1*0Sstevel@tonic-gate /* 2*0Sstevel@tonic-gate * CDDL HEADER START 3*0Sstevel@tonic-gate * 4*0Sstevel@tonic-gate * The contents of this file are subject to the terms of the 5*0Sstevel@tonic-gate * Common Development and Distribution License, Version 1.0 only 6*0Sstevel@tonic-gate * (the "License"). You may not use this file except in compliance 7*0Sstevel@tonic-gate * with the License. 8*0Sstevel@tonic-gate * 9*0Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10*0Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing. 11*0Sstevel@tonic-gate * See the License for the specific language governing permissions 12*0Sstevel@tonic-gate * and limitations under the License. 13*0Sstevel@tonic-gate * 14*0Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each 15*0Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16*0Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the 17*0Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying 18*0Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner] 19*0Sstevel@tonic-gate * 20*0Sstevel@tonic-gate * CDDL HEADER END 21*0Sstevel@tonic-gate */ 22*0Sstevel@tonic-gate /* 23*0Sstevel@tonic-gate * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 24*0Sstevel@tonic-gate * Use is subject to license terms. 25*0Sstevel@tonic-gate */ 26*0Sstevel@tonic-gate 27*0Sstevel@tonic-gate #pragma ident "%Z%%M% %I% %E% SMI" 28*0Sstevel@tonic-gate 29*0Sstevel@tonic-gate #include "lint.h" 30*0Sstevel@tonic-gate #include "thr_uberdata.h" 31*0Sstevel@tonic-gate #include <signal.h> 32*0Sstevel@tonic-gate #include <siginfo.h> 33*0Sstevel@tonic-gate #include <ucontext.h> 34*0Sstevel@tonic-gate #include <sys/systm.h> 35*0Sstevel@tonic-gate 36*0Sstevel@tonic-gate const sigset_t maskset = {MASKSET0, MASKSET1, 0, 0}; /* maskable signals */ 37*0Sstevel@tonic-gate 38*0Sstevel@tonic-gate /* 39*0Sstevel@tonic-gate * Return true if the valid signal bits in both sets are the same. 40*0Sstevel@tonic-gate */ 41*0Sstevel@tonic-gate int 42*0Sstevel@tonic-gate sigequalset(const sigset_t *s1, const sigset_t *s2) 43*0Sstevel@tonic-gate { 44*0Sstevel@tonic-gate /* 45*0Sstevel@tonic-gate * We only test valid signal bits, not rubbish following MAXSIG 46*0Sstevel@tonic-gate * (for speed). Algorithm: 47*0Sstevel@tonic-gate * if (s1 & fillset) == (s2 & fillset) then (s1 ^ s2) & fillset == 0 48*0Sstevel@tonic-gate */ 49*0Sstevel@tonic-gate return (!((s1->__sigbits[0] ^ s2->__sigbits[0]) | 50*0Sstevel@tonic-gate ((s1->__sigbits[1] ^ s2->__sigbits[1]) & FILLSET1))); 51*0Sstevel@tonic-gate } 52*0Sstevel@tonic-gate 53*0Sstevel@tonic-gate /* 54*0Sstevel@tonic-gate * Common code for calling the user-specified signal handler. 55*0Sstevel@tonic-gate */ 56*0Sstevel@tonic-gate void 57*0Sstevel@tonic-gate call_user_handler(int sig, siginfo_t *sip, ucontext_t *ucp) 58*0Sstevel@tonic-gate { 59*0Sstevel@tonic-gate ulwp_t *self = curthread; 60*0Sstevel@tonic-gate uberdata_t *udp = self->ul_uberdata; 61*0Sstevel@tonic-gate struct sigaction uact; 62*0Sstevel@tonic-gate volatile struct sigaction *sap; 63*0Sstevel@tonic-gate 64*0Sstevel@tonic-gate /* 65*0Sstevel@tonic-gate * If we are taking a signal while parked or about to be parked 66*0Sstevel@tonic-gate * on __lwp_park() then remove ourself from the sleep queue so 67*0Sstevel@tonic-gate * that we can grab locks. The code in mutex_lock_queue() and 68*0Sstevel@tonic-gate * cond_wait_common() will detect this and deal with it when 69*0Sstevel@tonic-gate * __lwp_park() returns. 70*0Sstevel@tonic-gate */ 71*0Sstevel@tonic-gate unsleep_self(); 72*0Sstevel@tonic-gate set_parking_flag(self, 0); 73*0Sstevel@tonic-gate 74*0Sstevel@tonic-gate if (__td_event_report(self, TD_CATCHSIG, udp)) { 75*0Sstevel@tonic-gate self->ul_td_evbuf.eventnum = TD_CATCHSIG; 76*0Sstevel@tonic-gate self->ul_td_evbuf.eventdata = (void *)(intptr_t)sig; 77*0Sstevel@tonic-gate tdb_event(TD_CATCHSIG, udp); 78*0Sstevel@tonic-gate } 79*0Sstevel@tonic-gate 80*0Sstevel@tonic-gate /* 81*0Sstevel@tonic-gate * Get a self-consistent set of flags, handler, and mask 82*0Sstevel@tonic-gate * while holding the sig's sig_lock for the least possible time. 83*0Sstevel@tonic-gate * We must acquire the sig's sig_lock because some thread running 84*0Sstevel@tonic-gate * in sigaction() might be establishing a new signal handler. 