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qemu-e2k/linux-user/signal.c
bellard edf779ffcc use kernel like macros for user access (will be useful someday to have a better error checking 
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@634 c046a42c-6fe2-441c-8c8c-71466251a162
2004-02-22 13:40:13 +00:00

1361 lines
37 KiB
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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, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <stdarg.h>
#include <unistd.h>
#include <signal.h>
#include <errno.h>
#include <sys/ucontext.h>
#ifdef __ia64__
#undef uc_mcontext
#undef uc_sigmask
#undef uc_stack
#undef uc_link
#endif
#include "qemu.h"
//#define DEBUG_SIGNAL
#define MAX_SIGQUEUE_SIZE 1024
struct sigqueue {
struct sigqueue *next;
target_siginfo_t info;
};
struct emulated_sigaction {
struct target_sigaction sa;
int pending; /* true if signal is pending */
struct sigqueue *first;
struct sigqueue info; /* in order to always have memory for the
first signal, we put it here */
};
static struct emulated_sigaction sigact_table[TARGET_NSIG];
static struct sigqueue sigqueue_table[MAX_SIGQUEUE_SIZE]; /* siginfo queue */
static struct sigqueue *first_free; /* first free siginfo queue entry */
static int signal_pending; /* non zero if a signal may be pending */
static void host_signal_handler(int host_signum, siginfo_t *info,
void *puc);
static uint8_t host_to_target_signal_table[65] = {
[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 */
};
static uint8_t target_to_host_signal_table[65];
static inline int host_to_target_signal(int sig)
{
return host_to_target_signal_table[sig];
}
static inline int target_to_host_signal(int sig)
{
return target_to_host_signal_table[sig];
}
void host_to_target_sigset(target_sigset_t *d, const sigset_t *s)
{
int i;
unsigned long sigmask;
uint32_t target_sigmask;
sigmask = ((unsigned long *)s)[0];
target_sigmask = 0;
for(i = 0; i < 32; i++) {
if (sigmask & (1 << i))
target_sigmask |= 1 << (host_to_target_signal(i + 1) - 1);
}
#if TARGET_LONG_BITS == 32 && HOST_LONG_BITS == 32
d->sig[0] = tswapl(target_sigmask);
for(i = 1;i < TARGET_NSIG_WORDS; i++) {
d->sig[i] = tswapl(((unsigned long *)s)[i]);
}
#elif TARGET_LONG_BITS == 32 && HOST_LONG_BITS == 64 && TARGET_NSIG_WORDS == 2
d->sig[0] = tswapl(target_sigmask);
d->sig[1] = tswapl(sigmask >> 32);
#else
#error host_to_target_sigset
#endif
}
void target_to_host_sigset(sigset_t *d, const target_sigset_t *s)
{
int i;
unsigned long sigmask;
target_ulong target_sigmask;
target_sigmask = tswapl(s->sig[0]);
sigmask = 0;
for(i = 0; i < 32; i++) {
if (target_sigmask & (1 << i))
sigmask |= 1 << (target_to_host_signal(i + 1) - 1);
}
#if TARGET_LONG_BITS == 32 && HOST_LONG_BITS == 32
((unsigned long *)d)[0] = sigmask;
for(i = 1;i < TARGET_NSIG_WORDS; i++) {
((unsigned long *)d)[i] = tswapl(s->sig[i]);
}
#elif TARGET_LONG_BITS == 32 && HOST_LONG_BITS == 64 && TARGET_NSIG_WORDS == 2
((unsigned long *)d)[0] = sigmask | ((unsigned long)tswapl(s->sig[1]) << 32);
#else
#error target_to_host_sigset
#endif /* TARGET_LONG_BITS */
}
void host_to_target_old_sigset(target_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 target_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);
}
/* siginfo conversion */
static inline void host_to_target_siginfo_noswap(target_siginfo_t *tinfo,
const siginfo_t *info)
{
int sig;
sig = host_to_target_signal(info->si_signo);
tinfo->si_signo = sig;
tinfo->si_errno = 0;
tinfo->si_code = 0;
if (sig == SIGILL || sig == SIGFPE || sig == SIGSEGV ||
sig == SIGBUS || sig == SIGTRAP) {
/* should never come here, but who knows. The information for
the target is irrelevant */
tinfo->_sifields._sigfault._addr = 0;
} else if (sig >= TARGET_SIGRTMIN) {
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 =
(target_ulong)info->si_value.sival_ptr;
}
}
static void tswap_siginfo(target_siginfo_t *tinfo,
const target_siginfo_t *info)
{
int sig;
sig = info->si_signo;
tinfo->si_signo = tswap32(sig);
tinfo->si_errno = tswap32(info->si_errno);
tinfo->si_code = tswap32(info->si_code);
if (sig == SIGILL || sig == SIGFPE || sig == SIGSEGV ||
sig == SIGBUS || sig == SIGTRAP) {
tinfo->_sifields._sigfault._addr =
tswapl(info->_sifields._sigfault._addr);
} else if (sig >= TARGET_SIGRTMIN) {
tinfo->_sifields._rt._pid = tswap32(info->_sifields._rt._pid);
