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Date:: Fri Jan 10 14:54:30 2020 UTC
Message:: Trivial changes: whitespace and modes. Remote whitespace at the ends of lines. Remove blank lines from the ends of files. Change modes on source files so that they are not executable. Signed-off-by: Dan Cross <cross@gajendra.net>
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  1 9acaad45 2004-10-23 devnull /*
  2 fa325e9b 2020-01-10 cross  * Signal handling for Plan 9 programs.
  3 fa325e9b 2020-01-10 cross  * We stubbornly use the strings from Plan 9 instead
  4 fa325e9b 2020-01-10 cross  * of the enumerated Unix constants.
  5 9acaad45 2004-10-23 devnull  * There are some weird translations.  In particular,
  6 9acaad45 2004-10-23 devnull  * a "kill" note is the same as SIGTERM in Unix.
  7 9acaad45 2004-10-23 devnull  * There is no equivalent note to Unix's SIGKILL, since
  8 9acaad45 2004-10-23 devnull  * it's not a deliverable signal anyway.
  9 9acaad45 2004-10-23 devnull  *
 10 5f8fa947 2004-12-26 devnull  * We do not handle SIGABRT or SIGSEGV, mainly because
 11 5f8fa947 2004-12-26 devnull  * the thread library queues its notes for later, and we want
 12 5f8fa947 2004-12-26 devnull  * to dump core with the state at time of delivery.
 13 9acaad45 2004-10-23 devnull  *
 14 9acaad45 2004-10-23 devnull  * We have to add some extra entry points to provide the
 15 9acaad45 2004-10-23 devnull  * ability to tweak which signals are deliverable and which
 16 9acaad45 2004-10-23 devnull  * are acted upon.  Notifydisable and notifyenable play with
 17 9acaad45 2004-10-23 devnull  * the process signal mask.  Notifyignore enables the signal
 18 9acaad45 2004-10-23 devnull  * but will not call notifyf when it comes in.  This is occasionally
 19 9acaad45 2004-10-23 devnull  * useful.
 20 9acaad45 2004-10-23 devnull  */
 21 9acaad45 2004-10-23 devnull 
 22 fd04aace 2003-11-23 devnull #include <u.h>
 23 8ad51794 2004-03-25 devnull #include <signal.h>
 24 fd04aace 2003-11-23 devnull #define NOPLAN9DEFINES
 25 fd04aace 2003-11-23 devnull #include <libc.h>
 26 fd04aace 2003-11-23 devnull 
 27 fd04aace 2003-11-23 devnull extern char *_p9sigstr(int, char*);
 28 9acaad45 2004-10-23 devnull extern int _p9strsig(char*);
 29 fd04aace 2003-11-23 devnull 
 30 9acaad45 2004-10-23 devnull typedef struct Sig Sig;
 31 9acaad45 2004-10-23 devnull struct Sig
 32 9acaad45 2004-10-23 devnull {
 33 9acaad45 2004-10-23 devnull 	int sig;			/* signal number */
 34 f3ecd8ae 2005-02-08 devnull 	int flags;
 35 9acaad45 2004-10-23 devnull };
 36 9acaad45 2004-10-23 devnull 
 37 f3ecd8ae 2005-02-08 devnull enum
 38 f3ecd8ae 2005-02-08 devnull {
 39 f3ecd8ae 2005-02-08 devnull 	Restart = 1<<0,
 40 d35c1bb2 2008-07-12 rsc 	Ignore = 1<<1,
 41 d35c1bb2 2008-07-12 rsc 	NoNotify = 1<<2,
 42 f3ecd8ae 2005-02-08 devnull };
 43 10f14b04 2005-01-16 devnull 
 44 9acaad45 2004-10-23 devnull static Sig sigs[] = {
 45 f3ecd8ae 2005-02-08 devnull 	SIGHUP,		0,
 46 f3ecd8ae 2005-02-08 devnull 	SIGINT,		0,
 47 f3ecd8ae 2005-02-08 devnull 	SIGQUIT,		0,
 48 f3ecd8ae 2005-02-08 devnull 	SIGILL,		0,