85*0Sstevel@tonic-gate * 86*0Sstevel@tonic-gate * Locking exceptions: 87*0Sstevel@tonic-gate * No locking for a child of vfork(). 88*0Sstevel@tonic-gate * If the signal is SIGPROF with an si_code of PROF_SIG, 89*0Sstevel@tonic-gate * then we assume that this signal was generated by 90*0Sstevel@tonic-gate * setitimer(ITIMER_REALPROF) set up by the dbx collector. 91*0Sstevel@tonic-gate * If the signal is SIGEMT with an si_code of EMT_CPCOVF, 92*0Sstevel@tonic-gate * then we assume that the signal was generated by 93*0Sstevel@tonic-gate * a hardware performance counter overflow. 94*0Sstevel@tonic-gate * In these cases, assume that we need no locking. It is the 95*0Sstevel@tonic-gate * monitoring program's responsibility to ensure correctness. 96*0Sstevel@tonic-gate */ 97*0Sstevel@tonic-gate sap = &udp->siguaction[sig].sig_uaction; 98*0Sstevel@tonic-gate if (self->ul_vfork || 99*0Sstevel@tonic-gate (sip != NULL && 100*0Sstevel@tonic-gate ((sig == SIGPROF && sip->si_code == PROF_SIG) || 101*0Sstevel@tonic-gate (sig == SIGEMT && sip->si_code == EMT_CPCOVF)))) { 102*0Sstevel@tonic-gate /* we wish this assignment could be atomic */ 103*0Sstevel@tonic-gate uact = *sap; 104*0Sstevel@tonic-gate } else { 105*0Sstevel@tonic-gate mutex_t *mp = &udp->siguaction[sig].sig_lock; 106*0Sstevel@tonic-gate lmutex_lock(mp); 107*0Sstevel@tonic-gate uact = *sap; 108*0Sstevel@tonic-gate if (sig == SIGCANCEL && (sap->sa_flags & SA_RESETHAND)) 109*0Sstevel@tonic-gate sap->sa_sigaction = SIG_DFL; 110*0Sstevel@tonic-gate lmutex_unlock(mp); 111*0Sstevel@tonic-gate } 112*0Sstevel@tonic-gate 113*0Sstevel@tonic-gate /* 114*0Sstevel@tonic-gate * Set the proper signal mask and call the user's signal handler. 115*0Sstevel@tonic-gate * (We overrode the user-requested signal mask with maskset 116*0Sstevel@tonic-gate * so we currently have all blockable signals blocked.) 117*0Sstevel@tonic-gate * 118*0Sstevel@tonic-gate * We would like to ASSERT() that the signal is not a member of the 119*0Sstevel@tonic-gate * signal mask at the previous level (ucp->uc_sigmask) or the specified 120*0Sstevel@tonic-gate * signal mask for sigsuspend() or pollsys() (self->ul_tmpmask) but 121*0Sstevel@tonic-gate * /proc can override this via PCSSIG, so we don't bother. 122*0Sstevel@tonic-gate * 123*0Sstevel@tonic-gate * We would also like to ASSERT() that the signal mask at the previous 124*0Sstevel@tonic-gate * level equals self->ul_sigmask (maskset for sigsuspend() / pollsys()), 125*0Sstevel@tonic-gate * but /proc can change the thread's signal mask via PCSHOLD, so we 126*0Sstevel@tonic-gate * don't bother with that either. 127*0Sstevel@tonic-gate */ 128*0Sstevel@tonic-gate ASSERT(ucp->uc_flags & UC_SIGMASK); 129*0Sstevel@tonic-gate if (self->ul_sigsuspend) { 130*0Sstevel@tonic-gate ucp->uc_sigmask = self->ul_sigmask; 131*0Sstevel@tonic-gate self->ul_sigsuspend = 0; 132*0Sstevel@tonic-gate /* the sigsuspend() or pollsys() signal mask */ 133*0Sstevel@tonic-gate sigorset(&uact.sa_mask, &self->ul_tmpmask); 134*0Sstevel@tonic-gate } else { 135*0Sstevel@tonic-gate /* the signal mask at the previous level */ 136*0Sstevel@tonic-gate sigorset(&uact.sa_mask, &ucp->uc_sigmask); 137*0Sstevel@tonic-gate } 138*0Sstevel@tonic-gate if (!(uact.sa_flags & SA_NODEFER)) /* add current signal */ 139*0Sstevel@tonic-gate (void) _private_sigaddset(&uact.sa_mask, sig); 140*0Sstevel@tonic-gate self->ul_sigmask = uact.sa_mask; 141*0Sstevel@tonic-gate self->ul_siglink = ucp; 142*0Sstevel@tonic-gate (void) __lwp_sigmask(SIG_SETMASK, &uact.sa_mask, NULL); 143*0Sstevel@tonic-gate 144*0Sstevel@tonic-gate /* 145*0Sstevel@tonic-gate * If this thread has been sent SIGCANCEL from the kernel 146*0Sstevel@tonic-gate * or from pthread_cancel(), it is being asked to exit. 147*0Sstevel@tonic-gate * The kernel may send SIGCANCEL without a siginfo struct. 