tinfo->_sifields._rt._uid = tswap32(info->_sifields._rt._uid);
tinfo->_sifields._rt._sigval.sival_ptr =
tswapl(info->_sifields._rt._sigval.sival_ptr);
}
}
void host_to_target_siginfo(target_siginfo_t *tinfo, const siginfo_t *info)
{
host_to_target_siginfo_noswap(tinfo, info);
tswap_siginfo(tinfo, tinfo);
}
/* XXX: we support only POSIX RT signals are used. */
/* XXX: find a solution for 64 bit (additionnal malloced data is needed) */
void target_to_host_siginfo(siginfo_t *info, const target_siginfo_t *tinfo)
{
info->si_signo = tswap32(tinfo->si_signo);
info->si_errno = tswap32(tinfo->si_errno);
info->si_code = tswap32(tinfo->si_code);
info->si_pid = tswap32(tinfo->_sifields._rt._pid);
info->si_uid = tswap32(tinfo->_sifields._rt._uid);
info->si_value.sival_ptr =
(void *)tswapl(tinfo->_sifields._rt._sigval.sival_ptr);
}
void signal_init(void)
{
struct sigaction act;
int i, j;
/* generate signal conversion tables */
for(i = 1; i <= 64; i++) {
if (host_to_target_signal_table[i] == 0)
host_to_target_signal_table[i] = i;
}
for(i = 1; i <= 64; i++) {
j = host_to_target_signal_table[i];
target_to_host_signal_table[j] = i;
}
/* set all host signal handlers. ALL signals are blocked during
the handlers to serialize them. */
sigfillset(&act.sa_mask);
act.sa_flags = SA_SIGINFO;
act.sa_sigaction = host_signal_handler;
for(i = 1; i < NSIG; i++) {
sigaction(i, &act, NULL);
}
memset(sigact_table, 0, sizeof(sigact_table));
first_free = &sigqueue_table[0];
for(i = 0; i < MAX_SIGQUEUE_SIZE - 1; i++)
sigqueue_table[i].next = &sigqueue_table[i + 1];
sigqueue_table[MAX_SIGQUEUE_SIZE - 1].next = NULL;
}
/* signal queue handling */
static inline struct sigqueue *alloc_sigqueue(void)
{
struct sigqueue *q = first_free;
if (!q)
return NULL;
first_free = q->next;
return q;
}
static inline void free_sigqueue(struct sigqueue *q)
{
q->next = first_free;
first_free = q;
}
/* abort execution with signal */
void __attribute((noreturn)) force_sig(int sig)
{
int host_sig;
host_sig = target_to_host_signal(sig);
fprintf(stderr, "qemu: uncaught target signal %d (%s) - exiting\n",
sig, strsignal(host_sig));
#if 1
_exit(-host_sig);
#else
{
struct sigaction act;
sigemptyset(&act.sa_mask);
act.sa_flags = SA_SIGINFO;
act.sa_sigaction = SIG_DFL;
sigaction(SIGABRT, &act, NULL);
abort();
}
#endif
}
/* queue a signal so that it will be send to the virtual CPU as soon
as possible */
int queue_signal(int sig, target_siginfo_t *info)
{
struct emulated_sigaction *k;
struct sigqueue *q, **pq;
target_ulong handler;
#if defined(DEBUG_SIGNAL)
fprintf(stderr, "queue_signal: sig=%d\n",
sig);
#endif
k = &sigact_table[sig - 1];
handler = k->sa._sa_handler;
if (handler == TARGET_SIG_DFL) {
/* default handler : ignore some signal. The other are fatal */
if (sig != TARGET_SIGCHLD &&
sig != TARGET_SIGURG &&
sig != TARGET_SIGWINCH) {
force_sig(sig);
} else {
return 0; /* indicate ignored */
}
} else if (handler == TARGET_SIG_IGN) {
/* ignore signal */
return 0;
} else if (handler == TARGET_SIG_ERR) {
force_sig(sig);
} else {
pq = &k->first;
if (sig < TARGET_SIGRTMIN) {
/* if non real time signal, we queue exactly one signal */
if (!k->pending)
q = &k->info;
else
return 0;
} else {
if (!k->pending) {
/* first signal */
q = &k->info;
} else {
q = alloc_sigqueue();
if (!q)
return -EAGAIN;
while (*pq != NULL)
pq = &(*pq)->next;
}
}
*pq = q;
q->info = *info;
q->next = NULL;
k->pending = 1;
/* signal that a new signal is pending */
signal_pending = 1;
return 1; /* indicates that the signal was queued */
}
}
static void host_signal_handler(int host_signum, siginfo_t *info,
void *puc)
{
int sig;
target_siginfo_t tinfo;
/* the CPU emulator uses some host signals to detect exceptions,
we we forward to it some signals */
if (host_signum == SIGSEGV || host_signum == SIGBUS
#if defined(TARGET_I386) && defined(USE_CODE_COPY)
|| host_signum == SIGFPE
#endif
) {
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;
#if defined(DEBUG_SIGNAL)
fprintf(stderr, "qemu: got signal %d\n", sig);
#endif
host_to_target_siginfo_noswap(&tinfo, info);
if (queue_signal(sig, &tinfo) == 1) {
/* interrupt the virtual CPU as soon as possible */
cpu_interrupt(global_env, CPU_INTERRUPT_EXIT);
}
}
int do_sigaction(int sig, const struct target_sigaction *act,
struct target_sigaction *oact)
{
struct emulated_sigaction *k;
