| /* | 
 |  *  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 "gdbstub/user.h" | 
 | #include "exec/page-protection.h" | 
 | #include "hw/core/tcg-cpu-ops.h" | 
 |  | 
 | #include <sys/ucontext.h> | 
 | #include <sys/resource.h> | 
 |  | 
 | #include "qemu.h" | 
 | #include "user-internals.h" | 
 | #include "strace.h" | 
 | #include "loader.h" | 
 | #include "trace.h" | 
 | #include "signal-common.h" | 
 | #include "host-signal.h" | 
 | #include "user/safe-syscall.h" | 
 | #include "tcg/tcg.h" | 
 |  | 
 | /* target_siginfo_t must fit in gdbstub's siginfo save area. */ | 
 | QEMU_BUILD_BUG_ON(sizeof(target_siginfo_t) > MAX_SIGINFO_LENGTH); | 
 |  | 
 | static struct target_sigaction sigact_table[TARGET_NSIG]; | 
 |  | 
 | static void host_signal_handler(int host_signum, siginfo_t *info, | 
 |                                 void *puc); | 
 |  | 
 | /* Fallback addresses into sigtramp page. */ | 
 | abi_ulong default_sigreturn; | 
 | abi_ulong default_rt_sigreturn; | 
 |  | 
 | /* | 
 |  * System includes define _NSIG as SIGRTMAX + 1, but qemu (like the kernel) | 
 |  * defines TARGET_NSIG as TARGET_SIGRTMAX and the first signal is 1. | 
 |  * Signal number 0 is reserved for use as kill(pid, 0), to test whether | 
 |  * a process exists without sending it a signal. | 
 |  */ | 
 | #ifdef __SIGRTMAX | 
 | QEMU_BUILD_BUG_ON(__SIGRTMAX + 1 != _NSIG); | 
 | #endif | 
 | static uint8_t host_to_target_signal_table[_NSIG] = { | 
 | #define MAKE_SIG_ENTRY(sig)     [sig] = TARGET_##sig, | 
 |         MAKE_SIGNAL_LIST | 
 | #undef MAKE_SIG_ENTRY | 
 | }; | 
 |  | 
 | static uint8_t target_to_host_signal_table[TARGET_NSIG + 1]; | 
 |  | 
 | /* valid sig is between 1 and _NSIG - 1 */ | 
 | int host_to_target_signal(int sig) | 
 | { | 
 |     if (sig < 1) { | 
 |         return sig; | 
 |     } | 
 |     if (sig >= _NSIG) { | 
 |         return TARGET_NSIG + 1; | 
 |     } | 
 |     return host_to_target_signal_table[sig]; | 
 | } | 
 |  | 
 | /* valid sig is between 1 and TARGET_NSIG */ | 
 | int target_to_host_signal(int sig) | 
 | { | 
 |     if (sig < 1) { | 
 |         return sig; | 
 |     } | 
 |     if (sig > TARGET_NSIG) { | 
 |         return _NSIG; | 
 |     } | 
 |     return target_to_host_signal_table[sig]; | 
 | } | 
 |  | 
 | 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); | 
 | } | 
 |  | 
 | void host_to_target_sigset_internal(target_sigset_t *d, | 
 |                                     const sigset_t *s) | 
 | { | 
 |     int host_sig, target_sig; | 
 |     target_sigemptyset(d); | 
 |     for (host_sig = 1; host_sig < _NSIG; host_sig++) { | 
 |         target_sig = host_to_target_signal(host_sig); | 
 |         if (target_sig < 1 || target_sig > TARGET_NSIG) { | 
 |             continue; | 
 |         } | 
 |         if (sigismember(s, host_sig)) { | 
 |             target_sigaddset(d, target_sig); | 
 |         } | 
 |     } | 
 | } | 
 |  | 
 | 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]); | 
 | } | 
 |  | 
 | void target_to_host_sigset_internal(sigset_t *d, | 
 |                                     const target_sigset_t *s) | 
 | { | 
 |     int host_sig, target_sig; | 
 |     sigemptyset(d); | 
 |     for (target_sig = 1; target_sig <= TARGET_NSIG; target_sig++) { | 
 |         host_sig = target_to_host_signal(target_sig); | 
 |         if (host_sig < 1 || host_sig >= _NSIG) { | 
 |             continue; | 
 |         } | 
 |         if (target_sigismember(s, target_sig)) { | 
 |             sigaddset(d, host_sig); | 
 |         } | 
 |     } | 
 | } | 
 |  | 
 | 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 = get_task_state(thread_cpu); | 
 |     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 qatomic_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 -QEMU_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 = get_task_state(thread_cpu); | 
 |  | 
 |     if (oldset) { | 
 |         *oldset = ts->signal_mask; | 
 |     } | 
 |  | 
 |     if (set) { | 
 |         int i; | 
 |  | 
 |         if (block_signals()) { | 
 |             return -QEMU_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; | 
 | } | 
 |  | 
 | /* Just set the guest's signal mask to the specified value; the | 
 |  * caller is assumed to have called block_signals() already. | 
 |  */ | 
 | void set_sigmask(const sigset_t *set) | 
 | { | 
 |     TaskState *ts = get_task_state(thread_cpu); | 
 |  | 
 |     ts->signal_mask = *set; | 
 | } | 
 |  | 
 | /* sigaltstack management */ | 
 |  | 
 | int on_sig_stack(unsigned long sp) | 
 | { | 