148*0Sstevel@tonic-gate * If the SIGCANCEL is process-directed (from kill() or 149*0Sstevel@tonic-gate * sigqueue()), treat it as an ordinary signal. 150*0Sstevel@tonic-gate */ 151*0Sstevel@tonic-gate if (sig == SIGCANCEL) { 152*0Sstevel@tonic-gate if (sip == NULL || SI_FROMKERNEL(sip) || 153*0Sstevel@tonic-gate sip->si_code == SI_LWP) { 154*0Sstevel@tonic-gate do_sigcancel(); 155*0Sstevel@tonic-gate goto out; 156*0Sstevel@tonic-gate } 157*0Sstevel@tonic-gate if (uact.sa_sigaction == SIG_DFL || 158*0Sstevel@tonic-gate uact.sa_sigaction == SIG_IGN) 159*0Sstevel@tonic-gate goto out; 160*0Sstevel@tonic-gate } 161*0Sstevel@tonic-gate 162*0Sstevel@tonic-gate if (!(uact.sa_flags & SA_SIGINFO)) 163*0Sstevel@tonic-gate sip = NULL; 164*0Sstevel@tonic-gate __sighndlr(sig, sip, ucp, uact.sa_sigaction); 165*0Sstevel@tonic-gate 166*0Sstevel@tonic-gate #if defined(sparc) || defined(__sparc) 167*0Sstevel@tonic-gate /* 168*0Sstevel@tonic-gate * If this is a floating point exception and the queue 169*0Sstevel@tonic-gate * is non-empty, pop the top entry from the queue. This 170*0Sstevel@tonic-gate * is to maintain expected behavior. 171*0Sstevel@tonic-gate */ 172*0Sstevel@tonic-gate if (sig == SIGFPE && ucp->uc_mcontext.fpregs.fpu_qcnt) { 173*0Sstevel@tonic-gate fpregset_t *fp = &ucp->uc_mcontext.fpregs; 174*0Sstevel@tonic-gate 175*0Sstevel@tonic-gate if (--fp->fpu_qcnt > 0) { 176*0Sstevel@tonic-gate unsigned char i; 177*0Sstevel@tonic-gate struct fq *fqp; 178*0Sstevel@tonic-gate 179*0Sstevel@tonic-gate fqp = fp->fpu_q; 180*0Sstevel@tonic-gate for (i = 0; i < fp->fpu_qcnt; i++) 181*0Sstevel@tonic-gate fqp[i] = fqp[i+1]; 182*0Sstevel@tonic-gate } 183*0Sstevel@tonic-gate } 184*0Sstevel@tonic-gate #endif /* sparc */ 185*0Sstevel@tonic-gate 186*0Sstevel@tonic-gate out: 187*0Sstevel@tonic-gate (void) _private_setcontext(ucp); 188*0Sstevel@tonic-gate thr_panic("call_user_handler(): _setcontext() returned"); 189*0Sstevel@tonic-gate } 190*0Sstevel@tonic-gate 191*0Sstevel@tonic-gate /* 192*0Sstevel@tonic-gate * take_deferred_signal() is called when ul_critical and ul_sigdefer become 193*0Sstevel@tonic-gate * zero and a deferred signal has been recorded on the current thread. 194*0Sstevel@tonic-gate * We are out of the critical region and are ready to take a signal. 195*0Sstevel@tonic-gate * The kernel has all signals blocked on this lwp, but our value of 196*0Sstevel@tonic-gate * ul_sigmask is the correct signal mask for the previous context. 197*0Sstevel@tonic-gate */ 198*0Sstevel@tonic-gate void 199*0Sstevel@tonic-gate take_deferred_signal(int sig) 200*0Sstevel@tonic-gate { 201*0Sstevel@tonic-gate ulwp_t *self = curthread; 202*0Sstevel@tonic-gate siginfo_t siginfo; 203*0Sstevel@tonic-gate siginfo_t *sip; 204*0Sstevel@tonic-gate ucontext_t uc; 205*0Sstevel@tonic-gate volatile int returning; 206*0Sstevel@tonic-gate 207*0Sstevel@tonic-gate ASSERT(self->ul_critical == 0); 208*0Sstevel@tonic-gate ASSERT(self->ul_sigdefer == 0); 209*0Sstevel@tonic-gate ASSERT(self->ul_cursig == 0); 210*0Sstevel@tonic-gate 211*0Sstevel@tonic-gate returning = 0; 212*0Sstevel@tonic-gate uc.uc_flags = UC_ALL; 213*0Sstevel@tonic-gate /* 214*0Sstevel@tonic-gate * We call _private_getcontext (a libc-private synonym for 215*0Sstevel@tonic-gate * _getcontext) rather than _getcontext because we need to 216*0Sstevel@tonic-gate * avoid the dynamic linker and link auditing problems here. 217*0Sstevel@tonic-gate */ 218*0Sstevel@tonic-gate (void) _private_getcontext(&uc); 219*0Sstevel@tonic-gate /* 220*0Sstevel@tonic-gate * If the application signal handler calls setcontext() on 221*0Sstevel@tonic-gate * the ucontext we give it, it returns here, then we return. 