struct sigaction act1;
int host_sig;
if (sig < 1 || sig > TARGET_NSIG)
return -EINVAL;
k = &sigact_table[sig - 1];
#if defined(DEBUG_SIGNAL)
fprintf(stderr, "sigaction sig=%d act=0x%08x, oact=0x%08x\n",
sig, (int)act, (int)oact);
#endif
if (oact) {
oact->_sa_handler = tswapl(k->sa._sa_handler);
oact->sa_flags = tswapl(k->sa.sa_flags);
oact->sa_restorer = tswapl(k->sa.sa_restorer);
oact->sa_mask = k->sa.sa_mask;
}
if (act) {
k->sa._sa_handler = tswapl(act->_sa_handler);
k->sa.sa_flags = tswapl(act->sa_flags);
k->sa.sa_restorer = tswapl(act->sa_restorer);
k->sa.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.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._sa_handler == TARGET_SIG_IGN) {
act1.sa_sigaction = (void *)SIG_IGN;
} else if (k->sa._sa_handler == TARGET_SIG_DFL) {
act1.sa_sigaction = (void *)SIG_DFL;
} else {
act1.sa_sigaction = host_signal_handler;
}
sigaction(host_sig, &act1, NULL);
}
}
return 0;
}
#ifndef offsetof
#define offsetof(type, field) ((size_t) &((type *)0)->field)
#endif
static inline int copy_siginfo_to_user(target_siginfo_t *tinfo,
const target_siginfo_t *info)
{
tswap_siginfo(tinfo, info);
return 0;
}
#ifdef TARGET_I386
/* 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 {
target_ulong element[4];
};
struct target_fpstate {
/* Regular FPU environment */
target_ulong cw;
target_ulong sw;
target_ulong tag;
target_ulong ipoff;
target_ulong cssel;
target_ulong dataoff;
target_ulong datasel;
struct target_fpreg _st[8];
uint16_t status;
uint16_t magic; /* 0xffff = regular FPU data only */
/* FXSR FPU environment */
target_ulong _fxsr_env[6]; /* FXSR FPU env is ignored */
target_ulong mxcsr;
target_ulong reserved;
struct target_fpxreg _fxsr_st[8]; /* FXSR FPU reg data is ignored */
struct target_xmmreg _xmm[8];
target_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;
target_ulong edi;
target_ulong esi;
target_ulong ebp;
target_ulong esp;
target_ulong ebx;
target_ulong edx;
target_ulong ecx;
target_ulong eax;
target_ulong trapno;
target_ulong err;
target_ulong eip;
uint16_t cs, __csh;
target_ulong eflags;
target_ulong esp_at_signal;
uint16_t ss, __ssh;
target_ulong fpstate; /* pointer */
target_ulong oldmask;
target_ulong cr2;
};
typedef struct target_sigaltstack {
target_ulong ss_sp;
int ss_flags;
target_ulong ss_size;
} target_stack_t;
struct target_ucontext {
target_ulong uc_flags;
target_ulong uc_link;
target_stack_t uc_stack;
struct target_sigcontext uc_mcontext;
target_sigset_t uc_sigmask; /* mask last for extensibility */
};
struct sigframe
{
target_ulong pretcode;
int sig;
struct target_sigcontext sc;
struct target_fpstate fpstate;
target_ulong extramask[TARGET_NSIG_WORDS-1];
char retcode[8];
};
struct rt_sigframe
{
target_ulong pretcode;
int sig;
target_ulong pinfo;
target_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 int
setup_sigcontext(struct target_sigcontext *sc, struct target_fpstate *fpstate,
CPUX86State *env, unsigned long mask)
{
int err = 0;
err |= __put_user(env->segs[R_GS].selector, (unsigned int *)&sc->gs);
err |= __put_user(env->segs[R_FS].selector, (unsigned int *)&sc->fs);
err |= __put_user(env->segs[R_ES].selector, (unsigned int *)&sc->es);
err |= __put_user(env->segs[R_DS].selector, (unsigned int *)&sc->ds);
err |= __put_user(env->regs[R_EDI], &sc->edi);
err |= __put_user(env->regs[R_ESI], &sc->esi);
err |= __put_user(env->regs[R_EBP], &sc->ebp);
err |= __put_user(env->regs[R_ESP], &sc->esp);
err |= __put_user(env->regs[R_EBX], &sc->ebx);
err |= __put_user(env->regs[R_EDX], &sc->edx);
err |= __put_user(env->regs[R_ECX], &sc->ecx);
err |= __put_user(env->regs[R_EAX], &sc->eax);
err |= __put_user(env->exception_index, &sc->trapno);
err |= __put_user(env->error_code, &sc->err);
err |= __put_user(env->eip, &sc->eip);
err |= __put_user(env->segs[R_CS].selector, (unsigned int *)&sc->cs);
err |= __put_user(env->eflags, &sc->eflags);
err |= __put_user(env->regs[R_ESP], &sc->esp_at_signal);
err |= __put_user(env->segs[R_SS].selector, (unsigned int *)&sc->ss);
cpu_x86_fsave(env, (void *)fpstate, 1);
fpstate->status = fpstate->sw;
err |= __put_user(0xffff, &fpstate->magic);
err |= __put_user(fpstate, &sc->fpstate);
/* non-iBCS2 extensions.. */
err |= __put_user(mask, &sc->oldmask);
err |= __put_user(env->cr[2], &sc->cr2);
return err;
}
/*
* Determine which stack to use..
