X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/21362eb3e66fd2c787aee132bce100a44d71a99c..527f99514973766e9c0382a4d8550dfb00f54939:/bsd/kern/kern_sig.c diff --git a/bsd/kern/kern_sig.c b/bsd/kern/kern_sig.c index 1492505f3..d390ded07 100644 --- a/bsd/kern/kern_sig.c +++ b/bsd/kern/kern_sig.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2000-2001 Apple Computer, Inc. All rights reserved. + * Copyright (c) 1995-2016 Apple Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * @@ -25,7 +25,6 @@ * * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ -/* Copyright (c) 1995-1998 Apple Computer, Inc. All Rights Reserved */ /* * Copyright (c) 1982, 1986, 1989, 1991, 1993 * The Regents of the University of California. All rights reserved. @@ -65,6 +64,12 @@ * * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 */ +/* + * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce + * support for mandatory and extensible security protections. This notice + * is included in support of clause 2.2 (b) of the Apple Public License, + * Version 2.0. + */ #define SIGPROP /* include signal properties table */ #include @@ -79,34 +84,41 @@ #include #include #include -#if KTRACE -#include -#endif #include #include #include #include +#include #include #include -#include - -#include +#include #include #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 +#include + +#if CONFIG_MACF +#include +#endif /* * Missing prototypes that Mach should export @@ -114,50 +126,93 @@ * +++ */ extern int thread_enable_fpe(thread_t act, int onoff); -extern void unix_syscall_return(int error); extern thread_t port_name_to_thread(mach_port_name_t port_name); -extern kern_return_t check_actforsig(task_t task, thread_t thread, int setast); extern kern_return_t get_signalact(task_t , thread_t *, int); -extern boolean_t thread_should_abort(thread_t); 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); /* * --- */ -extern void doexception(int exc, int code, int sub); +extern void doexception(int exc, mach_exception_code_t code, + mach_exception_subcode_t sub); -void stop(struct proc *p); -int cansignal(struct proc *, kauth_cred_t, struct proc *, int); -int killpg1(struct proc *, int, int, int); -void sigexit_locked(struct proc *, int); -int setsigvec(struct proc *, int, struct __user_sigaction *); -void exit1(struct proc *, int, int *); -void psignal_uthread(thread_t, int); +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); 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(void *, void *,time_t, int32_t, void (*)(int)); -kern_return_t semaphore_timedwait_trap_internal(void *, time_t, int32_t, void (*)(int)); -kern_return_t semaphore_wait_signal_trap_internal(void *, void *, void (*)(int)); -kern_return_t semaphore_wait_trap_internal(void *, void (*)(int)); +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)); +kern_return_t semaphore_timedwait_trap_internal(mach_port_name_t, unsigned int, clock_res_t, void (*)(kern_return_t)); +kern_return_t semaphore_wait_signal_trap_internal(mach_port_name_t, mach_port_name_t, void (*)(kern_return_t)); +kern_return_t semaphore_wait_trap_internal(mach_port_name_t, void (*)(kern_return_t)); -static int filt_sigattach(struct knote *kn); +static int filt_sigattach(struct knote *kn, struct kevent_internal_s *kev); static void filt_sigdetach(struct knote *kn); static int filt_signal(struct knote *kn, long hint); +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); + +SECURITY_READ_ONLY_EARLY(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 */ +struct killpg1_filtargs { + int posix; + proc_t cp; +}; + +struct killpg1_iterargs { + proc_t cp; + kauth_cred_t uc; + int signum; + int * nfoundp; + int zombie; +}; + +static int killpg1_filt(proc_t p, void * arg); +static int killpg1_pgrpfilt(proc_t p, __unused void * arg); +static int killpg1_callback(proc_t p, void * arg); + +static int pgsignal_filt(proc_t p, void * arg); +static int pgsignal_callback(proc_t p, void * arg); +static kern_return_t get_signalthread(proc_t, int, thread_t *); -struct filterops sig_filtops = - { 0, filt_sigattach, filt_sigdetach, filt_signal }; +/* flags for psignal_internal */ +#define PSIG_LOCKED 0x1 +#define PSIG_VFORK 0x2 +#define PSIG_THREAD 0x4 +#define PSIG_TRY_THREAD 0x8 + +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) */ static void -sigaltstack_64to32(struct user_sigaltstack *in, struct sigaltstack *out) +sigaltstack_kern_to_user32(struct kern_sigaltstack *in, struct user32_sigaltstack *out) +{ + out->ss_sp = CAST_DOWN_EXPLICIT(user32_addr_t, in->ss_sp); + out->ss_size = CAST_DOWN_EXPLICIT(user32_size_t, in->ss_size); + out->ss_flags = in->ss_flags; +} + +static void +sigaltstack_kern_to_user64(struct kern_sigaltstack *in, struct user64_sigaltstack *out) { - out->ss_sp = CAST_DOWN(void *,in->ss_sp); + out->ss_sp = in->ss_sp; out->ss_size = in->ss_size; out->ss_flags = in->ss_flags; } @@ -168,24 +223,39 @@ sigaltstack_64to32(struct user_sigaltstack *in, struct sigaltstack *out) * the beginning. */ static void -sigaltstack_32to64(struct sigaltstack *in, struct user_sigaltstack *out) +sigaltstack_user32_to_kern(struct user32_sigaltstack *in, struct kern_sigaltstack *out) +{ + out->ss_flags = in->ss_flags; + out->ss_size = in->ss_size; + out->ss_sp = CAST_USER_ADDR_T(in->ss_sp); +} +static void +sigaltstack_user64_to_kern(struct user64_sigaltstack *in, struct kern_sigaltstack *out) { out->ss_flags = in->ss_flags; out->ss_size = in->ss_size; - out->ss_sp = CAST_USER_ADDR_T(in->ss_sp); + out->ss_sp = in->ss_sp; } static void -sigaction_64to32(struct user_sigaction *in, struct sigaction *out) +sigaction_kern_to_user32(struct kern_sigaction *in, struct user32_sigaction *out) +{ + /* This assumes 32 bit __sa_handler is of type sig_t */ + out->__sigaction_u.__sa_handler = CAST_DOWN_EXPLICIT(user32_addr_t,in->__sigaction_u.__sa_handler); + out->sa_mask = in->sa_mask; + out->sa_flags = in->sa_flags; +} +static void +sigaction_kern_to_user64(struct kern_sigaction *in, struct user64_sigaction *out) { /* This assumes 32 bit __sa_handler is of type sig_t */ - out->__sigaction_u.__sa_handler = CAST_DOWN(sig_t,in->__sigaction_u.__sa_handler); + out->__sigaction_u.__sa_handler = in->__sigaction_u.__sa_handler; out->sa_mask = in->sa_mask; out->sa_flags = in->sa_flags; } static void -__sigaction_32to64(struct __sigaction *in, struct __user_sigaction *out) +__sigaction_user32_to_kern(struct __user32_sigaction *in, struct __kern_sigaction *out) { out->__sigaction_u.__sa_handler = CAST_USER_ADDR_T(in->__sigaction_u.__sa_handler); out->sa_tramp = CAST_USER_ADDR_T(in->sa_tramp); @@ -193,6 +263,14 @@ __sigaction_32to64(struct __sigaction *in, struct __user_sigaction *out) out->sa_flags = in->sa_flags; } +static void +__sigaction_user64_to_kern(struct __user64_sigaction *in, struct __kern_sigaction *out) +{ + out->__sigaction_u.__sa_handler = in->__sigaction_u.__sa_handler; + out->sa_tramp = in->sa_tramp; + out->sa_mask = in->sa_mask; + out->sa_flags = in->sa_flags; +} #if SIGNAL_DEBUG void ram_printf(int); @@ -206,150 +284,185 @@ ram_printf(int x) } #endif /* SIGNAL_DEBUG */ -int -signal_lock(struct proc *p) -{ -int error = 0; -#if DIAGNOSTIC -#if SIGNAL_DEBUG -#ifdef __ppc__ - { - int register sp, *fp, numsaved; - - __asm__ volatile("mr %0,r1" : "=r" (sp)); - - fp = (int *)*((int *)sp); - for (numsaved = 0; numsaved < 3; numsaved++) { - p->lockpc[numsaved] = fp[2]; - if ((int)fp <= 0) - break; - fp = (int *)*fp; - } - } -#endif /* __ppc__ */ -#endif /* SIGNAL_DEBUG */ -#endif /* DIAGNOSTIC */ - -siglock_retry: - error = lockmgr((struct lock__bsd__ *)&p->signal_lock[0], LK_EXCLUSIVE, 0, (struct proc *)0); - if (error == EINTR) - goto siglock_retry; - return(error); -} - -int -signal_unlock(struct proc *p) -{ -#if DIAGNOSTIC -#if SIGNAL_DEBUG -#ifdef __ppc__ - { - int register sp, *fp, numsaved; - - __asm__ volatile("mr %0,r1" : "=r" (sp)); - - fp = (int *)*((int *)sp); - for (numsaved = 0; numsaved < 3; numsaved++) { - p->unlockpc[numsaved] = fp[2]; - if ((int)fp <= 0) - break; - fp = (int *)*fp; - } - } -#endif /* __ppc__ */ -#endif /* SIGNAL_DEBUG */ -#endif /* DIAGNOSTIC */ - - /* TBD: check p last arg */ - return(lockmgr((struct lock__bsd__ *)&p->signal_lock[0], LK_RELEASE, (simple_lock_t)0, (struct proc *)0)); -} void -signal_setast(sig_actthread) -thread_t sig_actthread; +signal_setast(thread_t sig_actthread) { act_set_astbsd(sig_actthread); } /* * Can process p, with ucred uc, send the signal signum to process q? + * uc is refcounted by the caller so internal fileds can be used safely + * when called with zombie arg, list lock is held */ int -cansignal(p, uc, q, signum) - struct proc *p; - kauth_cred_t uc; - struct proc *q; - int signum; +cansignal(proc_t p, kauth_cred_t uc, proc_t q, int signum, int zombie) { + kauth_cred_t my_cred; + struct session * p_sessp = SESSION_NULL; + struct session * q_sessp = SESSION_NULL; +#if CONFIG_MACF + int error; + + error = mac_proc_check_signal(p, q, signum); + if (error) + return (0); +#endif + /* you can signal yourself */ 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 */ - if (signum == SIGCONT && q->p_session == p->p_session) + if (zombie == 0) + proc_list_lock(); + if (p->p_pgrp != PGRP_NULL) + p_sessp = p->p_pgrp->pg_session; + if (q->p_pgrp != PGRP_NULL) + q_sessp = q->p_pgrp->pg_session; + + if (signum == SIGCONT && q_sessp == p_sessp) { + if (zombie == 0) + proc_list_unlock(); return (1); /* SIGCONT in session */ + } + + if (zombie == 0) + proc_list_unlock(); /* - * Using kill(), only certain signals can be sent to setugid - * child processes + * If the real or effective UID of the sender matches the real + * or saved UID of the target, permit the signal to + * be sent. */ - if (q->p_flag & P_SUGID) { - switch (signum) { - case 0: - case SIGKILL: - case SIGINT: - case SIGTERM: - case SIGSTOP: - case SIGTTIN: - case SIGTTOU: - case SIGTSTP: - case SIGHUP: - case SIGUSR1: - case SIGUSR2: - if (uc->cr_ruid == q->p_ucred->cr_ruid || - kauth_cred_getuid(uc) == q->p_ucred->cr_ruid || - uc->cr_ruid == kauth_cred_getuid(q->p_ucred) || - kauth_cred_getuid(uc) == kauth_cred_getuid(q->p_ucred)) - return (1); - } - return (0); + if (zombie == 0) + my_cred = kauth_cred_proc_ref(q); + else + my_cred = proc_ucred(q); + + if (kauth_cred_getruid(uc) == kauth_cred_getruid(my_cred) || + kauth_cred_getruid(uc) == kauth_cred_getsvuid(my_cred) || + kauth_cred_getuid(uc) == kauth_cred_getruid(my_cred) || + kauth_cred_getuid(uc) == kauth_cred_getsvuid(my_cred)) { + if (zombie == 0) + kauth_cred_unref(&my_cred); + return (1); } - /* XXX - * because the P_SUGID test exists, this has extra tests which - * could be removed. - */ - if (uc->cr_ruid == q->p_ucred->cr_ruid || - uc->cr_ruid == q->p_ucred->cr_svuid || - kauth_cred_getuid(uc) == q->p_ucred->cr_ruid || - kauth_cred_getuid(uc) == q->p_ucred->cr_svuid || - uc->cr_ruid == kauth_cred_getuid(q->p_ucred) || - kauth_cred_getuid(uc) == kauth_cred_getuid(q->p_ucred)) - return (1); + if (zombie == 0) + kauth_cred_unref(&my_cred); + 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 + * EINVAL + * copyout:EFAULT + * copyin:EFAULT + * + * Notes: Uses current thread as a parameter to inform PPC to enable + * FPU exceptions via setsigvec(); this operation is not proxy + * safe! + */ /* ARGSUSED */ int -sigaction(struct proc *p, register struct sigaction_args *uap, __unused register_t *retval) +sigaction(proc_t p, struct sigaction_args *uap, __unused int32_t *retval) { - struct user_sigaction vec; - struct __user_sigaction __vec; + struct kern_sigaction vec; + struct __kern_sigaction __vec; - struct user_sigaction *sa = &vec; - register struct sigacts *ps = p->p_sigacts; + struct kern_sigaction *sa = &vec; + struct sigacts *ps = p->p_sigacts; - register int signum; + int signum; int bit, error=0; 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]; @@ -371,47 +484,45 @@ sigaction(struct proc *p, register struct sigaction_args *uap, __unused register sa->sa_flags |= SA_NOCLDWAIT; if (IS_64BIT_PROCESS(p)) { - error = copyout(sa, uap->osa, sizeof(struct user_sigaction)); + struct user64_sigaction vec64 = {}; + sigaction_kern_to_user64(sa, &vec64); + error = copyout(&vec64, uap->osa, sizeof(vec64)); } else { - struct sigaction vec32; - sigaction_64to32(sa, &vec32); - error = copyout(&vec32, uap->osa, sizeof(struct sigaction)); + 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)) { - error = copyin(uap->nsa, &__vec, sizeof(struct __user_sigaction)); - } else { - struct __sigaction __vec32; - error = copyin(uap->nsa, &__vec32, sizeof(struct __sigaction)); - __sigaction_32to64(&__vec32, &__vec); - } - if (error) - return (error); - error = setsigvec(p, signum, &__vec); + error = setsigvec(p, current_thread(), signum, &__vec, FALSE); } + return (error); } /* Routines to manipulate bits on all threads */ int -clear_procsiglist(struct proc *p, int bit) +clear_procsiglist(proc_t p, int bit, boolean_t in_signalstart) { struct uthread * uth; thread_t thact; - signal_lock(p); + proc_lock(p); + if (!in_signalstart) + proc_signalstart(p, 1); - if ((p->p_flag & P_INVFORK) && p->p_vforkact) { + if ((p->p_lflag & P_LINVFORK) && p->p_vforkact) { thact = p->p_vforkact; uth = (struct uthread *)get_bsdthread_info(thact); if (uth) { uth->uu_siglist &= ~bit; } - p->p_siglist &= ~bit; - signal_unlock(p); + if (!in_signalstart) + proc_signalend(p, 1); + proc_unlock(p); return(0); } @@ -419,93 +530,122 @@ clear_procsiglist(struct proc *p, int bit) uth->uu_siglist &= ~bit; } p->p_siglist &= ~bit; - signal_unlock(p); + if (!in_signalstart) + proc_signalend(p, 1); + proc_unlock(p); + return(0); } static int -unblock_procsigmask(struct proc *p, int bit) +unblock_procsigmask(proc_t p, int bit) { struct uthread * uth; thread_t thact; - signal_lock(p); - if ((p->p_flag & P_INVFORK) && p->p_vforkact) { + proc_lock(p); + proc_signalstart(p, 1); + + if ((p->p_lflag & P_LINVFORK) && p->p_vforkact) { thact = p->p_vforkact; uth = (struct uthread *)get_bsdthread_info(thact); if (uth) { uth->uu_sigmask &= ~bit; } p->p_sigmask &= ~bit; - signal_unlock(p); + proc_signalend(p, 1); + proc_unlock(p); return(0); } TAILQ_FOREACH(uth, &p->p_uthlist, uu_list) { uth->uu_sigmask &= ~bit; } p->p_sigmask &= ~bit; - signal_unlock(p); + + proc_signalend(p, 1); + proc_unlock(p); return(0); } - static int -block_procsigmask(struct proc *p, int bit) +block_procsigmask(proc_t p, int bit) { struct uthread * uth; thread_t thact; - signal_lock(p); - if ((p->p_flag & P_INVFORK) && p->p_vforkact) { + proc_lock(p); + proc_signalstart(p, 1); + + if ((p->p_lflag & P_LINVFORK) && p->p_vforkact) { thact = p->p_vforkact; uth = (struct uthread *)get_bsdthread_info(thact); if (uth) { uth->uu_sigmask |= bit; } p->p_sigmask |= bit; - signal_unlock(p); + proc_signalend(p, 1); + proc_unlock(p); return(0); } TAILQ_FOREACH(uth, &p->p_uthlist, uu_list) { uth->uu_sigmask |= bit; } p->p_sigmask |= bit; - signal_unlock(p); + + proc_signalend(p, 1); + proc_unlock(p); return(0); } int -set_procsigmask(struct proc *p, int bit) +set_procsigmask(proc_t p, int bit) { struct uthread * uth; thread_t thact; - signal_lock(p); - if ((p->p_flag & P_INVFORK) && p->p_vforkact) { + proc_lock(p); + proc_signalstart(p, 1); + + if ((p->p_lflag & P_LINVFORK) && p->p_vforkact) { thact = p->p_vforkact; uth = (struct uthread *)get_bsdthread_info(thact); if (uth) { uth->uu_sigmask = bit; } p->p_sigmask = bit; - signal_unlock(p); + proc_signalend(p, 1); + proc_unlock(p); return(0); } TAILQ_FOREACH(uth, &p->p_uthlist, uu_list) { uth->uu_sigmask = bit; } p->p_sigmask = bit; - signal_unlock(p); + proc_signalend(p, 1); + proc_unlock(p); + return(0); } /* XXX should be static? */ +/* + * Notes: The thread parameter is used in the PPC case to select the + * thread on which the floating point exception will be enabled + * or disabled. We can't simply take current_thread(), since + * this is called from posix_spawn() on the not currently running + * process/thread pair. + * + * We mark thread as unused to alow compilation without warning + * on non-PPC platforms. + */ int -setsigvec(struct proc *p, int signum, struct __user_sigaction *sa) +setsigvec(proc_t p, __unused thread_t thread, int signum, struct __kern_sigaction *sa, boolean_t in_sigstart) { - register struct sigacts *ps = p->p_sigacts; - register int bit; + struct sigacts *ps = p->p_sigacts; + int bit; + + assert(signum < NSIG); if ((signum == SIGKILL || signum == SIGSTOP) && sa->sa_handler != SIG_DFL) @@ -547,23 +687,15 @@ setsigvec(struct proc *p, int signum, struct __user_sigaction *sa) ps->ps_signodefer &= ~bit; if (signum == SIGCHLD) { if (sa->sa_flags & SA_NOCLDSTOP) - p->p_flag |= P_NOCLDSTOP; + OSBitOrAtomic(P_NOCLDSTOP, &p->p_flag); else - p->p_flag &= ~P_NOCLDSTOP; + OSBitAndAtomic(~((uint32_t)P_NOCLDSTOP), &p->p_flag); if ((sa->sa_flags & SA_NOCLDWAIT) || (sa->sa_handler == SIG_IGN)) - p->p_flag |= P_NOCLDWAIT; + OSBitOrAtomic(P_NOCLDWAIT, &p->p_flag); else - p->p_flag &= ~P_NOCLDWAIT; + OSBitAndAtomic(~((uint32_t)P_NOCLDWAIT), &p->p_flag); } -#ifdef __ppc__ - if (signum == SIGFPE) { - if (sa->sa_handler == SIG_DFL || sa->sa_handler == SIG_IGN) - thread_enable_fpe(current_thread(), 0); - else - thread_enable_fpe(current_thread(), 1); - } -#endif /* __ppc__ */ /* * Set bit in p_sigignore for signals that are set to SIG_IGN, * and for signals set to SIG_DFL where the default is to ignore. @@ -573,7 +705,7 @@ setsigvec(struct proc *p, int signum, struct __user_sigaction *sa) if (sa->sa_handler == SIG_IGN || (sigprop[signum] & SA_IGNORE && sa->sa_handler == SIG_DFL)) { - clear_procsiglist(p, bit); + clear_procsiglist(p, bit, in_sigstart); if (signum != SIGCONT) p->p_sigignore |= bit; /* easier in psignal */ p->p_sigcatch &= ~bit; @@ -592,12 +724,11 @@ setsigvec(struct proc *p, int signum, struct __user_sigaction *sa) * set to ignore signals that are ignored by default. */ void -siginit(p) - struct proc *p; +siginit(proc_t p) { - register int i; + int i; - for (i = 0; i < NSIG; i++) + for (i = 1; i < NSIG; i++) if (sigprop[i] & SA_IGNORE && i != SIGCONT) p->p_sigignore |= sigmask(i); } @@ -606,14 +737,26 @@ siginit(p) * Reset signals for an exec of the specified process. */ void -execsigs(p, thr_act) - register struct proc *p; - register thread_t thr_act; +execsigs(proc_t p, thread_t thread) { - register struct sigacts *ps = p->p_sigacts; - register int nc, mask; + struct sigacts *ps = p->p_sigacts; + int nc, mask; struct uthread *ut; + ut = (struct uthread *)get_bsdthread_info(thread); + + /* + * transfer saved signal states from the process + * back to the current thread. + * + * NOTE: We do this without the process locked, + * because we are guaranteed to be single-threaded + * by this point in exec and the p_siglist is + * only accessed by threads inside the process. + */ + ut->uu_siglist |= p->p_siglist; + p->p_siglist = 0; + /* * Reset caught signals. Held signals remain held * through p_sigmask (unless they were caught, @@ -626,23 +769,22 @@ execsigs(p, thr_act) if (sigprop[nc] & SA_IGNORE) { if (nc != SIGCONT) p->p_sigignore |= mask; - if (thr_act){ - ut = (struct uthread *)get_bsdthread_info(thr_act); - ut->uu_siglist &= ~mask; - p->p_siglist &= ~mask; - } else - clear_procsiglist(p, mask); + ut->uu_siglist &= ~mask; } ps->ps_sigact[nc] = SIG_DFL; } + /* * Reset stack state to the user stack. * Clear set of signals caught on the signal stack. */ - ps->ps_sigstk.ss_flags = SA_DISABLE; - ps->ps_sigstk.ss_size = 0; - ps->ps_sigstk.ss_sp = USER_ADDR_NULL; - ps->ps_flags = 0; + /* thread */ + ut->uu_sigstk.ss_flags = SA_DISABLE; + ut->uu_sigstk.ss_size = 0; + ut->uu_sigstk.ss_sp = USER_ADDR_NULL; + ut->uu_flag &= ~UT_ALTSTACK; + /* process */ + ps->ps_sigonstack = 0; } /* @@ -652,7 +794,7 @@ execsigs(p, thr_act) * the library stub does the rest. */ int -sigprocmask(register struct proc *p, struct sigprocmask_args *uap, __unused register_t *retval) +sigprocmask(proc_t p, struct sigprocmask_args *uap, __unused int32_t *retval) { int error = 0; sigset_t oldmask, nmask; @@ -697,7 +839,7 @@ out: } int -sigpending(__unused struct proc *p, register struct sigpending_args *uap, __unused register_t *retval) +sigpending(__unused proc_t p, struct sigpending_args *uap, __unused int32_t *retval) { struct uthread *ut; sigset_t pendlist; @@ -710,7 +852,6 @@ sigpending(__unused struct proc *p, register struct sigpending_args *uap, __unus return(0); } - /* * Suspend process until signal, providing mask to be set * in the meantime. Note nonstandard calling convention: @@ -721,11 +862,18 @@ static int sigcontinue(__unused int error) { // struct uthread *ut = get_bsdthread_info(current_thread()); - unix_syscall_return(EINTR); + unix_syscall_return(EINTR); +} + +int +sigsuspend(proc_t p, struct sigsuspend_args *uap, int32_t *retval) +{ + __pthread_testcancel(1); + return(sigsuspend_nocancel(p, (struct sigsuspend_nocancel_args *)uap, retval)); } int -sigsuspend(register struct proc *p, struct sigsuspend_args *uap, __unused register_t *retval) +sigsuspend_nocancel(proc_t p, struct sigsuspend_nocancel_args *uap, __unused int32_t *retval) { struct uthread *ut; @@ -748,29 +896,47 @@ sigsuspend(register struct proc *p, struct sigsuspend_args *uap, __unused regist int -__disable_threadsignal(struct proc *p, - __unused register struct __disable_threadsignal_args *uap, - __unused register_t *retval) +__disable_threadsignal(__unused proc_t p, + __unused struct __disable_threadsignal_args *uap, + __unused int32_t *retval) { struct uthread *uth; uth = (struct uthread *)get_bsdthread_info(current_thread()); /* No longer valid to have any signal delivered */ - signal_lock(p); - uth->uu_flag |= UT_NO_SIGMASK; - signal_unlock(p); + uth->uu_flag |= (UT_NO_SIGMASK | UT_CANCELDISABLE); return(0); } +void +__pthread_testcancel(int presyscall) +{ + + thread_t self = current_thread(); + struct uthread * uthread; + + uthread = (struct uthread *)get_bsdthread_info(self); + + + uthread->uu_flag &= ~UT_NOTCANCELPT; + + if ((uthread->uu_flag & (UT_CANCELDISABLE | UT_CANCEL | UT_CANCELED)) == UT_CANCEL) { + if(presyscall != 0) { + unix_syscall_return(EINTR); + /* NOTREACHED */ + } else + thread_abort_safely(self); + } +} + + int -__pthread_markcancel(p, uap, retval) - struct proc *p; - register struct __pthread_markcancel_args *uap; - register_t *retval; +__pthread_markcancel(__unused proc_t p, + struct __pthread_markcancel_args *uap, __unused int32_t *retval) { thread_act_t target_act; int error = 0; @@ -784,7 +950,7 @@ __pthread_markcancel(p, uap, retval) uth = (struct uthread *)get_bsdthread_info(target_act); /* if the thread is in vfork do not cancel */ - if ((uth->uu_flag & (P_VFORK | UT_CANCEL | UT_CANCELED )) == 0) { + if ((uth->uu_flag & (UT_VFORK | UT_CANCEL | UT_CANCELED )) == 0) { uth->uu_flag |= (UT_CANCEL | UT_NO_SIGMASK); if (((uth->uu_flag & UT_NOTCANCELPT) == 0) && ((uth->uu_flag & UT_CANCELDISABLE) == 0)) @@ -801,17 +967,15 @@ __pthread_markcancel(p, uap, retval) * if action = 2; Disable the cancel handling */ int -__pthread_canceled(p, uap, retval) - struct proc *p; - register struct __pthread_canceled_args *uap; - register_t *retval; +__pthread_canceled(__unused proc_t p, + struct __pthread_canceled_args *uap, __unused int32_t *retval) { - thread_act_t thr_act; + thread_act_t thread; struct uthread *uth; int action = uap->action; - thr_act = current_act(); - uth = (struct uthread *)get_bsdthread_info(thr_act); + thread = current_thread(); + uth = (struct uthread *)get_bsdthread_info(thread); switch (action) { case 1: @@ -833,6 +997,7 @@ __pthread_canceled(p, uap, retval) return(EINVAL); } +__attribute__((noreturn)) void __posix_sem_syscall_return(kern_return_t kern_result) { @@ -850,50 +1015,184 @@ __posix_sem_syscall_return(kern_return_t kern_result) /* does not return */ } - +#if OLD_SEMWAIT_SIGNAL +/* + * Returns: 0 Success + * EINTR + * ETIMEDOUT + * EINVAL + * EFAULT if timespec is NULL + */ int -__semwait_signal(p, uap, retval) - struct proc *p; - register struct __semwait_signal_args *uap; - register_t *retval; +__old_semwait_signal(proc_t p, struct __old_semwait_signal_args *uap, + int32_t *retval) { + __pthread_testcancel(0); + return(__old_semwait_signal_nocancel(p, (struct __old_semwait_signal_nocancel_args *)uap, retval)); +} +int +__old_semwait_signal_nocancel(proc_t p, struct __old_semwait_signal_nocancel_args *uap, + __unused int32_t *retval) +{ + kern_return_t kern_result; + int error; mach_timespec_t then; struct timespec now; - + struct user_timespec ts; + boolean_t truncated_timeout = FALSE; + if(uap->timeout) { - + + if (IS_64BIT_PROCESS(p)) { + struct user64_timespec ts64; + error = copyin(uap->ts, &ts64, sizeof(ts64)); + ts.tv_sec = ts64.tv_sec; + ts.tv_nsec = ts64.tv_nsec; + } else { + struct user32_timespec ts32; + error = copyin(uap->ts, &ts32, sizeof(ts32)); + ts.tv_sec = ts32.tv_sec; + ts.tv_nsec = ts32.tv_nsec; + } + + if (error) { + return error; + } + + if ((ts.tv_sec & 0xFFFFFFFF00000000ULL) != 0) { + ts.tv_sec = 0xFFFFFFFF; + ts.tv_nsec = 0; + truncated_timeout = TRUE; + } + if (uap->relative) { - then.tv_sec = uap->tv_sec; - then.tv_nsec = uap->tv_nsec; + then.tv_sec = ts.tv_sec; + then.tv_nsec = ts.tv_nsec; } else { nanotime(&now); - then.tv_sec = uap->tv_sec - now.tv_sec; - then.tv_nsec = uap->tv_nsec - now.tv_nsec; - if (then.tv_nsec < 0) { - then.tv_nsec += NSEC_PER_SEC; - then.tv_sec--; + + /* if time has elapsed, set time to null timepsec to bailout rightaway */ + if (now.tv_sec == ts.tv_sec ? + now.tv_nsec > ts.tv_nsec : + now.tv_sec > ts.tv_sec) { + then.tv_sec = 0; + then.tv_nsec = 0; + } else { + then.tv_sec = ts.tv_sec - now.tv_sec; + then.tv_nsec = ts.tv_nsec - now.tv_nsec; + if (then.tv_nsec < 0) { + then.tv_nsec += NSEC_PER_SEC; + then.tv_sec--; + } } } - - if (uap->mutex_sem == (void *)NULL) - kern_result = semaphore_timedwait_trap_internal(uap->cond_sem, then.tv_sec, then.tv_nsec, __posix_sem_syscall_return); + + if (uap->mutex_sem == 0) + kern_result = semaphore_timedwait_trap_internal((mach_port_name_t)uap->cond_sem, then.tv_sec, then.tv_nsec, __posix_sem_syscall_return); else kern_result = semaphore_timedwait_signal_trap_internal(uap->cond_sem, uap->mutex_sem, then.tv_sec, then.tv_nsec, __posix_sem_syscall_return); - + } else { - - if (uap->mutex_sem == (void *)NULL) + + if (uap->mutex_sem == 0) kern_result = semaphore_wait_trap_internal(uap->cond_sem, __posix_sem_syscall_return); else - + kern_result = semaphore_wait_signal_trap_internal(uap->cond_sem, uap->mutex_sem, __posix_sem_syscall_return); } - -out: - if (kern_result == KERN_SUCCESS) + + if (kern_result == KERN_SUCCESS && !truncated_timeout) return(0); + else if (kern_result == KERN_SUCCESS && truncated_timeout) + return(EINTR); /* simulate an exceptional condition because Mach doesn't support a longer timeout */ + else if (kern_result == KERN_ABORTED) + return(EINTR); + else if (kern_result == KERN_OPERATION_TIMED_OUT) + return(ETIMEDOUT); + else + return(EINVAL); +} +#endif /* OLD_SEMWAIT_SIGNAL*/ + +/* + * Returns: 0 Success + * EINTR + * ETIMEDOUT + * EINVAL + * EFAULT if timespec is NULL + */ +int +__semwait_signal(proc_t p, struct __semwait_signal_args *uap, + int32_t *retval) +{ + __pthread_testcancel(0); + return(__semwait_signal_nocancel(p, (struct __semwait_signal_nocancel_args *)uap, retval)); +} + +int +__semwait_signal_nocancel(__unused proc_t p, struct __semwait_signal_nocancel_args *uap, + __unused int32_t *retval) +{ + + kern_return_t kern_result; + mach_timespec_t then; + struct timespec now; + struct user_timespec ts; + boolean_t truncated_timeout = FALSE; + + if(uap->timeout) { + + ts.tv_sec = uap->tv_sec; + ts.tv_nsec = uap->tv_nsec; + + if ((ts.tv_sec & 0xFFFFFFFF00000000ULL) != 0) { + ts.tv_sec = 0xFFFFFFFF; + ts.tv_nsec = 0; + truncated_timeout = TRUE; + } + + if (uap->relative) { + then.tv_sec = ts.tv_sec; + then.tv_nsec = ts.tv_nsec; + } else { + nanotime(&now); + + /* if time has elapsed, set time to null timepsec to bailout rightaway */ + if (now.tv_sec == ts.tv_sec ? + now.tv_nsec > ts.tv_nsec : + now.tv_sec > ts.tv_sec) { + then.tv_sec = 0; + then.tv_nsec = 0; + } else { + then.tv_sec = ts.tv_sec - now.tv_sec; + then.tv_nsec = ts.tv_nsec - now.tv_nsec; + if (then.tv_nsec < 0) { + then.tv_nsec += NSEC_PER_SEC; + then.tv_sec--; + } + } + } + + if (uap->mutex_sem == 0) + kern_result = semaphore_timedwait_trap_internal((mach_port_name_t)uap->cond_sem, then.tv_sec, then.tv_nsec, __posix_sem_syscall_return); + else + kern_result = semaphore_timedwait_signal_trap_internal(uap->cond_sem, uap->mutex_sem, then.tv_sec, then.tv_nsec, __posix_sem_syscall_return); + + } else { + + if (uap->mutex_sem == 0) + kern_result = semaphore_wait_trap_internal(uap->cond_sem, __posix_sem_syscall_return); + else + + kern_result = semaphore_wait_signal_trap_internal(uap->cond_sem, uap->mutex_sem, __posix_sem_syscall_return); + } + + if (kern_result == KERN_SUCCESS && !truncated_timeout) + return(0); + else if (kern_result == KERN_SUCCESS && truncated_timeout) + return(EINTR); /* simulate an exceptional condition because Mach doesn't support a longer timeout */ else if (kern_result == KERN_ABORTED) return(EINTR); else if (kern_result == KERN_OPERATION_TIMED_OUT) @@ -904,9 +1203,8 @@ out: int -__pthread_kill(__unused struct proc *p, - register struct __pthread_kill_args *uap, - __unused register_t *retval) +__pthread_kill(__unused proc_t p, struct __pthread_kill_args *uap, + __unused int32_t *retval) { thread_t target_act; int error = 0; @@ -938,9 +1236,8 @@ out: int -pthread_sigmask(__unused register struct proc *p, - register struct pthread_sigmask_args *uap, - __unused register_t *retval) +__pthread_sigmask(__unused proc_t p, struct __pthread_sigmask_args *uap, + __unused int32_t *retval) { user_addr_t set = uap->set; user_addr_t oset = uap->oset; @@ -987,9 +1284,21 @@ out: return(error); } +/* + * Returns: 0 Success + * EINVAL + * copyin:EFAULT + * copyout:EFAULT + */ +int +__sigwait(proc_t p, struct __sigwait_args *uap, int32_t *retval) +{ + __pthread_testcancel(1); + return(__sigwait_nocancel(p, (struct __sigwait_nocancel_args *)uap, retval)); +} int -sigwait(register struct proc *p, register struct sigwait_args *uap, __unused register_t *retval) +__sigwait_nocancel(proc_t p, struct __sigwait_nocancel_args *uap, __unused int32_t *retval) { struct uthread *ut; struct uthread *uth; @@ -1013,18 +1322,20 @@ sigwait(register struct proc *p, register struct sigwait_args *uap, __unused reg if (siglist == 0) return(EINVAL); - signal_lock(p); - if ((p->p_flag & P_INVFORK) && p->p_vforkact) { - signal_unlock(p); + proc_lock(p); + if ((p->p_lflag & P_LINVFORK) && p->p_vforkact) { + proc_unlock(p); return(EINVAL); } else { + proc_signalstart(p, 1); TAILQ_FOREACH(uth, &p->p_uthlist, uu_list) { if ( (sigw = uth->uu_siglist & siglist) ) { break; } } + proc_signalend(p, 1); } - signal_unlock(p); + if (sigw) { /* The signal was pending on a thread */ goto sigwait1; @@ -1036,17 +1347,21 @@ sigwait(register struct proc *p, register struct sigwait_args *uap, __unused reg * save it here and mark the sigacts structure * to indicate this. */ + uth = ut; /* wait for it to be delivered to us */ ut->uu_oldmask = ut->uu_sigmask; ut->uu_flag |= UT_SAS_OLDMASK; - if (siglist == (sigset_t)0) + if (siglist == (sigset_t)0) { + proc_unlock(p); return(EINVAL); + } /* SIGKILL and SIGSTOP are not maskable as well */ ut->uu_sigmask = ~(siglist|sigcantmask); ut->uu_sigwait = siglist; + /* No Continuations for now */ - error = tsleep((caddr_t)&ut->uu_sigwait, PPAUSE|PCATCH, "pause", 0); + error = msleep((caddr_t)&ut->uu_sigwait, &p->p_mlock, PPAUSE|PCATCH, "pause", 0); - if ((error == EINTR) || (error == ERESTART)) + if (error == ERESTART) error = 0; sigw = (ut->uu_sigwait & siglist); @@ -1059,33 +1374,47 @@ sigwait1: signum = ffs((unsigned int)sigw); if (!signum) panic("sigwait with no signal wakeup"); - ut->uu_siglist &= ~(sigmask(signum)); + /* Clear the pending signal in the thread it was delivered */ + uth->uu_siglist &= ~(sigmask(signum)); + +#if CONFIG_DTRACE + DTRACE_PROC2(signal__clear, int, signum, siginfo_t *, &(ut->t_dtrace_siginfo)); +#endif + + proc_unlock(p); if (uap->sig != USER_ADDR_NULL) error = copyout(&signum, uap->sig, sizeof(int)); - } + } else + proc_unlock(p); return(error); } - int -sigaltstack(struct proc *p, register struct sigaltstack_args *uap, __unused register_t *retval) +sigaltstack(__unused proc_t p, struct sigaltstack_args *uap, __unused int32_t *retval) { - struct sigacts *psp; - struct user_sigaltstack ss; + struct kern_sigaltstack ss; + struct kern_sigaltstack *pstk; int error; + struct uthread *uth; + int onstack; - psp = p->p_sigacts; - if ((psp->ps_flags & SAS_ALTSTACK) == 0) - psp->ps_sigstk.ss_flags |= SA_DISABLE; + uth = (struct uthread *)get_bsdthread_info(current_thread()); + + pstk = &uth->uu_sigstk; + if ((uth->uu_flag & UT_ALTSTACK) == 0) + uth->uu_sigstk.ss_flags |= SA_DISABLE; + onstack = pstk->ss_flags & SA_ONSTACK; if (uap->oss) { if (IS_64BIT_PROCESS(p)) { - error = copyout(&psp->ps_sigstk, uap->oss, sizeof(struct user_sigaltstack)); + struct user64_sigaltstack ss64 = {}; + sigaltstack_kern_to_user64(pstk, &ss64); + error = copyout(&ss64, uap->oss, sizeof(ss64)); } else { - struct sigaltstack ss32; - sigaltstack_64to32(&psp->ps_sigstk, &ss32); - error = copyout(&ss32, uap->oss, sizeof(struct sigaltstack)); + struct user32_sigaltstack ss32 = {}; + sigaltstack_kern_to_user32(pstk, &ss32); + error = copyout(&ss32, uap->oss, sizeof(ss32)); } if (error) return (error); @@ -1093,11 +1422,13 @@ sigaltstack(struct proc *p, register struct sigaltstack_args *uap, __unused regi if (uap->nss == USER_ADDR_NULL) return (0); if (IS_64BIT_PROCESS(p)) { - error = copyin(uap->nss, &ss, sizeof(struct user_sigaltstack)); + struct user64_sigaltstack ss64; + error = copyin(uap->nss, &ss64, sizeof(ss64)); + sigaltstack_user64_to_kern(&ss64, &ss); } else { - struct sigaltstack ss32; - error = copyin(uap->nss, &ss32, sizeof(struct sigaltstack)); - sigaltstack_32to64(&ss32,&ss); + struct user32_sigaltstack ss32; + error = copyin(uap->nss, &ss32, sizeof(ss32)); + sigaltstack_user32_to_kern(&ss32, &ss); } if (error) return (error); @@ -1106,26 +1437,30 @@ sigaltstack(struct proc *p, register struct sigaltstack_args *uap, __unused regi } if (ss.ss_flags & SA_DISABLE) { - if (psp->ps_sigstk.ss_flags & SA_ONSTACK) + /* if we are here we are not in the signal handler ;so no need to check */ + if (uth->uu_sigstk.ss_flags & SA_ONSTACK) return (EINVAL); - psp->ps_flags &= ~SAS_ALTSTACK; - psp->ps_sigstk.ss_flags = ss.ss_flags; + uth->uu_flag &= ~UT_ALTSTACK; + uth->uu_sigstk.ss_flags = ss.ss_flags; return (0); } + if (onstack) + return (EPERM); /* The older stacksize was 8K, enforce that one so no compat problems */ #define OLDMINSIGSTKSZ 8*1024 if (ss.ss_size < OLDMINSIGSTKSZ) return (ENOMEM); - psp->ps_flags |= SAS_ALTSTACK; - psp->ps_sigstk= ss; + uth->uu_flag |= UT_ALTSTACK; + uth->uu_sigstk= ss; return (0); } int -kill(struct proc *cp, struct kill_args *uap, __unused register_t *retval) +kill(proc_t cp, struct kill_args *uap, __unused int32_t *retval) { - register struct proc *p; + proc_t p; kauth_cred_t uc = kauth_cred_get(); + int posix = uap->posix; /* !0 if posix behaviour desired */ AUDIT_ARG(pid, uap->pid); AUDIT_ARG(signum, uap->signum); @@ -1134,7 +1469,7 @@ kill(struct proc *cp, struct kill_args *uap, __unused register_t *retval) return (EINVAL); if (uap->pid > 0) { /* kill single process */ - if ((p = proc_findref(uap->pid)) == NULL) { + if ((p = proc_find(uap->pid)) == NULL) { if ((p = pzfind(uap->pid)) != NULL) { /* * IEEE Std 1003.1-2001: return success @@ -1145,772 +1480,839 @@ kill(struct proc *cp, struct kill_args *uap, __unused register_t *retval) return (ESRCH); } AUDIT_ARG(process, p); - if (!cansignal(cp, uc, p, uap->signum)) { - proc_dropref(p); + if (!cansignal(cp, uc, p, uap->signum, 0)) { + proc_rele(p); return(EPERM); } if (uap->signum) psignal(p, uap->signum); - proc_dropref(p); + proc_rele(p); return (0); } switch (uap->pid) { case -1: /* broadcast signal */ - return (killpg1(cp, uap->signum, 0, 1)); + return (killpg1(cp, uap->signum, 0, 1, posix)); case 0: /* signal own process group */ - return (killpg1(cp, uap->signum, 0, 0)); + return (killpg1(cp, uap->signum, 0, 0, posix)); default: /* negative explicit process group */ - return (killpg1(cp, uap->signum, -(uap->pid), 0)); + return (killpg1(cp, uap->signum, -(uap->pid), 0, posix)); } /* NOTREACHED */ } - -/* - * Common code for kill process group/broadcast kill. - * cp is calling process. - */ -int -killpg1(cp, signum, pgid, all) - register struct proc *cp; - int signum, pgid, all; +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) { - register struct proc *p; - kauth_cred_t uc = cp->p_ucred; - struct pgrp *pgrp; - int nfound = 0; - - if (all) { - /* - * broadcast - */ - for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) { - if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || - p == cp || !cansignal(cp, uc, p, signum)) - continue; - nfound++; - if (signum) - psignal(p, signum); + 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; } - } else { - if (pgid == 0) - /* - * zero pgid means send to my process group. - */ - pgrp = cp->p_pgrp; - else { - pgrp = pgfind(pgid); - if (pgrp == NULL) - return (ESRCH); + } + + 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; + } } - for (p = pgrp->pg_members.lh_first; p != 0; - p = p->p_pglist.le_next) { - if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || - p->p_stat == SZOMB || - !cansignal(cp, uc, p, signum)) - continue; - nfound++; - if (signum) - psignal(p, signum); + } + + 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; + } } } - return (nfound ? 0 : ESRCH); -} -/* - * Send a signal to a process group. - */ -void -gsignal(pgid, signum) - int pgid, signum; -{ - struct pgrp *pgrp; + if (reason_user_desc != NULL) { + kfree(reason_user_desc, EXIT_REASON_USER_DESC_MAX_LEN); + reason_user_desc = NULL; + reason_user_desc_len = 0; + } - if (pgid && (pgrp = pgfind(pgid))) - pgsignal(pgrp, signum, 0); -} + return exit_reason; -/* - * Send a signal to a process group. If checktty is 1, - * limit to members which have a controlling terminal. - */ -void -pgsignal(pgrp, signum, checkctty) - struct pgrp *pgrp; - int signum, checkctty; -{ - register struct proc *p; +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; + } - if (pgrp) - for (p = pgrp->pg_members.lh_first; p != 0; - p = p->p_pglist.le_next) - if (checkctty == 0 || p->p_flag & P_CONTROLT) - psignal(p, signum); + exit_reason->osr_flags |= OS_REASON_FLAG_FAILED_DATA_COPYIN; + os_reason_alloc_buffer(exit_reason, 0); + return exit_reason; } -/* - * Send signal to a backgrounded process blocked due to tty access - * In FreeBSD, the backgrounded process wakes up every second and - * discovers whether it is foregounded or not. In our case, we block - * the thread in tsleep as we want to avoid storm of processes as well - * as the suspend is only at AST level - */ -void -tty_pgsignal(pgrp, signum) - struct pgrp *pgrp; - int signum; +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) { - register struct proc *p; + proc_t target_proc = PROC_NULL; + kauth_cred_t cur_cred = kauth_cred_get(); - if (pgrp) - for (p = pgrp->pg_members.lh_first; p != 0; - p = p->p_pglist.le_next) - if ((p->p_flag & P_TTYSLEEP) && (p->p_flag & P_CONTROLT)) - psignal(p, signum); -} + os_reason_t signal_reason = OS_REASON_NULL; -/* - * Send a signal caused by a trap to a specific thread. - */ -void -threadsignal(thread_t sig_actthread, int signum, u_long code) -{ - register struct uthread *uth; - register struct task * sig_task; - register struct proc *p ; - int mask; + AUDIT_ARG(pid, target_pid); + if ((target_pid <= 0)) { + return EINVAL; + } - if ((u_int)signum >= NSIG || signum == 0) - return; + target_proc = proc_find(target_pid); + if (target_proc == PROC_NULL) { + return ESRCH; + } - mask = sigmask(signum); - if ((mask & threadmask) == 0) - return; - sig_task = get_threadtask(sig_actthread); - p = (struct proc *)(get_bsdtask_info(sig_task)); + AUDIT_ARG(process, target_proc); - uth = get_bsdthread_info(sig_actthread); - if (uth && (uth->uu_flag & UT_VFORK)) - p = uth->uu_proc; + if (!cansignal(cur_proc, cur_cred, target_proc, SIGKILL, 0)) { + proc_rele(target_proc); + return EPERM; + } - if (!(p->p_flag & P_TRACED) && (p->p_sigignore & mask)) - return; + 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); - uth->uu_siglist |= mask; - p->p_siglist |= mask; /* just for lame ones looking here */ - uth->uu_code = code; - /* mark on process as well */ - signal_setast(sig_actthread); + signal_reason = build_userspace_exit_reason(reason_namespace, reason_code, payload, payload_size, + reason_string, (reason_flags | OS_REASON_FLAG_NO_CRASHED_TID)); + + 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; } - -void -psignal(p, signum) - register struct proc *p; - register int signum; +int +terminate_with_payload(struct proc *cur_proc, struct terminate_with_payload_args *args, + __unused int32_t *retval) { - psignal_lock(p, signum, 1); + 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); } -void -psignal_vfork(struct proc *p, task_t new_task, thread_t thr_act, int signum) +static int +killpg1_filt(proc_t p, void * arg) { - register int prop; - register sig_t action; - int mask; - struct uthread *uth; + struct killpg1_filtargs * kfargp = (struct killpg1_filtargs *)arg; + proc_t cp = kfargp->cp; + int posix = kfargp->posix; - if ((u_int)signum >= NSIG || signum == 0) - panic("psignal signal number"); - mask = sigmask(signum); - prop = sigprop[signum]; -#if SIGNAL_DEBUG - if(rdebug_proc && (p == rdebug_proc)) { - ram_printf(3); - } -#endif /* SIGNAL_DEBUG */ + if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || + (!posix && p == cp)) + return(0); + else + return(1); +} - if ((new_task == TASK_NULL) || (thr_act == (thread_t)NULL) || is_kerneltask(new_task)) - return; +static int +killpg1_pgrpfilt(proc_t p, __unused void * arg) +{ + if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || + (p->p_stat == SZOMB)) + return(0); + else + return(1); +} - uth = get_bsdthread_info(thr_act); - signal_lock(p); - /* - * proc is traced, always give parent a chance. - */ - action = SIG_DFL; - if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) && - (p->p_flag & P_TRACED) == 0) - p->p_nice = NZERO; +static int +killpg1_callback(proc_t p, void * arg) +{ + struct killpg1_iterargs * kargp = (struct killpg1_iterargs *)arg; + proc_t cp = kargp->cp; + kauth_cred_t uc = kargp->uc; /* refcounted by the caller safe to use internal fields */ + int signum = kargp->signum; + int * nfoundp = kargp->nfoundp; + int n; + int zombie = 0; + int error = 0; - if (prop & SA_CONT) { - p->p_siglist &= ~stopsigmask; - uth->uu_siglist &= ~stopsigmask; - } + if ((kargp->zombie != 0) && ((p->p_listflag & P_LIST_EXITED) == P_LIST_EXITED)) + zombie = 1; - if (prop & SA_STOP) { - /* - * If sending a tty stop signal to a member of an orphaned - * process group, discard the signal here if the action - * is default; don't stop the process below if sleeping, - * and don't clear any pending SIGCONT. - */ - if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 && - action == SIG_DFL) - goto psigout; - uth->uu_siglist &= ~contsigmask; - p->p_siglist &= ~contsigmask; - } - uth->uu_siglist |= mask; - p->p_siglist |= mask; /* just for lame ones looking here */ + if (zombie != 0) { + proc_list_lock(); + error = cansignal(cp, uc, p, signum, zombie); + proc_list_unlock(); - /* Deliver signal to the activation passed in */ - act_set_astbsd(thr_act); - - /* - * 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. - */ - if ((signum == SIGKILL) && (p->p_nice > NZERO)) { - p->p_nice = NZERO; - } + if (error != 0 && nfoundp != NULL) { + n = *nfoundp; + *nfoundp = n+1; + } + } else { + if (cansignal(cp, uc, p, signum, 0) == 0) + return(PROC_RETURNED); - /* - * This Process is traced - wake it up (if not already - * stopped) so that it can discover the signal in - * issig() and stop for the parent. - */ - if (p->p_flag & P_TRACED) { - if (p->p_stat != SSTOP) - goto run; - else - goto psigout; - } -run: - /* - * If we're being traced (possibly because someone attached us - * while we were stopped), check for a signal from the debugger. - */ - if (p->p_stat == SSTOP) { - if ((p->p_flag & P_TRACED) != 0 && p->p_xstat != 0) { - uth->uu_siglist |= sigmask(p->p_xstat); - p->p_siglist |= mask; /* just for lame ones looking here */ + if (nfoundp != NULL) { + n = *nfoundp; + *nfoundp = n+1; } + if (signum != 0) + psignal(p, signum); } - /* - * setrunnable(p) in BSD - */ - p->p_stat = SRUN; - -psigout: - signal_unlock(p); + return(PROC_RETURNED); } -static thread_t -get_signalthread(struct proc *p, int signum) +/* + * Common code for kill process group/broadcast kill. + * cp is calling process. + */ +int +killpg1(proc_t cp, int signum, int pgid, int all, int posix) { - struct uthread *uth; - thread_t thr_act; - sigset_t mask = sigmask(signum); - thread_t sig_thread_act; - struct task * sig_task = p->task; - kern_return_t kret; + kauth_cred_t uc; + struct pgrp *pgrp; + int nfound = 0; + struct killpg1_iterargs karg; + struct killpg1_filtargs kfarg; + int error = 0; - if ((p->p_flag & P_INVFORK) && p->p_vforkact) { - sig_thread_act = p->p_vforkact; - kret = check_actforsig(sig_task, sig_thread_act, 1); - if (kret == KERN_SUCCESS) - return(sig_thread_act); - else - return(THREAD_NULL); - } + uc = kauth_cred_proc_ref(cp); + if (all) { + /* + * broadcast + */ + kfarg.posix = posix; + kfarg.cp = cp; - 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_act, 1) == KERN_SUCCESS) - return(uth->uu_act); + karg.cp = cp; + karg.uc = uc; + karg.nfoundp = &nfound; + karg.signum = signum; + karg.zombie = 1; + + proc_iterate((PROC_ALLPROCLIST | PROC_ZOMBPROCLIST), killpg1_callback, &karg, killpg1_filt, (void *)&kfarg); + + } else { + if (pgid == 0) { + /* + * zero pgid means send to my process group. + */ + pgrp = proc_pgrp(cp); + } else { + pgrp = pgfind(pgid); + if (pgrp == NULL) { + error = ESRCH; + goto out; + } } + + karg.nfoundp = &nfound; + karg.uc = uc; + karg.signum = signum; + karg.cp = cp; + karg.zombie = 0; + + + /* PGRP_DROPREF drops the pgrp refernce */ + pgrp_iterate(pgrp, PGRP_DROPREF, killpg1_callback, &karg, + killpg1_pgrpfilt, NULL); } - if (get_signalact(p->task, &thr_act, 1) == KERN_SUCCESS) { - return(thr_act); + error = (nfound ? 