| /* | |
| * 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 "qemu/cutils.h" | |
| #include "gdbstub/user.h" | |
| #include "exec/page-protection.h" | |
| #include "accel/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/cpu_loop.h" | |
| #include "user/page-protection.h" | |
| #include "user/safe-syscall.h" | |
| #include "user/signal.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; | |
| abi_ulong vdso_sigreturn_region_start; | |
| abi_ulong vdso_sigreturn_region_end; | |
| /* | |
| * 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); | |
| } | |
| } | |
| int host_interrupt_signal; | |
| static void signal_table_init(const char *rtsig_map) | |
| { | |
| int hsig, tsig, count; | |
| if (rtsig_map) { | |
| /* | |
| * Map host RT signals to target RT signals according to the | |
| * user-provided specification. | |
| */ | |
| const char *s = rtsig_map; | |
| while (true) { | |
| int i; | |
| if (qemu_strtoi(s, &s, 10, &tsig) || *s++ != ' ') { | |
| fprintf(stderr, "Malformed target signal in QEMU_RTSIG_MAP\n"); | |
| exit(EXIT_FAILURE); | |
| } | |
| if (qemu_strtoi(s, &s, 10, &hsig) || *s++ != ' ') { | |
| fprintf(stderr, "Malformed host signal in QEMU_RTSIG_MAP\n"); | |
| exit(EXIT_FAILURE); | |
| } | |
| if (qemu_strtoi(s, &s, 10, &count) || (*s && *s != ',')) { | |
| fprintf(stderr, "Malformed signal count in QEMU_RTSIG_MAP\n"); | |
| exit(EXIT_FAILURE); | |
| } | |
| for (i = 0; i < count; i++, tsig++, hsig++) { | |
| if (tsig < TARGET_SIGRTMIN || tsig > TARGET_NSIG) { | |
| fprintf(stderr, "%d is not a target rt signal\n", tsig); | |
| exit(EXIT_FAILURE); | |
| } | |
| if (hsig < SIGRTMIN || hsig > SIGRTMAX) { | |
| fprintf(stderr, "%d is not a host rt signal\n", hsig); | |
| exit(EXIT_FAILURE); | |
| } | |
| if (host_to_target_signal_table[hsig]) { | |
| fprintf(stderr, "%d already maps %d\n", | |
| hsig, host_to_target_signal_table[hsig]); | |
| exit(EXIT_FAILURE); | |
| } | |
| host_to_target_signal_table[hsig] = tsig; | |
| } | |
| if (*s) { | |
| s++; | |
| } else { | |
| break; | |
| } | |
| } | |
| } else { | |
| /* | |
| * Default host-to-target RT signal mapping. | |
| * | |
| * 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. | |
| * | |
| * Reserve two signals for internal usage (see below). | |
| */ | |
| hsig = SIGRTMIN + 2; | |
| for (tsig = TARGET_SIGRTMIN; | |
| hsig <= SIGRTMAX && tsig <= TARGET_NSIG; | |
| hsig++, tsig++) { | |
| host_to_target_signal_table[hsig] = tsig; | |
| } | |
| } | |
| /* | |
| * 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. | |
| */ | |
| host_to_target_signal_table[SIGABRT] = 0; | |
| for (hsig = SIGRTMIN; hsig <= SIGRTMAX; hsig++) { | |
| if (!host_to_target_signal_table[hsig]) { | |
| if (host_interrupt_signal) { | |
| host_to_target_signal_table[hsig] = TARGET_SIGABRT; | |
| break; | |
| } else { | |
| host_interrupt_signal = hsig; | |
| } | |
| } | |
| } | |
| if (hsig > SIGRTMAX) { | |
| fprintf(stderr, | |
| "No rt signals left for interrupt and SIGABRT mapping\n"); | |
| exit(EXIT_FAILURE); | |
| } | |
| /* Invert the mapping that has already been assigned. */ | |
| for (hsig = 1; hsig < _NSIG; hsig++) { | |
| tsig = host_to_target_signal_table[hsig]; | |
| if (tsig) { | |
| if (target_to_host_signal_table[tsig]) { | |
| fprintf(stderr, "%d is already mapped to %d\n", | |
| tsig, target_to_host_signal_table[tsig]); | |
| exit(EXIT_FAILURE); | |
| } | |
| 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(const char *rtsig_map) | |
| { | |
| TaskState *ts = get_task_state(thread_cpu); | |
| struct sigaction act, oact; | |
| /* initialize signal conversion tables */ | |
| signal_table_init(rtsig_map); | |
| /* 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; | |
| } | |
| sigaction(host_interrupt_signal, &act, NULL); | |
| } | |
| /* 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, vaddr addr, | |
| MMUAccessType access_type, bool maperr, uintptr_t ra) | |
| { | |
| const TCGCPUOps *tcg_ops = cpu->cc->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, vaddr addr, | |
| MMUAccessType access_type, uintptr_t ra) | |
| { | |
| const TCGCPUOps *tcg_ops = cpu->cc->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); | |
| qemu_log_mask(LOG_GUEST_ERROR, "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; | |
| if (host_sig == host_interrupt_signal) { | |
| ts->signal_pending = 1; | |
| cpu_exit(thread_cpu); | |
| return; | |
| } | |
| /* | |
| * 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); | |
| /* | |
| * Restart scan from the beginning, as handle_pending_signal | |
| * might have resulted in a new synchronous signal (eg SIGSEGV). | |
| */ | |
| goto restart_scan; | |
| } | |
| 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, explained above. */ | |
| 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; | |
| } |