*/
static inline void *
get_sigframe(struct emulated_sigaction *ka, CPUX86State *env, size_t frame_size)
{
unsigned long esp;
/* Default to using normal stack */
esp = env->regs[R_ESP];
#if 0
/* This is the X/Open sanctioned signal stack switching. */
if (ka->sa.sa_flags & SA_ONSTACK) {
if (sas_ss_flags(esp) == 0)
esp = current->sas_ss_sp + current->sas_ss_size;
}
/* This is the legacy signal stack switching. */
else
#endif
if ((env->segs[R_SS].selector & 0xffff) != __USER_DS &&
!(ka->sa.sa_flags & TARGET_SA_RESTORER) &&
ka->sa.sa_restorer) {
esp = (unsigned long) ka->sa.sa_restorer;
}
return (void *)((esp - frame_size) & -8ul);
}
static void setup_frame(int sig, struct emulated_sigaction *ka,
target_sigset_t *set, CPUX86State *env)
{
struct sigframe *frame;
int err = 0;
frame = get_sigframe(ka, env, sizeof(*frame));
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
goto give_sigsegv;
err |= __put_user((/*current->exec_domain
&& current->exec_domain->signal_invmap
&& sig < 32
? current->exec_domain->signal_invmap[sig]
: */ sig),
&frame->sig);
if (err)
goto give_sigsegv;
setup_sigcontext(&frame->sc, &frame->fpstate, env, set->sig[0]);
if (err)
goto give_sigsegv;
if (TARGET_NSIG_WORDS > 1) {
err |= __copy_to_user(frame->extramask, &set->sig[1],
sizeof(frame->extramask));
}
if (err)
goto give_sigsegv;
/* Set up to return from userspace. If provided, use a stub
already in userspace. */
if (ka->sa.sa_flags & TARGET_SA_RESTORER) {
err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
} else {
err |= __put_user(frame->retcode, &frame->pretcode);
/* This is popl %eax ; movl $,%eax ; int $0x80 */
err |= __put_user(0xb858, (short *)(frame->retcode+0));
err |= __put_user(TARGET_NR_sigreturn, (int *)(frame->retcode+2));
err |= __put_user(0x80cd, (short *)(frame->retcode+6));
}
if (err)
goto give_sigsegv;
/* Set up registers for signal handler */
env->regs[R_ESP] = (unsigned long) frame;
env->eip = (unsigned long) ka->sa._sa_handler;
cpu_x86_load_seg(env, R_DS, __USER_DS);
cpu_x86_load_seg(env, R_ES, __USER_DS);
cpu_x86_load_seg(env, R_SS, __USER_DS);
cpu_x86_load_seg(env, R_CS, __USER_CS);
env->eflags &= ~TF_MASK;
return;
give_sigsegv:
if (sig == TARGET_SIGSEGV)
ka->sa._sa_handler = TARGET_SIG_DFL;
force_sig(TARGET_SIGSEGV /* , current */);
}
static void setup_rt_frame(int sig, struct emulated_sigaction *ka,
target_siginfo_t *info,
target_sigset_t *set, CPUX86State *env)
{
struct rt_sigframe *frame;
int err = 0;
frame = get_sigframe(ka, env, sizeof(*frame));
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
goto give_sigsegv;
err |= __put_user((/*current->exec_domain
&& current->exec_domain->signal_invmap
&& sig < 32
? current->exec_domain->signal_invmap[sig]
: */sig),
&frame->sig);
err |= __put_user((target_ulong)&frame->info, &frame->pinfo);
err |= __put_user((target_ulong)&frame->uc, &frame->puc);
err |= copy_siginfo_to_user(&frame->info, info);
if (err)
goto give_sigsegv;
/* Create the ucontext. */
err |= __put_user(0, &frame->uc.uc_flags);
err |= __put_user(0, &frame->uc.uc_link);
err |= __put_user(/*current->sas_ss_sp*/ 0, &frame->uc.uc_stack.ss_sp);
err |= __put_user(/* sas_ss_flags(regs->esp) */ 0,
&frame->uc.uc_stack.ss_flags);
err |= __put_user(/* current->sas_ss_size */ 0, &frame->uc.uc_stack.ss_size);
err |= setup_sigcontext(&frame->uc.uc_mcontext, &frame->fpstate,
env, set->sig[0]);
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
if (err)
goto give_sigsegv;
/* Set up to return from userspace. If provided, use a stub
already in userspace. */
if (ka->sa.sa_flags & TARGET_SA_RESTORER) {
err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
} else {
err |= __put_user(frame->retcode, &frame->pretcode);
/* This is movl $,%eax ; int $0x80 */
err |= __put_user(0xb8, (char *)(frame->retcode+0));
err |= __put_user(TARGET_NR_rt_sigreturn, (int *)(frame->retcode+1));
err |= __put_user(0x80cd, (short *)(frame->retcode+5));
}
if (err)
goto give_sigsegv;
/* Set up registers for signal handler */
env->regs[R_ESP] = (unsigned long) frame;