 49 f3ecd8ae 2005-02-08 devnull 	SIGTRAP,		0,
 50 f3ecd8ae 2005-02-08 devnull /*	SIGABRT, 		0, 	*/
 51 d2c4ee9e 2003-11-24 devnull #ifdef SIGEMT
 52 f3ecd8ae 2005-02-08 devnull 	SIGEMT,		0,
 53 d2c4ee9e 2003-11-24 devnull #endif
 54 f3ecd8ae 2005-02-08 devnull 	SIGFPE,		0,
 55 f3ecd8ae 2005-02-08 devnull 	SIGBUS,		0,
 56 f3ecd8ae 2005-02-08 devnull /*	SIGSEGV, 		0, 	*/
 57 f3ecd8ae 2005-02-08 devnull 	SIGCHLD,		Restart|Ignore,
 58 f3ecd8ae 2005-02-08 devnull 	SIGSYS,		0,
 59 f3ecd8ae 2005-02-08 devnull 	SIGPIPE,		Ignore,
 60 f3ecd8ae 2005-02-08 devnull 	SIGALRM,		0,
 61 f3ecd8ae 2005-02-08 devnull 	SIGTERM,		0,
 62 d35c1bb2 2008-07-12 rsc 	SIGTSTP,		Restart|Ignore|NoNotify,
 63 1dd11f59 2005-03-18 devnull /*	SIGTTIN,		Restart|Ignore, */
 64 1dd11f59 2005-03-18 devnull /*	SIGTTOU,		Restart|Ignore, */
 65 f3ecd8ae 2005-02-08 devnull 	SIGXCPU,		0,
 66 f3ecd8ae 2005-02-08 devnull 	SIGXFSZ,		0,
 67 f3ecd8ae 2005-02-08 devnull 	SIGVTALRM,	0,
 68 f3ecd8ae 2005-02-08 devnull 	SIGUSR1,		0,
 69 f3ecd8ae 2005-02-08 devnull 	SIGUSR2,		0,
 70 bc7da029 2005-05-07 devnull #ifdef SIGWINCH
 71 d35c1bb2 2008-07-12 rsc 	SIGWINCH,	Restart|Ignore|NoNotify,
 72 bc7da029 2005-05-07 devnull #endif
 73 d2c4ee9e 2003-11-24 devnull #ifdef SIGINFO
 74 d35c1bb2 2008-07-12 rsc 	SIGINFO,		Restart|Ignore|NoNotify,
 75 d2c4ee9e 2003-11-24 devnull #endif
 76 fd04aace 2003-11-23 devnull };
 77 fd04aace 2003-11-23 devnull 
 78 9acaad45 2004-10-23 devnull static Sig*
 79 9acaad45 2004-10-23 devnull findsig(int s)
 80 9acaad45 2004-10-23 devnull {
 81 9acaad45 2004-10-23 devnull 	int i;
 82 9acaad45 2004-10-23 devnull 
 83 9acaad45 2004-10-23 devnull 	for(i=0; i<nelem(sigs); i++)
 84 9acaad45 2004-10-23 devnull 		if(sigs[i].sig == s)
 85 9acaad45 2004-10-23 devnull 			return &sigs[i];
 86 9acaad45 2004-10-23 devnull 	return nil;
 87 9acaad45 2004-10-23 devnull }
 88 9acaad45 2004-10-23 devnull 
 89 9acaad45 2004-10-23 devnull /*
 90 9acaad45 2004-10-23 devnull  * The thread library initializes _notejmpbuf to its own
 91 9acaad45 2004-10-23 devnull  * routine which provides a per-pthread jump buffer.
 92 9acaad45 2004-10-23 devnull  * If we're not using the thread library, we assume we are
 93 9acaad45 2004-10-23 devnull  * single-threaded.
 94 9acaad45 2004-10-23 devnull  */
 95 05d8c6df 2004-09-23 devnull typedef struct Jmp Jmp;
 96 05d8c6df 2004-09-23 devnull struct Jmp
 97 05d8c6df 2004-09-23 devnull {
 98 05d8c6df 2004-09-23 devnull 	p9jmp_buf b;
 99 05d8c6df 2004-09-23 devnull };
100 05d8c6df 2004-09-23 devnull 
101 05d8c6df 2004-09-23 devnull static Jmp onejmp;
102 05d8c6df 2004-09-23 devnull 
103 05d8c6df 2004-09-23 devnull static Jmp*
104 05d8c6df 2004-09-23 devnull getonejmp(void)
105 05d8c6df 2004-09-23 devnull {
106 05d8c6df 2004-09-23 devnull 	return &onejmp;
107 05d8c6df 2004-09-23 devnull }
108 05d8c6df 2004-09-23 devnull 
109 05d8c6df 2004-09-23 devnull Jmp *(*_notejmpbuf)(void) = getonejmp;
110 9acaad45 2004-10-23 devnull static void noteinit(void);
111 fd04aace 2003-11-23 devnull 
112 9acaad45 2004-10-23 devnull /*
113 fa325e9b 2020-01-10 cross  * Actual signal handler.