 |     TaskState *ts = get_task_state(thread_cpu); | 
 |  | 
 |     return (sp - ts->sigaltstack_used.ss_sp | 
 |             < ts->sigaltstack_used.ss_size); | 
 | } | 
 |  | 
 | int sas_ss_flags(unsigned long sp) | 
 | { | 
 |     TaskState *ts = get_task_state(thread_cpu); | 
 |  | 
 |     return (ts->sigaltstack_used.ss_size == 0 ? SS_DISABLE | 
 |             : on_sig_stack(sp) ? SS_ONSTACK : 0); | 
 | } | 
 |  | 
 | abi_ulong target_sigsp(abi_ulong sp, struct target_sigaction *ka) | 
 | { | 
 |     /* | 
 |      * This is the X/Open sanctioned signal stack switching. | 
 |      */ | 
 |     TaskState *ts = get_task_state(thread_cpu); | 
 |  | 
 |     if ((ka->sa_flags & TARGET_SA_ONSTACK) && !sas_ss_flags(sp)) { | 
 |         return ts->sigaltstack_used.ss_sp + ts->sigaltstack_used.ss_size; | 
 |     } | 
 |     return sp; | 
 | } | 
 |  | 
 | void target_save_altstack(target_stack_t *uss, CPUArchState *env) | 
 | { | 
 |     TaskState *ts = get_task_state(thread_cpu); | 
 |  | 
 |     __put_user(ts->sigaltstack_used.ss_sp, &uss->ss_sp); | 
 |     __put_user(sas_ss_flags(get_sp_from_cpustate(env)), &uss->ss_flags); | 
 |     __put_user(ts->sigaltstack_used.ss_size, &uss->ss_size); | 
 | } | 
 |  | 
 | abi_long target_restore_altstack(target_stack_t *uss, CPUArchState *env) | 
 | { | 
 |     TaskState *ts = get_task_state(thread_cpu); | 
 |     size_t minstacksize = TARGET_MINSIGSTKSZ; | 
 |     target_stack_t ss; | 
 |  | 
 | #if defined(TARGET_PPC64) | 
 |     /* ELF V2 for PPC64 has a 4K minimum stack size for signal handlers */ | 
 |     struct image_info *image = ts->info; | 
 |     if (get_ppc64_abi(image) > 1) { | 
 |         minstacksize = 4096; | 
 |     } | 
 | #endif | 
 |  | 
 |     __get_user(ss.ss_sp, &uss->ss_sp); | 
 |     __get_user(ss.ss_size, &uss->ss_size); | 
 |     __get_user(ss.ss_flags, &uss->ss_flags); | 
 |  | 
 |     if (on_sig_stack(get_sp_from_cpustate(env))) { | 
 |         return -TARGET_EPERM; | 
 |     } | 
 |  | 
 |     switch (ss.ss_flags) { | 
 |     default: | 
 |         return -TARGET_EINVAL; | 
 |  | 
 |     case TARGET_SS_DISABLE: | 
 |         ss.ss_size = 0; | 
 |         ss.ss_sp = 0; | 
 |         break; | 
 |  | 
 |     case TARGET_SS_ONSTACK: | 
 |     case 0: | 
 |         if (ss.ss_size < minstacksize) { | 
 |             return -TARGET_ENOMEM; | 
 |         } | 
 |         break; | 
 |     } | 
 |  | 
 |     ts->sigaltstack_used.ss_sp = ss.ss_sp; | 
 |     ts->sigaltstack_used.ss_size = ss.ss_size; | 
 |     return 0; | 
 | } | 
 |  | 
 | /* 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; | 
 |             if (si_code == CLD_EXITED) | 
 |                 tinfo->_sifields._sigchld._status = info->si_status; | 
 |             else | 
 |                 tinfo->_sifields._sigchld._status | 
 |                     = host_to_target_signal(info->si_status & 0x7f) | 
 |                         | (info->si_status & ~0x7f); | 
 |             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; | 
 | } | 
 |  | 
 | /* 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); | 
 |     } | 
 | } | 
 |  | 
 | static void signal_table_init(void) | 
 | { | 
 |     int hsig, tsig, count; | 
 |  | 
 |     /* | 
 |      * Signals are supported starting from TARGET_SIGRTMIN and going up | 
 |      * until we run out of host realtime signals.  Glibc uses the lower 2 | 
 |      * RT signals and (hopefully) nobody uses the upper ones. | 
 |      * This is why SIGRTMIN (34) is generally greater than __SIGRTMIN (32). | 
 |      * To fix this properly we would need to do manual signal delivery | 
 |      * multiplexed over a single host signal. | 
 |      * Attempts for configure "missing" signals via sigaction will be | 
 |      * silently ignored. | 
 |      * | 
 |      * Remap the target SIGABRT, so that we can distinguish host abort | 
 |      * from guest abort.  When the guest registers a signal handler or | 
 |      * calls raise(SIGABRT), the host will raise SIG_RTn.  If the guest | 
 |      * arrives at dump_core_and_abort(), we will map back to host SIGABRT | 
 |      * so that the parent (native or emulated) sees the correct signal. | 
 |      * Finally, also map host to guest SIGABRT so that the emulated | 
 |      * parent sees the correct mapping from wait status. | 
 |      */ | 
 |  | 
 |     hsig = SIGRTMIN; | 
 |     host_to_target_signal_table[SIGABRT] = 0; | 
 |     host_to_target_signal_table[hsig++] = TARGET_SIGABRT; | 
 |  | 
 |     for (tsig = TARGET_SIGRTMIN; | 
 |          hsig <= SIGRTMAX && tsig <= TARGET_NSIG; | 