env->eip = (unsigned long) ka->sa._sa_handler;
cpu_x86_load_seg(env, R_DS, __USER_DS);
cpu_x86_load_seg(env, R_ES, __USER_DS);
cpu_x86_load_seg(env, R_SS, __USER_DS);
cpu_x86_load_seg(env, R_CS, __USER_CS);
env->eflags &= ~TF_MASK;
return;
give_sigsegv:
if (sig == TARGET_SIGSEGV)
ka->sa._sa_handler = TARGET_SIG_DFL;
force_sig(TARGET_SIGSEGV /* , current */);
}
static int
restore_sigcontext(CPUX86State *env, struct target_sigcontext *sc, int *peax)
{
unsigned int err = 0;
cpu_x86_load_seg(env, R_GS, lduw(&sc->gs));
cpu_x86_load_seg(env, R_FS, lduw(&sc->fs));
cpu_x86_load_seg(env, R_ES, lduw(&sc->es));
cpu_x86_load_seg(env, R_DS, lduw(&sc->ds));
env->regs[R_EDI] = ldl(&sc->edi);
env->regs[R_ESI] = ldl(&sc->esi);
env->regs[R_EBP] = ldl(&sc->ebp);
env->regs[R_ESP] = ldl(&sc->esp);
env->regs[R_EBX] = ldl(&sc->ebx);
env->regs[R_EDX] = ldl(&sc->edx);
env->regs[R_ECX] = ldl(&sc->ecx);
env->eip = ldl(&sc->eip);
cpu_x86_load_seg(env, R_CS, lduw(&sc->cs) | 3);
cpu_x86_load_seg(env, R_SS, lduw(&sc->ss) | 3);
{
unsigned int tmpflags;
tmpflags = ldl(&sc->eflags);
env->eflags = (env->eflags & ~0x40DD5) | (tmpflags & 0x40DD5);
// regs->orig_eax = -1; /* disable syscall checks */
}
{
struct _fpstate * buf;
buf = (void *)ldl(&sc->fpstate);
if (buf) {
#if 0
if (verify_area(VERIFY_READ, buf, sizeof(*buf)))
goto badframe;
#endif
cpu_x86_frstor(env, (void *)buf, 1);
}
}
*peax = ldl(&sc->eax);
return err;
#if 0
badframe:
return 1;
#endif
}
long do_sigreturn(CPUX86State *env)
{
struct sigframe *frame = (struct sigframe *)(env->regs[R_ESP] - 8);
target_sigset_t target_set;
sigset_t set;
int eax, i;
#if defined(DEBUG_SIGNAL)
fprintf(stderr, "do_sigreturn\n");
#endif
/* set blocked signals */
target_set.sig[0] = frame->sc.oldmask;
for(i = 1; i < TARGET_NSIG_WORDS; i++)
target_set.sig[i] = frame->extramask[i - 1];
target_to_host_sigset(&set, &target_set);
sigprocmask(SIG_SETMASK, &set, NULL);
/* restore registers */
if (restore_sigcontext(env, &frame->sc, &eax))
goto badframe;
return eax;
badframe:
force_sig(TARGET_SIGSEGV);
return 0;
}
long do_rt_sigreturn(CPUX86State *env)
{
struct rt_sigframe *frame = (struct rt_sigframe *)(env->regs[R_ESP] - 4);
target_sigset_t target_set;
sigset_t set;
// stack_t st;
int eax;
#if 0
if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
#endif
memcpy(&target_set, &frame->uc.uc_sigmask, sizeof(target_sigset_t));
target_to_host_sigset(&set, &target_set);
sigprocmask(SIG_SETMASK, &set, NULL);
if (restore_sigcontext(env, &frame->uc.uc_mcontext, &eax))
goto badframe;
#if 0
if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st)))
goto badframe;
/* It is more difficult to avoid calling this function than to
call it and ignore errors. */
do_sigaltstack(&st, NULL, regs->esp);
#endif
return eax;
badframe:
force_sig(TARGET_SIGSEGV);
return 0;
}
#elif defined(TARGET_ARM)
struct target_sigcontext {
target_ulong trap_no;
target_ulong error_code;
target_ulong oldmask;
target_ulong arm_r0;
target_ulong arm_r1;
target_ulong arm_r2;
target_ulong arm_r3;
target_ulong arm_r4;
target_ulong arm_r5;
target_ulong arm_r6;
target_ulong arm_r7;
target_ulong arm_r8;
target_ulong arm_r9;
target_ulong arm_r10;
target_ulong arm_fp;
target_ulong arm_ip;
target_ulong arm_sp;
target_ulong arm_lr;
target_ulong arm_pc;
target_ulong arm_cpsr;
target_ulong fault_address;
};
typedef struct target_sigaltstack {
target_ulong ss_sp;
int ss_flags;
target_ulong ss_size;
} target_stack_t;
struct target_ucontext {
target_ulong uc_flags;
target_ulong uc_link;
target_stack_t uc_stack;
struct target_sigcontext uc_mcontext;
target_sigset_t uc_sigmask; /* mask last for extensibility */
};
struct sigframe
{
struct target_sigcontext sc;
target_ulong extramask[TARGET_NSIG_WORDS-1];
target_ulong retcode;
};
struct rt_sigframe
{
struct target_siginfo *pinfo;
void *puc;
struct target_siginfo info;
struct target_ucontext uc;
target_ulong retcode;
};
#define TARGET_CONFIG_CPU_32 1
/*
* For ARM syscalls, we encode the syscall number into the instruction.