114 9acaad45 2004-10-23 devnull  */
115 aa200fe3 2004-10-22 devnull 
116 9acaad45 2004-10-23 devnull static void (*notifyf)(void*, char*);	/* Plan 9 handler */
117 9acaad45 2004-10-23 devnull 
118 aa200fe3 2004-10-22 devnull static void
119 9acaad45 2004-10-23 devnull signotify(int sig)
120 fd04aace 2003-11-23 devnull {
121 fd04aace 2003-11-23 devnull 	char tmp[64];
122 05d8c6df 2004-09-23 devnull 	Jmp *j;
123 f3ecd8ae 2005-02-08 devnull 	Sig *s;
124 fd04aace 2003-11-23 devnull 
125 05d8c6df 2004-09-23 devnull 	j = (*_notejmpbuf)();
126 9acaad45 2004-10-23 devnull 	switch(p9setjmp(j->b)){
127 9acaad45 2004-10-23 devnull 	case 0:
128 9acaad45 2004-10-23 devnull 		if(notifyf)
129 9acaad45 2004-10-23 devnull 			(*notifyf)(nil, _p9sigstr(sig, tmp));
130 9acaad45 2004-10-23 devnull 		/* fall through */
131 9acaad45 2004-10-23 devnull 	case 1:	/* noted(NDFLT) */
132 9acaad45 2004-10-23 devnull 		if(0)print("DEFAULT %d\n", sig);
133 f3ecd8ae 2005-02-08 devnull 		s = findsig(sig);
134 f3ecd8ae 2005-02-08 devnull 		if(s && (s->flags&Ignore))
135 f3ecd8ae 2005-02-08 devnull 			return;
136 9acaad45 2004-10-23 devnull 		signal(sig, SIG_DFL);
137 9acaad45 2004-10-23 devnull 		raise(sig);
138 9acaad45 2004-10-23 devnull 		_exit(1);
139 9acaad45 2004-10-23 devnull 	case 2:	/* noted(NCONT) */
140 05d8c6df 2004-09-23 devnull 		if(0)print("HANDLED %d\n", sig);
141 fd04aace 2003-11-23 devnull 		return;
142 fd04aace 2003-11-23 devnull 	}
143 fd04aace 2003-11-23 devnull }
144 05d8c6df 2004-09-23 devnull 
145 9acaad45 2004-10-23 devnull static void
146 9acaad45 2004-10-23 devnull signonotify(int sig)
147 9acaad45 2004-10-23 devnull {
148 9acaad45 2004-10-23 devnull 	USED(sig);
149 9acaad45 2004-10-23 devnull }
150 9acaad45 2004-10-23 devnull 
151 fd04aace 2003-11-23 devnull int
152 05d8c6df 2004-09-23 devnull noted(int v)
153 05d8c6df 2004-09-23 devnull {
154 05d8c6df 2004-09-23 devnull 	p9longjmp((*_notejmpbuf)()->b, v==NCONT ? 2 : 1);
155 05d8c6df 2004-09-23 devnull 	abort();
156 05d8c6df 2004-09-23 devnull 	return 0;
157 05d8c6df 2004-09-23 devnull }
158 05d8c6df 2004-09-23 devnull 
159 9acaad45 2004-10-23 devnull int
160 9acaad45 2004-10-23 devnull notify(void (*f)(void*, char*))
161 9acaad45 2004-10-23 devnull {
162 9acaad45 2004-10-23 devnull 	static int init;
163 9acaad45 2004-10-23 devnull 
164 9acaad45 2004-10-23 devnull 	notifyf = f;
165 9acaad45 2004-10-23 devnull 	if(!init){
166 9acaad45 2004-10-23 devnull 		init = 1;
167 9acaad45 2004-10-23 devnull 		noteinit();
168 9acaad45 2004-10-23 devnull 	}
169 9acaad45 2004-10-23 devnull 	return 0;
170 9acaad45 2004-10-23 devnull }
171 9acaad45 2004-10-23 devnull 
172 9acaad45 2004-10-23 devnull /*
173 9acaad45 2004-10-23 devnull  * Nonsense about enabling and disabling signals.
