_signum == SIGSEGV || host_signum == SIGBUS)
&& info->si_code > 0) {
if (cpu_signal_handler(host_signum, info, puc))
return;
}
/* get target signal number */
sig = host_to_target_signal(host_signum);
if (sig < 1 || sig > TARGET_NSIG)
return;
trace_user_host_signal(env, host_signum, sig);
rewind_if_in_safe_syscall(puc);
host_to_target_siginfo_noswap(&tinfo, info);
k = &ts->sigtab[sig - 1];
k->info = tinfo;
k->pending = sig;
ts->signal_pending = 1;
/* Block host signals until target signal handler entered. We
* can't block SIGSEGV or SIGBUS while we're executing guest
* code in case the guest code provokes one in the window between
* now and it getting out to the main loop. Signals will be
* unblocked again in process_pending_signals().
*
* WARNING: we cannot use sigfillset() here because the uc_sigmask
* field is a kernel sigset_t, which is much smaller than the
* libc sigset_t which sigfillset() operates on. Using sigfillset()
* would write 0xff bytes off the end of the structure and trash
* data on the struct.
* We can't use sizeof(uc->uc_sigmask) either, because the libc
* headers define the struct field with the wrong (too large) type.
*/
memset(&uc->uc_sigmask, 0xff, SIGSET_T_SIZE);
sigdelset(&uc->uc_sigmask, SIGSEGV);
sigdelset(&uc->uc_sigmask, SIGBUS);
/* interrupt the virtual CPU as soon as possible */
cpu_exit(thread_cpu);
}
/* do_sigaltstack() returns target values and errnos. */
/* compare linux/kernel/signal.c:do_sigaltstack() */
abi_long do_sigaltstack(abi_ulong uss_addr, abi_ulong uoss_addr, abi_ulong sp)
{
int ret;
struct target_sigaltstack oss;
/* XXX: test errors */
if(uoss_addr)
{
__put_user(target_sigaltstack_used.ss_sp, &oss.ss_sp);
__put_user(target_sigaltstack_used.ss_size, &oss.ss_size);
__put_user(sas_ss_flags(sp), &oss.ss_flags);
}
if(uss_addr)
{
struct target_sigaltstack *uss;
struct target_sigaltstack ss;
size_t minstacksize = TARGET_MINSIGSTKSZ;
#if defined(TARGET_PPC64)
/* ELF V2 for PPC64 has a 4K minimum stack size for signal handlers */
struct image_info *image = ((TaskState *)thread_cpu->opaque)->info;
if (get_ppc64_abi(image) > 1) {
minstacksize = 4096;
}
#endif
ret = -TARGET_EFAULT;
if (!lock_user_struct(VERIFY_READ, uss, uss_addr, 1)) {
goto out;
}
__get_user(ss.ss_sp, &uss->ss_sp);
__get_user(ss.ss_size, &uss->ss_size);
__get_user(ss.ss_flags, &uss->ss_flags);
unlock_user_struct(uss, uss_addr, 0);
ret = -TARGET_EPERM;
if (on_sig_stack(sp))
goto out;
ret = -TARGET_EINVAL;
if (ss.ss_flags != TARGET_SS_DISABLE
&& ss.ss_flags != TARGET_SS_ONSTACK
&& ss.ss_flags != 0)
goto out;
if (ss.ss_flags == TARGET_SS_DISABLE) {
ss.ss_size = 0;
ss.ss_sp = 0;
} else {
ret = -TARGET_ENOMEM;
if (ss.ss_size < minstacksize) {
goto out;
}
}
target_sigaltstack_used.ss_sp = ss.ss_sp;
target_sigaltstack_used.ss_size = ss.ss_size;
}
if (uoss_addr) {
ret = -TARGET_EFAULT;
if (copy_to_user(uoss_addr, &oss, sizeof(oss)))
goto out;
}
ret = 0;
out:
return ret;
}
/* do_sigaction() return target values and host errnos */
int do_sigaction(int sig, const struct target_sigaction *act,
struct target_sigaction *oact)
{
struct target_sigaction *k;
struct sigaction act1;
int host_sig;
int ret = 0;
if (sig < 1 || sig > TARGET_NSIG || sig == TARGET_SIGKILL || sig == TARGET_SIGSTOP) {