222*0Sstevel@tonic-gate */ 223*0Sstevel@tonic-gate if (returning) 224*0Sstevel@tonic-gate return; 225*0Sstevel@tonic-gate returning = 1; 226*0Sstevel@tonic-gate ASSERT(sigequalset(&uc.uc_sigmask, &maskset)); 227*0Sstevel@tonic-gate if (self->ul_siginfo.si_signo == 0) 228*0Sstevel@tonic-gate sip = NULL; 229*0Sstevel@tonic-gate else { 230*0Sstevel@tonic-gate siginfo = self->ul_siginfo; 231*0Sstevel@tonic-gate sip = &siginfo; 232*0Sstevel@tonic-gate } 233*0Sstevel@tonic-gate uc.uc_sigmask = self->ul_sigmask; 234*0Sstevel@tonic-gate call_user_handler(sig, sip, &uc); 235*0Sstevel@tonic-gate } 236*0Sstevel@tonic-gate 237*0Sstevel@tonic-gate void 238*0Sstevel@tonic-gate sigacthandler(int sig, siginfo_t *sip, void *uvp) 239*0Sstevel@tonic-gate { 240*0Sstevel@tonic-gate ucontext_t *ucp = uvp; 241*0Sstevel@tonic-gate ulwp_t *self = curthread; 242*0Sstevel@tonic-gate 243*0Sstevel@tonic-gate /* 244*0Sstevel@tonic-gate * Do this in case we took a signal while in a cancelable system call. 245*0Sstevel@tonic-gate * It does no harm if we were not in such a system call. 246*0Sstevel@tonic-gate */ 247*0Sstevel@tonic-gate self->ul_sp = 0; 248*0Sstevel@tonic-gate if (sig != SIGCANCEL) 249*0Sstevel@tonic-gate self->ul_cancel_async = self->ul_save_async; 250*0Sstevel@tonic-gate 251*0Sstevel@tonic-gate /* 252*0Sstevel@tonic-gate * If we are not in a critical region and are 253*0Sstevel@tonic-gate * not deferring signals, take the signal now. 254*0Sstevel@tonic-gate */ 255*0Sstevel@tonic-gate if ((self->ul_critical + self->ul_sigdefer) == 0) { 256*0Sstevel@tonic-gate call_user_handler(sig, sip, ucp); 257*0Sstevel@tonic-gate return; /* call_user_handler() cannot return */ 258*0Sstevel@tonic-gate } 259*0Sstevel@tonic-gate 260*0Sstevel@tonic-gate /* 261*0Sstevel@tonic-gate * We are in a critical region or we are deferring signals. When 262*0Sstevel@tonic-gate * we emerge from the region we will call take_deferred_signal(). 263*0Sstevel@tonic-gate */ 264*0Sstevel@tonic-gate ASSERT(self->ul_cursig == 0); 265*0Sstevel@tonic-gate self->ul_cursig = (char)sig; 266*0Sstevel@tonic-gate if (sip != NULL) 267*0Sstevel@tonic-gate self->ul_siginfo = *sip; 268*0Sstevel@tonic-gate else 269*0Sstevel@tonic-gate self->ul_siginfo.si_signo = 0; 270*0Sstevel@tonic-gate 271*0Sstevel@tonic-gate /* 272*0Sstevel@tonic-gate * Make sure that if we return to a call to __lwp_park() 273*0Sstevel@tonic-gate * or ___lwp_cond_wait() that it returns right away 274*0Sstevel@tonic-gate * (giving us a spurious wakeup but not a deadlock). 275*0Sstevel@tonic-gate */ 276*0Sstevel@tonic-gate set_parking_flag(self, 0); 277*0Sstevel@tonic-gate 278*0Sstevel@tonic-gate /* 279*0Sstevel@tonic-gate * Return to the previous context with all signals blocked. 280*0Sstevel@tonic-gate * We will restore the signal mask in take_deferred_signal(). 281*0Sstevel@tonic-gate * Note that we are calling the system call trap here, not 282*0Sstevel@tonic-gate * the _setcontext() wrapper. We don't want to change the 283*0Sstevel@tonic-gate * thread's ul_sigmask by this operation. 284*0Sstevel@tonic-gate */ 285*0Sstevel@tonic-gate ucp->uc_sigmask = maskset; 286*0Sstevel@tonic-gate (void) __setcontext_syscall(ucp); 287*0Sstevel@tonic-gate thr_panic("sigacthandler(): __setcontext() returned"); 288*0Sstevel@tonic-gate } 289*0Sstevel@tonic-gate 290*0Sstevel@tonic-gate #pragma weak sigaction = _sigaction 291*0Sstevel@tonic-gate int 292*0Sstevel@tonic-gate _sigaction(int sig, const struct sigaction *nact, struct sigaction *oact) 293*0Sstevel@tonic-gate { 294*0Sstevel@tonic-gate ulwp_t *self = curthread; 295*0Sstevel@tonic-gate uberdata_t *udp = self->ul_uberdata; 296*0Sstevel@tonic-gate struct sigaction oaction; 297*0Sstevel@tonic-gate struct sigaction tact; 298*0Sstevel@tonic-gate struct sigaction *tactp = NULL; 299*0Sstevel@tonic-gate int rv; 300*0Sstevel@tonic-gate 301*0Sstevel@tonic-gate if (sig <= 0 || sig >= NSIG) { 302*0Sstevel@tonic-gate errno = EINVAL; 303*0Sstevel@tonic-gate return (-1); 304*0Sstevel@tonic-gate } 305*0Sstevel@tonic-gate 306*0Sstevel@tonic-gate if (!self->ul_vfork) 307*0Sstevel@tonic-gate lmutex_lock(&udp->siguaction[sig].sig_lock); 308*0Sstevel@tonic-gate 309*0Sstevel@tonic-gate oaction = udp->siguaction[sig].sig_uaction; 310*0Sstevel@tonic-gate 311*0Sstevel@tonic-gate if (nact != NULL) { 312*0Sstevel@tonic-gate tact = *nact; /* make a copy so we can modify it */ 313*0Sstevel@tonic-gate tactp = &tact; 314*0Sstevel@tonic-gate delete_reserved_signals(&tact.sa_mask); 315*0Sstevel@tonic-gate 316*0Sstevel@tonic-gate #if !defined(_LP64) 317*0Sstevel@tonic-gate tact.sa_resv[0] = tact.sa_resv[1] = 0; /* cleanliness */ 318*0Sstevel@tonic-gate #endif 319*0Sstevel@tonic-gate /* 320*0Sstevel@tonic-gate * To be compatible with the behavior of SunOS 4.x: 321*0Sstevel@tonic-gate * If the new signal handler is SIG_IGN or SIG_DFL, do 322*0Sstevel@tonic-gate * not change the signal's entry in the siguaction array. 