int _sigsuspend(const sigset_t *set) { struct pthread *curthread = _get_curthread(); sigset_t oldmask, newmask, tempset; int ret = -1; if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM) return (__sys_sigsuspend(set)); /* Check if a new signal set was provided by the caller: */ if (set != NULL) { newmask = *set; SIG_CANTMASK(newmask); THR_LOCK_SWITCH(curthread); /* Save current sigmask: */ oldmask = curthread->sigmask; curthread->oldsigmask = &oldmask; /* Change the caller's mask: */ curthread->sigmask = newmask; tempset = curthread->sigpend; SIGSETNAND(tempset, newmask); if (SIGISEMPTY(tempset)) { THR_SET_STATE(curthread, PS_SIGSUSPEND); /* Wait for a signal: */ _thr_sched_switch_unlocked(curthread); } else { curthread->check_pending = 1; THR_UNLOCK_SWITCH(curthread); /* check pending signal I can handle: */ _thr_sig_check_pending(curthread); } if ((curthread->cancelflags & THR_CANCELLING) != 0) curthread->oldsigmask = NULL; else { THR_ASSERT(curthread->oldsigmask == NULL, "oldsigmask is not cleared"); } /* Always return an interrupted error: */ errno = EINTR; } else { /* Return an invalid argument error: */ errno = EINVAL; } /* Return the completion status: */ return (ret); }
/* * Process an asynchronous software trap. * This is relatively easy. * This function will return with preemption disabled. */ void ast(struct trapframe *framep) { struct thread *td; struct proc *p; int flags; int sig; td = curthread; p = td->td_proc; CTR3(KTR_SYSC, "ast: thread %p (pid %d, %s)", td, p->p_pid, p->p_comm); KASSERT(TRAPF_USERMODE(framep), ("ast in kernel mode")); WITNESS_WARN(WARN_PANIC, NULL, "Returning to user mode"); mtx_assert(&Giant, MA_NOTOWNED); THREAD_LOCK_ASSERT(td, MA_NOTOWNED); td->td_frame = framep; td->td_pticks = 0; /* * This updates the td_flag's for the checks below in one * "atomic" operation with turning off the astpending flag. * If another AST is triggered while we are handling the * AST's saved in flags, the astpending flag will be set and * ast() will be called again. */ thread_lock(td); flags = td->td_flags; td->td_flags &= ~(TDF_ASTPENDING | TDF_NEEDSIGCHK | TDF_NEEDSUSPCHK | TDF_NEEDRESCHED | TDF_ALRMPEND | TDF_PROFPEND | TDF_MACPEND); thread_unlock(td); PCPU_INC(cnt.v_trap); if (td->td_ucred != p->p_ucred) cred_update_thread(td); if (td->td_pflags & TDP_OWEUPC && p->p_flag & P_PROFIL) { addupc_task(td, td->td_profil_addr, td->td_profil_ticks); td->td_profil_ticks = 0; td->td_pflags &= ~TDP_OWEUPC; } #ifdef HWPMC_HOOKS /* Handle Software PMC callchain capture. */ if (PMC_IS_PENDING_CALLCHAIN(td)) PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_USER_CALLCHAIN_SOFT, (void *) framep); #endif if (flags & TDF_ALRMPEND) { PROC_LOCK(p); kern_psignal(p, SIGVTALRM); PROC_UNLOCK(p); } if (flags & TDF_PROFPEND) { PROC_LOCK(p); kern_psignal(p, SIGPROF); PROC_UNLOCK(p); } #ifdef MAC if (flags & TDF_MACPEND) mac_thread_userret(td); #endif if (flags & TDF_NEEDRESCHED) { #ifdef KTRACE if (KTRPOINT(td, KTR_CSW)) ktrcsw(1, 1, __func__); #endif thread_lock(td); sched_prio(td, td->td_user_pri); mi_switch(SW_INVOL | SWT_NEEDRESCHED, NULL); thread_unlock(td); #ifdef KTRACE if (KTRPOINT(td, KTR_CSW)) ktrcsw(0, 1, __func__); #endif } /* * Check for signals. Unlocked reads of p_pendingcnt or * p_siglist might cause process-directed signal to be handled * later. */ if (flags & TDF_NEEDSIGCHK || p->p_pendingcnt > 0 || !SIGISEMPTY(p->p_siglist)) { PROC_LOCK(p); mtx_lock(&p->p_sigacts->ps_mtx); while ((sig = cursig(td)) != 0) postsig(sig); mtx_unlock(&p->p_sigacts->ps_mtx); PROC_UNLOCK(p); } /* * We need to check to see if we have to exit or wait due to a * single threading requirement or some other STOP condition. */ if (flags & TDF_NEEDSUSPCHK) { PROC_LOCK(p); thread_suspend_check(0); PROC_UNLOCK(p); } if (td->td_pflags & TDP_OLDMASK) { td->td_pflags &= ~TDP_OLDMASK; kern_sigprocmask(td, SIG_SETMASK, &td->td_oldsigmask, NULL, 0); } userret(td, framep); }