/* * 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 #include #include #include #include #include #include #include #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; } #define __put_user(x,ptr)\ ({\ int size = sizeof(*ptr);\ switch(size) {\ case 1:\ stb(ptr, (typeof(*ptr))(x));\ break;\ case 2:\ stw(ptr, (typeof(*ptr))(x));\ break;\ case 4:\ stl(ptr, (typeof(*ptr))(x));\ break;\ case 8:\ stq(ptr, (typeof(*ptr))(x));\ break;\ default:\ abort();\ }\ 0;\ }) #define __get_user(x, ptr) \ ({\ int size = sizeof(*ptr);\ switch(size) {\ case 1:\ x = (typeof(*ptr))ldub(ptr);\ break;\ case 2:\ x = (typeof(*ptr))lduw(ptr);\ break;\ case 4:\ x = (typeof(*ptr))ldl(ptr);\ break;\ case 8:\ x = (typeof(*ptr))ldq(ptr);\ break;\ default:\ abort();\ }\ 0;\ }) #define __copy_to_user(dst, src, size)\ ({\ memcpy(dst, src, size);\ 0;\ }) #define __copy_from_user(dst, src, size)\ ({\ memcpy(dst, src, size);\ 0;\ }) #define __clear_user(dst, size)\ ({\ memset(dst, 0, size);\ 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 0 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) goto give_sigsegv; #endif 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 0 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) goto give_sigsegv; #endif 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 0 if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame))) return 1; #endif __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 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); }