 |          hsig++, tsig++) { | 
 |         host_to_target_signal_table[hsig] = tsig; | 
 |     } | 
 |  | 
 |     /* Invert the mapping that has already been assigned. */ | 
 |     for (hsig = 1; hsig < _NSIG; hsig++) { | 
 |         tsig = host_to_target_signal_table[hsig]; | 
 |         if (tsig) { | 
 |             assert(target_to_host_signal_table[tsig] == 0); | 
 |             target_to_host_signal_table[tsig] = hsig; | 
 |         } | 
 |     } | 
 |  | 
 |     host_to_target_signal_table[SIGABRT] = TARGET_SIGABRT; | 
 |  | 
 |     /* Map everything else out-of-bounds. */ | 
 |     for (hsig = 1; hsig < _NSIG; hsig++) { | 
 |         if (host_to_target_signal_table[hsig] == 0) { | 
 |             host_to_target_signal_table[hsig] = TARGET_NSIG + 1; | 
 |         } | 
 |     } | 
 |     for (count = 0, tsig = 1; tsig <= TARGET_NSIG; tsig++) { | 
 |         if (target_to_host_signal_table[tsig] == 0) { | 
 |             target_to_host_signal_table[tsig] = _NSIG; | 
 |             count++; | 
 |         } | 
 |     } | 
 |  | 
 |     trace_signal_table_init(count); | 
 | } | 
 |  | 
 | void signal_init(void) | 
 | { | 
 |     TaskState *ts = get_task_state(thread_cpu); | 
 |     struct sigaction act, oact; | 
 |  | 
 |     /* initialize signal conversion tables */ | 
 |     signal_table_init(); | 
 |  | 
 |     /* Set the signal mask from the host mask. */ | 
 |     sigprocmask(0, 0, &ts->signal_mask); | 
 |  | 
 |     sigfillset(&act.sa_mask); | 
 |     act.sa_flags = SA_SIGINFO; | 
 |     act.sa_sigaction = host_signal_handler; | 
 |  | 
 |     /* | 
 |      * A parent process may configure ignored signals, but all other | 
 |      * signals are default.  For any target signals that have no host | 
 |      * mapping, set to ignore.  For all core_dump_signal, install our | 
 |      * host signal handler so that we may invoke dump_core_and_abort. | 
 |      * This includes SIGSEGV and SIGBUS, which are also need our signal | 
 |      * handler for paging and exceptions. | 
 |      */ | 
 |     for (int tsig = 1; tsig <= TARGET_NSIG; tsig++) { | 
 |         int hsig = target_to_host_signal(tsig); | 
 |         abi_ptr thand = TARGET_SIG_IGN; | 
 |  | 
 |         if (hsig >= _NSIG) { | 
 |             continue; | 
 |         } | 
 |  | 
 |         /* As we force remap SIGABRT, cannot probe and install in one step. */ | 
 |         if (tsig == TARGET_SIGABRT) { | 
 |             sigaction(SIGABRT, NULL, &oact); | 
 |             sigaction(hsig, &act, NULL); | 
 |         } else { | 
 |             struct sigaction *iact = core_dump_signal(tsig) ? &act : NULL; | 
 |             sigaction(hsig, iact, &oact); | 
 |         } | 
 |  | 
 |         if (oact.sa_sigaction != (void *)SIG_IGN) { | 
 |             thand = TARGET_SIG_DFL; | 
 |         } | 
 |         sigact_table[tsig - 1]._sa_handler = thand; | 
 |     } | 
 | } | 
 |  | 
 | /* 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(). | 
 |  */ | 
 | void force_sig(int sig) | 
 | { | 
 |     CPUState *cpu = thread_cpu; | 
 |     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(cpu_env(cpu), info.si_signo, QEMU_SI_KILL, &info); | 
 | } | 
 |  | 
 | /* | 
 |  * Force a synchronously taken QEMU_SI_FAULT signal. For QEMU the | 
 |  * 'force' part is handled in process_pending_signals(). | 
 |  */ | 
 | void force_sig_fault(int sig, int code, abi_ulong addr) | 
 | { | 
 |     CPUState *cpu = thread_cpu; | 
 |     target_siginfo_t info = {}; | 
 |  | 
 |     info.si_signo = sig; | 
 |     info.si_errno = 0; | 
 |     info.si_code = code; | 
 |     info._sifields._sigfault._addr = addr; | 
 |     queue_signal(cpu_env(cpu), sig, QEMU_SI_FAULT, &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. | 
 |  */ | 
 | #if !defined(TARGET_RISCV) | 
 | 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 | 
 |  | 
 | void cpu_loop_exit_sigsegv(CPUState *cpu, target_ulong addr, | 
 |                            MMUAccessType access_type, bool maperr, uintptr_t ra) | 
 | { | 
 |     const TCGCPUOps *tcg_ops = CPU_GET_CLASS(cpu)->tcg_ops; | 
 |  | 
 |     if (tcg_ops->record_sigsegv) { | 
 |         tcg_ops->record_sigsegv(cpu, addr, access_type, maperr, ra); | 
 |     } | 
 |  | 
 |     force_sig_fault(TARGET_SIGSEGV, | 
 |                     maperr ? TARGET_SEGV_MAPERR : TARGET_SEGV_ACCERR, | 
 |                     addr); | 
 |     cpu->exception_index = EXCP_INTERRUPT; | 
 |     cpu_loop_exit_restore(cpu, ra); | 
 | } | 
 |  | 
 | void cpu_loop_exit_sigbus(CPUState *cpu, target_ulong addr, | 