return -TARGET_EINVAL;
}
if (block_signals()) {
return -TARGET_ERESTARTSYS;
}
k = &sigact_table[sig - 1];
if (oact) {
__put_user(k->_sa_handler, &oact->_sa_handler);
__put_user(k->sa_flags, &oact->sa_flags);
#if !defined(TARGET_MIPS)
__put_user(k->sa_restorer, &oact->sa_restorer);
#endif
/* Not swapped. */
oact->sa_mask = k->sa_mask;
}
if (act) {
/* FIXME: This is not threadsafe. */
__get_user(k->_sa_handler, &act->_sa_handler);
__get_user(k->sa_flags, &act->sa_flags);
#if !defined(TARGET_MIPS)
__get_user(k->sa_restorer, &act->sa_restorer);
#endif
/* To be swapped in target_to_host_sigset. */
k->sa_mask = act->sa_mask;
/* we update the host linux signal state */
host_sig = target_to_host_signal(sig);
if (host_sig != SIGSEGV && host_sig != SIGBUS) {
sigfillset(&act1.sa_mask);
act1.sa_flags = SA_SIGINFO;
if (k->sa_flags & TARGET_SA_RESTART)
act1.sa_flags |= SA_RESTART;
/* NOTE: it is important to update the host kernel signal
ignore state to avoid getting unexpected interrupted
syscalls */
if (k->_sa_handler == TARGET_SIG_IGN) {
act1.sa_sigaction = (void *)SIG_IGN;
} else if (k->_sa_handler == TARGET_SIG_DFL) {
if (fatal_signal (sig))
act1.sa_sigaction = host_signal_handler;
else
act1.sa_sigaction = (void *)SIG_DFL;
} else {
act1.sa_sigaction = host_signal_handler;
}
ret = sigaction(host_sig, &act1, NULL);
}
}
return ret;
}
#if defined(TARGET_I386) && TARGET_ABI_BITS == 32
/* from the Linux kernel */
struct target_fpreg {
uint16_t significand[4];
uint16_t exponent;
};
struct target_fpxreg {
uint16_t significand[4];
uint16_t exponent;
uint16_t padding[3];
};
struct target_xmmreg {
abi_ulong element[4];
};
struct target_fpstate {
/* Regular FPU environment */
abi_ulong cw;
abi_ulong sw;
abi_ulong tag;
abi_ulong ipoff;
abi_ulong cssel;
abi_ulong dataoff;
abi_ulong datasel;
struct target_fpreg _st[8];
uint16_t status;
uint16_t magic; /* 0xffff = regular FPU data only */
/* FXSR FPU environment */
abi_ulong _fxsr_env[6]; /* FXSR FPU env is ignored */
abi_ulong mxcsr;
abi_ulong reserved;
struct target_fpxreg _fxsr_st[8]; /* FXSR FPU reg data is ignored */
struct target_xmmreg _xmm[8];
abi_ulong padding[56];
};
#define X86_FXSR_MAGIC 0x0000
struct target_sigcontext {
uint16_t gs, __gsh;
uint16_t fs, __fsh;
uint16_t es, __esh;
uint16_t ds, __dsh;
abi_ulong edi;
abi_ulong esi;
abi_ulong ebp;
abi_ulong esp;
abi_ulong ebx;
abi_ulong edx;
abi_ulong ecx;
abi_ulong eax;
abi_ulong trapno;
abi_ulong err;
abi_ulong eip;
uint16_t cs, __csh;
abi_ulong eflags;
abi_ulong esp_at_signal;
uint16_t ss, __ssh;
abi_ulong fpstate; /* pointer */
abi_ulong oldmask;
abi_ulong cr2;
};
struct target_ucontext {
abi_ulong tuc_flags;
abi_ulong tuc_link;
target_stack_t tuc_stack;
struct target_sigcontext tuc_mcontext;
target_sigset_t tuc_sigmask; /* mask last for extensibility */
};
struct sigframe
{
abi_ulong pretcode;
int sig;
struct target_sigcontext sc;
struct target_fpstate fpstate;
abi_ulong extramask[TARGET_NSIG_WORDS-1];
char retcode[8];
};
struct rt_sigframe
{
abi_ulong pretcode;
int sig;
abi_ulong pinfo;
abi_ulong puc;
struct target_siginfo info;
struct target_ucontext uc;
struct target_fpstate fpstate;
char retcode[8];
};
/*
* Set up a signal frame.
