X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/316670eb35587141e969394ae8537d66b9211e80..4d15aeb193b2c68f1d38666c317f8d3734f5f083:/bsd/kern/kern_sig.c diff --git a/bsd/kern/kern_sig.c b/bsd/kern/kern_sig.c index d656dcaf3..5d38f292e 100644 --- a/bsd/kern/kern_sig.c +++ b/bsd/kern/kern_sig.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 1995-2007 Apple Inc. All rights reserved. + * Copyright (c) 1995-2016 Apple Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * @@ -88,6 +88,7 @@ #include #include #include +#include #include #include @@ -101,17 +102,20 @@ #include #include /* for coredump */ #include /* for APC support */ -#include +#include #include /* extern void *get_bsdtask_info(task_t); */ #include #include #include +#include + #include #include #include #include #include +#include /* * Missing prototypes that Mach should export @@ -122,6 +126,8 @@ extern int thread_enable_fpe(thread_t act, int onoff); extern thread_t port_name_to_thread(mach_port_name_t port_name); extern kern_return_t get_signalact(task_t , thread_t *, int); extern unsigned int get_useraddr(void); +extern boolean_t task_did_exec(task_t task); +extern boolean_t task_is_exec_copy(task_t task); /* * --- @@ -133,10 +139,9 @@ extern void doexception(int exc, mach_exception_code_t code, static void stop(proc_t, proc_t); int cansignal(proc_t, kauth_cred_t, proc_t, int, int); int killpg1(proc_t, int, int, int, int); -int setsigvec(proc_t, thread_t, int, struct __kern_sigaction *, boolean_t in_sigstart); -static void psignal_uthread(thread_t, int); kern_return_t do_bsdexception(int, int, int); void __posix_sem_syscall_return(kern_return_t); +char *proc_name_address(void *p); /* implementations in osfmk/kern/sync_sema.c. We do not want port.h in this scope, so void * them */ kern_return_t semaphore_timedwait_signal_trap_internal(mach_port_name_t, mach_port_name_t, unsigned int, clock_res_t, void (*)(kern_return_t)); @@ -147,14 +152,15 @@ kern_return_t semaphore_wait_trap_internal(mach_port_name_t, void (*)(kern_retur static int filt_sigattach(struct knote *kn); static void filt_sigdetach(struct knote *kn); static int filt_signal(struct knote *kn, long hint); -static void filt_signaltouch(struct knote *kn, struct kevent64_s *kev, - long type); +static int filt_signaltouch(struct knote *kn, struct kevent_internal_s *kev); +static int filt_signalprocess(struct knote *kn, struct filt_process_s *data, struct kevent_internal_s *kev); struct filterops sig_filtops = { .f_attach = filt_sigattach, .f_detach = filt_sigdetach, .f_event = filt_signal, .f_touch = filt_signaltouch, + .f_process = filt_signalprocess, }; /* structures and fns for killpg1 iterartion callback and filters */ @@ -184,9 +190,10 @@ static kern_return_t get_signalthread(proc_t, int, thread_t *); #define PSIG_LOCKED 0x1 #define PSIG_VFORK 0x2 #define PSIG_THREAD 0x4 +#define PSIG_TRY_THREAD 0x8 - -static void psignal_internal(proc_t p, task_t task, thread_t thread, int flavor, int signum); +static os_reason_t build_signal_reason(int signum, const char *procname); +static void psignal_internal(proc_t p, task_t task, thread_t thread, int flavor, int signum, os_reason_t signal_reason); /* * NOTE: Source and target may *NOT* overlap! (target is smaller) @@ -304,6 +311,10 @@ cansignal(proc_t p, kauth_cred_t uc, proc_t q, int signum, int zombie) if (p == q) return(1); + /* you can't send launchd SIGKILL, even if root */ + if (signum == SIGKILL && q == initproc) + return(0); + if (!suser(uc, NULL)) return (1); /* root can always signal */ @@ -348,6 +359,53 @@ cansignal(proc_t p, kauth_cred_t uc, proc_t q, int signum, int zombie) return (0); } +/* + * Some signals can be restricted from being handled, + * forcing the default action for that signal. This behavior applies only to + * non-root (EUID != 0) processes, and is configured with the "sigrestrict=x" + * bootarg: + * + * 0 (default): Disallow use of restricted signals. Trying to register a handler + * returns ENOTSUP, which userspace may use to take special action (e.g. abort). + * 1: As above, but return EINVAL. Restricted signals behave similarly to SIGKILL. + * 2: Usual POSIX semantics. + */ +unsigned sigrestrict_arg = 0; + +#if PLATFORM_WatchOS +static int +sigrestrictmask(void) +{ + if (kauth_getuid() != 0 && sigrestrict_arg != 2) { + return SIGRESTRICTMASK; + } + return 0; +} + +static int +signal_is_restricted(proc_t p, int signum) +{ + if (sigmask(signum) & sigrestrictmask()) { + if (sigrestrict_arg == 0 && + task_get_apptype(p->task) == TASK_APPTYPE_APP_DEFAULT) { + return ENOTSUP; + } else { + return EINVAL; + } + } + return 0; +} + +#else + +static inline int +signal_is_restricted(proc_t p, int signum) +{ + (void)p; + (void)signum; + return 0; +} +#endif /* !PLATFORM_WatchOS */ /* * Returns: 0 Success @@ -374,9 +432,34 @@ sigaction(proc_t p, struct sigaction_args *uap, __unused int32_t *retval) signum = uap->signum; if (signum <= 0 || signum >= NSIG || - signum == SIGKILL || signum == SIGSTOP) + signum == SIGKILL || signum == SIGSTOP) return (EINVAL); + if (uap->nsa) { + if (IS_64BIT_PROCESS(p)) { + struct __user64_sigaction __vec64; + error = copyin(uap->nsa, &__vec64, sizeof(__vec64)); + __sigaction_user64_to_kern(&__vec64, &__vec); + } else { + struct __user32_sigaction __vec32; + error = copyin(uap->nsa, &__vec32, sizeof(__vec32)); + __sigaction_user32_to_kern(&__vec32, &__vec); + } + if (error) + return (error); + __vec.sa_flags &= SA_USERSPACE_MASK; /* Only pass on valid sa_flags */ + + if ((__vec.sa_flags & SA_SIGINFO) || __vec.sa_handler != SIG_DFL) { + if ((error = signal_is_restricted(p, signum))) { + if (error == ENOTSUP) { + printf("%s(%d): denied attempt to register action for signal %d\n", + proc_name_address(p), proc_pid(p), signum); + } + return error; + } + } + } + if (uap->osa) { sa->sa_handler = ps->ps_sigact[signum]; sa->sa_mask = ps->ps_catchmask[signum]; @@ -399,35 +482,21 @@ sigaction(proc_t p, struct sigaction_args *uap, __unused int32_t *retval) if (IS_64BIT_PROCESS(p)) { struct user64_sigaction vec64; - sigaction_kern_to_user64(sa, &vec64); error = copyout(&vec64, uap->osa, sizeof(vec64)); } else { struct user32_sigaction vec32; - sigaction_kern_to_user32(sa, &vec32); error = copyout(&vec32, uap->osa, sizeof(vec32)); } if (error) return (error); } + if (uap->nsa) { - if (IS_64BIT_PROCESS(p)) { - struct __user64_sigaction __vec64; - - error = copyin(uap->nsa, &__vec64, sizeof(__vec64)); - __sigaction_user64_to_kern(&__vec64, &__vec); - } else { - struct __user32_sigaction __vec32; - - error = copyin(uap->nsa, &__vec32, sizeof(__vec32)); - __sigaction_user32_to_kern(&__vec32, &__vec); - } - if (error) - return (error); - __vec.sa_flags &= SA_USERSPACE_MASK; /* Only pass on valid sa_flags */ error = setsigvec(p, current_thread(), signum, &__vec, FALSE); } + return (error); } @@ -573,6 +642,8 @@ setsigvec(proc_t p, __unused thread_t thread, int signum, struct __kern_sigactio struct sigacts *ps = p->p_sigacts; int bit; + assert(signum < NSIG); + if ((signum == SIGKILL || signum == SIGSTOP) && sa->sa_handler != SIG_DFL) return(EINVAL); @@ -923,6 +994,7 @@ __pthread_canceled(__unused proc_t p, return(EINVAL); } +__attribute__((noreturn)) void __posix_sem_syscall_return(kern_return_t kern_result) { @@ -1425,6 +1497,203 @@ kill(proc_t cp, struct kill_args *uap, __unused int32_t *retval) /* NOTREACHED */ } +os_reason_t +build_userspace_exit_reason(uint32_t reason_namespace, uint64_t reason_code, user_addr_t payload, uint32_t payload_size, + user_addr_t reason_string, uint64_t reason_flags) +{ + os_reason_t exit_reason = OS_REASON_NULL; + + int error = 0; + int num_items_to_copy = 0; + uint32_t user_data_to_copy = 0; + char *reason_user_desc = NULL; + size_t reason_user_desc_len = 0; + + exit_reason = os_reason_create(reason_namespace, reason_code); + if (exit_reason == OS_REASON_NULL) { + printf("build_userspace_exit_reason: failed to allocate exit reason\n"); + return exit_reason; + } + + exit_reason->osr_flags |= OS_REASON_FLAG_FROM_USERSPACE; + + /* + * Only apply flags that are allowed to be passed from userspace. + */ + exit_reason->osr_flags |= (reason_flags & OS_REASON_FLAG_MASK_ALLOWED_FROM_USER); + if ((reason_flags & OS_REASON_FLAG_MASK_ALLOWED_FROM_USER) != reason_flags) { + printf("build_userspace_exit_reason: illegal flags passed from userspace (some masked off) 0x%llx, ns: %u, code 0x%llx\n", + reason_flags, reason_namespace, reason_code); + } + + if (!(exit_reason->osr_flags & OS_REASON_FLAG_NO_CRASH_REPORT)) { + exit_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT; + } + + if (payload != USER_ADDR_NULL) { + if (payload_size == 0) { + printf("build_userspace_exit_reason: exit reason with namespace %u, nonzero payload but zero length\n", + reason_namespace); + exit_reason->osr_flags |= OS_REASON_FLAG_BAD_PARAMS; + payload = USER_ADDR_NULL; + } else { + num_items_to_copy++; + + if (payload_size > EXIT_REASON_PAYLOAD_MAX_LEN) { + exit_reason->osr_flags |= OS_REASON_FLAG_PAYLOAD_TRUNCATED; + payload_size = EXIT_REASON_PAYLOAD_MAX_LEN; + } + + user_data_to_copy += payload_size; + } + } + + if (reason_string != USER_ADDR_NULL) { + reason_user_desc = (char *) kalloc(EXIT_REASON_USER_DESC_MAX_LEN); + + if (reason_user_desc != NULL) { + error = copyinstr(reason_string, (void *) reason_user_desc, + EXIT_REASON_USER_DESC_MAX_LEN, &reason_user_desc_len); + + if (error == 0) { + num_items_to_copy++; + user_data_to_copy += reason_user_desc_len; + } else if (error == ENAMETOOLONG) { + num_items_to_copy++; + reason_user_desc[EXIT_REASON_USER_DESC_MAX_LEN - 1] = '\0'; + user_data_to_copy += reason_user_desc_len; + } else { + exit_reason->osr_flags |= OS_REASON_FLAG_FAILED_DATA_COPYIN; + kfree(reason_user_desc, EXIT_REASON_USER_DESC_MAX_LEN); + reason_user_desc = NULL; + reason_user_desc_len = 0; + } + } + } + + if (num_items_to_copy != 0) { + uint32_t reason_buffer_size_estimate = 0; + mach_vm_address_t data_addr = 0; + + reason_buffer_size_estimate = kcdata_estimate_required_buffer_size(num_items_to_copy, user_data_to_copy); + + error = os_reason_alloc_buffer(exit_reason, reason_buffer_size_estimate); + if (error != 0) { + printf("build_userspace_exit_reason: failed to allocate signal reason buffer\n"); + goto out_failed_copyin; + } + + if (reason_user_desc != NULL && reason_user_desc_len != 0) { + if (KERN_SUCCESS == kcdata_get_memory_addr(&exit_reason->osr_kcd_descriptor, + EXIT_REASON_USER_DESC, + reason_user_desc_len, + &data_addr)) { + + kcdata_memcpy(&exit_reason->osr_kcd_descriptor, (mach_vm_address_t) data_addr, + reason_user_desc, reason_user_desc_len); + } else { + printf("build_userspace_exit_reason: failed to allocate space for reason string\n"); + goto out_failed_copyin; + } + } + + if (payload != USER_ADDR_NULL) { + if (KERN_SUCCESS == + kcdata_get_memory_addr(&exit_reason->osr_kcd_descriptor, + EXIT_REASON_USER_PAYLOAD, + payload_size, + &data_addr)) { + error = copyin(payload, (void *) data_addr, payload_size); + if (error) { + printf("build_userspace_exit_reason: failed to copy in payload data with error %d\n", error); + goto out_failed_copyin; + } + } else { + printf("build_userspace_exit_reason: failed to allocate space for payload data\n"); + goto out_failed_copyin; + } + } + } + + if (reason_user_desc != NULL) { + kfree(reason_user_desc, EXIT_REASON_USER_DESC_MAX_LEN); + reason_user_desc = NULL; + reason_user_desc_len = 0; + } + + return exit_reason; + +out_failed_copyin: + + if (reason_user_desc != NULL) { + kfree(reason_user_desc, EXIT_REASON_USER_DESC_MAX_LEN); + reason_user_desc = NULL; + reason_user_desc_len = 0; + } + + exit_reason->osr_flags |= OS_REASON_FLAG_FAILED_DATA_COPYIN; + os_reason_alloc_buffer(exit_reason, 0); + return exit_reason; +} + +static