0 : (posix ? EPERM : ESRCH)); +out: + kauth_cred_unref(&uc); + return (error); +} + + +/* + * Send a signal to a process group. + */ +void +gsignal(int pgid, int signum) +{ + struct pgrp *pgrp; + + if (pgid && (pgrp = pgfind(pgid))) { + pgsignal(pgrp, signum, 0); + pg_rele(pgrp); } +} - return(THREAD_NULL); +/* + * Send a signal to a process group. If checkctty is 1, + * limit to members which have a controlling terminal. + */ + +static int +pgsignal_filt(proc_t p, void * arg) +{ + int checkctty = *(int*)arg; + + if ((checkctty == 0) || p->p_flag & P_CONTROLT) + return(1); + else + return(0); } + +static int +pgsignal_callback(proc_t p, void * arg) +{ + int signum = *(int*)arg; + + psignal(p, signum); + return(PROC_RETURNED); +} + + +void +pgsignal(struct pgrp *pgrp, int signum, int checkctty) +{ + if (pgrp != PGRP_NULL) { + pgrp_iterate(pgrp, 0, pgsignal_callback, &signum, pgsignal_filt, &checkctty); + } +} + + +void +tty_pgsignal(struct tty *tp, int signum, int checkctty) +{ + struct pgrp * pg; + + pg = tty_pgrp(tp); + if (pg != PGRP_NULL) { + pgrp_iterate(pg, 0, pgsignal_callback, &signum, pgsignal_filt, &checkctty); + pg_rele(pg); + } +} /* - * 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. - * - * Exceptions: - * o When a stop signal is sent to a sleeping process that takes the - * default action, the process is stopped without awakening it. - * o SIGCONT restarts stopped processes (or puts them back to sleep) - * regardless of the signal action (eg, blocked or ignored). - * - * Other ignored signals are discarded immediately. + * Send a signal caused by a trap to a specific thread. */ void -psignal_lock(p, signum, withlock) - register struct proc *p; - register int signum; - register int withlock; -{ - register int s, prop; - register sig_t action; - thread_t sig_thread_act; - register task_t sig_task; - int mask; +threadsignal(thread_t sig_actthread, int signum, mach_exception_code_t code, boolean_t set_exitreason) +{ struct uthread *uth; - boolean_t funnel_state = FALSE; - int sw_funnel = 0; + struct task * sig_task; + proc_t p; + int mask; if ((u_int)signum >= NSIG || signum == 0) - panic("psignal signal number"); - mask = sigmask(signum); - prop = sigprop[signum]; - -#if SIGNAL_DEBUG - if(rdebug_proc && (p == rdebug_proc)) { - ram_printf(3); - } -#endif /* SIGNAL_DEBUG */ + return; - if (thread_funnel_get() == (funnel_t *)0) { - sw_funnel = 1; - funnel_state = thread_funnel_set(kernel_flock, TRUE); - } - /* - * We will need the task pointer later. Grab it now to - * check for a zombie process. Also don't send signals - * to kernel internal tasks. - */ - if (((sig_task = p->task) == TASK_NULL) || is_kerneltask(sig_task)) { - if (sw_funnel) - thread_funnel_set(kernel_flock, funnel_state); + mask = sigmask(signum); + if ((mask & threadmask) == 0) return; - } + sig_task = get_threadtask(sig_actthread); + p = (proc_t)(get_bsdtask_info(sig_task)); - s = splhigh(); - KNOTE(&p->p_klist, NOTE_SIGNAL | signum); - splx(s); + uth = get_bsdthread_info(sig_actthread); + if (uth->uu_flag & UT_VFORK) + p = uth->uu_proc; - /* - * do not send signals to the process that has the thread - * doing a reboot(). Not doing so will mark that thread aborted - * and can cause IO failures wich will cause data loss. - */ - if (ISSET(p->p_flag, P_REBOOT)) { - if (sw_funnel) - thread_funnel_set(kernel_flock, funnel_state); + proc_lock(p); + if (!(p->p_lflag & P_LTRACED) && (p->p_sigignore & mask)) { + proc_unlock(p); return; } - if (withlock) - signal_lock(p); + uth->uu_siglist |= mask; + uth->uu_code = code; - /* - * 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. - */ - - if (((p->p_flag & P_TRACED) == 0) && (p->p_sigignore & mask)) - goto psigout; + /* 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 successful return with ast set */ - sig_thread_act = get_signalthread(p, signum); + 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); - if (sig_thread_act == THREAD_NULL) { - /* XXXX FIXME - * if it is sigkill, may be we should - * inject a thread to terminate - */ -#if SIGNAL_DEBUG - ram_printf(1); -#endif /* SIGNAL_DEBUG */ - goto psigout; - } + os_reason_t signal_reason = build_signal_reason(signum, "exc handler"); - uth = get_bsdthread_info(sig_thread_act); + set_thread_exit_reason(sig_actthread, signal_reason, TRUE); - /* - * If proc is traced, always give parent a chance. - */ - if (p->p_flag & P_TRACED) - action = SIG_DFL; - else { - /* - * If the signal is being ignored, - * then we forget about it immediately. - * (Note: we don't set SIGCONT in p_sigignore, - * and if it is set to SIG_IGN, - * action will be SIG_DFL here.) - */ - if (p->p_sigignore & mask) - goto psigout; - /* sigwait takes precedence */ - if (uth->uu_sigwait & mask) - action = KERN_SIG_WAIT; - else if (uth->uu_sigmask & mask) - action = KERN_SIG_HOLD; - else if (p->p_sigcatch & mask) - action = KERN_SIG_CATCH; - else - action = SIG_DFL; + /* We dropped/consumed the reference in set_thread_exit_reason() */ + signal_reason = OS_REASON_NULL; + } } - if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) && - (p->p_flag & P_TRACED) == 0) - p->p_nice = NZERO; + proc_unlock(p); - if (prop & SA_CONT) { - uth->uu_siglist &= ~stopsigmask; - p->p_siglist &= ~stopsigmask; - } + /* mark on process as well */ + signal_setast(sig_actthread); +} - if (prop & SA_STOP) { - /* - * If sending a tty stop signal to a member of an orphaned - * process group, discard the signal here if the action - * is default; don't stop the process below if sleeping, - * and don't clear any pending SIGCONT. - */ - if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 && - action == SIG_DFL) - goto psigout; - uth->uu_siglist &= ~contsigmask; - p->p_siglist &= ~contsigmask; - } - uth->uu_siglist |= mask; - p->p_siglist |= mask; /* just for lame ones looking here */ +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; - - /* - * Defer further processing for signals which are held, - * except that stopped processes must be continued by SIGCONT. - */ - if (action == KERN_SIG_HOLD && ((prop & SA_CONT) == 0 || p->p_stat != SSTOP)) { - goto psigout; - } - /* - * 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. - */ - if ((signum == SIGKILL) && (p->p_nice > NZERO)) { - p->p_nice = NZERO; - } + os_reason_t exit_reason = (os_reason_t)reason; - /* - * Process is traced - wake it up (if not already - * stopped) so that it can discover the signal in - * issig() and stop for the parent. - */ - if (p->p_flag & P_TRACED) { - if (p->p_stat != SSTOP) - goto run; - else - goto psigout; - } + if (exit_reason == OS_REASON_NULL) + return; - if (action == KERN_SIG_WAIT) { - uth->uu_sigwait = mask; - uth->uu_siglist &= ~mask; - p->p_siglist &= ~mask; - wakeup(&uth->uu_sigwait); - /* if it is SIGCONT resume whole process */ - if (prop & SA_CONT) { - p->p_flag |= P_CONTINUED; - (void) task_resume(sig_task); - } - goto psigout; + if (!proc_locked) { + targ_task = get_threadtask(th); + targ_proc = (proc_t)(get_bsdtask_info(targ_task)); + + proc_lock(targ_proc); } - if (action != SIG_DFL) { - /* - * User wants to catch the signal. - * Wake up the thread, but don't un-suspend it - * (except for SIGCONT). - */ - if (prop & SA_CONT) { - if (p->p_flag & P_TTYSLEEP) { - p->p_flag &= ~P_TTYSLEEP; - wakeup(&p->p_siglist); - } else { - p->p_flag |= P_CONTINUED; - (void) task_resume(sig_task); - } - p->p_stat = SRUN; - } else if (p->p_stat == SSTOP) - goto psigout; - goto run; + if (targ_uth->uu_exit_reason == OS_REASON_NULL) { + targ_uth->uu_exit_reason = exit_reason; } else { - /* Default action - varies */ - if (mask & stopsigmask) { - /* - * These are the signals which by default - * stop a process. - * - * Don't clog system with children of init - * stopped from the keyboard. - */ - if (!(prop & SA_STOP) && p->p_pptr == initproc) { - psignal_lock(p, SIGKILL, 0); - uth->uu_siglist &= ~mask; - p->p_siglist &= ~mask; - goto psigout; - } - - /* - * Stop the task - * if task hasn't already been stopped by - * a signal. - */ - uth->uu_siglist &= ~mask; - p->p_siglist &= ~mask; - if (p->p_stat != SSTOP) { - p->p_xstat = signum; - stop(p); - if ((p->p_pptr->p_flag & P_NOCLDSTOP) == 0) { - struct proc *pp = p->p_pptr; + /* The caller expects that we drop a reference on the exit reason */ + os_reason_free(exit_reason); + } - pp->si_pid = p->p_pid; - pp->si_status = p->p_xstat; - pp->si_code = CLD_STOPPED; - pp->si_uid = p->p_ucred->cr_ruid; - psignal(pp, SIGCHLD); - } + 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) +{ + struct uthread *uth; + sigset_t mask = sigmask(signum); + 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) { + sig_thread = p->p_vforkact; + kret = check_actforsig(sig_task, sig_thread, 1); + if (kret == KERN_SUCCESS) { + *thr = sig_thread; + return(KERN_SUCCESS); + }else + return(KERN_FAILURE); + } + + 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; + return(KERN_SUCCESS); } - goto psigout; } + } + if (get_signalact(p->task, thr, 1) == KERN_SUCCESS) { + return(KERN_SUCCESS); + } - switch (signum) { - /* - * Signals ignored by default have been dealt - * with already, since their bits are on in - * p_sigignore. - */ - - case SIGKILL: - /* - * Kill signal always sets process running and - * unsuspends it. - */ - /* - * Process will be running after 'run' - */ - p->p_stat = SRUN; + return(KERN_FAILURE); +} - thread_abort(sig_thread_act); +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; - goto psigout; + 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; + } - case SIGCONT: - /* - * Let the process run. If it's sleeping on an - * event, it remains so. - */ - if (p->p_flag & P_TTYSLEEP) { - p->p_flag &= ~P_TTYSLEEP; - wakeup(&p->p_siglist); - } else { - p->p_flag |= P_CONTINUED; - (void) task_resume(sig_task); - } - uth->uu_siglist &= ~mask; - p->p_siglist &= ~mask; - p->p_stat = SRUN; + reason_buffer_size_estimate = kcdata_estimate_required_buffer_size(2, sizeof(sender_proc->p_name) + + sizeof(sender_proc->p_pid)); - goto psigout; + 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; + } - default: - /* - * All other signals wake up the process, but don't - * resume it. - */ - if (p->p_stat == SSTOP) - goto psigout; - goto run; + 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); } - } - /*NOTREACHED*/ -run: - /* - * If we're being traced (possibly because someone attached us - * while we were stopped), check for a signal from the debugger. - */ - if (p->p_stat == SSTOP) { - if ((p->p_flag & P_TRACED) != 0 && p->p_xstat != 0) - uth->uu_siglist |= sigmask(p->p_xstat); } else { - /* - * setrunnable(p) in BSD and - * Wake up the thread if it is interruptible. - */ - p->p_stat = SRUN; - thread_abort_safely(sig_thread_act); + printf("build_signal_reason: exceeded space in signal reason buf, unable to log procname\n"); } -psigout: - if (withlock) - signal_unlock(p); - if (sw_funnel) - thread_funnel_set(kernel_flock, funnel_state); -} + return signal_reason; +} -/* psignal_lock(p, signum, withlock ) */ -void -psignal_uthread(thr_act, signum) - thread_t thr_act; - int signum; +/* + * 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. + * o SIGCONT restarts stopped processes (or puts them back to sleep) + * regardless of the signal action (eg, blocked or ignored). + * + * Other ignored signals are discarded immediately. + */ +static void +psignal_internal(proc_t p, task_t task, thread_t thread, int flavor, int signum, os_reason_t signal_reason) { - struct proc *p; - register int prop; - register sig_t action; - thread_t sig_thread_act; - register task_t sig_task; - int mask; - struct uthread *uth; - kern_return_t kret; - int error = 0; + int prop; + 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; - p = (struct proc *)get_bsdtask_info(get_threadtask(thr_act)); if ((u_int)signum >= NSIG || signum == 0) - panic("Invalid signal number in psignal_uthread"); + panic("psignal: bad signal number %d", signum); + mask = sigmask(signum); prop = sigprop[signum]; #if SIGNAL_DEBUG - if(rdebug_proc && (p == rdebug_proc)) { + if(rdebug_proc && (p != PROC_NULL) && (p == rdebug_proc)) { ram_printf(3); } #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 * to kernel internal tasks. */ - if (((sig_task = p->task) == TASK_NULL) || is_kerneltask(sig_task)) { + if (flavor & PSIG_VFORK) { + sig_task = task; + sig_thread = thread; + sig_proc = p; + } else if (flavor & PSIG_THREAD) { + 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 = THREAD_NULL; + sig_proc = p; + } + + if ((sig_task == TASK_NULL) || is_kerneltask(sig_task)) { + os_reason_free(signal_reason); return; } - sig_thread_act = thr_act; /* * do not send signals to the process that has the thread * doing a reboot(). Not doing so will mark that thread aborted - * and can cause IO failures wich will cause data loss. + * and can cause IO failures wich will cause data loss. There's + * also no need to send a signal to a process that is in the middle + * of being torn down. */ - if (ISSET(p->p_flag, P_REBOOT)) { + 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; } - signal_lock(p); + if( (flavor & (PSIG_VFORK | PSIG_THREAD)) == 