*/
/* XXX: save x87 state */
static void setup_sigcontext(struct target_sigcontext *sc,
struct target_fpstate *fpstate, CPUX86State *env, abi_ulong mask,
abi_ulong fpstate_addr)
{
CPUState *cs = CPU(x86_env_get_cpu(env));
uint16_t magic;
/* already locked in setup_frame() */
__put_user(env->segs[R_GS].selector, (unsigned int *)&sc->gs);
__put_user(env->segs[R_FS].selector, (unsigned int *)&sc->fs);
__put_user(env->segs[R_ES].selector, (unsigned int *)&sc->es);
__put_user(env->segs[R_DS].selector, (unsigned int *)&sc->ds);
__put_user(env->regs[R_EDI], &sc->edi);
__put_user(env->regs[R_ESI], &sc->esi);
__put_user(env->regs[R_EBP], &sc->ebp);
__put_user(env->regs[R_ESP], &sc->esp);
__put_user(env->regs[R_EBX], &sc->ebx);
__put_user(env->regs[R_EDX], &sc->edx);
__put_user(env->regs[R_ECX], &sc->ecx);
__put_user(env->regs[R_EAX], &sc->eax);
__put_user(cs->exception_index, &sc->trapno);
__put_user(env->error_code, &sc->err);
__put_user(env->eip, &sc->eip);
__put_user(env->segs[R_CS].selector, (unsigned int *)&sc->cs);
__put_user(env->eflags, &sc->eflags);
__put_user(env->regs[R_ESP], &sc->esp_at_signal);
__put_user(env->segs[R_SS].selector, (unsigned int *)&sc->ss);
cpu_x86_fsave(env, fpstate_addr, 1);
fpstate->status = fpstate->sw;
magic = 0xffff;
__put_user(magic, &fpstate->magic);
__put_user(fpstate_addr, &sc->fpstate);
/* non-iBCS2 extensions.. */
__put_user(mask, &sc->oldmask);
__put_user(env->cr[2], &sc->cr2);
}
/*
* Determine which stack to use..
*/
static inline abi_ulong
get_sigframe(struct target_sigaction *ka, CPUX86State *env, size_t frame_size)
{
unsigned long esp;
/* Default to using normal stack */
esp = env->regs[R_ESP];
/* This is the X/Open sanctioned signal stack switching. */
if (ka->sa_flags & TARGET_SA_ONSTACK) {
if (sas_ss_flags(esp) == 0) {
esp = target_sigaltstack_used.ss_sp + target_sigaltstack_used.ss_size;
}
} else {
/* This is the legacy signal stack switching. */
if ((env->segs[R_SS].selector & 0xffff) != __USER_DS &&
!(ka->sa_flags & TARGET_SA_RESTORER) &&
ka->sa_restorer) {
esp = (unsigned long) ka->sa_restorer;
}
}
return (esp - frame_size) & -8ul;
}
/* compare linux/arch/i386/kernel/signal.c:setup_frame() */
static void setup_frame(int sig, struct target_sigaction *ka,
target_sigset_t *set, CPUX86State *env)
{
abi_ulong frame_addr;
struct sigframe *frame;
int i;
frame_addr = get_sigframe(ka, env, sizeof(*frame));