xref: /titanic_51/usr/src/cmd/csh/sparc/signal.c (revision 06e46062ef4f5f4b687cbafb4518fb123fe23920)
1 /*
2  * Copyright 2005 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(int sig, siginfo_t *sip, ucontext_t *ucp)
68 {
69 	struct sigcontext sc;
70 	int code;
71 	char *addr;
72 	int i, j;
73 	int gwinswitch = 0;
74 
75 	sc.sc_onstack = ((ucp->uc_stack.ss_flags & SS_ONSTACK) != 0);
76 	sc.sc_mask = set2mask(&ucp->uc_sigmask);
77 
78 	/*
79 	 * Machine dependent code begins
80 	 */
81 	sc.sc_sp = ucp->uc_mcontext.gregs[REG_O6];
82 	sc.sc_pc = ucp->uc_mcontext.gregs[REG_PC];
83 	sc.sc_npc = ucp->uc_mcontext.gregs[REG_nPC];
84 	sc.sc_psr = ucp->uc_mcontext.gregs[REG_PSR];
85 	sc.sc_g1 = ucp->uc_mcontext.gregs[REG_G1];
86 	sc.sc_o0 = ucp->uc_mcontext.gregs[REG_O0];
87 	if (ucp->uc_mcontext.gwins != (gwindows_t *)0) {
88 		gwinswitch = 1;
89 		sc.sc_wbcnt = ucp->uc_mcontext.gwins->wbcnt;
90 		for (i = 0; i < MAXWINDOW; i++) {
91 			for (j = 0; j < 16; j++)
92 				sc.sc_spbuf[i][j] = (int)ucp->uc_mcontext.gwins->spbuf[j];
93 			for (j = 0; j < 8; j++)
94 				sc.sc_wbuf[i][j] = ucp->uc_mcontext.gwins->wbuf[i].rw_local[j];
95 			for (j = 0; j < 8; j++)
96 				sc.sc_wbuf[i][j+8] = ucp->uc_mcontext.gwins->wbuf[i].rw_in[j];
97 		}
98 	}
99 	/*
100 	 * Machine dependent code ends
101 	 */
102 
103 	if (sip != NULL)
104 		if ((code = sip->si_code) == BUS_OBJERR)
105 			code = SEGV_MAKE_ERR(sip->si_errno);
106 
107 	if (sig == SIGILL || sig == SIGFPE || sig == SIGSEGV || sig == SIGBUS)
108 		if (sip != NULL)
109 			addr = (char *)sip->si_addr;
110 	else
111 		addr = SIG_NOADDR;
112 
113 	(*_siguhandler[sig])(sig, code, &sc, addr);
114 
115 	if (sc.sc_onstack)
116 		ucp->uc_stack.ss_flags |= SS_ONSTACK;
117 	else
118 		ucp->uc_stack.ss_flags &= ~SS_ONSTACK;
119 	mask2set(sc.sc_mask, &ucp->uc_sigmask);
120 
121 	/*
122 	 * Machine dependent code begins
123 	 */
124 	ucp->uc_mcontext.gregs[REG_O6] = sc.sc_sp;
125 	ucp->uc_mcontext.gregs[REG_PC] = sc.sc_pc;
126 	ucp->uc_mcontext.gregs[REG_nPC] = sc.sc_npc;
127 	ucp->uc_mcontext.gregs[REG_PSR] = sc.sc_psr;
128 	ucp->uc_mcontext.gregs[REG_G1] = sc.sc_g1;
129 	ucp->uc_mcontext.gregs[REG_O0] = sc.sc_o0;
130 	if (gwinswitch == 1) {
131 		ucp->uc_mcontext.gwins->wbcnt = sc.sc_wbcnt;
132 		for (i = 0; i < MAXWINDOW; i++) {
133 			for (j = 0; j < 16; j++)
134 				ucp->uc_mcontext.gwins->spbuf[j] = (greg_t *)sc.sc_spbuf[i][j];
135 			for (j = 0; j < 8; j++)
136 				ucp->uc_mcontext.gwins->wbuf[i].rw_local[j] = sc.sc_wbuf[i][j];
137 			for (j = 0; j < 8; j++)
138 				ucp->uc_mcontext.gwins->wbuf[i].rw_in[j] = sc.sc_wbuf[i][j+8];
139 		}
140 	}
141 	/*
142 	 * Machine dependent code ends
143 	 */
144 
145 	setcontext (ucp);
146 }
147 
148 int
149 sigsetmask(int mask)
150 {
151 	sigset_t oset;
152 	sigset_t nset;
153 
154 	(void) sigprocmask(0, (sigset_t *)0, &nset);
155 	mask2set(mask, &nset);
156 	(void) sigprocmask(SIG_SETMASK, &nset, &oset);
157 	return set2mask(&oset);
158 }
159 
160 int
161 sigblock(int mask)
162 {
163 	sigset_t oset;
164 	sigset_t nset;