323*0Sstevel@tonic-gate * This allows a child of vfork(2) to set signal handlers 324*0Sstevel@tonic-gate * to SIG_IGN or SIG_DFL without affecting the parent. 325*0Sstevel@tonic-gate * 326*0Sstevel@tonic-gate * This also covers a race condition with some thread 327*0Sstevel@tonic-gate * setting the signal action to SIG_DFL or SIG_IGN 328*0Sstevel@tonic-gate * when the thread has also received and deferred 329*0Sstevel@tonic-gate * that signal. When the thread takes the deferred 330*0Sstevel@tonic-gate * signal, even though it has set the action to SIG_DFL 331*0Sstevel@tonic-gate * or SIG_IGN, it will execute the old signal handler 332*0Sstevel@tonic-gate * anyway. This is an inherent signaling race condition 333*0Sstevel@tonic-gate * and is not a bug. 334*0Sstevel@tonic-gate * 335*0Sstevel@tonic-gate * A child of vfork() is not allowed to change signal 336*0Sstevel@tonic-gate * handlers to anything other than SIG_DFL or SIG_IGN. 337*0Sstevel@tonic-gate */ 338*0Sstevel@tonic-gate if (self->ul_vfork) { 339*0Sstevel@tonic-gate if (tact.sa_sigaction != SIG_IGN) 340*0Sstevel@tonic-gate tact.sa_sigaction = SIG_DFL; 341*0Sstevel@tonic-gate } else if (sig == SIGCANCEL) { 342*0Sstevel@tonic-gate /* 343*0Sstevel@tonic-gate * Always catch SIGCANCEL. 344*0Sstevel@tonic-gate * We need it for pthread_cancel() to work. 345*0Sstevel@tonic-gate */ 346*0Sstevel@tonic-gate udp->siguaction[sig].sig_uaction = tact; 347*0Sstevel@tonic-gate if (tact.sa_sigaction == SIG_DFL || 348*0Sstevel@tonic-gate tact.sa_sigaction == SIG_IGN) 349*0Sstevel@tonic-gate tact.sa_flags = SA_SIGINFO; 350*0Sstevel@tonic-gate else { 351*0Sstevel@tonic-gate tact.sa_flags |= SA_SIGINFO; 352*0Sstevel@tonic-gate tact.sa_flags &= ~(SA_NODEFER | SA_RESETHAND); 353*0Sstevel@tonic-gate } 354*0Sstevel@tonic-gate tact.sa_sigaction = udp->sigacthandler; 355*0Sstevel@tonic-gate tact.sa_mask = maskset; 356*0Sstevel@tonic-gate } else if (tact.sa_sigaction != SIG_DFL && 357*0Sstevel@tonic-gate tact.sa_sigaction != SIG_IGN) { 358*0Sstevel@tonic-gate udp->siguaction[sig].sig_uaction = tact; 359*0Sstevel@tonic-gate tact.sa_flags &= ~SA_NODEFER; 360*0Sstevel@tonic-gate tact.sa_sigaction = udp->sigacthandler; 361*0Sstevel@tonic-gate tact.sa_mask = maskset; 362*0Sstevel@tonic-gate } 363*0Sstevel@tonic-gate } 364*0Sstevel@tonic-gate 365*0Sstevel@tonic-gate if ((rv = __sigaction(sig, tactp, oact)) != 0) 366*0Sstevel@tonic-gate udp->siguaction[sig].sig_uaction = oaction; 367*0Sstevel@tonic-gate else if (oact != NULL && 368*0Sstevel@tonic-gate oact->sa_sigaction != SIG_DFL && 369*0Sstevel@tonic-gate oact->sa_sigaction != SIG_IGN) 370*0Sstevel@tonic-gate *oact = oaction; 371*0Sstevel@tonic-gate 372*0Sstevel@tonic-gate if (!self->ul_vfork) 373*0Sstevel@tonic-gate lmutex_unlock(&udp->siguaction[sig].sig_lock); 374*0Sstevel@tonic-gate return (rv); 375*0Sstevel@tonic-gate } 376*0Sstevel@tonic-gate 377*0Sstevel@tonic-gate /* 378*0Sstevel@tonic-gate * Calling set_parking_flag(curthread, 1) informs the kernel that we are 379*0Sstevel@tonic-gate * calling __lwp_park or ___lwp_cond_wait(). If we take a signal in 380*0Sstevel@tonic-gate * the unprotected (from signals) interval before reaching the kernel, 381*0Sstevel@tonic-gate * sigacthandler() will call set_parking_flag(curthread, 0) to inform 382*0Sstevel@tonic-gate * the kernel to return immediately from these system calls, giving us 383*0Sstevel@tonic-gate * a spurious wakeup but not a deadlock. 