 |                           MMUAccessType access_type, uintptr_t ra) | 
 | { | 
 |     const TCGCPUOps *tcg_ops = CPU_GET_CLASS(cpu)->tcg_ops; | 
 |  | 
 |     if (tcg_ops->record_sigbus) { | 
 |         tcg_ops->record_sigbus(cpu, addr, access_type, ra); | 
 |     } | 
 |  | 
 |     force_sig_fault(TARGET_SIGBUS, TARGET_BUS_ADRALN, addr); | 
 |     cpu->exception_index = EXCP_INTERRUPT; | 
 |     cpu_loop_exit_restore(cpu, ra); | 
 | } | 
 |  | 
 | /* abort execution with signal */ | 
 | static G_NORETURN | 
 | void die_with_signal(int host_sig) | 
 | { | 
 |     struct sigaction act = { | 
 |         .sa_handler = SIG_DFL, | 
 |     }; | 
 |  | 
 |     /* | 
 |      * 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 | 
 |      * the signal and we wait for it to arrive. | 
 |      */ | 
 |     sigfillset(&act.sa_mask); | 
 |     sigaction(host_sig, &act, NULL); | 
 |  | 
 |     kill(getpid(), host_sig); | 
 |  | 
 |     /* Make sure the signal isn't masked (reusing the mask inside of act). */ | 
 |     sigdelset(&act.sa_mask, host_sig); | 
 |     sigsuspend(&act.sa_mask); | 
 |  | 
 |     /* unreachable */ | 
 |     _exit(EXIT_FAILURE); | 
 | } | 
 |  | 
 | static G_NORETURN | 
 | void dump_core_and_abort(CPUArchState *env, int target_sig) | 
 | { | 
 |     CPUState *cpu = env_cpu(env); | 
 |     TaskState *ts = get_task_state(cpu); | 
 |     int host_sig, core_dumped = 0; | 
 |  | 
 |     /* On exit, undo the remapping of SIGABRT. */ | 
 |     if (target_sig == TARGET_SIGABRT) { | 
 |         host_sig = SIGABRT; | 
 |     } else { | 
 |         host_sig = target_to_host_signal(target_sig); | 
 |     } | 
 |     trace_user_dump_core_and_abort(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" ); | 
 |     } | 
 |  | 
 |     preexit_cleanup(env, 128 + target_sig); | 
 |     die_with_signal(host_sig); | 
 | } | 
 |  | 
 | /* queue a signal so that it will be send to the virtual CPU as soon | 
 |    as possible */ | 
 | void queue_signal(CPUArchState *env, int sig, int si_type, | 
 |                   target_siginfo_t *info) | 
 | { | 
 |     CPUState *cpu = env_cpu(env); | 
 |     TaskState *ts = get_task_state(cpu); | 
 |  | 
 |     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 */ | 
 |     qatomic_set(&ts->signal_pending, 1); | 
 | } | 
 |  | 
 |  | 
 | /* Adjust the signal context to rewind out of safe-syscall if we're in it */ | 
 | static inline void rewind_if_in_safe_syscall(void *puc) | 
 | { | 
 |     host_sigcontext *uc = (host_sigcontext *)puc; | 
 |     uintptr_t pcreg = host_signal_pc(uc); | 
 |  | 
 |     if (pcreg > (uintptr_t)safe_syscall_start | 
 |         && pcreg < (uintptr_t)safe_syscall_end) { | 
 |         host_signal_set_pc(uc, (uintptr_t)safe_syscall_start); | 
 |     } | 
 | } | 
 |  | 
 | static G_NORETURN | 
 | void die_from_signal(siginfo_t *info) | 
 | { | 
 |     char sigbuf[4], codebuf[12]; | 
 |     const char *sig, *code = NULL; | 
 |  | 
 |     switch (info->si_signo) { | 
 |     case SIGSEGV: | 
 |         sig = "SEGV"; | 
 |         switch (info->si_code) { | 
 |         case SEGV_MAPERR: | 
 |             code = "MAPERR"; | 
 |             break; | 
 |         case SEGV_ACCERR: | 
 |             code = "ACCERR"; | 
 |             break; | 
 |         } | 
 |         break; | 
 |     case SIGBUS: | 
 |         sig = "BUS"; | 
 |         switch (info->si_code) { | 
 |         case BUS_ADRALN: | 
 |             code = "ADRALN"; | 
 |             break; | 
 |         case BUS_ADRERR: | 
 |             code = "ADRERR"; | 
 |             break; | 
 |         } | 
 |         break; | 
 |     case SIGILL: | 
 |         sig = "ILL"; | 
 |         switch (info->si_code) { | 
 |         case ILL_ILLOPC: | 
 |             code = "ILLOPC"; | 
 |             break; | 
 |         case ILL_ILLOPN: | 
 |             code = "ILLOPN"; | 
 |             break; | 
 |         case ILL_ILLADR: | 
 |             code = "ILLADR"; | 
 |             break; | 
 |         case ILL_PRVOPC: | 
 |             code = "PRVOPC"; | 
 |             break; | 
 |         case ILL_PRVREG: | 
 |             code = "PRVREG"; | 
 |             break; | 
 |         case ILL_COPROC: | 
 |             code = "COPROC"; | 
 |             break; | 
 |         } | 
 |         break; | 
 |     case SIGFPE: | 
 |         sig = "FPE"; | 
 |         switch (info->si_code) { | 
 |         case FPE_INTDIV: | 
 |             code = "INTDIV"; | 
 |             break; | 
 |         case FPE_INTOVF: | 
 |             code = "INTOVF"; | 
 |             break; | 
 |         } | 
 |         break; | 