0) { + proc_knote(sig_proc, NOTE_SIGNAL | signum); + } + + if ((flavor & PSIG_LOCKED)== 0) + proc_signalstart(sig_proc, 0); + + /* 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 sigout_unlocked; + } /* - * 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. + * 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? */ - - if (((p->p_flag & P_TRACED) == 0) && (p->p_sigignore & mask)) - goto puthout; + proc_lock(sig_proc); - kret = check_actforsig(sig_task, sig_thread_act, 1); + 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); + } else { + /* If successful return with ast set */ + kret = get_signalthread(sig_proc, signum, &sig_thread); + } if (kret != KERN_SUCCESS) { - error = EINVAL; - goto puthout; + 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_act); + uth = get_bsdthread_info(sig_thread); /* * If proc is traced, always give parent a chance. */ - if (p->p_flag & P_TRACED) - action = SIG_DFL; - else { - /* - * If the signal is being ignored, - * then we forget about it immediately. - * (Note: we don't set SIGCONT in p_sigignore, - * and if it is set to SIG_IGN, - * action will be SIG_DFL here.) - */ - if (p->p_sigignore & mask) - goto puthout; - /* sigwait takes precedence */ - if (uth->uu_sigwait & mask) - action = KERN_SIG_WAIT; - else if (uth->uu_sigmask & mask) - action = KERN_SIG_HOLD; - else if (p->p_sigcatch & mask) - action = KERN_SIG_CATCH; - else + + if ((flavor & PSIG_VFORK) == 0) { + if (sig_proc->p_lflag & P_LTRACED) action = SIG_DFL; + else { + /* + * If the signal is being ignored, + * then we forget about it immediately. + * (Note: we don't set SIGCONT in p_sigignore, + * and if it is set to SIG_IGN, + * action will be SIG_DFL here.) + */ + if (sig_proc->p_sigignore & mask) + goto sigout_locked; + + if (uth->uu_sigwait & mask) + action = KERN_SIG_WAIT; + else if (uth->uu_sigmask & mask) + action = KERN_SIG_HOLD; + else if (sig_proc->p_sigcatch & mask) + action = KERN_SIG_CATCH; + else + action = SIG_DFL; + } } - if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) && - (p->p_flag & P_TRACED) == 0) - p->p_nice = NZERO; + /* 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; - if (prop & SA_CONT) { + if (prop & SA_CONT) uth->uu_siglist &= ~stopsigmask; - p->p_siglist &= ~stopsigmask; - } if (prop & SA_STOP) { + struct pgrp *pg; /* * If sending a tty stop signal to a member of an orphaned * process group, discard the signal here if the action * is default; don't stop the process below if sleeping, * and don't clear any pending SIGCONT. */ - if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 && - action == SIG_DFL) - goto puthout; + pg = proc_pgrp(sig_proc); + if (prop & SA_TTYSTOP && pg->pg_jobc == 0 && + action == SIG_DFL) { + pg_rele(pg); + goto sigout_locked; + } + pg_rele(pg); uth->uu_siglist &= ~contsigmask; - p->p_siglist &= ~contsigmask; } + uth->uu_siglist |= mask; - p->p_siglist |= mask; /* just for lame ones looking here */ /* * Defer further processing for signals which are held, * except that stopped processes must be continued by SIGCONT. */ - if (action == KERN_SIG_HOLD && ((prop & SA_CONT) == 0 || p->p_stat != SSTOP)) - goto puthout; - + /* vfork will not go thru as action is SIG_DFL */ + 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) && (p->p_nice > NZERO)) { - p->p_nice = NZERO; + if ((signum == SIGKILL) && (sig_proc->p_nice > NZERO)) { + sig_proc->p_nice = NZERO; } /* @@ -1918,24 +2320,41 @@ psignal_uthread(thr_act, signum) * stopped) so that it can discover the signal in * issig() and stop for the parent. */ - if (p->p_flag & P_TRACED) { - if (p->p_stat != SSTOP) - goto psurun; + if (sig_proc->p_lflag & P_LTRACED) { + if (sig_proc->p_stat != SSTOP) + goto runlocked; else - goto puthout; + goto sigout_locked; } + if ((flavor & PSIG_VFORK) != 0) + goto runlocked; + if (action == KERN_SIG_WAIT) { +#if CONFIG_DTRACE + /* + * DTrace proc signal-clear returns a siginfo_t. Collect the needed info. + */ + r_uid = kauth_getruid(); /* per thread credential; protected by our thread context */ + + bzero((caddr_t)&(uth->t_dtrace_siginfo), sizeof(uth->t_dtrace_siginfo)); + + uth->t_dtrace_siginfo.si_signo = signum; + uth->t_dtrace_siginfo.si_pid = current_proc()->p_pid; + uth->t_dtrace_siginfo.si_status = W_EXITCODE(signum, 0); + uth->t_dtrace_siginfo.si_uid = r_uid; + uth->t_dtrace_siginfo.si_code = 0; +#endif uth->uu_sigwait = mask; uth->uu_siglist &= ~mask; - p->p_siglist &= ~mask; wakeup(&uth->uu_sigwait); /* if it is SIGCONT resume whole process */ if (prop & SA_CONT) { - p->p_flag |= P_CONTINUED; - (void) task_resume(sig_task); + OSBitOrAtomic(P_CONTINUED, &sig_proc->p_flag); + sig_proc->p_contproc = current_proc()->p_pid; + (void) task_resume_internal(sig_task); } - goto puthout; + goto sigout_locked; } if (action != SIG_DFL) { @@ -1945,13 +2364,38 @@ psignal_uthread(thr_act, signum) * (except for SIGCONT). */ if (prop & SA_CONT) { - p->p_flag |= P_CONTINUED; - (void) task_resume(sig_task); + OSBitOrAtomic(P_CONTINUED, &sig_proc->p_flag); + (void) task_resume_internal(sig_task); + sig_proc->p_stat = SRUN; + } else if (sig_proc->p_stat == SSTOP) { + goto sigout_locked; + } + /* + * Fill out siginfo structure information to pass to the + * signalled process/thread sigaction handler, when it + * wakes up. si_code is 0 because this is an ordinary + * signal, not a SIGCHLD, and so si_status is the signal + * number itself, instead of the child process exit status. + * We shift this left because it will be shifted right before + * it is passed to user space. kind of ugly to use W_EXITCODE + * this way, but it beats defining a new macro. + * + * Note: Avoid the SIGCHLD recursion case! + */ + if (signum != SIGCHLD) { + r_uid = kauth_getruid(); + + sig_proc->si_pid = current_proc()->p_pid; + sig_proc->si_status = W_EXITCODE(signum, 0); + sig_proc->si_uid = r_uid; + sig_proc->si_code = 0; } - goto psurun; + + goto runlocked; } else { /* Default action - varies */ if (mask & stopsigmask) { + assert(signal_reason == NULL); /* * These are the signals which by default * stop a process. @@ -1959,36 +2403,64 @@ psignal_uthread(thr_act, signum) * Don't clog system with children of init * stopped from the keyboard. */ - if (!(prop & SA_STOP) && p->p_pptr == initproc) { - psignal_lock(p, SIGKILL, 0); + if (!(prop & SA_STOP) && sig_proc->p_pptr == initproc) { uth->uu_siglist &= ~mask; - p->p_siglist &= ~mask; - goto puthout; + proc_unlock(sig_proc); + /* 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 * a signal. */ uth->uu_siglist &= ~mask; - p->p_siglist &= ~mask; - if (p->p_stat != SSTOP) { - p->p_xstat = signum; - if ((p->p_pptr->p_flag & P_NOCLDSTOP) == 0) { - struct proc *pp = p->p_pptr; - - pp->si_pid = p->p_pid; - pp->si_status = p->p_xstat; + if (sig_proc->p_stat != SSTOP) { + sig_proc->p_xstat = signum; + sig_proc->p_stat = SSTOP; + OSBitAndAtomic(~((uint32_t)P_CONTINUED), &sig_proc->p_flag); + sig_proc->p_lflag &= ~P_LWAITED; + proc_unlock(sig_proc); + + pp = proc_parentholdref(sig_proc); + stop(sig_proc, pp); + if (( pp != PROC_NULL) && ((pp->p_flag & P_NOCLDSTOP) == 0)) { + + my_cred = kauth_cred_proc_ref(sig_proc); + r_uid = kauth_cred_getruid(my_cred); + kauth_cred_unref(&my_cred); + + proc_lock(sig_proc); + pp->si_pid = sig_proc->p_pid; + /* + * POSIX: sigaction for a stopped child + * when sent to the parent must set the + * child's signal number into si_status. + */ + if (signum != SIGSTOP) + pp->si_status = WEXITSTATUS(sig_proc->p_xstat); + else + pp->si_status = W_EXITCODE(signum, signum); pp->si_code = CLD_STOPPED; - pp->si_uid = p->p_ucred->cr_ruid; + pp->si_uid = r_uid; + proc_unlock(sig_proc); + psignal(pp, SIGCHLD); } - stop(p); + if (pp != PROC_NULL) { + proc_parentdropref(pp, 0); + } + + goto sigout_unlocked; } - goto puthout; + + goto sigout_locked; } + DTRACE_PROC3(signal__send, thread_t, sig_thread, proc_t, p, int, signum); + switch (signum) { /* * Signals ignored by default have been dealt @@ -2004,101 +2476,197 @@ psignal_uthread(thr_act, signum) /* * Process will be running after 'run' */ - p->p_stat = SRUN; + sig_proc->p_stat = SRUN; + /* + * In scenarios where suspend/resume are racing + * the signal we are missing AST_BSD by the time + * we get here, set again to avoid races. This + * was the scenario with spindump enabled shutdowns. + * We would need to cover this approp down the line. + */ + act_set_astbsd(sig_thread); + kret = thread_abort(sig_thread); + update_thread_policy = (kret == KERN_SUCCESS); - thread_abort(sig_thread_act); + 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 puthout; + goto sigout_locked; case SIGCONT: /* * Let the process run. If it's sleeping on an * event, it remains so. */ - if (p->p_flag & P_TTYSLEEP) { - p->p_flag &= ~P_TTYSLEEP; - wakeup(&p->p_siglist); - } else { - p->p_flag |= P_CONTINUED; - (void) task_resume(sig_task); + assert(signal_reason == NULL); + OSBitOrAtomic(P_CONTINUED, &sig_proc->p_flag); + sig_proc->p_contproc = sig_proc->p_pid; + sig_proc->p_xstat = signum; + + (void) task_resume_internal(sig_task); + + /* + * When processing a SIGCONT, we need to check + * to see if there are signals pending that + * were not delivered because we had been + * previously stopped. If that's the case, + * we need to thread_abort_safely() to trigger + * interruption of the current system call to + * cause their handlers to fire. If it's only + * the SIGCONT, then don't wake up. + */ + if (((flavor & (PSIG_VFORK|PSIG_THREAD)) == 0) && (((uth->uu_siglist & ~uth->uu_sigmask) & ~sig_proc->p_sigignore) & ~mask)) { + uth->uu_siglist &= ~mask; + sig_proc->p_stat = SRUN; + goto runlocked; } + uth->uu_siglist &= ~mask; - p->p_siglist &= ~mask; - p->p_stat = SRUN; - goto puthout; + sig_proc->p_stat = SRUN; + goto sigout_locked; default: + /* + * A signal which has a default action of killing + * the process, and for which there is no handler, + * needs to act like SIGKILL + */ + if (((flavor & (PSIG_VFORK|PSIG_THREAD)) == 0) && (action == SIG_DFL) && (prop & SA_KILL)) { + sig_proc->p_stat = SRUN; + 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; + } + /* * All other signals wake up the process, but don't * resume it. */ - goto psurun; + if (sig_proc->p_stat == SSTOP) { + goto sigout_locked; + } + goto runlocked; } } /*NOTREACHED*/ -psurun: + +runlocked: /* * If we're being traced (possibly because someone attached us * while we were stopped), check for a signal from the debugger. */ - if (p->p_stat == SSTOP) { - if ((p->p_flag & P_TRACED) != 0 && p->p_xstat != 0) { - uth->uu_siglist |= sigmask(p->p_xstat); - p->p_siglist |= sigmask(p->p_xstat); + 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); + + if ((flavor & PSIG_VFORK) != 0) { + sig_proc->p_stat = SRUN; } } else { /* * setrunnable(p) in BSD and * Wake up the thread if it is interruptible. */ - p->p_stat = SRUN; - thread_abort_safely(sig_thread_act); + sig_proc->p_stat = SRUN; + if ((flavor & PSIG_VFORK) == 0) + thread_abort_safely(sig_thread); + } + +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); } -puthout: - signal_unlock(p); + proc_unlock(sig_proc); + +sigout_unlocked: + os_reason_free(signal_reason); + if ((flavor & PSIG_LOCKED)== 0) { + proc_signalend(sig_proc, 0); + } } +void +psignal(proc_t p, int signum) +{ + psignal_internal(p, NULL, NULL, 0, signum, NULL); +} -__inline__ void -sig_lock_to_exit(struct proc *p) +void +psignal_with_reason(proc_t p, int signum, struct os_reason *signal_reason) { - thread_t self = current_thread(); + psignal_internal(p, NULL, NULL, 0, signum, signal_reason); +} - p->exit_thread = self; - (void) task_suspend(p->task); +void +psignal_locked(proc_t p, int signum) +{ + psignal_internal(p, NULL, NULL, PSIG_LOCKED, signum, NULL); } -__inline__ int -sig_try_locked(struct proc *p) +void +psignal_vfork_with_reason(proc_t p, task_t new_task, thread_t thread, int signum, struct os_reason *signal_reason) { - thread_t self = current_thread(); + psignal_internal(p, new_task, thread, PSIG_VFORK, signum, signal_reason); +} - while (p->sigwait || p->exit_thread) { - if (p->exit_thread) { - if (p->exit_thread != self) { - /* - * Already exiting - no signals. - */ - thread_abort(self); - } - return(0); - } - if(assert_wait_possible()) { - assert_wait((caddr_t)&p->sigwait_thread, - (THREAD_INTERRUPTIBLE)); - } - signal_unlock(p); - thread_block(THREAD_CONTINUE_NULL); - signal_lock(p); - if (thread_should_abort(self)) { - /* - * Terminate request - clean up. - */ - return -1; - } - } - return 1; + +void +psignal_vfork(proc_t p, task_t new_task, thread_t thread, int signum) +{ + psignal_internal(p, new_task, thread, PSIG_VFORK, signum, NULL); +} + +void +psignal_uthread(thread_t thread, int 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); } /* @@ -2114,140 +2682,149 @@ sig_try_locked(struct proc *p) * postsig(signum); */ int -issignal(p) - register struct proc *p; +issignal_locked(proc_t p) { - register int signum, mask, prop, sigbits; + int signum, mask, prop, sigbits; thread_t cur_act; struct uthread * ut; - struct proc *pp; + proc_t pp; + kauth_cred_t my_cred; + int retval = 0; + uid_t r_uid; 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 */ - signal_lock(p); /* * Try to grab the signal lock. */ if (sig_try_locked(p) <= 0) { - signal_unlock(p); - 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_flag & P_PPWAIT) + if (p->p_lflag & P_LPPWAIT) sigbits &= ~stopsigmask; if (sigbits == 0) { /* no signal to send */ - signal_unlock(p); - return (0); + retval = 0; + goto out; } + signum = ffs((long)sigbits); mask = sigmask(signum); prop = sigprop[signum]; /* * We should see pending but ignored signals - * only if P_TRACED was on when they were posted. + * only if P_LTRACED was on when they were posted. */ - if (mask & p->p_sigignore && (p->p_flag & P_TRACED) == 0) { - ut->uu_siglist &= ~mask; /* take the signal! */ - p->p_siglist &= ~mask; /* take the signal! */ + if (mask & p->p_sigignore && (p->p_lflag & P_LTRACED) == 0) { + ut->uu_siglist &= ~mask; continue; } - if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { - register task_t task; + + if (p->p_lflag & P_LTRACED && (p->p_lflag & P_LPPWAIT) == 0) { /* - * 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; - pp = p->p_pptr; - if (p->p_flag & P_SIGEXC) { + + if (p->p_lflag & P_LSIGEXC) { p->sigwait = TRUE; p->sigwait_thread = cur_act; p->p_stat = SSTOP; - p->p_flag &= ~(P_WAITED|P_CONTINUED); - ut->uu_siglist &= ~mask; /* clear the old signal */ - p->p_siglist &= ~mask; /* clear the old signal */ - signal_unlock(p); + OSBitAndAtomic(~((uint32_t)P_CONTINUED), &p->p_flag); + p->p_lflag &= ~P_LWAITED; + 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); - signal_lock(p); + proc_lock(p); + proc_signalstart(p, 1); } else { -// panic("Unsupportef gdb option \n");; - pp->si_pid = p->p_pid; - pp->si_status = p->p_xstat; - pp->si_code = CLD_TRAPPED; - pp->si_uid = p->p_ucred->cr_ruid; - psignal(pp, SIGCHLD); + proc_unlock(p); + my_cred = kauth_cred_proc_ref(p); + r_uid = kauth_cred_getruid(my_cred); + kauth_cred_unref(&my_cred); + + pp = proc_parentholdref(p); + if (pp != PROC_NULL) { + proc_lock(pp); + + pp->si_pid = p->p_pid; + pp->p_xhighbits = p->p_xhighbits; + p->p_xhighbits = 0; + pp->si_status = p->p_xstat; + pp->si_code = CLD_TRAPPED; + pp->si_uid = r_uid; + + proc_unlock(pp); + } + /* * 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_hold(task); + task_suspend_internal(task); + + proc_lock(p); p->sigwait = TRUE; p->sigwait_thread = cur_act; p->p_stat = SSTOP; - p->p_flag &= ~(P_WAITED|P_CONTINUED); - ut->uu_siglist &= ~mask; /* clear the old signal */ - p->p_siglist &= ~mask; /* clear the old signal */ + OSBitAndAtomic(~((uint32_t)P_CONTINUED), &p->p_flag); + p->p_lflag &= ~P_LWAITED; + ut->uu_siglist &= ~mask; + + proc_signalend(p, 1); + proc_unlock(p); + + if (pp != PROC_NULL) { + psignal(pp, SIGCHLD); + proc_list_lock(); + wakeup((caddr_t)pp); + proc_parentdropref(pp, 1); + proc_list_unlock(); + } - wakeup((caddr_t)p->p_pptr); - signal_unlock(p); assert_wait((caddr_t)&p->sigwait, (THREAD_INTERRUPTIBLE)); thread_block(THREAD_CONTINUE_NULL); - signal_lock(p); + proc_lock(p); + proc_signalstart(p, 1); } p->sigwait = FALSE; 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.) - */ - signal_unlock(p); - exit1(p,signum, (int *)NULL); - return(0); + signum = SIGKILL; + goto deliver_sig; } - /* - * We may have to quit - */ + /* We may have to quit. */ if (thread_should_abort(current_thread())) { - signal_unlock(p); - return(0); + retval = 0; + goto out; } + /* * If parent wants us to take the signal, * then it will leave it in p->p_xstat; @@ -2256,13 +2833,13 @@ issignal(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. */ mask = sigmask(signum); ut->uu_siglist |= mask; - p->p_siglist |= mask; /* just for lame ones looking here */ if (ut->uu_sigmask & mask) continue; } @@ -2274,23 +2851,8 @@ issignal(p) */ switch ((long)p->p_sigacts->ps_sigact[signum]) { - + case (long)SIG_DFL: - /* - * Don't take default actions on system processes. - */ - if (p->p_pptr->p_pid == 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, @@ -2299,36 +2861,55 @@ issignal(p) * process group, ignore tty stop signals. */ if (prop & SA_STOP) { - if (p->p_flag & P_TRACED || - (p->p_pgrp->pg_jobc == 0 && - prop & SA_TTYSTOP)) - break; /* == ignore */ + struct pgrp * pg; + + proc_unlock(p); + pg = proc_pgrp(p); + if (p->p_lflag & P_LTRACED || + (pg->pg_jobc == 0 && + prop & SA_TTYSTOP)) { + proc_lock(p); + pg_rele(pg); + break; /* ignore signal */ + } + pg_rele(pg); if (p->p_stat != SSTOP) { + proc_lock(p); p->p_xstat = signum; - stop(p); - if ((p->p_pptr->p_flag & P_NOCLDSTOP) == 0) { - pp = p->p_pptr; + p->p_stat = SSTOP; + p->p_lflag &= ~P_LWAITED; + proc_unlock(p); + + pp = proc_parentholdref(p); + stop(p, pp); + if ((pp != PROC_NULL) && ((pp->p_flag & P_NOCLDSTOP) == 0)) { + my_cred = kauth_cred_proc_ref(p); + r_uid = kauth_cred_getruid(my_cred); + kauth_cred_unref(&my_cred); + + proc_lock(pp); pp->si_pid = p->p_pid; - pp->si_status = p->p_xstat; + pp->si_status = WEXITSTATUS(p->p_xstat); pp->si_code = CLD_STOPPED; - pp->si_uid = p->p_ucred->cr_ruid; + pp->si_uid = r_uid; + proc_unlock(pp); + psignal(pp, SIGCHLD); } + if (pp != PROC_NULL) + proc_parentdropref(pp, 0); } + proc_lock(p); break; } else if (prop & SA_IGNORE) { /* * 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! */ - p->p_siglist &= ~mask; /* take the signal! */ - signal_unlock(p); - return (signum); + goto deliver_sig; } - /*NOTREACHED*/ case (long)SIG_IGN: /* @@ -2337,32 +2918,36 @@ issignal(p) * than SIGCONT, unless process is traced. */ if ((prop & SA_CONT) == 0 && - (p->p_flag & P_TRACED) == 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! */ - p->p_siglist &= ~mask; /* take the signal! */ - signal_unlock(p); - return (signum); - } - ut->uu_siglist &= ~mask; /* take the signal! */ - p->p_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; } /* called from _sleep */ int -CURSIG(p) - register struct proc *p; +CURSIG(proc_t p) { - register int signum, mask, prop, sigbits; + int signum, mask, prop, sigbits; thread_t cur_act; struct uthread * ut; int retnum = 0; @@ -2375,13 +2960,13 @@ CURSIG(p) if (ut->uu_siglist == 0) return (0); - if (((ut->uu_siglist & ~ut->uu_sigmask) == 0) && ((p->p_flag & P_TRACED) == 0)) + if (((ut->uu_siglist & ~ut->uu_sigmask) == 0) && ((p->p_lflag & P_LTRACED) == 0)) return (0); sigbits = ut->uu_siglist & ~ut->uu_sigmask; for(;;) { - if (p->p_flag & P_PPWAIT) + if (p->p_lflag & P_LPPWAIT) sigbits &= ~stopsigmask; if (sigbits == 0) { /* no signal to send */ return (retnum); @@ -2390,22 +2975,17 @@ CURSIG(p) signum = ffs((long)sigbits); mask = sigmask(signum); prop = sigprop[signum]; + sigbits &= ~mask; /* take the signal out */ /* * We should see pending but ignored signals - * only if P_TRACED was on when they were posted. + * only if P_LTRACED was on when they were posted. */ - if (mask & p->p_sigignore && (p->p_flag & P_TRACED) == 0) { + if (mask & p->p_sigignore && (p->p_lflag & P_LTRACED) == 0) { continue; } - if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { - /* - * Put the new signal into p_siglist. If the - * signal is being masked, look for other signals. - */ - mask = sigmask(signum); - if (ut->uu_sigmask & mask) - continue; + + if (p->p_lflag & P_LTRACED && (p->p_lflag & P_LPPWAIT) == 0) { return(signum); } @@ -2418,21 +2998,6 @@ CURSIG(p) switch ((long)p->p_sigacts->ps_sigact[signum]) { case (long)SIG_DFL: - /* - * Don't take default actions on system processes. - */ - if (p->p_pptr->p_pid == 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, @@ -2441,10 +3006,17 @@ CURSIG(p) * process group, ignore tty stop signals. */ if (prop & SA_STOP) { - if (p->p_flag & P_TRACED || - (p->p_pgrp->pg_jobc == 0 && - prop & SA_TTYSTOP)) + struct pgrp *pg; + + pg = proc_pgrp(p); + + if (p->p_lflag & P_LTRACED || + (pg->pg_jobc == 0 && + prop & SA_TTYSTOP)) { + pg_rele(pg); break; /* == ignore */ + } + pg_rele(pg); retnum = signum; break; } else if (prop & SA_IGNORE) { @@ -2465,7 +3037,7 @@ CURSIG(p) * than SIGCONT, unless process is traced. */ if ((prop & SA_CONT) == 0 && - (p->p_flag & P_TRACED) == 0) + (p->p_lflag & P_LTRACED) == 0) printf("issignal\n"); break; /* == ignore */ @@ -2476,7 +3048,6 @@ CURSIG(p) */ return (signum); } - sigbits &= ~mask; /* take the signal! */ } /* NOTREACHED */ } @@ -2486,15 +3057,16 @@ CURSIG(p) * via wakeup. Signals are handled elsewhere. The process must not be * on the run queue. */ -void -stop(p) - register struct proc *p; +static void +stop(proc_t p, proc_t parent) { - p->p_stat = SSTOP; - p->p_flag &= ~(P_WAITED|P_CONTINUED); - if (p->p_pptr->p_stat != SSTOP) - wakeup((caddr_t)p->p_pptr); - (void) task_suspend(p->task); /*XXX*/ + OSBitAndAtomic(~((uint32_t)P_CONTINUED), &p->p_flag); + if ((parent != PROC_NULL) && (parent->p_stat != SSTOP)) { + proc_list_lock(); + wakeup((caddr_t)parent); + proc_list_unlock(); + } + (void) task_suspend_internal(p->task); } /* @@ -2502,12 +3074,12 @@ stop(p) * from the current set of pending signals. */ void -postsig(int signum) +postsig_locked(int signum) { - struct proc *p = current_proc(); + proc_t p = current_proc(); struct sigacts *ps = p->p_sigacts; user_addr_t catcher; - u_long code; + uint32_t code; int mask, returnmask; struct uthread * ut; @@ -2521,36 +3093,73 @@ postsig(int signum) panic("psig not on master"); #endif - signal_lock(p); /* * Try to grab the signal lock. */ if (sig_try_locked(p) <= 0) { - signal_unlock(p); return; } + proc_signalstart(p, 1); + ut = (struct uthread *)get_bsdthread_info(current_thread()); mask = sigmask(signum); ut->uu_siglist &= ~mask; - p->p_siglist &= ~mask; catcher = ps->ps_sigact[signum]; -#if KTRACE - //LP64: catcher argument is a 64 bit user space handler address - if (KTRPOINT(p, KTR_PSIG)) - ktrpsig(p->p_tracep, - signum, CAST_DOWN(void *,catcher), ut->uu_flag & UT_SAS_OLDMASK ? - &ut->uu_oldmask : &ut->uu_sigmask, 0); -#endif if (catcher == SIG_DFL) { /* * Default catcher, where the default is to kill * the process. (Other cases were ignored above.) */ - /* called with signal_lock() held */ - sigexit_locked(p, signum); + sig_lock_to_exit(p); + p->p_acflag |= AXSIG; + if (sigprop[signum] & SA_CORE) { + p->p_sigacts->ps_sig = signum; + proc_signalend(p, 1); + proc_unlock(p); +#if CONFIG_COREDUMP + if (coredump(p, 0, 0) == 0) + signum |= WCOREFLAG; +#endif + } else { + proc_signalend(p, 1); + proc_unlock(p); + } + +#if CONFIG_DTRACE + bzero((caddr_t)&(ut->t_dtrace_siginfo), sizeof(ut->t_dtrace_siginfo)); + + ut->t_dtrace_siginfo.si_signo = signum; + ut->t_dtrace_siginfo.si_pid = p->si_pid; + ut->t_dtrace_siginfo.si_uid = p->si_uid; + ut->t_dtrace_siginfo.si_status = WEXITSTATUS(p->si_status); + + /* Fire DTrace proc:::fault probe when signal is generated by hardware. */ + switch (signum) { + case SIGILL: case SIGBUS: case