384*0Sstevel@tonic-gate */ 385*0Sstevel@tonic-gate void 386*0Sstevel@tonic-gate set_parking_flag(ulwp_t *self, int park) 387*0Sstevel@tonic-gate { 388*0Sstevel@tonic-gate volatile sc_shared_t *scp; 389*0Sstevel@tonic-gate 390*0Sstevel@tonic-gate enter_critical(self); 391*0Sstevel@tonic-gate if ((scp = self->ul_schedctl) != NULL || 392*0Sstevel@tonic-gate (scp = setup_schedctl()) != NULL) 393*0Sstevel@tonic-gate scp->sc_park = park; 394*0Sstevel@tonic-gate else if (park == 0) /* schedctl failed, do it the long way */ 395*0Sstevel@tonic-gate __lwp_unpark(self->ul_lwpid); 396*0Sstevel@tonic-gate exit_critical(self); 397*0Sstevel@tonic-gate } 398*0Sstevel@tonic-gate 399*0Sstevel@tonic-gate /* 400*0Sstevel@tonic-gate * Tell the kernel to block all signals. 401*0Sstevel@tonic-gate * Use the schedctl interface, or failing that, use __lwp_sigmask(). 402*0Sstevel@tonic-gate * This action can be rescinded only by making a system call that 403*0Sstevel@tonic-gate * sets the signal mask: 404*0Sstevel@tonic-gate * __lwp_sigmask(), __sigprocmask(), __setcontext(), 405*0Sstevel@tonic-gate * __sigsuspend() or __pollsys(). 406*0Sstevel@tonic-gate * In particular, this action cannot be reversed by assigning 407*0Sstevel@tonic-gate * scp->sc_sigblock = 0. That would be a way to lose signals. 408*0Sstevel@tonic-gate * See the definition of restore_signals(self). 409*0Sstevel@tonic-gate */ 410*0Sstevel@tonic-gate void 411*0Sstevel@tonic-gate block_all_signals(ulwp_t *self) 412*0Sstevel@tonic-gate { 413*0Sstevel@tonic-gate volatile sc_shared_t *scp; 414*0Sstevel@tonic-gate 415*0Sstevel@tonic-gate enter_critical(self); 416*0Sstevel@tonic-gate if ((scp = self->ul_schedctl) != NULL || 417*0Sstevel@tonic-gate (scp = setup_schedctl()) != NULL) 418*0Sstevel@tonic-gate scp->sc_sigblock = 1; 419*0Sstevel@tonic-gate else 420*0Sstevel@tonic-gate (void) __lwp_sigmask(SIG_SETMASK, &maskset, NULL); 421*0Sstevel@tonic-gate exit_critical(self); 422*0Sstevel@tonic-gate } 423*0Sstevel@tonic-gate 424*0Sstevel@tonic-gate #pragma weak setcontext = _private_setcontext 425*0Sstevel@tonic-gate #pragma weak _setcontext = _private_setcontext 426*0Sstevel@tonic-gate int 427*0Sstevel@tonic-gate _private_setcontext(const ucontext_t *ucp) 428*0Sstevel@tonic-gate { 429*0Sstevel@tonic-gate ulwp_t *self = curthread; 430*0Sstevel@tonic-gate int ret; 431*0Sstevel@tonic-gate ucontext_t uc; 432*0Sstevel@tonic-gate 433*0Sstevel@tonic-gate /* 434*0Sstevel@tonic-gate * Returning from the main context (uc_link == NULL) causes 435*0Sstevel@tonic-gate * the thread to exit. See setcontext(2) and makecontext(3C). 436*0Sstevel@tonic-gate */ 437*0Sstevel@tonic-gate if (ucp == NULL) 438*0Sstevel@tonic-gate _thr_exit(NULL); 439*0Sstevel@tonic-gate uc = *ucp; 440*0Sstevel@tonic-gate 441*0Sstevel@tonic-gate /* 442*0Sstevel@tonic-gate * Restore previous signal mask and context link. 443*0Sstevel@tonic-gate */ 444*0Sstevel@tonic-gate if (uc.uc_flags & UC_SIGMASK) { 445*0Sstevel@tonic-gate block_all_signals(self); 446*0Sstevel@tonic-gate delete_reserved_signals(&uc.uc_sigmask); 447*0Sstevel@tonic-gate self->ul_sigmask = uc.uc_sigmask; 448*0Sstevel@tonic-gate if (self->ul_cursig) { 449*0Sstevel@tonic-gate /* 450*0Sstevel@tonic-gate * We have a deferred signal present. 451*0Sstevel@tonic-gate * The signal mask will be set when the 452*0Sstevel@tonic-gate * signal is taken in take_deferred_signal(). 453*0Sstevel@tonic-gate */ 454*0Sstevel@tonic-gate ASSERT(self->ul_critical + self->ul_sigdefer != 0); 455*0Sstevel@tonic-gate uc.uc_flags &= ~UC_SIGMASK; 456*0Sstevel@tonic-gate } 457*0Sstevel@tonic-gate } 458*0Sstevel@tonic-gate self->ul_siglink = uc.uc_link; 459*0Sstevel@tonic-gate 460*0Sstevel@tonic-gate /* 461*0Sstevel@tonic-gate * We don't know where this context structure has been. 462*0Sstevel@tonic-gate * Preserve the curthread pointer, at least. 463*0Sstevel@tonic-gate */ 464*0Sstevel@tonic-gate #if defined(__sparc) 465*0Sstevel@tonic-gate uc.uc_mcontext.gregs[REG_G7] = (greg_t)self; 466*0Sstevel@tonic-gate #elif defined(__amd64) 467*0Sstevel@tonic-gate uc.uc_mcontext.gregs[REG_FS] = (greg_t)self->ul_gs; 468*0Sstevel@tonic-gate #elif defined(__i386) 469*0Sstevel@tonic-gate uc.uc_mcontext.gregs[GS] = (greg_t)self->ul_gs; 470*0Sstevel@tonic-gate #else 471*0Sstevel@tonic-gate #error "none of __sparc, __amd64, __i386 defined" 472*0Sstevel@tonic-gate #endif 473*0Sstevel@tonic-gate /* 474*0Sstevel@tonic-gate * Make sure that if we return to a call to __lwp_park() 475*0Sstevel@tonic-gate * or ___lwp_cond_wait() that it returns right away 476*0Sstevel@tonic-gate * (giving us a spurious wakeup but not a deadlock). 