 |     case SIGTRAP: | 
 |         sig = "TRAP"; | 
 |         break; | 
 |     default: | 
 |         snprintf(sigbuf, sizeof(sigbuf), "%d", info->si_signo); | 
 |         sig = sigbuf; | 
 |         break; | 
 |     } | 
 |     if (code == NULL) { | 
 |         snprintf(codebuf, sizeof(sigbuf), "%d", info->si_code); | 
 |         code = codebuf; | 
 |     } | 
 |  | 
 |     error_report("QEMU internal SIG%s {code=%s, addr=%p}", | 
 |                  sig, code, info->si_addr); | 
 |     die_with_signal(info->si_signo); | 
 | } | 
 |  | 
 | static void host_sigsegv_handler(CPUState *cpu, siginfo_t *info, | 
 |                                  host_sigcontext *uc) | 
 | { | 
 |     uintptr_t host_addr = (uintptr_t)info->si_addr; | 
 |     /* | 
 |      * Convert forcefully to guest address space: addresses outside | 
 |      * reserved_va are still valid to report via SEGV_MAPERR. | 
 |      */ | 
 |     bool is_valid = h2g_valid(host_addr); | 
 |     abi_ptr guest_addr = h2g_nocheck(host_addr); | 
 |     uintptr_t pc = host_signal_pc(uc); | 
 |     bool is_write = host_signal_write(info, uc); | 
 |     MMUAccessType access_type = adjust_signal_pc(&pc, is_write); | 
 |     bool maperr; | 
 |  | 
 |     /* If this was a write to a TB protected page, restart. */ | 
 |     if (is_write | 
 |         && is_valid | 
 |         && info->si_code == SEGV_ACCERR | 
 |         && handle_sigsegv_accerr_write(cpu, host_signal_mask(uc), | 
 |                                        pc, guest_addr)) { | 
 |         return; | 
 |     } | 
 |  | 
 |     /* | 
 |      * If the access was not on behalf of the guest, within the executable | 
 |      * mapping of the generated code buffer, then it is a host bug. | 
 |      */ | 
 |     if (access_type != MMU_INST_FETCH | 
 |         && !in_code_gen_buffer((void *)(pc - tcg_splitwx_diff))) { | 
 |         die_from_signal(info); | 
 |     } | 
 |  | 
 |     maperr = true; | 
 |     if (is_valid && info->si_code == SEGV_ACCERR) { | 
 |         /* | 
 |          * With reserved_va, the whole address space is PROT_NONE, | 
 |          * which means that we may get ACCERR when we want MAPERR. | 
 |          */ | 
 |         if (page_get_flags(guest_addr) & PAGE_VALID) { | 
 |             maperr = false; | 
 |         } else { | 
 |             info->si_code = SEGV_MAPERR; | 
 |         } | 
 |     } | 
 |  | 
 |     sigprocmask(SIG_SETMASK, host_signal_mask(uc), NULL); | 
 |     cpu_loop_exit_sigsegv(cpu, guest_addr, access_type, maperr, pc); | 
 | } | 
 |  | 
 | static uintptr_t host_sigbus_handler(CPUState *cpu, siginfo_t *info, | 
 |                                 host_sigcontext *uc) | 
 | { | 
 |     uintptr_t pc = host_signal_pc(uc); | 
 |     bool is_write = host_signal_write(info, uc); | 
 |     MMUAccessType access_type = adjust_signal_pc(&pc, is_write); | 
 |  | 
 |     /* | 
 |      * If the access was not on behalf of the guest, within the executable | 
 |      * mapping of the generated code buffer, then it is a host bug. | 
 |      */ | 
 |     if (!in_code_gen_buffer((void *)(pc - tcg_splitwx_diff))) { | 
 |         die_from_signal(info); | 
 |     } | 
 |  | 
 |     if (info->si_code == BUS_ADRALN) { | 
 |         uintptr_t host_addr = (uintptr_t)info->si_addr; | 
 |         abi_ptr guest_addr = h2g_nocheck(host_addr); | 
 |  | 
 |         sigprocmask(SIG_SETMASK, host_signal_mask(uc), NULL); | 
 |         cpu_loop_exit_sigbus(cpu, guest_addr, access_type, pc); | 
 |     } | 
 |     return pc; | 
 | } | 
 |  | 
 | static void host_signal_handler(int host_sig, siginfo_t *info, void *puc) | 
 | { | 
 |     CPUState *cpu = thread_cpu; | 
 |     CPUArchState *env = cpu_env(cpu); | 
 |     TaskState *ts = get_task_state(cpu); | 
 |     target_siginfo_t tinfo; | 
 |     host_sigcontext *uc = puc; | 
 |     struct emulated_sigtable *k; | 
 |     int guest_sig; | 
 |     uintptr_t pc = 0; | 
 |     bool sync_sig = false; | 
 |     void *sigmask; | 
 |  | 
 |     /* | 
 |      * Non-spoofed SIGSEGV and SIGBUS are synchronous, and need special | 
 |      * handling wrt signal blocking and unwinding.  Non-spoofed SIGILL, | 
 |      * SIGFPE, SIGTRAP are always host bugs. | 
 |      */ | 
 |     if (info->si_code > 0) { | 
 |         switch (host_sig) { | 
 |         case SIGSEGV: | 
 |             /* Only returns on handle_sigsegv_accerr_write success. */ | 
 |             host_sigsegv_handler(cpu, info, uc); | 
 |             return; | 
 |         case SIGBUS: | 
 |             pc = host_sigbus_handler(cpu, info, uc); | 
 |             sync_sig = true; | 