SIGSEGV: case SIGFPE: case SIGTRAP: + DTRACE_PROC2(fault, int, (int)(ut->uu_code), siginfo_t *, &(ut->t_dtrace_siginfo)); + break; + default: + break; + } + + + DTRACE_PROC3(signal__handle, int, signum, siginfo_t *, &(ut->t_dtrace_siginfo), + void (*)(void), SIG_DFL); +#endif + + KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_FRCEXIT) | DBG_FUNC_NONE, + p->p_pid, W_EXITCODE(0, signum), 3, 0, 0); + + /* + * 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; - /* NOTREACHED */ } else { /* * If we get here, the signal must be caught. @@ -2560,6 +3169,7 @@ postsig(int signum) log(LOG_WARNING, "postsig: processing masked or ignored signal\n"); #endif + /* * Set the new mask value and also defer further * occurences of this signal. @@ -2585,12 +3195,6 @@ postsig(int signum) ps->ps_siginfo &= ~mask; ps->ps_signodefer &= ~mask; } -#ifdef __ppc__ - /* Needs to disable to run in user mode */ - if (signum == SIGFPE) { - thread_enable_fpe(current_thread(), 0); - } -#endif /* __ppc__ */ if (ps->ps_sig != signum) { code = 0; @@ -2598,69 +3202,61 @@ postsig(int signum) code = ps->ps_code; ps->ps_code = 0; } - p->p_stats->p_ru.ru_nsignals++; + OSIncrementAtomicLong(&p->p_stats->p_ru.ru_nsignals); sendsig(p, catcher, signum, returnmask, code); } - signal_unlock(p); + proc_signalend(p, 1); } /* - * Force the current process to exit with the specified signal, dumping core - * if appropriate. We bypass the normal tests for masked and caught signals, - * allowing unrecoverable failures to terminate the process without changing - * signal state. Mark the accounting record with the signal termination. - * If dumping core, save the signal number for the debugger. Calls exit and - * does not return. + * Attach a signal knote to the list of knotes for this process. + * + * Signal knotes share the knote list with proc knotes. This + * could be avoided by using a signal-specific knote list, but + * probably isn't worth the trouble. */ - /* called with signal lock */ -void -sigexit_locked(p, signum) - register struct proc *p; - int signum; -{ - - sig_lock_to_exit(p); - p->p_acflag |= AXSIG; - if (sigprop[signum] & SA_CORE) { - p->p_sigacts->ps_sig = signum; - signal_unlock(p); - if (coredump(p) == 0) - signum |= WCOREFLAG; - } else - signal_unlock(p); - - exit1(p, W_EXITCODE(0, signum), (int *)NULL); - /* NOTREACHED */ -} - static int -filt_sigattach(struct knote *kn) +filt_sigattach(struct knote *kn, __unused struct kevent_internal_s *kev) { - struct proc *p = current_proc(); + proc_t p = current_proc(); /* can attach only to oneself */ + + proc_klist_lock(); kn->kn_ptr.p_proc = p; - kn->kn_flags |= EV_CLEAR; /* automatically set */ - /* XXX lock the proc here while adding to the list? */ KNOTE_ATTACH(&p->p_klist, kn); + proc_klist_unlock(); + + /* edge-triggered events can't have fired before we attached */ return (0); } +/* + * remove the knote from the process list, if it hasn't already + * been removed by exit processing. + */ + static void filt_sigdetach(struct knote *kn) { - struct proc *p = kn->kn_ptr.p_proc; + proc_t p = kn->kn_ptr.p_proc; + proc_klist_lock(); + kn->kn_ptr.p_proc = NULL; KNOTE_DETACH(&p->p_klist, kn); + proc_klist_unlock(); } /* - * signal knotes are shared with proc knotes, so we apply a mask to - * the hint in order to differentiate them from process hints. This - * could be avoided by using a signal-specific knote list, but probably - * isn't worth the trouble. + * Post an event to the signal filter. Because we share the same list + * as process knotes, we have to filter out and handle only signal events. + * + * We assume that we process fdfree() before we post the NOTE_EXIT for + * a process during exit. Therefore, since signal filters can only be + * set up "in-process", we should have already torn down the kqueue + * hosting the EVFILT_SIGNAL knote and should never see NOTE_EXIT. */ static int filt_signal(struct knote *kn, long hint) @@ -2671,109 +3267,219 @@ filt_signal(struct knote *kn, long hint) if (kn->kn_id == (unsigned int)hint) kn->kn_data++; + } else if (hint & NOTE_EXIT) { + panic("filt_signal: detected NOTE_EXIT event"); } + return (kn->kn_data != 0); } +static int +filt_signaltouch( + struct knote *kn, + struct kevent_internal_s *kev) +{ +#pragma unused(kev) + + int res; + + proc_klist_lock(); + + 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 -bsd_ast(thread_t thr_act) +bsd_ast(thread_t thread) { - struct proc *p = current_proc(); - struct uthread *ut = get_bsdthread_info(thr_act); + proc_t p = current_proc(); + struct uthread *ut = get_bsdthread_info(thread); int signum; user_addr_t pc; - boolean_t funnel_state; static int bsd_init_done = 0; if (p == NULL) return; - funnel_state = thread_funnel_set(kernel_flock, TRUE); + /* 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); - p->p_flag &= ~P_OWEUPC; + OSBitAndAtomic(~((uint32_t)P_OWEUPC), &p->p_flag); } - if (CHECK_SIGNALS(p, current_thread(), ut)) { - while ( (signum = issignal(p)) ) - postsig(signum); + if (timerisset(&p->p_vtimer_user.it_value)) { + uint32_t microsecs; + + task_vtimer_update(p->task, TASK_VTIMER_USER, µsecs); + + if (!itimerdecr(p, &p->p_vtimer_user, microsecs)) { + if (timerisset(&p->p_vtimer_user.it_value)) + task_vtimer_set(p->task, TASK_VTIMER_USER); + else + task_vtimer_clear(p->task, TASK_VTIMER_USER); + + psignal_try_thread(p, thread, SIGVTALRM); + } } - if (!bsd_init_done) { - bsd_init_done = 1; - bsdinit_task(); + + if (timerisset(&p->p_vtimer_prof.it_value)) { + uint32_t microsecs; + + task_vtimer_update(p->task, TASK_VTIMER_PROF, µsecs); + + if (!itimerdecr(p, &p->p_vtimer_prof, microsecs)) { + if (timerisset(&p->p_vtimer_prof.it_value)) + task_vtimer_set(p->task, TASK_VTIMER_PROF); + else + task_vtimer_clear(p->task, TASK_VTIMER_PROF); + + psignal_try_thread(p, thread, SIGPROF); + } } - (void) thread_funnel_set(kernel_flock, FALSE); -} + if (timerisset(&p->p_rlim_cpu)) { + struct timeval tv; -/* - * Follwing routines are called using callout from bsd_hardclock - * so that psignals are called in a thread context and are funneled - */ -void -psignal_vtalarm(struct proc *p) -{ - boolean_t funnel_state; + task_vtimer_update(p->task, TASK_VTIMER_RLIM, (uint32_t *) &tv.tv_usec); - if (p == NULL) - return; - funnel_state = thread_funnel_set(kernel_flock, TRUE); - psignal_lock(p, SIGVTALRM, 1); - (void) thread_funnel_set(kernel_flock, FALSE); -} + proc_spinlock(p); + if (p->p_rlim_cpu.tv_sec > 0 || p->p_rlim_cpu.tv_usec > tv.tv_usec) { + tv.tv_sec = 0; + timersub(&p->p_rlim_cpu, &tv, &p->p_rlim_cpu); + proc_spinunlock(p); + } else { -void -psignal_xcpu(struct proc *p) -{ - boolean_t funnel_state; + timerclear(&p->p_rlim_cpu); + proc_spinunlock(p); - if (p == NULL) - return; - funnel_state = thread_funnel_set(kernel_flock, TRUE); - psignal_lock(p, SIGXCPU, 1); - (void) thread_funnel_set(kernel_flock, FALSE); -} + task_vtimer_clear(p->task, TASK_VTIMER_RLIM); -void -psignal_sigprof(struct proc *p) -{ - boolean_t funnel_state; + psignal_try_thread(p, thread, SIGXCPU); + } + } - if (p == NULL) - return; - funnel_state = thread_funnel_set(kernel_flock, TRUE); - psignal_lock(p, SIGPROF, 1); - (void) thread_funnel_set(kernel_flock, FALSE); +#if CONFIG_DTRACE + if (ut->t_dtrace_sig) { + uint8_t dt_action_sig = ut->t_dtrace_sig; + ut->t_dtrace_sig = 0; + psignal(p, dt_action_sig); + } + + if (ut->t_dtrace_stop) { + ut->t_dtrace_stop = 0; + proc_lock(p); + p->p_dtrace_stop = 1; + proc_unlock(p); + (void)task_suspend_internal(p->task); + } + + if (ut->t_dtrace_resumepid) { + proc_t resumeproc = proc_find(ut->t_dtrace_resumepid); + ut->t_dtrace_resumepid = 0; + if (resumeproc != PROC_NULL) { + proc_lock(resumeproc); + /* We only act on processes stopped by dtrace */ + if (resumeproc->p_dtrace_stop) { + resumeproc->p_dtrace_stop = 0; + proc_unlock(resumeproc); + task_resume_internal(resumeproc->task); + } + else { + proc_unlock(resumeproc); + } + proc_rele(resumeproc); + } + } + +#endif /* CONFIG_DTRACE */ + + proc_lock(p); + if (CHECK_SIGNALS(p, current_thread(), ut)) { + while ( (signum = issignal_locked(p)) ) + postsig_locked(signum); + } + proc_unlock(p); + +#ifdef CONFIG_32BIT_TELEMETRY + if (task_consume_32bit_log_flag(p->task)) { + proc_log_32bit_telemetry(p); + } +#endif /* CONFIG_32BIT_TELEMETRY */ + + if (!bsd_init_done) { + bsd_init_done = 1; + bsdinit_task(); + } } -/* ptrace set runnalbe */ +/* ptrace set runnable */ void -pt_setrunnable(struct proc *p) +pt_setrunnable(proc_t p) { -task_t task; + task_t task; task = p->task; - if (p->p_flag & P_TRACED) { + if (p->p_lflag & P_LTRACED) { + proc_lock(p); p->p_stat = SRUN; + proc_unlock(p); if (p->sigwait) { wakeup((caddr_t)&(p->sigwait)); - task_release(task); + if ((p->p_lflag & P_LSIGEXC) == 0) { // 5878479 + task_release(task); + } } } } - kern_return_t do_bsdexception( int exc, int code, int sub) { - exception_data_type_t codes[EXCEPTION_CODE_MAX]; + mach_exception_data_type_t codes[EXCEPTION_CODE_MAX]; codes[0] = code; codes[1] = sub; @@ -2781,28 +3487,19 @@ do_bsdexception( } int -proc_pendingsignals(struct proc *p, sigset_t mask) +proc_pendingsignals(proc_t p, sigset_t mask) { struct uthread * uth; thread_t th; sigset_t bits = 0; - int error; + proc_lock(p); /* If the process is in proc exit return no signal info */ - if (p->p_lflag & P_LPEXIT) - return(0); - - /* duplicate the signal lock code to enable recursion; as exit - * holds the lock too long. All this code is being reworked - * this is just a workaround for regressions till new code - * arrives. - */ -ppend_retry: - error = lockmgr((struct lock__bsd__ *)&p->signal_lock[0], (LK_EXCLUSIVE | LK_CANRECURSE), 0, (struct proc *)0); - if (error == EINTR) - goto ppend_retry; + if (p->p_lflag & P_LPEXIT) { + goto out; + } - if ((p->p_flag & P_INVFORK) && p->p_vforkact) { + if ((p->p_lflag & P_LINVFORK) && p->p_vforkact) { th = p->p_vforkact; uth = (struct uthread *)get_bsdthread_info(th); if (uth) { @@ -2816,7 +3513,7 @@ ppend_retry: bits |= (((uth->uu_siglist & ~uth->uu_sigmask) & ~p->p_sigignore) & mask); } out: - signal_unlock(p); + proc_unlock(p); return(bits); } @@ -2826,11 +3523,105 @@ thread_issignal(proc_t p, thread_t th, sigset_t mask) struct uthread * uth; sigset_t bits=0; + proc_lock(p); + uth = (struct uthread *)get_bsdthread_info(th); + if (uth) { + bits = (((uth->uu_siglist & ~uth->uu_sigmask) & ~p->p_sigignore) & mask); + } + proc_unlock(p); + return(bits); +} - uth = (struct uthread *)get_bsdthread_info(th); - if (uth) { - bits = (((uth->uu_siglist & ~uth->uu_sigmask) & ~p->p_sigignore) & mask); - } - return(bits); +/* + * Allow external reads of the sigprop array. + */ +int +hassigprop(int sig, int prop) +{ + return (sigprop[sig] & prop); +} + +void +pgsigio(pid_t pgid, int sig) +{ + proc_t p = PROC_NULL; + + if (pgid < 0) + gsignal(-(pgid), sig); + + else if (pgid > 0 && (p = proc_find(pgid)) != 0) + psignal(p, sig); + if (p != PROC_NULL) + proc_rele(p); +} + +void +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); + p->p_sigwaitcnt--; + + p->p_lflag |= P_LINSIGNAL; + p->p_signalholder = current_thread(); + if (!locked) + proc_unlock(p); } +void +proc_signalend(proc_t p, int locked) +{ + if (!locked) + proc_lock(p); + p->p_lflag &= ~P_LINSIGNAL; + + if (p->p_sigwaitcnt > 0) + wakeup(&p->p_sigmask); + + p->p_signalholder = NULL; + if (!locked) + proc_unlock(p); +} + +void +sig_lock_to_exit(proc_t p) +{ + thread_t self = current_thread(); + + p->exit_thread = self; + proc_unlock(p); + + task_hold(p->task); + task_wait(p->task, FALSE); + + proc_lock(p); +} + +int +sig_try_locked(proc_t p) +{ + thread_t self = current_thread(); + + while (p->sigwait || p->exit_thread) { + if (p->exit_thread) { + return(0); + } + msleep((caddr_t)&p->sigwait_thread, &p->p_mlock, PCATCH | PDROP, 0, 0); + if (thread_should_abort(self)) { + /* + * Terminate request - clean up. + */ + proc_lock(p); + return -1; + } + proc_lock(p); + } + return 1; +}