477*0Sstevel@tonic-gate */ 478*0Sstevel@tonic-gate set_parking_flag(self, 0); 479*0Sstevel@tonic-gate self->ul_sp = 0; 480*0Sstevel@tonic-gate ret = __setcontext_syscall(&uc); 481*0Sstevel@tonic-gate 482*0Sstevel@tonic-gate /* 483*0Sstevel@tonic-gate * It is OK for setcontext() to return if the user has not specified 484*0Sstevel@tonic-gate * UC_CPU. 485*0Sstevel@tonic-gate */ 486*0Sstevel@tonic-gate if (uc.uc_flags & UC_CPU) 487*0Sstevel@tonic-gate thr_panic("setcontext(): __setcontext() returned"); 488*0Sstevel@tonic-gate return (ret); 489*0Sstevel@tonic-gate } 490*0Sstevel@tonic-gate 491*0Sstevel@tonic-gate #pragma weak thr_sigsetmask = _thr_sigsetmask 492*0Sstevel@tonic-gate #pragma weak pthread_sigmask = _thr_sigsetmask 493*0Sstevel@tonic-gate #pragma weak _pthread_sigmask = _thr_sigsetmask 494*0Sstevel@tonic-gate int 495*0Sstevel@tonic-gate _thr_sigsetmask(int how, const sigset_t *set, sigset_t *oset) 496*0Sstevel@tonic-gate { 497*0Sstevel@tonic-gate ulwp_t *self = curthread; 498*0Sstevel@tonic-gate sigset_t saveset; 499*0Sstevel@tonic-gate 500*0Sstevel@tonic-gate if (set == NULL) { 501*0Sstevel@tonic-gate enter_critical(self); 502*0Sstevel@tonic-gate if (oset != NULL) 503*0Sstevel@tonic-gate *oset = self->ul_sigmask; 504*0Sstevel@tonic-gate exit_critical(self); 505*0Sstevel@tonic-gate } else { 506*0Sstevel@tonic-gate switch (how) { 507*0Sstevel@tonic-gate case SIG_BLOCK: 508*0Sstevel@tonic-gate case SIG_UNBLOCK: 509*0Sstevel@tonic-gate case SIG_SETMASK: 510*0Sstevel@tonic-gate break; 511*0Sstevel@tonic-gate default: 512*0Sstevel@tonic-gate return (EINVAL); 513*0Sstevel@tonic-gate } 514*0Sstevel@tonic-gate 515*0Sstevel@tonic-gate /* 516*0Sstevel@tonic-gate * The assignments to self->ul_sigmask must be protected from 517*0Sstevel@tonic-gate * signals. The nuances of this code are subtle. Be careful. 518*0Sstevel@tonic-gate */ 519*0Sstevel@tonic-gate block_all_signals(self); 520*0Sstevel@tonic-gate if (oset != NULL) 521*0Sstevel@tonic-gate saveset = self->ul_sigmask; 522*0Sstevel@tonic-gate switch (how) { 523*0Sstevel@tonic-gate case SIG_BLOCK: 524*0Sstevel@tonic-gate self->ul_sigmask.__sigbits[0] |= set->__sigbits[0]; 525*0Sstevel@tonic-gate self->ul_sigmask.__sigbits[1] |= set->__sigbits[1]; 526*0Sstevel@tonic-gate break; 527*0Sstevel@tonic-gate case SIG_UNBLOCK: 528*0Sstevel@tonic-gate self->ul_sigmask.__sigbits[0] &= ~set->__sigbits[0]; 529*0Sstevel@tonic-gate self->ul_sigmask.__sigbits[1] &= ~set->__sigbits[1]; 530*0Sstevel@tonic-gate break; 531*0Sstevel@tonic-gate case SIG_SETMASK: 532*0Sstevel@tonic-gate self->ul_sigmask.__sigbits[0] = set->__sigbits[0]; 533*0Sstevel@tonic-gate self->ul_sigmask.__sigbits[1] = set->__sigbits[1]; 534*0Sstevel@tonic-gate break; 535*0Sstevel@tonic-gate } 536*0Sstevel@tonic-gate delete_reserved_signals(&self->ul_sigmask); 537*0Sstevel@tonic-gate if (oset != NULL) 538*0Sstevel@tonic-gate *oset = saveset; 539*0Sstevel@tonic-gate restore_signals(self); 540*0Sstevel@tonic-gate } 541*0Sstevel@tonic-gate 542*0Sstevel@tonic-gate return (0); 543*0Sstevel@tonic-gate } 544*0Sstevel@tonic-gate 545*0Sstevel@tonic-gate #pragma weak sigprocmask = _sigprocmask 546*0Sstevel@tonic-gate int 547*0Sstevel@tonic-gate _sigprocmask(int how, const sigset_t *set, sigset_t *oset) 548*0Sstevel@tonic-gate { 549*0Sstevel@tonic-gate int error; 550*0Sstevel@tonic-gate 551*0Sstevel@tonic-gate /* 552*0Sstevel@tonic-gate * Guard against children of vfork(). 553*0Sstevel@tonic-gate */ 554*0Sstevel@tonic-gate if (curthread->ul_vfork) 555*0Sstevel@tonic-gate return (__lwp_sigmask(how, set, oset)); 556*0Sstevel@tonic-gate 557*0Sstevel@tonic-gate if ((error = _thr_sigsetmask(how, set, oset)) != 0) { 558*0Sstevel@tonic-gate errno = error; 559*0Sstevel@tonic-gate return (-1); 560*0Sstevel@tonic-gate } 561*0Sstevel@tonic-gate 562*0Sstevel@tonic-gate return (0); 563*0Sstevel@tonic-gate } 564*0Sstevel@tonic-gate 565*0Sstevel@tonic-gate /* 566*0Sstevel@tonic-gate * Called at library initialization to set up signal handling. 