 |             break; | 
 |         case SIGILL: | 
 |         case SIGFPE: | 
 |         case SIGTRAP: | 
 |             die_from_signal(info); | 
 |         } | 
 |     } | 
 |  | 
 |     /* get target signal number */ | 
 |     guest_sig = host_to_target_signal(host_sig); | 
 |     if (guest_sig < 1 || guest_sig > TARGET_NSIG) { | 
 |         return; | 
 |     } | 
 |     trace_user_host_signal(env, host_sig, guest_sig); | 
 |  | 
 |     host_to_target_siginfo_noswap(&tinfo, info); | 
 |     k = &ts->sigtab[guest_sig - 1]; | 
 |     k->info = tinfo; | 
 |     k->pending = guest_sig; | 
 |     ts->signal_pending = 1; | 
 |  | 
 |     /* | 
 |      * For synchronous signals, unwind the cpu state to the faulting | 
 |      * insn and then exit back to the main loop so that the signal | 
 |      * is delivered immediately. | 
 |      */ | 
 |     if (sync_sig) { | 
 |         cpu->exception_index = EXCP_INTERRUPT; | 
 |         cpu_loop_exit_restore(cpu, pc); | 
 |     } | 
 |  | 
 |     rewind_if_in_safe_syscall(puc); | 
 |  | 
 |     /* | 
 |      * 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 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. | 
 |      */ | 
 |     sigmask = host_signal_mask(uc); | 
 |     memset(sigmask, 0xff, SIGSET_T_SIZE); | 
 |     sigdelset(sigmask, SIGSEGV); | 
 |     sigdelset(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, | 
 |                         CPUArchState *env) | 
 | { | 
 |     target_stack_t oss, *uoss = NULL; | 
 |     abi_long ret = -TARGET_EFAULT; | 
 |  | 
 |     if (uoss_addr) { | 
 |         /* Verify writability now, but do not alter user memory yet. */ | 
 |         if (!lock_user_struct(VERIFY_WRITE, uoss, uoss_addr, 0)) { | 
 |             goto out; | 
 |         } | 
 |         target_save_altstack(&oss, env); | 
 |     } | 
 |  | 
 |     if (uss_addr) { | 
 |         target_stack_t *uss; | 
 |  | 
 |         if (!lock_user_struct(VERIFY_READ, uss, uss_addr, 1)) { | 
 |             goto out; | 
 |         } | 
 |         ret = target_restore_altstack(uss, env); | 
 |         if (ret) { | 
 |             goto out; | 
 |         } | 
 |     } | 
 |  | 
 |     if (uoss_addr) { | 
 |         memcpy(uoss, &oss, sizeof(oss)); | 
 |         unlock_user_struct(uoss, uoss_addr, 1); | 
 |         uoss = NULL; | 
 |     } | 
 |     ret = 0; | 
 |  | 
 |  out: | 
 |     if (uoss) { | 
 |         unlock_user_struct(uoss, uoss_addr, 0); | 
 |     } | 
 |     return ret; | 
 | } | 
 |  | 
 | /* do_sigaction() return target values and host errnos */ | 
 | int do_sigaction(int sig, const struct target_sigaction *act, | 
 |                  struct target_sigaction *oact, abi_ulong ka_restorer) | 
 | { | 
 |     struct target_sigaction *k; | 
 |     int host_sig; | 
 |     int ret = 0; | 
 |  | 
 |     trace_signal_do_sigaction_guest(sig, TARGET_NSIG); | 
 |  | 
 |     if (sig < 1 || sig > TARGET_NSIG) { | 
 |         return -TARGET_EINVAL; | 
 |     } | 
 |  | 
 |     if (act && (sig == TARGET_SIGKILL || sig == TARGET_SIGSTOP)) { | 
 |         return -TARGET_EINVAL; | 
 |     } | 
 |  | 
 |     if (block_signals()) { | 
 |         return -QEMU_ERESTARTSYS; | 
 |     } | 
 |  | 
 |     k = &sigact_table[sig - 1]; | 
 |     if (oact) { | 
 |         __put_user(k->_sa_handler, &oact->_sa_handler); | 
 |         __put_user(k->sa_flags, &oact->sa_flags); | 
 | #ifdef TARGET_ARCH_HAS_SA_RESTORER | 
 |         __put_user(k->sa_restorer, &oact->sa_restorer); | 
 | #endif | 
 |         /* Not swapped.  */ | 
 |         oact->sa_mask = k->sa_mask; | 
 |     } | 
 |     if (act) { | 
 |         __get_user(k->_sa_handler, &act->_sa_handler); | 
 |         __get_user(k->sa_flags, &act->sa_flags); | 
 | #ifdef TARGET_ARCH_HAS_SA_RESTORER | 
 |         __get_user(k->sa_restorer, &act->sa_restorer); | 
 | #endif | 
 | #ifdef TARGET_ARCH_HAS_KA_RESTORER | 
 |         k->ka_restorer = ka_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); | 
 |         trace_signal_do_sigaction_host(host_sig, TARGET_NSIG); | 
 |         if (host_sig > SIGRTMAX) { | 
 |             /* we don't have enough host signals to map all target signals */ | 
 |             qemu_log_mask(LOG_UNIMP, "Unsupported target signal #%d, ignored\n", | 
 |                           sig); | 
 |             /* | 
 |              * we don't return an error here because some programs try to | 
 |              * register an handler for all possible rt signals even if they | 
 |              * don't need it. | 
 |              * An error here can abort them whereas there can be no problem | 