165 
166 	(void) sigprocmask(0, (sigset_t *)0, &nset);
167 	mask2set(mask, &nset);
168 	(void) sigprocmask(SIG_BLOCK, &nset, &oset);
169 	return set2mask(&oset);
170 }
171 
172 int
173 sigpause(int mask)
174 {
175 	sigset_t set;
176 
177 	(void) sigprocmask(0, (sigset_t *)0, &set);
178 	mask2set(mask, &set);
179 	return (sigsuspend(&set));
180 }
181 
182 int
183 sigvec(int sig, struct sigvec *nvec, struct sigvec *ovec)
184 {
185         struct sigaction nact;
186         struct sigaction oact;
187         struct sigaction *nactp;
188         void (*ohandler)(), (*nhandler)();
189 
190         if (sig <= 0 || sig >= NSIG) {
191                 errno = EINVAL;
192                 return -1;
193         }
194 
195         ohandler = _siguhandler[sig];
196 
197         if (nvec) {
198 		_sigaction(sig, (struct sigaction *)0, &nact);
199                 nhandler = nvec->sv_handler;
200                 _siguhandler[sig] = nhandler;
201                 if (nhandler != SIG_DFL && nhandler != SIG_IGN)
202                         nact.sa_handler = (void (*)())sigvechandler;
203 		else
204 			nact.sa_handler = nhandler;
205 		mask2set(nvec->sv_mask, &nact.sa_mask);
206 		/*
207 		if ( sig == SIGTSTP || sig == SIGSTOP )
208 			nact.sa_handler = SIG_DFL; 	*/
209 		nact.sa_flags = SA_SIGINFO;
210 		if (!(nvec->sv_flags & SV_INTERRUPT))
211 			nact.sa_flags |= SA_RESTART;
212 		if (nvec->sv_flags & SV_RESETHAND)
213 			nact.sa_flags |= SA_RESETHAND;
214 		if (nvec->sv_flags & SV_ONSTACK)
215 			nact.sa_flags |= SA_ONSTACK;
216 		nactp = &nact;
217         } else
218 		nactp = (struct sigaction *)0;
219 
220         if (_sigaction(sig, nactp, &oact) < 0) {
221                 _siguhandler[sig] = ohandler;
222                 return -1;
223         }
224 
225         if (ovec) {
226 		if (oact.sa_handler == SIG_DFL || oact.sa_handler == SIG_IGN)
227 			ovec->sv_handler = oact.sa_handler;
228 		else
229 			ovec->sv_handler = ohandler;
230 		ovec->sv_mask = set2mask(&oact.sa_mask);
231 		ovec->sv_flags = 0;
232 		if (oact.sa_flags & SA_ONSTACK)
233 			ovec->sv_flags |= SV_ONSTACK;
234 		if (oact.sa_flags & SA_RESETHAND)
235 			ovec->sv_flags |= SV_RESETHAND;
236 		if (!(oact.sa_flags & SA_RESTART))
237 			ovec->sv_flags |= SV_INTERRUPT;
238 	}
239 
240         return 0;
241 }
242 
243 
244 void (*
245 signal(int s, void (*a)()))()
246 {
247         struct sigvec osv;
248 	struct sigvec nsv;
249         static int mask[NSIG];
250         static int flags[NSIG];
251 
252 	nsv.sv_handler = a;
253 	nsv.sv_mask = mask[s];
254 	nsv.sv_flags = flags[s];
255         if (sigvec(s, &nsv, &osv) < 0)
256                 return (SIG_ERR);
257         if (nsv.sv_mask != osv.sv_mask || nsv.sv_flags != osv.sv_flags) {
258                 mask[s] = nsv.sv_mask = osv.sv_mask;
259                 flags[s] = nsv.sv_flags = osv.sv_flags & ~SV_RESETHAND;
260                 if (sigvec(s, &nsv, (struct sigvec *)0) < 0)
261                         return (SIG_ERR);
262         }
263         return (osv.sv_handler);
264 }
265