int +terminate_with_payload_internal(struct proc *cur_proc, int target_pid, uint32_t reason_namespace, + uint64_t reason_code, user_addr_t payload, uint32_t payload_size, + user_addr_t reason_string, uint64_t reason_flags) +{ + proc_t target_proc = PROC_NULL; + kauth_cred_t cur_cred = kauth_cred_get(); + + os_reason_t signal_reason = OS_REASON_NULL; + + AUDIT_ARG(pid, target_pid); + if ((target_pid <= 0)) { + return EINVAL; + } + + target_proc = proc_find(target_pid); + if (target_proc == PROC_NULL) { + return ESRCH; + } + + AUDIT_ARG(process, target_proc); + + if (!cansignal(cur_proc, cur_cred, target_proc, SIGKILL, 0)) { + proc_rele(target_proc); + return EPERM; + } + + KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE, + target_proc->p_pid, reason_namespace, + reason_code, 0, 0); + + signal_reason = build_userspace_exit_reason(reason_namespace, reason_code, payload, payload_size, + reason_string, reason_flags); + + if (target_pid == cur_proc->p_pid) { + /* + * psignal_thread_with_reason() will pend a SIGKILL on the specified thread or + * return if the thread and/or task are already terminating. Either way, the + * current thread won't return to userspace. + */ + psignal_thread_with_reason(target_proc, current_thread(), SIGKILL, signal_reason); + } else { + psignal_with_reason(target_proc, SIGKILL, signal_reason); + } + + proc_rele(target_proc); + + return 0; +} + +int +terminate_with_payload(struct proc *cur_proc, struct terminate_with_payload_args *args, + __unused int32_t *retval) +{ + return terminate_with_payload_internal(cur_proc, args->pid, args->reason_namespace, args->reason_code, args->payload, + args->payload_size, args->reason_string, args->reason_flags); +} + static int killpg1_filt(proc_t p, void * arg) { @@ -1544,7 +1813,7 @@ killpg1(proc_t cp, int signum, int pgid, int all, int posix) /* PGRP_DROPREF drops the pgrp refernce */ - pgrp_iterate(pgrp, PGRP_BLOCKITERATE | PGRP_DROPREF, killpg1_callback, &karg, + pgrp_iterate(pgrp, PGRP_DROPREF, killpg1_callback, &karg, killpg1_pgrpfilt, NULL); } error = (nfound ? 0 : (posix ? EPERM : ESRCH)); @@ -1599,7 +1868,7 @@ void pgsignal(struct pgrp *pgrp, int signum, int checkctty) { if (pgrp != PGRP_NULL) { - pgrp_iterate(pgrp, PGRP_BLOCKITERATE, pgsignal_callback, &signum, pgsignal_filt, &checkctty); + pgrp_iterate(pgrp, 0, pgsignal_callback, &signum, pgsignal_filt, &checkctty); } } @@ -1611,7 +1880,7 @@ tty_pgsignal(struct tty *tp, int signum, int checkctty) pg = tty_pgrp(tp); if (pg != PGRP_NULL) { - pgrp_iterate(pg, PGRP_BLOCKITERATE, pgsignal_callback, &signum, pgsignal_filt, &checkctty); + pgrp_iterate(pg, 0, pgsignal_callback, &signum, pgsignal_filt, &checkctty); pg_rele(pg); } } @@ -1619,7 +1888,7 @@ tty_pgsignal(struct tty *tp, int signum, int checkctty) * Send a signal caused by a trap to a specific thread. */ void -threadsignal(thread_t sig_actthread, int signum, mach_exception_code_t code) +threadsignal(thread_t sig_actthread, int signum, mach_exception_code_t code, boolean_t set_exitreason) { struct uthread *uth; struct task * sig_task; @@ -1647,12 +1916,75 @@ threadsignal(thread_t sig_actthread, int signum, mach_exception_code_t code) uth->uu_siglist |= mask; uth->uu_code = code; + + /* Attempt to establish whether the signal will be fatal (mirrors logic in psignal_internal()) */ + if (set_exitreason && ((p->p_lflag & P_LTRACED) || (!(uth->uu_sigwait & mask) + && !(uth->uu_sigmask & mask) && !(p->p_sigcatch & mask))) && + !(mask & stopsigmask) && !(mask & contsigmask)) { + + if (uth->uu_exit_reason == OS_REASON_NULL) { + KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE, + p->p_pid, OS_REASON_SIGNAL, signum, 0, 0); + + os_reason_t signal_reason = build_signal_reason(signum, "exc handler"); + + set_thread_exit_reason(sig_actthread, signal_reason, TRUE); + + /* We dropped/consumed the reference in set_thread_exit_reason() */ + signal_reason = OS_REASON_NULL; + } + } + proc_unlock(p); /* mark on process as well */ signal_setast(sig_actthread); } +void +set_thread_exit_reason(void *th, void *reason, boolean_t proc_locked) +{ + struct uthread *targ_uth = get_bsdthread_info(th); + struct task *targ_task = NULL; + proc_t targ_proc = NULL; + + os_reason_t exit_reason = (os_reason_t)reason; + + if (exit_reason == OS_REASON_NULL) + return; + + if (!proc_locked) { + targ_task = get_threadtask(th); + targ_proc = (proc_t)(get_bsdtask_info(targ_task)); + + proc_lock(targ_proc); + } + + if (targ_uth->uu_exit_reason == OS_REASON_NULL) { + targ_uth->uu_exit_reason = exit_reason; + } else { + /* The caller expects that we drop a reference on the exit reason */ + os_reason_free(exit_reason); + } + + if (!proc_locked) { + assert(targ_proc != NULL); + proc_unlock(targ_proc); + } +} + +/* + * get_signalthread + * + * Picks an appropriate thread from a process to target with a signal. + * + * Called with proc locked. + * Returns thread with BSD ast set. + * + * We attempt to deliver a proc-wide signal to the first thread in the task. + * This allows single threaded applications which use signals to + * be able to be linked with multithreaded libraries. + */ static kern_return_t get_signalthread(proc_t p, int signum, thread_t * thr) { @@ -1661,7 +1993,7 @@ get_signalthread(proc_t p, int signum, thread_t * thr) thread_t sig_thread; struct task * sig_task = p->task; kern_return_t kret; - + *thr = THREAD_NULL; if ((p->p_lflag & P_LINVFORK) && p->p_vforkact) { @@ -1672,20 +2004,17 @@ get_signalthread(proc_t p, int signum, thread_t * thr) return(KERN_SUCCESS); }else return(KERN_FAILURE); - } + } - proc_lock(p); TAILQ_FOREACH(uth, &p->p_uthlist, uu_list) { if(((uth->uu_flag & UT_NO_SIGMASK)== 0) && (((uth->uu_sigmask & mask) == 0) || (uth->uu_sigwait & mask))) { if (check_actforsig(p->task, uth->uu_context.vc_thread, 1) == KERN_SUCCESS) { *thr = uth->uu_context.vc_thread; - proc_unlock(p); return(KERN_SUCCESS); } } } - proc_unlock(p); if (get_signalact(p->task, thr, 1) == KERN_SUCCESS) { return(KERN_SUCCESS); } @@ -1693,11 +2022,71 @@ get_signalthread(proc_t p, int signum, thread_t * thr) return(KERN_FAILURE); } +static os_reason_t +build_signal_reason(int signum, const char *procname) +{ + os_reason_t signal_reason = OS_REASON_NULL; + proc_t sender_proc = current_proc(); + uint32_t reason_buffer_size_estimate = 0, proc_name_length = 0; + const char *default_sender_procname = "unknown"; + mach_vm_address_t data_addr; + int ret; + + signal_reason = os_reason_create(OS_REASON_SIGNAL, signum); + if (signal_reason == OS_REASON_NULL) { + printf("build_signal_reason: unable to allocate signal reason structure.