 |              * to not have the signal available later. | 
 |              * This is the case for golang, | 
 |              *   See https://github.com/golang/go/issues/33746 | 
 |              * So we silently ignore the error. | 
 |              */ | 
 |             return 0; | 
 |         } | 
 |         if (host_sig != SIGSEGV && host_sig != SIGBUS) { | 
 |             struct sigaction act1; | 
 |  | 
 |             sigfillset(&act1.sa_mask); | 
 |             act1.sa_flags = SA_SIGINFO; | 
 |             if (k->_sa_handler == TARGET_SIG_IGN) { | 
 |                 /* | 
 |                  * It is important to update the host kernel signal ignore | 
 |                  * state to avoid getting unexpected interrupted syscalls. | 
 |                  */ | 
 |                 act1.sa_sigaction = (void *)SIG_IGN; | 
 |             } else if (k->_sa_handler == TARGET_SIG_DFL) { | 
 |                 if (core_dump_signal(sig)) { | 
 |                     act1.sa_sigaction = host_signal_handler; | 
 |                 } else { | 
 |                     act1.sa_sigaction = (void *)SIG_DFL; | 
 |                 } | 
 |             } else { | 
 |                 act1.sa_sigaction = host_signal_handler; | 
 |                 if (k->sa_flags & TARGET_SA_RESTART) { | 
 |                     act1.sa_flags |= SA_RESTART; | 
 |                 } | 
 |             } | 
 |             ret = sigaction(host_sig, &act1, NULL); | 
 |         } | 
 |     } | 
 |     return ret; | 
 | } | 
 |  | 
 | static void handle_pending_signal(CPUArchState *cpu_env, int sig, | 
 |                                   struct emulated_sigtable *k) | 
 | { | 
 |     CPUState *cpu = env_cpu(cpu_env); | 
 |     abi_ulong handler; | 
 |     sigset_t set; | 
 |     target_siginfo_t unswapped; | 
 |     target_sigset_t target_old_set; | 
 |     struct target_sigaction *sa; | 
 |     TaskState *ts = get_task_state(cpu); | 
 |  | 
 |     trace_user_handle_signal(cpu_env, sig); | 
 |     /* dequeue signal */ | 
 |     k->pending = 0; | 
 |  | 
 |     /* | 
 |      * Writes out siginfo values byteswapped, accordingly to the target. | 
 |      * It also cleans the si_type from si_code making it correct for | 
 |      * the target.  We must hold on to the original unswapped copy for | 
 |      * strace below, because si_type is still required there. | 
 |      */ | 
 |     if (unlikely(qemu_loglevel_mask(LOG_STRACE))) { | 
 |         unswapped = k->info; | 
 |     } | 
 |     tswap_siginfo(&k->info, &k->info); | 
 |  | 
 |     sig = gdb_handlesig(cpu, sig, NULL, &k->info, sizeof(k->info)); | 
 |     if (!sig) { | 
 |         sa = NULL; | 
 |         handler = TARGET_SIG_IGN; | 
 |     } else { | 
 |         sa = &sigact_table[sig - 1]; | 
 |         handler = sa->_sa_handler; | 
 |     } | 
 |  | 
 |     if (unlikely(qemu_loglevel_mask(LOG_STRACE))) { | 
 |         print_taken_signal(sig, &unswapped); | 
 |     } | 
 |  | 
 |     if (handler == TARGET_SIG_DFL) { | 
 |         /* default handler : ignore some signal. The other are job control or fatal */ | 
 |         if (sig == TARGET_SIGTSTP || sig == TARGET_SIGTTIN || sig == TARGET_SIGTTOU) { | 
 |             kill(getpid(),SIGSTOP); | 
 |         } else if (sig != TARGET_SIGCHLD && | 
 |                    sig != TARGET_SIGURG && | 
 |                    sig != TARGET_SIGWINCH && | 
 |                    sig != TARGET_SIGCONT) { | 
 |             dump_core_and_abort(cpu_env, sig); | 
 |         } | 
 |     } else if (handler == TARGET_SIG_IGN) { | 
 |         /* ignore sig */ | 
 |     } else if (handler == TARGET_SIG_ERR) { | 
 |         dump_core_and_abort(cpu_env, sig); | 
 |     } else { | 
 |         /* compute the blocked signals during the handler execution */ | 
 |         sigset_t *blocked_set; | 
 |  | 
 |         target_to_host_sigset(&set, &sa->sa_mask); | 
 |         /* SA_NODEFER indicates that the current signal should not be | 
 |            blocked during the handler */ | 
 |         if (!(sa->sa_flags & TARGET_SA_NODEFER)) | 
 |             sigaddset(&set, target_to_host_signal(sig)); | 
 |  | 
 |         /* save the previous blocked signal state to restore it at the | 
 |            end of the signal execution (see do_sigreturn) */ | 
 |         host_to_target_sigset_internal(&target_old_set, &ts->signal_mask); | 
 |  | 
 |         /* block signals in the handler */ | 
 |         blocked_set = ts->in_sigsuspend ? | 
 |             &ts->sigsuspend_mask : &ts->signal_mask; | 
 |         sigorset(&ts->signal_mask, blocked_set, &set); | 