*/
#define SWI_SYS_SIGRETURN (0xef000000|(TARGET_NR_sigreturn + ARM_SYSCALL_BASE))
#define SWI_SYS_RT_SIGRETURN (0xef000000|(TARGET_NR_rt_sigreturn + ARM_SYSCALL_BASE))
/*
* For Thumb syscalls, we pass the syscall number via r7. We therefore
* need two 16-bit instructions.
*/
#define SWI_THUMB_SIGRETURN (0xdf00 << 16 | 0x2700 | (TARGET_NR_sigreturn))
#define SWI_THUMB_RT_SIGRETURN (0xdf00 << 16 | 0x2700 | (TARGET_NR_rt_sigreturn))
static const target_ulong retcodes[4] = {
SWI_SYS_SIGRETURN, SWI_THUMB_SIGRETURN,
SWI_SYS_RT_SIGRETURN, SWI_THUMB_RT_SIGRETURN
};
#define __put_user_error(x,p,e) __put_user(x, p)
#define __get_user_error(x,p,e) __get_user(x, p)
static inline int valid_user_regs(CPUState *regs)
{
return 1;
}
static int
setup_sigcontext(struct target_sigcontext *sc, /*struct _fpstate *fpstate,*/
CPUState *env, unsigned long mask)
{
int err = 0;
__put_user_error(env->regs[0], &sc->arm_r0, err);
__put_user_error(env->regs[1], &sc->arm_r1, err);
__put_user_error(env->regs[2], &sc->arm_r2, err);
__put_user_error(env->regs[3], &sc->arm_r3, err);
__put_user_error(env->regs[4], &sc->arm_r4, err);
__put_user_error(env->regs[5], &sc->arm_r5, err);
__put_user_error(env->regs[6], &sc->arm_r6, err);
__put_user_error(env->regs[7], &sc->arm_r7, err);
__put_user_error(env->regs[8], &sc->arm_r8, err);
__put_user_error(env->regs[9], &sc->arm_r9, err);
__put_user_error(env->regs[10], &sc->arm_r10, err);
__put_user_error(env->regs[11], &sc->arm_fp, err);
__put_user_error(env->regs[12], &sc->arm_ip, err);
__put_user_error(env->regs[13], &sc->arm_sp, err);
__put_user_error(env->regs[14], &sc->arm_lr, err);
__put_user_error(env->regs[15], &sc->arm_pc, err);
#ifdef TARGET_CONFIG_CPU_32
__put_user_error(env->cpsr, &sc->arm_cpsr, err);
#endif
__put_user_error(/* current->thread.trap_no */ 0, &sc->trap_no, err);
__put_user_error(/* current->thread.error_code */ 0, &sc->error_code, err);
__put_user_error(/* current->thread.address */ 0, &sc->fault_address, err);
__put_user_error(mask, &sc->oldmask, err);
return err;
}
static inline void *
get_sigframe(struct emulated_sigaction *ka, CPUState *regs, int framesize)
{
unsigned long sp = regs->regs[13];
#if 0
/*
* This is the X/Open sanctioned signal stack switching.
*/
if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
sp = current->sas_ss_sp + current->sas_ss_size;
#endif
/*
* ATPCS B01 mandates 8-byte alignment
*/
return (void *)((sp - framesize) & ~7);
}
static int
setup_return(CPUState *env, struct emulated_sigaction *ka,
target_ulong *rc, void *frame, int usig)
{
target_ulong handler = (target_ulong)ka->sa._sa_handler;
target_ulong retcode;
int thumb = 0;
#if defined(TARGET_CONFIG_CPU_32)
target_ulong cpsr = env->cpsr;
#if 0
/*
* Maybe we need to deliver a 32-bit signal to a 26-bit task.