\n"); + return signal_reason; + } + + reason_buffer_size_estimate = kcdata_estimate_required_buffer_size(2, sizeof(sender_proc->p_name) + + sizeof(sender_proc->p_pid)); + + ret = os_reason_alloc_buffer_noblock(signal_reason, reason_buffer_size_estimate); + if (ret != 0) { + printf("build_signal_reason: unable to allocate signal reason buffer.\n"); + return signal_reason; + } + + if (KERN_SUCCESS == kcdata_get_memory_addr(&signal_reason->osr_kcd_descriptor, KCDATA_TYPE_PID, + sizeof(sender_proc->p_pid), &data_addr)) { + kcdata_memcpy(&signal_reason->osr_kcd_descriptor, data_addr, &sender_proc->p_pid, + sizeof(sender_proc->p_pid)); + } else { + printf("build_signal_reason: exceeded space in signal reason buf, unable to log PID\n"); + } + + proc_name_length = sizeof(sender_proc->p_name); + if (KERN_SUCCESS == kcdata_get_memory_addr(&signal_reason->osr_kcd_descriptor, KCDATA_TYPE_PROCNAME, + proc_name_length, &data_addr)) { + if (procname) { + char truncated_procname[proc_name_length]; + strncpy((char *) &truncated_procname, procname, proc_name_length); + truncated_procname[proc_name_length - 1] = '\0'; + + kcdata_memcpy(&signal_reason->osr_kcd_descriptor, data_addr, truncated_procname, + strlen((char *) &truncated_procname)); + } else if (*sender_proc->p_name) { + kcdata_memcpy(&signal_reason->osr_kcd_descriptor, data_addr, &sender_proc->p_name, + sizeof(sender_proc->p_name)); + } else { + kcdata_memcpy(&signal_reason->osr_kcd_descriptor, data_addr, &default_sender_procname, + strlen(default_sender_procname) + 1); + } + } else { + printf("build_signal_reason: exceeded space in signal reason buf, unable to log procname\n"); + } + + return signal_reason; +} + /* * Send the signal to the process. If the signal has an action, the action * is usually performed by the target process rather than the caller; we add * the signal to the set of pending signals for the process. * + * Always drops a reference on a signal_reason if one is provided, whether via + * passing it to a thread or deallocating directly. + * * Exceptions: * o When a stop signal is sent to a sleeping process that takes the * default action, the process is stopped without awakening it. @@ -1707,22 +2096,25 @@ get_signalthread(proc_t p, int signum, thread_t * thr) * Other ignored signals are discarded immediately. */ static void -psignal_internal(proc_t p, task_t task, thread_t thread, int flavor, int signum) +psignal_internal(proc_t p, task_t task, thread_t thread, int flavor, int signum, os_reason_t signal_reason) { int prop; - sig_t action = NULL; - proc_t sig_proc; - thread_t sig_thread; - register task_t sig_task; - int mask; - struct uthread *uth; - kern_return_t kret; - uid_t r_uid; - proc_t pp; - kauth_cred_t my_cred; + user_addr_t action = USER_ADDR_NULL; + proc_t sig_proc; + thread_t sig_thread; + task_t sig_task; + int mask; + struct uthread *uth; + kern_return_t kret; + uid_t r_uid; + proc_t pp; + kauth_cred_t my_cred; + char *launchd_exit_reason_desc = NULL; + boolean_t update_thread_policy = FALSE; if ((u_int)signum >= NSIG || signum == 0) - panic("psignal signal number"); + panic("psignal: bad signal number %d", signum); + mask = sigmask(signum); prop = sigprop[signum]; @@ -1732,6 +2124,22 @@ psignal_internal(proc_t p, task_t task, thread_t thread, int flavor, int signum) } #endif /* SIGNAL_DEBUG */ + /* catch unexpected initproc kills early for easier debuggging */ + if (signum == SIGKILL && p == initproc) { + if (signal_reason == NULL) { + panic_plain("unexpected SIGKILL of %s %s (no reason provided)", + (p->p_name[0] != '\0' ? p->p_name : "initproc"), + ((p->p_csflags & CS_KILLED) ? "(CS_KILLED)" : "")); + } else { + launchd_exit_reason_desc = launchd_exit_reason_get_string_desc(signal_reason); + panic_plain("unexpected SIGKILL of %s %s with reason -- namespace %d code 0x%llx description %." LAUNCHD_PANIC_REASON_STRING_MAXLEN "s", + (p->p_name[0] != '\0' ? p->p_name : "initproc"), + ((p->p_csflags & CS_KILLED) ? "(CS_KILLED)" : ""), + signal_reason->osr_namespace, signal_reason->osr_code, + launchd_exit_reason_desc ? launchd_exit_reason_desc : "none"); + } + } + /* * We will need the task pointer later. Grab it now to * check for a zombie process. Also don't send signals @@ -1745,14 +2153,21 @@ psignal_internal(proc_t p, task_t task, thread_t thread, int flavor, int signum) sig_task = get_threadtask(thread); sig_thread = thread; sig_proc = (proc_t)get_bsdtask_info(sig_task); + } else if (flavor & PSIG_TRY_THREAD) { + assert((thread == current_thread()) && (p == current_proc())); + sig_task = p->task; + sig_thread = thread; + sig_proc = p; } else { sig_task = p->task; - sig_thread = (struct thread *)0; + sig_thread = THREAD_NULL; sig_proc = p; } - if ((sig_task == TASK_NULL) || is_kerneltask(sig_task)) + if ((sig_task == TASK_NULL) || is_kerneltask(sig_task)) { + os_reason_free(signal_reason); return; + } /* * do not send signals to the process that has the thread @@ -1761,9 +2176,11 @@ psignal_internal(proc_t p, task_t task, thread_t thread, int flavor, int signum) * also no need to send a signal to a process that is in the middle * of being torn down. */ - if (ISSET(sig_proc->p_flag, P_REBOOT) || - ISSET(sig_proc->p_lflag, P_LEXIT)) + if (ISSET(sig_proc->p_flag, P_REBOOT) || ISSET(sig_proc->p_lflag, P_LEXIT)) { + DTRACE_PROC3(signal__discard, thread_t, sig_thread, proc_t, sig_proc, int, signum); + os_reason_free(signal_reason); return; + } if( (flavor & (PSIG_VFORK | PSIG_THREAD)) == 0) { proc_knote(sig_proc, NOTE_SIGNAL | signum); @@ -1772,26 +2189,36 @@ psignal_internal(proc_t p, task_t task, thread_t thread, int flavor, int signum) if ((flavor & PSIG_LOCKED)== 0) proc_signalstart(sig_proc, 0); - /* - * Deliver the signal to the first thread in the task. This - * allows single threaded applications which use signals to - * be able to be linked with multithreaded libraries. We have - * an implicit reference to the current thread, but need - * an explicit one otherwise. The thread reference keeps - * the corresponding task data structures around too. This - * reference is released by thread_deallocate. - */ - - + /* Don't send signals to a process that has ignored them. */ if (((flavor & PSIG_VFORK) == 0) && ((sig_proc->p_lflag & P_LTRACED) == 0) && (sig_proc->p_sigignore & mask)) { DTRACE_PROC3(signal__discard, thread_t, sig_thread, proc_t, sig_proc, int, signum); - goto psigout; + goto sigout_unlocked; } + /* + * The proc_lock prevents the targeted thread from being deallocated + * or handling the signal until we're done signaling it. + * + * Once the proc_lock is dropped, we have no guarantee the thread or uthread exists anymore. + * + * XXX: What if the thread goes inactive after the thread passes bsd ast point? + */ + proc_lock(sig_proc); + if (flavor & PSIG_VFORK) { action = SIG_DFL; act_set_astbsd(sig_thread); kret = KERN_SUCCESS; + } else if (flavor & PSIG_TRY_THREAD) { + uth = get_bsdthread_info(sig_thread); + if (((uth->uu_flag & UT_NO_SIGMASK) == 0) && + (((uth->uu_sigmask & mask) == 0) || (uth->uu_sigwait & mask)) && + ((kret = check_actforsig(sig_proc->task, sig_thread, 1)) == KERN_SUCCESS)) { + /* deliver to specified thread */ + } else { + /* deliver to any willing thread */ + kret = get_signalthread(sig_proc, signum, &sig_thread); + } } else if (flavor & PSIG_THREAD) { /* If successful return with ast set */ kret = check_actforsig(sig_task, sig_thread, 1); @@ -1799,14 +2226,13 @@ psignal_internal(proc_t p, task_t task, thread_t thread, int flavor, int signum) /* If successful return with ast set */ kret = get_signalthread(sig_proc, signum, &sig_thread); } + if (kret != KERN_SUCCESS) { -#if SIGNAL_DEBUG - ram_printf(1); -#endif /* SIGNAL_DEBUG */ - goto psigout; + DTRACE_PROC3(signal__discard, thread_t, sig_thread, proc_t, sig_proc, int, signum); + proc_unlock(sig_proc); + goto sigout_unlocked; } - uth = get_bsdthread_info(sig_thread); /* @@ -1825,7 +2251,8 @@ psignal_internal(proc_t p, task_t task, thread_t thread, int flavor, int signum) * action will be SIG_DFL here.) */ if (sig_proc->p_sigignore & mask) - goto psigout; + goto sigout_locked; + if (uth->uu_sigwait & mask) action = KERN_SIG_WAIT; else if (uth->uu_sigmask & mask) @@ -1837,9 +2264,7 @@ psignal_internal(proc_t p, task_t task, thread_t thread, int flavor, int signum) } } - - proc_lock(sig_proc); - + /* TODO: p_nice isn't hooked up to the scheduler... */ if (sig_proc->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) && (sig_proc->p_lflag & P_LTRACED) == 0) sig_proc->p_nice = NZERO; @@ -1855,41 +2280,33 @@ psignal_internal(proc_t p, task_t task, thread_t thread, int flavor, int signum) * is default; don't stop the process below if sleeping, * and don't clear any pending SIGCONT. */ - proc_unlock(sig_proc); pg = proc_pgrp(sig_proc); if (prop & SA_TTYSTOP && pg->pg_jobc == 0 && action == SIG_DFL) { pg_rele(pg); - goto psigout; + goto sigout_locked; } pg_rele(pg); - proc_lock(sig_proc); uth->uu_siglist &= ~contsigmask; } uth->uu_siglist |= mask; - /* - * Repost AST incase sigthread has processed - * ast and missed signal post. - */ - if (action == KERN_SIG_CATCH) - act_set_astbsd(sig_thread); - /* * Defer further processing for signals which are held, * except that stopped processes must be continued by SIGCONT. */ /* vfork will not go thru as action is SIG_DFL */ - if ((action == KERN_SIG_HOLD) && ((prop & SA_CONT) == 0 || sig_proc->p_stat != SSTOP)) { - proc_unlock(sig_proc); - goto psigout; - } + if ((action == KERN_SIG_HOLD) && ((prop & SA_CONT) == 0 || sig_proc->p_stat != SSTOP)) + goto sigout_locked; + /* * SIGKILL priority twiddling moved here from above because * it needs sig_thread. Could merge it into large switch * below if we didn't care about priority for tracing * as SIGKILL's action is always SIG_DFL. + * + * TODO: p_nice isn't hooked up to the scheduler... */ if ((signum == SIGKILL) && (sig_proc->p_nice > NZERO)) { sig_proc->p_nice = NZERO; @@ -1903,11 +2320,10 @@ psignal_internal(proc_t p, task_t task, thread_t thread, int flavor, int signum) if (sig_proc->p_lflag & P_LTRACED) { if (sig_proc->p_stat != SSTOP) goto runlocked; - else { - proc_unlock(sig_proc); - goto psigout; - } + else + goto sigout_locked; } + if ((flavor & PSIG_VFORK) != 0) goto runlocked; @@ -1933,13 +2349,9 @@ psignal_internal(proc_t p, task_t task, thread_t thread, int flavor, int signum) if (prop & SA_CONT) { OSBitOrAtomic(P_CONTINUED, &sig_proc->p_flag); sig_proc->p_contproc = current_proc()->p_pid; - - proc_unlock(sig_proc); - (void) task_resume(sig_task); - goto psigout; + (void) task_resume_internal(sig_task); } - proc_unlock(sig_proc); - goto psigout; + goto sigout_locked; } if (action != SIG_DFL) { @@ -1950,13 +2362,10 @@ psignal_internal(proc_t p, task_t task, thread_t thread, int flavor, int signum) */ if (prop & SA_CONT) { OSBitOrAtomic(P_CONTINUED, &sig_proc->p_flag); - proc_unlock(sig_proc); - (void) task_resume(sig_task); - proc_lock(sig_proc); + (void) task_resume_internal(sig_task); sig_proc->p_stat = SRUN; } else if (sig_proc->p_stat == SSTOP) { - proc_unlock(sig_proc); - goto psigout; + goto sigout_locked; } /* * Fill out siginfo structure information to pass to the @@ -1971,9 +2380,7 @@ psignal_internal(proc_t p, task_t task, thread_t thread, int flavor, int signum) * Note: Avoid the SIGCHLD recursion case! */ if (signum != SIGCHLD) { - proc_unlock(sig_proc); r_uid = kauth_getruid(); - proc_lock(sig_proc); sig_proc->si_pid = current_proc()->p_pid; sig_proc->si_status = W_EXITCODE(signum, 0); @@ -1985,6 +2392,7 @@ psignal_internal(proc_t p, task_t task, thread_t thread, int flavor, int signum) } else { /* Default action - varies */ if (mask & stopsigmask) { + assert(signal_reason == NULL); /* * These are the signals which by default * stop a process. @@ -1993,14 +2401,13 @@ psignal_internal(proc_t p, task_t task, thread_t thread, int flavor, int signum) * stopped from the keyboard. */ if (!(prop & SA_STOP) && sig_proc->p_pptr == initproc) { - proc_unlock(sig_proc); - psignal_locked(sig_proc, SIGKILL); - proc_lock(sig_proc); uth->uu_siglist &= ~mask; proc_unlock(sig_proc); - goto psigout; + /* siglock still locked, proc_lock not locked */ + psignal_locked(sig_proc, SIGKILL); + goto sigout_unlocked; } - + /* * Stop the task * if task hasn't already been stopped by @@ -2039,19 +2446,18 @@ psignal_internal(proc_t p, task_t task, thread_t thread, int flavor, int signum) psignal(pp, SIGCHLD); } - if (pp != PROC_NULL) + if (pp != PROC_NULL) { proc_parentdropref(pp, 0); - } else - proc_unlock(sig_proc); - goto psigout; + } + + goto sigout_unlocked; + } + + goto sigout_locked; } DTRACE_PROC3(signal__send, thread_t, sig_thread, proc_t, p, int, signum); - /* - * enters switch with sig_proc lock held but dropped when - * gets out of switch - */ switch (signum) { /* * Signals ignored by default have been dealt @@ -2076,22 +2482,34 @@ psignal_internal(proc_t p, task_t task, thread_t thread, int flavor, int signum) * We would need to cover this approp down the line. */ act_set_astbsd(sig_thread); - thread_abort(sig_thread); - proc_unlock(sig_proc); + kret = thread_abort(sig_thread); + update_thread_policy = (kret == KERN_SUCCESS); + + if (uth->uu_exit_reason == OS_REASON_NULL) { + if (signal_reason == OS_REASON_NULL) { + KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE, + sig_proc->p_pid, OS_REASON_SIGNAL, signum, 0, 0); + + signal_reason = build_signal_reason(signum, NULL); + } + + os_reason_ref(signal_reason); + set_thread_exit_reason(sig_thread, signal_reason, TRUE); + } - goto psigout; + goto sigout_locked; case SIGCONT: /* * Let the process run. If it's sleeping on an * event, it remains so. */ + assert(signal_reason == NULL); OSBitOrAtomic(P_CONTINUED, &sig_proc->p_flag); sig_proc->p_contproc = sig_proc->p_pid; - proc_unlock(sig_proc); - (void) task_resume(sig_task); - proc_lock(sig_proc); + (void) task_resume_internal(sig_task); + /* * When processing a SIGCONT, we need to check * to see if there are signals pending that @@ -2110,8 +2528,7 @@ psignal_internal(proc_t p, task_t task, thread_t thread, int flavor, int signum) uth->uu_siglist &= ~mask; sig_proc->p_stat = SRUN; - proc_unlock(sig_proc); - goto psigout; + goto sigout_locked; default: /* @@ -2121,9 +2538,22 @@ psignal_internal(proc_t p, task_t task, thread_t thread, int flavor, int signum) */ if (((flavor & (PSIG_VFORK|PSIG_THREAD)) == 0) && (action == SIG_DFL) && (prop & SA_KILL)) { sig_proc->p_stat = SRUN; - proc_unlock(sig_proc); - thread_abort(sig_thread); - goto psigout; + kret = thread_abort(sig_thread); + update_thread_policy = (kret == KERN_SUCCESS); + + if (uth->uu_exit_reason == OS_REASON_NULL) { + if (signal_reason == OS_REASON_NULL) { + KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE, + sig_proc->p_pid, OS_REASON_SIGNAL, signum, 0, 0); + + signal_reason = build_signal_reason(signum, NULL); + } + + os_reason_ref(signal_reason); + set_thread_exit_reason(sig_thread, signal_reason, TRUE); + } + + goto sigout_locked; } /* @@ -2131,8 +2561,7 @@ psignal_internal(proc_t p, task_t task, thread_t thread, int flavor, int signum) * resume it. */ if (sig_proc->p_stat == SSTOP) { - proc_unlock(sig_proc); - goto psigout; + goto sigout_locked; } goto runlocked; } @@ -2146,22 +2575,35 @@ runlocked: */ if (sig_proc->p_stat == SSTOP) { if ((sig_proc->p_lflag & P_LTRACED) != 0 && sig_proc->p_xstat != 0) - uth->uu_siglist |= sigmask(sig_proc->p_xstat); + uth->uu_siglist |= sigmask(sig_proc->p_xstat); + if ((flavor & PSIG_VFORK) != 0) { sig_proc->p_stat = SRUN; } - proc_unlock(sig_proc); } else { /* * setrunnable(p) in BSD and * Wake up the thread if it is interruptible. */ sig_proc->p_stat = SRUN; - proc_unlock(sig_proc); if ((flavor & PSIG_VFORK) == 0) thread_abort_safely(sig_thread); } -psigout: + +sigout_locked: + if (update_thread_policy) { + /* + * Update the thread policy to heading to terminate, increase priority if + * necessary. This needs to be done before we drop the proc lock because the + * thread can take the fatal signal once it's dropped. + */ + proc_set_thread_policy(sig_thread, TASK_POLICY_ATTRIBUTE, TASK_POLICY_TERMINATED, TASK_POLICY_ENABLE); + } + + proc_unlock(sig_proc); + +sigout_unlocked: + os_reason_free(signal_reason); if ((flavor & PSIG_LOCKED)== 0) { proc_signalend(sig_proc, 0); } @@ -2170,27 +2612,58 @@ psigout: void psignal(proc_t p, int signum) { - psignal_internal(p, NULL, NULL, 0, signum); + psignal_internal(p, NULL, NULL, 0, signum, NULL); +} + +void +psignal_with_reason(proc_t p, int signum, struct os_reason *signal_reason) +{ + psignal_internal(p, NULL, NULL, 0, signum, signal_reason); } void psignal_locked(proc_t p, int signum) { - psignal_internal(p, NULL, NULL, PSIG_LOCKED, signum); + psignal_internal(p, NULL, NULL, PSIG_LOCKED, signum, NULL); +} + +void +psignal_vfork_with_reason(proc_t p, task_t new_task, thread_t thread, int signum, struct os_reason *signal_reason) +{ + psignal_internal(p, new_task, thread, PSIG_VFORK, signum, signal_reason); } + void psignal_vfork(proc_t p, task_t new_task, thread_t thread, int signum) { - psignal_internal(p, new_task, thread, PSIG_VFORK, signum); + psignal_internal(p, new_task, thread, PSIG_VFORK, signum, NULL); } -static void +void psignal_uthread(thread_t thread, int signum) { - psignal_internal(PROC_NULL, TASK_NULL, thread, PSIG_THREAD, signum); + psignal_internal(PROC_NULL, TASK_NULL, thread, PSIG_THREAD, signum, NULL); +} + +/* same as psignal(), but prefer delivery to 'thread' if possible */ +void +psignal_try_thread(proc_t p, thread_t thread, int signum) +{ + psignal_internal(p, NULL, thread, PSIG_TRY_THREAD, signum, NULL); +} + +void +psignal_try_thread_with_reason(proc_t p, thread_t thread, int signum, struct os_reason *signal_reason) +{ + psignal_internal(p, TASK_NULL, thread, PSIG_TRY_THREAD, signum, signal_reason); } +void +psignal_thread_with_reason(proc_t p, thread_t thread, int signum, struct os_reason *signal_reason) +{ + psignal_internal(p, TASK_NULL, thread, PSIG_THREAD, signum, signal_reason); +} /* * If the current process has received a signal (should be caught or cause @@ -2218,23 +2691,23 @@ issignal_locked(proc_t p) cur_act = current_thread(); #if SIGNAL_DEBUG - if(rdebug_proc && (p == rdebug_proc)) { - ram_printf(3); - } + if(rdebug_proc && (p == rdebug_proc)) { + ram_printf(3); + } #endif /* SIGNAL_DEBUG */ /* * Try to grab the signal lock. */ if (sig_try_locked(p) <= 0) { - return(0); + return 0; } proc_signalstart(p, 1); ut = get_bsdthread_info(cur_act); - for(;;) { - sigbits = ut->uu_siglist & ~ut->uu_sigmask; + for (;;) { + sigbits = ut->uu_siglist & ~ut->uu_sigmask; if (p->p_lflag & P_LPPWAIT) sigbits &= ~stopsigmask; @@ -2252,25 +2725,25 @@ issignal_locked(proc_t p) * only if P_LTRACED was on when they were posted. */ if (mask & p->p_sigignore && (p->p_lflag & P_LTRACED) == 0) { - ut->uu_siglist &= ~mask; /* take the signal! */ + ut->uu_siglist &= ~mask; continue; } + if (p->p_lflag & P_LTRACED && (p->p_lflag & P_LPPWAIT) == 0) { - task_t task; /* - * If traced, always stop, and stay - * stopped until released by the debugger. + * If traced, deliver the signal to the debugger, and wait to be + * released. */ - /* ptrace debugging */ + task_t task; p->p_xstat = signum; - + if (p->p_lflag & P_LSIGEXC) { p->sigwait = TRUE; p->sigwait_thread = cur_act; p->p_stat = SSTOP; OSBitAndAtomic(~((uint32_t)P_CONTINUED), &p->p_flag); p->p_lflag &= ~P_LWAITED; - ut->uu_siglist &= ~mask; /* clear the old signal */ + ut->uu_siglist &= ~mask; /* clear the current signal from the pending list */ proc_signalend(p, 1); proc_unlock(p); do_bsdexception(EXC_SOFTWARE, EXC_SOFT_SIGNAL, signum); @@ -2297,12 +2770,9 @@ issignal_locked(proc_t p) /* * XXX Have to really stop for debuggers; * XXX stop() doesn't do the right thing. - * XXX Inline the task_suspend because we - * XXX have to diddle Unix state in the - * XXX middle of it. */ task = p->task; - task_suspend(task); + task_suspend_internal(task); proc_lock(p); p->sigwait = TRUE; @@ -2310,7 +2780,7 @@ issignal_locked(proc_t p) p->p_stat = SSTOP; OSBitAndAtomic(~((uint32_t)P_CONTINUED), &p->p_flag); p->p_lflag &= ~P_LWAITED; - ut->uu_siglist &= ~mask; /* clear the old signal */ + ut->uu_siglist &= ~mask; proc_signalend(p, 1); proc_unlock(p); @@ -2333,43 +2803,22 @@ issignal_locked(proc_t p) p->sigwait_thread = NULL; wakeup((caddr_t)&p->sigwait_thread); - /* - * This code is to detect when gdb is killed - * even as the traced program is attached. - * pgsignal would get the SIGKILL to traced program - * That's what we are trying to see (I hope) - */ - if (ut->uu_siglist & sigmask(SIGKILL)) { + if (signum == SIGKILL || ut->uu_siglist & sigmask(SIGKILL)) { /* - * Wait event may still be outstanding; - * clear it, since sig_lock_to_exit will - * wait. + * Deliver a pending sigkill even if it's not the current signal. + * Necessary for PT_KILL, which should not be delivered to the + * debugger, but we can't differentiate it from any other KILL. */ - clear_wait(current_thread(), THREAD_INTERRUPTED); - sig_lock_to_exit(p); - /* - * Since this thread will be resumed - * to allow the current syscall to - * be completed, must save u_qsave - * before calling exit(). (Since exit() - * calls closef() which can trash u_qsave.) - */ - proc_signalend(p, 1); - proc_unlock(p); - KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_FRCEXIT) | DBG_FUNC_NONE, - p->p_pid, W_EXITCODE(0, SIGKILL), 2, 0, 0); - exit1(p, W_EXITCODE(0, SIGKILL), (int *)NULL); - proc_lock(p); - return(0); + signum = SIGKILL; + goto deliver_sig; } - /* - * We may have to quit - */ + /* We may have to quit. */ if (thread_should_abort(current_thread())) { retval = 0; goto out; } + /* * If parent wants us to take the signal, * then it will leave it in p->p_xstat; @@ -2378,6 +2827,7 @@ issignal_locked(proc_t p) signum = p->p_xstat; if (signum == 0) continue; + /* * Put the new signal into p_siglist. If the * signal is being masked, look for other signals. @@ -2395,23 +2845,8 @@ issignal_locked(proc_t p) */ switch ((long)p->p_sigacts->ps_sigact[signum]) { - + case (long)SIG_DFL: - /* - * Don't take default actions on system processes. - */ - if (p->p_ppid == 0) { -#if DIAGNOSTIC - /* - * Are you sure you want to ignore SIGSEGV - * in init? XXX - */ - printf("Process (pid %d) got signal %d\n", - p->p_pid, signum); -#endif - break; /* == ignore */ - } - /* * If there is a pending stop signal to process * with default action, stop here, @@ -2429,13 +2864,12 @@ issignal_locked(proc_t p) prop & SA_TTYSTOP)) { proc_lock(p); pg_rele(pg); - break; /* == ignore */ + break; /* ignore signal */ } pg_rele(pg); if (p->p_stat != SSTOP) { proc_lock(p); p->p_xstat = signum; - p->p_stat = SSTOP; p->p_lflag &= ~P_LWAITED; proc_unlock(p); @@ -2466,16 +2900,11 @@ issignal_locked(proc_t p) * Except