 |         ts->in_sigsuspend = 0; | 
 |  | 
 |         /* if the CPU is in VM86 mode, we restore the 32 bit values */ | 
 | #if defined(TARGET_I386) && !defined(TARGET_X86_64) | 
 |         { | 
 |             CPUX86State *env = cpu_env; | 
 |             if (env->eflags & VM_MASK) | 
 |                 save_v86_state(env); | 
 |         } | 
 | #endif | 
 |         /* prepare the stack frame of the virtual CPU */ | 
 | #if defined(TARGET_ARCH_HAS_SETUP_FRAME) | 
 |         if (sa->sa_flags & TARGET_SA_SIGINFO) { | 
 |             setup_rt_frame(sig, sa, &k->info, &target_old_set, cpu_env); | 
 |         } else { | 
 |             setup_frame(sig, sa, &target_old_set, cpu_env); | 
 |         } | 
 | #else | 
 |         /* These targets do not have traditional signals.  */ | 
 |         setup_rt_frame(sig, sa, &k->info, &target_old_set, cpu_env); | 
 | #endif | 
 |         if (sa->sa_flags & TARGET_SA_RESETHAND) { | 
 |             sa->_sa_handler = TARGET_SIG_DFL; | 
 |         } | 
 |     } | 
 | } | 
 |  | 
 | void process_pending_signals(CPUArchState *cpu_env) | 
 | { | 
 |     CPUState *cpu = env_cpu(cpu_env); | 
 |     int sig; | 
 |     TaskState *ts = get_task_state(cpu); | 
 |     sigset_t set; | 
 |     sigset_t *blocked_set; | 
 |  | 
 |     while (qatomic_read(&ts->signal_pending)) { | 
 |         sigfillset(&set); | 
 |         sigprocmask(SIG_SETMASK, &set, 0); | 
 |  | 
 |     restart_scan: | 
 |         sig = ts->sync_signal.pending; | 
 |         if (sig) { | 
 |             /* Synchronous signals are forced, | 
 |              * see force_sig_info() and callers in Linux | 
 |              * Note that not all of our queue_signal() calls in QEMU correspond | 
 |              * to force_sig_info() calls in Linux (some are send_sig_info()). | 
 |              * However it seems like a kernel bug to me to allow the process | 
 |              * to block a synchronous signal since it could then just end up | 
 |              * looping round and round indefinitely. | 
 |              */ | 
 |             if (sigismember(&ts->signal_mask, target_to_host_signal_table[sig]) | 
 |                 || sigact_table[sig - 1]._sa_handler == TARGET_SIG_IGN) { | 
 |                 sigdelset(&ts->signal_mask, target_to_host_signal_table[sig]); | 
 |                 sigact_table[sig - 1]._sa_handler = TARGET_SIG_DFL; | 
 |             } | 
 |  | 
 |             handle_pending_signal(cpu_env, sig, &ts->sync_signal); | 
 |         } | 
 |  | 
 |         for (sig = 1; sig <= TARGET_NSIG; sig++) { | 
 |             blocked_set = ts->in_sigsuspend ? | 
 |                 &ts->sigsuspend_mask : &ts->signal_mask; | 
 |  | 
 |             if (ts->sigtab[sig - 1].pending && | 
 |                 (!sigismember(blocked_set, | 
 |                               target_to_host_signal_table[sig]))) { | 
 |                 handle_pending_signal(cpu_env, sig, &ts->sigtab[sig - 1]); | 
 |                 /* Restart scan from the beginning, as handle_pending_signal | 
 |                  * might have resulted in a new synchronous signal (eg SIGSEGV). | 
 |                  */ | 
 |                 goto restart_scan; | 
 |             } | 
 |         } | 
 |  | 
 |         /* if no signal is pending, unblock signals and recheck (the act | 
 |          * of unblocking might cause us to take another host signal which | 
 |          * will set signal_pending again). | 
 |          */ | 
 |         qatomic_set(&ts->signal_pending, 0); | 
 |         ts->in_sigsuspend = 0; | 
 |         set = ts->signal_mask; | 
 |         sigdelset(&set, SIGSEGV); | 
 |         sigdelset(&set, SIGBUS); | 
 |         sigprocmask(SIG_SETMASK, &set, 0); | 
 |     } | 
 |     ts->in_sigsuspend = 0; | 
 | } | 
 |  | 
 | int process_sigsuspend_mask(sigset_t **pset, target_ulong sigset, | 
 |                             target_ulong sigsize) | 
 | { | 
 |     TaskState *ts = get_task_state(thread_cpu); | 
 |     sigset_t *host_set = &ts->sigsuspend_mask; | 
 |     target_sigset_t *target_sigset; | 
 |  | 
 |     if (sigsize != sizeof(*target_sigset)) { | 
 |         /* Like the kernel, we enforce correct size sigsets */ | 
 |         return -TARGET_EINVAL; | 
 |     } | 
 |  | 
 |     target_sigset = lock_user(VERIFY_READ, sigset, sigsize, 1); | 
 |     if (!target_sigset) { | 
 |         return -TARGET_EFAULT; | 
 |     } | 
 |     target_to_host_sigset(host_set, target_sigset); | 
 |     unlock_user(target_sigset, sigset, 0); | 
 |  | 
 |     *pset = host_set; | 
 |     return 0; | 
 | } |