567*0Sstevel@tonic-gate * All we really do is initialize the sig_lock mutexes. 568*0Sstevel@tonic-gate * All signal handlers are either SIG_DFL or SIG_IGN on exec(). 569*0Sstevel@tonic-gate * However, if any signal handlers were established on alternate 570*0Sstevel@tonic-gate * link maps before the primary link map has been initialized, 571*0Sstevel@tonic-gate * then inform the kernel of the new sigacthandler. 572*0Sstevel@tonic-gate */ 573*0Sstevel@tonic-gate void 574*0Sstevel@tonic-gate signal_init() 575*0Sstevel@tonic-gate { 576*0Sstevel@tonic-gate uberdata_t *udp = curthread->ul_uberdata; 577*0Sstevel@tonic-gate struct sigaction *sap; 578*0Sstevel@tonic-gate struct sigaction act; 579*0Sstevel@tonic-gate int sig; 580*0Sstevel@tonic-gate 581*0Sstevel@tonic-gate for (sig = 0; sig < NSIG; sig++) { 582*0Sstevel@tonic-gate udp->siguaction[sig].sig_lock.mutex_magic = MUTEX_MAGIC; 583*0Sstevel@tonic-gate sap = &udp->siguaction[sig].sig_uaction; 584*0Sstevel@tonic-gate if (sap->sa_sigaction != SIG_DFL && 585*0Sstevel@tonic-gate sap->sa_sigaction != SIG_IGN && 586*0Sstevel@tonic-gate __sigaction(sig, NULL, &act) == 0 && 587*0Sstevel@tonic-gate act.sa_sigaction != SIG_DFL && 588*0Sstevel@tonic-gate act.sa_sigaction != SIG_IGN) { 589*0Sstevel@tonic-gate act = *sap; 590*0Sstevel@tonic-gate act.sa_flags &= ~SA_NODEFER; 591*0Sstevel@tonic-gate act.sa_sigaction = udp->sigacthandler; 592*0Sstevel@tonic-gate act.sa_mask = maskset; 593*0Sstevel@tonic-gate (void) __sigaction(sig, &act, NULL); 594*0Sstevel@tonic-gate } 595*0Sstevel@tonic-gate } 596*0Sstevel@tonic-gate } 597*0Sstevel@tonic-gate 598*0Sstevel@tonic-gate /* 599*0Sstevel@tonic-gate * Common code for cancelling self in _sigcancel() and pthread_cancel(). 600*0Sstevel@tonic-gate * If the thread is at a cancellation point (ul_cancelable) then just 601*0Sstevel@tonic-gate * return and let _canceloff() do the exit, else exit immediately if 602*0Sstevel@tonic-gate * async mode is in effect. 603*0Sstevel@tonic-gate */ 604*0Sstevel@tonic-gate void 605*0Sstevel@tonic-gate do_sigcancel() 606*0Sstevel@tonic-gate { 607*0Sstevel@tonic-gate ulwp_t *self = curthread; 608*0Sstevel@tonic-gate 609*0Sstevel@tonic-gate ASSERT(self->ul_critical == 0); 610*0Sstevel@tonic-gate ASSERT(self->ul_sigdefer == 0); 611*0Sstevel@tonic-gate self->ul_cancel_pending = 1; 612*0Sstevel@tonic-gate if (self->ul_cancel_async && 613*0Sstevel@tonic-gate !self->ul_cancel_disabled && 614*0Sstevel@tonic-gate !self->ul_cancelable) 615*0Sstevel@tonic-gate _pthread_exit(PTHREAD_CANCELED); 616*0Sstevel@tonic-gate } 617*0Sstevel@tonic-gate 618*0Sstevel@tonic-gate /* 619*0Sstevel@tonic-gate * Set up the SIGCANCEL handler for threads cancellation 620*0Sstevel@tonic-gate * (needed only when we have more than one thread). 621*0Sstevel@tonic-gate * We need no locks here because we are called from 622*0Sstevel@tonic-gate * finish_init() while still single-threaded. 623*0Sstevel@tonic-gate */ 624*0Sstevel@tonic-gate void 625*0Sstevel@tonic-gate init_sigcancel() 626*0Sstevel@tonic-gate { 627*0Sstevel@tonic-gate uberdata_t *udp = curthread->ul_uberdata; 628*0Sstevel@tonic-gate struct sigaction act; 629*0Sstevel@tonic-gate 630*0Sstevel@tonic-gate act = udp->siguaction[SIGCANCEL].sig_uaction; 631*0Sstevel@tonic-gate if (act.sa_sigaction == SIG_DFL || 632*0Sstevel@tonic-gate act.sa_sigaction == SIG_IGN) 633*0Sstevel@tonic-gate act.sa_flags = SA_SIGINFO; 634*0Sstevel@tonic-gate else { 635*0Sstevel@tonic-gate act.sa_flags |= SA_SIGINFO; 636*0Sstevel@tonic-gate act.sa_flags &= ~(SA_NODEFER | SA_RESETHAND); 637*0Sstevel@tonic-gate } 638*0Sstevel@tonic-gate act.sa_sigaction = udp->sigacthandler; 639*0Sstevel@tonic-gate act.sa_mask = maskset; 640*0Sstevel@tonic-gate (void) __sigaction(SIGCANCEL, &act, NULL); 641*0Sstevel@tonic-gate } 642