*/
if (ka->sa.sa_flags & SA_THIRTYTWO)
cpsr = (cpsr & ~MODE_MASK) | USR_MODE;
#ifdef CONFIG_ARM_THUMB
if (elf_hwcap & HWCAP_THUMB) {
/*
* The LSB of the handler determines if we're going to
* be using THUMB or ARM mode for this signal handler.
*/
thumb = handler & 1;
if (thumb)
cpsr |= T_BIT;
else
cpsr &= ~T_BIT;
}
#endif
#endif
#endif /* TARGET_CONFIG_CPU_32 */
if (ka->sa.sa_flags & TARGET_SA_RESTORER) {
retcode = (target_ulong)ka->sa.sa_restorer;
} else {
unsigned int idx = thumb;
if (ka->sa.sa_flags & TARGET_SA_SIGINFO)
idx += 2;
if (__put_user(retcodes[idx], rc))
return 1;
#if 0
flush_icache_range((target_ulong)rc,
(target_ulong)(rc + 1));
#endif
retcode = ((target_ulong)rc) + thumb;
}
env->regs[0] = usig;
env->regs[13] = (target_ulong)frame;
env->regs[14] = retcode;
env->regs[15] = handler & (thumb ? ~1 : ~3);
#ifdef TARGET_CONFIG_CPU_32
env->cpsr = cpsr;
#endif
return 0;
}
static void setup_frame(int usig, struct emulated_sigaction *ka,
target_sigset_t *set, CPUState *regs)
{
struct sigframe *frame = get_sigframe(ka, regs, sizeof(*frame));
int err = 0;
err |= setup_sigcontext(&frame->sc, /*&frame->fpstate,*/ regs, set->sig[0]);
if (TARGET_NSIG_WORDS > 1) {
err |= __copy_to_user(frame->extramask, &set->sig[1],
sizeof(frame->extramask));
}
if (err == 0)
err = setup_return(regs, ka, &frame->retcode, frame, usig);
// return err;
}
static void setup_rt_frame(int usig, struct emulated_sigaction *ka,
target_siginfo_t *info,
target_sigset_t *set, CPUState *env)
{
struct rt_sigframe *frame = get_sigframe(ka, env, sizeof(*frame));
int err = 0;
if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
return /* 1 */;
__put_user_error(&frame->info, (target_ulong *)&frame->pinfo, err);
__put_user_error(&frame->uc, (target_ulong *)&frame->puc, err);
err |= copy_siginfo_to_user(&frame->info, info);
/* Clear all the bits of the ucontext we don't use. */
err |= __clear_user(&frame->uc, offsetof(struct ucontext, uc_mcontext));
err |= setup_sigcontext(&frame->uc.uc_mcontext, /*&frame->fpstate,*/
env, set->sig[0]);
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
if (err == 0)
err = setup_return(env, ka, &frame->retcode, frame, usig);
if (err == 0) {
/*
* For realtime signals we must also set the second and third
* arguments for the signal handler.
* -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06
*/
env->regs[1] = (target_ulong)frame->pinfo;
env->regs[2] = (target_ulong)frame->puc;
}
// return err;
}
static int
restore_sigcontext(CPUState *env, struct target_sigcontext *sc)
{
int err = 0;
__get_user_error(env->regs[0], &sc->arm_r0, err);
__get_user_error(env->regs[1], &sc->arm_r1, err);
__get_user_error(env->regs[2], &sc->arm_r2, err);
__get_user_error(env->regs[3], &sc->arm_r3, err);
__get_user_error(env->regs[4], &sc->arm_r4, err);
__get_user_error(env->regs[5], &sc->arm_r5, err);
__get_user_error(env->regs[6], &sc->arm_r6, err);
__get_user_error(env->regs[7], &sc->arm_r7, err);
__get_user_error(env->regs[8], &sc->arm_r8, err);
__get_user_error(env->regs[9], &sc->arm_r9, err);
__get_user_error(env->regs[10], &sc->arm_r10, err);
__get_user_error(env->regs[11], &sc->arm_fp, err);
__get_user_error(env->regs[12], &sc->arm_ip, err);
__get_user_error(env->regs[13], &sc->arm_sp, err);
__get_user_error(env->regs[14], &sc->arm_lr, err);
__get_user_error(env->regs[15], &sc->arm_pc, err);
#ifdef TARGET_CONFIG_CPU_32
__get_user_error(env->cpsr, &sc->arm_cpsr, err);
#endif
err |= !valid_user_regs(env);
return err;
}
long do_sigreturn(CPUState *env)
{
struct sigframe *frame;
target_sigset_t set;
sigset_t host_set;
/*
* Since we stacked the signal on a 64-bit boundary,
* then 'sp' should be word aligned here. If it's
* not, then the user is trying to mess with us.