for SIGCONT, shouldn't get here. * Default action is to ignore; drop it. */ - break; /* == ignore */ + break; /* ignore signal */ } else { - ut->uu_siglist &= ~mask; /* take the signal! */ - retval = signum; - goto out; + goto deliver_sig; } - /*NOTREACHED*/ - break; - case (long)SIG_IGN: /* * Masking above should prevent us ever trying @@ -2485,23 +2914,27 @@ issignal_locked(proc_t p) if ((prop & SA_CONT) == 0 && (p->p_lflag & P_LTRACED) == 0) printf("issignal\n"); - break; /* == ignore */ + break; /* ignore signal */ default: - /* - * This signal has an action, let - * postsig() process it. - */ - ut->uu_siglist &= ~mask; /* take the signal! */ - retval = signum; - goto out; - } - ut->uu_siglist &= ~mask; /* take the signal! */ + /* This signal has an action - deliver it. */ + goto deliver_sig; } + + /* If we dropped through, the signal was ignored - remove it from pending list. */ + ut->uu_siglist &= ~mask; + + } /* for(;;) */ + /* NOTREACHED */ + +deliver_sig: + ut->uu_siglist &= ~mask; + retval = signum; + out: proc_signalend(p, 1); - return(retval); + return retval; } /* called from _sleep */ @@ -2559,21 +2992,6 @@ CURSIG(proc_t p) switch ((long)p->p_sigacts->ps_sigact[signum]) { case (long)SIG_DFL: - /* - * Don't take default actions on system processes. - */ - if (p->p_ppid == 0) { -#if DIAGNOSTIC - /* - * Are you sure you want to ignore SIGSEGV - * in init? XXX - */ - printf("Process (pid %d) got signal %d\n", - p->p_pid, signum); -#endif - break; /* == ignore */ - } - /* * If there is a pending stop signal to process * with default action, stop here, @@ -2642,7 +3060,7 @@ stop(proc_t p, proc_t parent) wakeup((caddr_t)parent); proc_list_unlock(); } - (void) task_suspend(p->task); /*XXX*/ + (void) task_suspend_internal(p->task); } /* @@ -2693,8 +3111,10 @@ postsig_locked(int signum) p->p_sigacts->ps_sig = signum; proc_signalend(p, 1); proc_unlock(p); - if (coredump(p) == 0) +#if CONFIG_COREDUMP + if (coredump(p, 0, 0) == 0) signum |= WCOREFLAG; +#endif } else { proc_signalend(p, 1); proc_unlock(p); @@ -2724,7 +3144,14 @@ postsig_locked(int signum) KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_FRCEXIT) | DBG_FUNC_NONE, p->p_pid, W_EXITCODE(0, signum), 3, 0, 0); - exit1(p, W_EXITCODE(0, signum), (int *)NULL); + + /* + * exit_with_reason() will consume a reference to the thread's exit reason, so we take another + * reference for the thread. This reference will be destroyed in uthread_cleanup(). + */ + os_reason_ref(ut->uu_exit_reason); + exit_with_reason(p, W_EXITCODE(0, signum), (int *)NULL, TRUE, TRUE, 0, ut->uu_exit_reason); + proc_lock(p); return; } else { @@ -2791,12 +3218,12 @@ filt_sigattach(struct knote *kn) proc_klist_lock(); kn->kn_ptr.p_proc = p; - kn->kn_flags |= EV_CLEAR; /* automatically set */ KNOTE_ATTACH(&p->p_klist, kn); proc_klist_unlock(); + /* edge-triggered events can't have fired before we attached */ return (0); } @@ -2841,27 +3268,54 @@ filt_signal(struct knote *kn, long hint) return (kn->kn_data != 0); } -static void -filt_signaltouch(struct knote *kn, struct kevent64_s *kev, long type) +static int +filt_signaltouch( + struct knote *kn, + struct kevent_internal_s *kev) { +#pragma unused(kev) + + int res; + proc_klist_lock(); - switch (type) { - case EVENT_REGISTER: - kn->kn_sfflags = kev->fflags; - kn->kn_sdata = kev->data; - break; - case EVENT_PROCESS: - *kev = kn->kn_kevent; - if (kn->kn_flags & EV_CLEAR) { - kn->kn_data = 0; - kn->kn_fflags = 0; - } - break; - default: - panic("filt_machporttouch() - invalid type (%ld)", type); - break; + + if ((kn->kn_status & KN_UDATA_SPECIFIC) == 0) + kn->kn_udata = kev->udata; + /* + * No data to save - + * just capture if it is already fired + */ + res = (kn->kn_data > 0); + + proc_klist_unlock(); + + return res; +} + +static int +filt_signalprocess( + struct knote *kn, + __unused struct filt_process_s *data, + struct kevent_internal_s *kev) +{ + proc_klist_lock(); + + if (kn->kn_data == 0) { + proc_klist_unlock(); + return 0; } + + /* + * Snapshot the event data. + * All signal events are EV_CLEAR, so + * add that and clear out the data field. + */ + *kev = kn->kn_kevent; + kev->flags |= EV_CLEAR; + kn->kn_data = 0; + proc_klist_unlock(); + return 1; } void @@ -2876,6 +3330,11 @@ bsd_ast(thread_t thread) if (p == NULL) return; + /* don't run bsd ast on exec copy or exec'ed tasks */ + if (task_did_exec(current_task()) || task_is_exec_copy(current_task())) { + return; + } + if ((p->p_flag & P_OWEUPC) && (p->p_flag & P_PROFIL)) { pc = get_useraddr(); addupc_task(p, pc, 1); @@ -2893,7 +3352,7 @@ bsd_ast(thread_t thread) else task_vtimer_clear(p->task, TASK_VTIMER_USER); - psignal(p, SIGVTALRM); + psignal_try_thread(p, thread, SIGVTALRM); } } @@ -2908,7 +3367,7 @@ bsd_ast(thread_t thread) else task_vtimer_clear(p->task, TASK_VTIMER_PROF); - psignal(p, SIGPROF); + psignal_try_thread(p, thread, SIGPROF); } } @@ -2929,7 +3388,7 @@ bsd_ast(thread_t thread) task_vtimer_clear(p->task, TASK_VTIMER_RLIM); - psignal(p, SIGXCPU); + psignal_try_thread(p, thread, SIGXCPU); } } @@ -2945,7 +3404,7 @@ bsd_ast(thread_t thread) proc_lock(p); p->p_dtrace_stop = 1; proc_unlock(p); - (void)task_suspend(p->task); + (void)task_suspend_internal(p->task); } if (ut->t_dtrace_resumepid) { @@ -2957,7 +3416,7 @@ bsd_ast(thread_t thread) if (resumeproc->p_dtrace_stop) { resumeproc->p_dtrace_stop = 0; proc_unlock(resumeproc); - task_resume(resumeproc->task); + task_resume_internal(resumeproc->task); } else { proc_unlock(resumeproc); @@ -3090,6 +3549,10 @@ proc_signalstart(proc_t p, int locked) { if (!locked) proc_lock(p); + + if(p->p_signalholder == current_thread()) + panic("proc_signalstart: thread attempting to signal a process for which it holds the signal lock"); + p->p_sigwaitcnt++; while ((p->p_lflag & P_LINSIGNAL) == P_LINSIGNAL) msleep(&p->p_sigmask, &p->p_mlock, 0, "proc_signstart", NULL);