1 /* 2 * Copyright 2003 Sun Microsystems, Inc. All rights reserved. 3 * Use is subject to license terms. 4 */ 5 6 /* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */ 7 /* All Rights Reserved */ 8 9 /* 10 * Copyright (c) 1980 Regents of the University of California. 11 * All rights reserved. The Berkeley Software License Agreement 12 * specifies the terms and conditions for redistribution. 13 */ 14 15 #pragma ident "%Z%%M% %I% %E% SMI" 16 17 /* 18 * 4.3BSD signal compatibility functions 19 * 20 * the implementation interprets signal masks equal to -1 as "all of the 21 * signals in the signal set", thereby allowing signals with numbers 22 * above 32 to be blocked when referenced in code such as: 23 * 24 * for (i = 0; i < NSIG; i++) 25 * mask |= sigmask(i) 26 */ 27 28 #include <sys/types.h> 29 #include <sys/siginfo.h> 30 #include <sys/ucontext.h> 31 #include <signal.h> 32 #include "signal.h" 33 #include <errno.h> 34 #include <stdio.h> 35 36 #define set2mask(setp) ((setp)->__sigbits[0]) 37 #define mask2set(mask, setp) \ 38 ((mask) == -1 ? sigfillset(setp) : sigemptyset(setp), (((setp)->__sigbits[0]) = (mask))) 39 40 void (*_siguhandler[NSIG])() = { 0 }; 41 42 /* 43 * sigstack is emulated with sigaltstack by guessing an appropriate 44 * value for the stack size - on machines that have stacks that grow 45 * upwards, the ss_sp arguments for both functions mean the same thing, 46 * (the initial stack pointer sigstack() is also the stack base 47 * sigaltstack()), so a "very large" value should be chosen for the 48 * stack size - on machines that have stacks that grow downwards, the 49 * ss_sp arguments mean opposite things, so 0 should be used (hopefully 50 * these machines don't have hardware stack bounds registers that pay 51 * attention to sigaltstack()'s size argument. 52 */ 53 54 #ifdef sun 55 #define SIGSTACKSIZE 0 56 #endif 57 58 59 /* 60 * sigvechandler is the real signal handler installed for all 61 * signals handled in the 4.3BSD compatibility interface - it translates 62 * SVR4 signal hander arguments into 4.3BSD signal handler arguments 63 * and then calls the real handler 64 */ 65 66 static void 67 sigvechandler(sig, sip, ucp) 68 int sig; 69 siginfo_t *sip; 70 ucontext_t *ucp; 71 { 72 struct sigcontext sc; 73 int code; 74 char *addr; 75 register int i, j; 76 int gwinswitch = 0; 77 78 sc.sc_onstack = ((ucp->uc_stack.ss_flags & SS_ONSTACK) != 0); 79 sc.sc_mask = set2mask(&ucp->uc_sigmask); 80 81 /* 82 * Machine dependent code begins 83 */ 84 sc.sc_sp = (int) ucp->uc_mcontext.gregs[UESP]; 85 sc.sc_pc = (int) ucp->uc_mcontext.gregs[EIP]; 86 sc.sc_ps = (int) ucp->uc_mcontext.gregs[EFL]; 87 sc.sc_eax = (int) ucp->uc_mcontext.gregs[EAX]; 88 sc.sc_edx = (int) ucp->uc_mcontext.gregs[EDX]; 89 90 /* 91 * Machine dependent code ends 92 */ 93 94 if (sip != NULL) 95 if ((code = sip->si_code) == BUS_OBJERR) 96 code = SEGV_MAKE_ERR(sip->si_errno); 97 98 if (sig == SIGILL || sig == SIGFPE || sig == SIGSEGV || sig == SIGBUS) 99 if (sip != NULL) 100 addr = (char *)sip->si_addr; 101 else 102 addr = SIG_NOADDR; 103 104 (*_siguhandler[sig])(sig, code, &sc, addr); 105 106 if (sc.sc_onstack) 107 ucp->uc_stack.ss_flags |= SS_ONSTACK; 108 else 109 ucp->uc_stack.ss_flags &= ~SS_ONSTACK; 110 mask2set(sc.sc_mask, &ucp->uc_sigmask); 111 112 /* 113 * Machine dependent code begins 114 */ 115 ucp->uc_mcontext.gregs[UESP] = (int) sc.sc_sp; 116 ucp->uc_mcontext.gregs[EIP] = (int) sc.sc_pc; 117 ucp->uc_mcontext.gregs[EFL] = (int) sc.sc_ps; 118 ucp->uc_mcontext.gregs[EAX] = (int) sc.sc_eax; 119 ucp->uc_mcontext.gregs[EDX] = (int) sc.sc_edx; 120 /* 121 * Machine dependent code ends 122 */ 123 124 setcontext (ucp); 125 } 126 127 sigsetmask(mask) 128 int mask; 129 { 130 sigset_t oset; 131 sigset_t nset; 132 133 (void) sigprocmask(0, (sigset_t *)0, &nset); 134 mask2set(mask, &nset); 135 (void) sigprocmask(SIG_SETMASK, &nset, &oset); 136 return set2mask(&oset); 137 } 138 139 sigblock(mask) 140 int mask; 141 { 142 sigset_t oset; 143 sigset_t nset; 144 145 (void) sigprocmask(0, (sigset_t *)0, &nset); 146 mask2set(mask, &nset); 147 (void) sigprocmask(SIG_BLOCK, &nset, &oset); 148 return set2mask(&oset); 149 } 150 151 sigpause(mask) 152 int mask; 153 { 154 sigset_t set; 155 156 (void) sigprocmask(0, (sigset_t *)0, &set); 157 mask2set(mask, &set); 158 return (sigsuspend(&set)); 159 } 160 161 sigvec(sig, nvec, ovec) 162 int sig; 163 struct sigvec *nvec; 164 struct sigvec *ovec; 165 { 166 struct sigaction nact; 167 struct sigaction oact; 168 struct sigaction *nactp; 169 void (*ohandler)(), (*nhandler)(); 170 171 if (sig <= 0 || sig >= NSIG) { 172 errno = EINVAL; 173 return -1; 174 } 175 176 ohandler = _siguhandler[sig]; 177 178 if (nvec) { 179 _sigaction(sig, (struct sigaction *)0, &nact); 180 nhandler = nvec->sv_handler; 181 _siguhandler[sig] = nhandler; 182 if (nhandler != SIG_DFL && nhandler != SIG_IGN) 183 nact.sa_handler = (void (*)())sigvechandler; 184 else 185 nact.sa_handler = nhandler; 186 mask2set(nvec->sv_mask, &nact.sa_mask); 187 /* 188 if ( sig == SIGTSTP || sig == SIGSTOP ) 189 nact.sa_handler = SIG_DFL; */ 190 nact.sa_flags = SA_SIGINFO; 191 if (!(nvec->sv_flags & SV_INTERRUPT)) 192 nact.sa_flags |= SA_RESTART; 193 if (nvec->sv_flags & SV_RESETHAND) 194 nact.sa_flags |= SA_RESETHAND; 195 if (nvec->sv_flags & SV_ONSTACK) 196 nact.sa_flags |= SA_ONSTACK; 197 nactp = &nact; 198 } else 199 nactp = (struct sigaction *)0; 200 201 if (_sigaction(sig, nactp, &oact) < 0) { 202 _siguhandler[sig] = ohandler; 203 return -1; 204 } 205 206 if (ovec) { 207 if (oact.sa_handler == SIG_DFL || oact.sa_handler == SIG_IGN) 208 ovec->sv_handler = oact.sa_handler; 209 else 210 ovec->sv_handler = ohandler; 211 ovec->sv_mask = set2mask(&oact.sa_mask); 212 ovec->sv_flags = 0; 213 if (oact.sa_flags & SA_ONSTACK) 214 ovec->sv_flags |= SV_ONSTACK; 215 if (oact.sa_flags & SA_RESETHAND) 216 ovec->sv_flags |= SV_RESETHAND; 217 if (!(oact.sa_flags & SA_RESTART)) 218 ovec->sv_flags |= SV_INTERRUPT; 219 } 220 221 return 0; 222 } 223 224 225 void (* 226 signal(s, a))() 227 int s; 228 void (*a)(); 229 { 230 struct sigvec osv; 231 struct sigvec nsv; 232 static int mask[NSIG]; 233 static int flags[NSIG]; 234 235 nsv.sv_handler = a; 236 nsv.sv_mask = mask[s]; 237 nsv.sv_flags = flags[s]; 238 if (sigvec(s, &nsv, &osv) < 0) 239 return (SIG_ERR); 240 if (nsv.sv_mask != osv.sv_mask || nsv.sv_flags != osv.sv_flags) { 241 mask[s] = nsv.sv_mask = osv.sv_mask; 242 flags[s] = nsv.sv_flags = osv.sv_flags & ~SV_RESETHAND; 243 if (sigvec(s, &nsv, (struct sigvec *)0) < 0) 244 return (SIG_ERR); 245 } 246 return (osv.sv_handler); 247 } 248