*/
if (env->regs[13] & 7)
goto badframe;
frame = (struct sigframe *)env->regs[13];
#if 0
if (verify_area(VERIFY_READ, frame, sizeof (*frame)))
goto badframe;
#endif
if (__get_user(set.sig[0], &frame->sc.oldmask)
|| (TARGET_NSIG_WORDS > 1
&& __copy_from_user(&set.sig[1], &frame->extramask,
sizeof(frame->extramask))))
goto badframe;
target_to_host_sigset(&host_set, &set);
sigprocmask(SIG_SETMASK, &host_set, NULL);
if (restore_sigcontext(env, &frame->sc))
goto badframe;
#if 0
/* Send SIGTRAP if we're single-stepping */
if (ptrace_cancel_bpt(current))
send_sig(SIGTRAP, current, 1);
#endif
return env->regs[0];
badframe:
force_sig(SIGSEGV /* , current */);
return 0;
}
long do_rt_sigreturn(CPUState *env)
{
struct rt_sigframe *frame;
target_sigset_t set;
sigset_t host_set;
/*
* Since we stacked the signal on a 64-bit boundary,
* then 'sp' should be word aligned here. If it's
* not, then the user is trying to mess with us.
*/
if (env->regs[13] & 7)
goto badframe;
frame = (struct rt_sigframe *)env->regs[13];
#if 0
if (verify_area(VERIFY_READ, frame, sizeof (*frame)))
goto badframe;
#endif
if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
goto badframe;
target_to_host_sigset(&host_set, &set);
sigprocmask(SIG_SETMASK, &host_set, NULL);
if (restore_sigcontext(env, &frame->uc.uc_mcontext))
goto badframe;
#if 0
/* Send SIGTRAP if we're single-stepping */
if (ptrace_cancel_bpt(current))
send_sig(SIGTRAP, current, 1);
#endif
return env->regs[0];
badframe:
force_sig(SIGSEGV /* , current */);
return 0;
}
#else
static void setup_frame(int sig, struct emulated_sigaction *ka,
target_sigset_t *set, CPUState *env)
{
fprintf(stderr, "setup_frame: not implemented\n");
}
static void setup_rt_frame(int sig, struct emulated_sigaction *ka,
target_siginfo_t *info,
target_sigset_t *set, CPUState *env)
{
fprintf(stderr, "setup_rt_frame: not implemented\n");
}
long do_sigreturn(CPUState *env)
{
fprintf(stderr, "do_sigreturn: not implemented\n");
return -ENOSYS;
}
long do_rt_sigreturn(CPUState *env)
{
fprintf(stderr, "do_rt_sigreturn: not implemented\n");
return -ENOSYS;
}
#endif
void process_pending_signals(void *cpu_env)
{
int sig;
target_ulong handler;
sigset_t set, old_set;
target_sigset_t target_old_set;
struct emulated_sigaction *k;
struct sigqueue *q;
if (!signal_pending)
return;
k = sigact_table;
for(sig = 1; sig <= TARGET_NSIG; sig++) {
if (k->pending)
goto handle_signal;
k++;
}
/* if no signal is pending, just return */
signal_pending = 0;
return;
handle_signal:
#ifdef DEBUG_SIGNAL
fprintf(stderr, "qemu: process signal %d\n", sig);
#endif
/* dequeue signal */
q = k->first;
k->first = q->next;
if (!k->first)
k->pending = 0;
handler = k->sa._sa_handler;
if (handler == TARGET_SIG_DFL) {
/* default handler : ignore some signal. The other are fatal */
if (sig != TARGET_SIGCHLD &&
sig != TARGET_SIGURG &&
sig != TARGET_SIGWINCH) {
force_sig(sig);
}
} else if (handler == TARGET_SIG_IGN) {
/* ignore sig */
} else if (handler == TARGET_SIG_ERR) {
force_sig(sig);
} else {
/* compute the blocked signals during the handler execution */
target_to_host_sigset(&set, &k->sa.sa_mask);
/* SA_NODEFER indicates that the current signal should not be
blocked during the handler */
if (!(k->sa.sa_flags & TARGET_SA_NODEFER))
sigaddset(&set, target_to_host_signal(sig));
/* block signals in the handler using Linux */
sigprocmask(SIG_BLOCK, &set, &old_set);
/* save the previous blocked signal state to restore it at the
end of the signal execution (see do_sigreturn) */
host_to_target_sigset(&target_old_set, &old_set);
/* if the CPU is in VM86 mode, we restore the 32 bit values */
#ifdef TARGET_I386
{
CPUX86State *env = cpu_env;
if (env->eflags & VM_MASK)
save_v86_state(env);
}
#endif
/* prepare the stack frame of the virtual CPU */
if (k->sa.sa_flags & TARGET_SA_SIGINFO)
setup_rt_frame(sig, k, &q->info, &target_old_set, cpu_env);
else
setup_frame(sig, k, &target_old_set, cpu_env);
if (k->sa.sa_flags & TARGET_SA_RESETHAND)
k->sa._sa_handler = TARGET_SIG_DFL;
}
if (q != &k->info)
free_sigqueue(q);
}
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