174 9acaad45 2004-10-23 devnull  */
175 5f8fa947 2004-12-26 devnull typedef void Sighandler(int);
176 5f8fa947 2004-12-26 devnull static Sighandler*
177 9acaad45 2004-10-23 devnull handler(int s)
178 9acaad45 2004-10-23 devnull {
179 9acaad45 2004-10-23 devnull 	struct sigaction sa;
180 9acaad45 2004-10-23 devnull 
181 9acaad45 2004-10-23 devnull 	sigaction(s, nil, &sa);
182 9acaad45 2004-10-23 devnull 	return sa.sa_handler;
183 9acaad45 2004-10-23 devnull }
184 9acaad45 2004-10-23 devnull 
185 10f14b04 2005-01-16 devnull static int
186 5f8fa947 2004-12-26 devnull notesetenable(int sig, int enabled)
187 fd04aace 2003-11-23 devnull {
188 10f14b04 2005-01-16 devnull 	sigset_t mask, omask;
189 fd04aace 2003-11-23 devnull 
190 9acaad45 2004-10-23 devnull 	if(sig == 0)
191 10f14b04 2005-01-16 devnull 		return -1;
192 aa200fe3 2004-10-22 devnull 
193 9acaad45 2004-10-23 devnull 	sigemptyset(&mask);
194 9acaad45 2004-10-23 devnull 	sigaddset(&mask, sig);
195 10f14b04 2005-01-16 devnull 	sigprocmask(enabled ? SIG_UNBLOCK : SIG_BLOCK, &mask, &omask);
196 fa325e9b 2020-01-10 cross 	return !sigismember(&omask, sig);
197 9acaad45 2004-10-23 devnull }
198 9acaad45 2004-10-23 devnull 
199 10f14b04 2005-01-16 devnull int
200 5f8fa947 2004-12-26 devnull noteenable(char *msg)
201 9acaad45 2004-10-23 devnull {
202 10f14b04 2005-01-16 devnull 	return notesetenable(_p9strsig(msg), 1);
203 9acaad45 2004-10-23 devnull }
204 9acaad45 2004-10-23 devnull 
205 10f14b04 2005-01-16 devnull int
206 5f8fa947 2004-12-26 devnull notedisable(char *msg)
207 9acaad45 2004-10-23 devnull {
208 10f14b04 2005-01-16 devnull 	return notesetenable(_p9strsig(msg), 0);
209 9acaad45 2004-10-23 devnull }
210 9acaad45 2004-10-23 devnull 
211 10f14b04 2005-01-16 devnull static int
212 9acaad45 2004-10-23 devnull notifyseton(int s, int on)
213 9acaad45 2004-10-23 devnull {
214 9acaad45 2004-10-23 devnull 	Sig *sig;
215 10f14b04 2005-01-16 devnull 	struct sigaction sa, osa;
216 9acaad45 2004-10-23 devnull 
217 9acaad45 2004-10-23 devnull 	sig = findsig(s);
218 9acaad45 2004-10-23 devnull 	if(sig == nil)
219 10f14b04 2005-01-16 devnull 		return -1;
220 669250d1 2003-12-03 devnull 	memset(&sa, 0, sizeof sa);
221 9acaad45 2004-10-23 devnull 	sa.sa_handler = on ? signotify : signonotify;
222 f3ecd8ae 2005-02-08 devnull 	if(sig->flags&Restart)
223 9acaad45 2004-10-23 devnull 		sa.sa_flags |= SA_RESTART;
224 aa200fe3 2004-10-22 devnull 
225 aa200fe3 2004-10-22 devnull 	/*
226 9acaad45 2004-10-23 devnull 	 * We can't allow signals within signals because there's
227 9acaad45 2004-10-23 devnull 	 * only one jump buffer.
228 aa200fe3 2004-10-22 devnull 	 */
229 aa200fe3 2004-10-22 devnull 	sigfillset(&sa.sa_mask);
230 9acaad45 2004-10-23 devnull 
231 9acaad45 2004-10-23 devnull 	/*
232 9acaad45 2004-10-23 devnull 	 * Install handler.
233 9acaad45 2004-10-23 devnull 	 */
234 10f14b04 2005-01-16 devnull 	sigaction(sig->sig, &sa, &osa);
235 10f14b04 2005-01-16 devnull 	return osa.sa_handler == signotify;
236 aa200fe3 2004-10-22 devnull }
237 aa200fe3 2004-10-22 devnull 
238 10f14b04 2005-01-16 devnull int
239 9acaad45 2004-10-23 devnull notifyon(char *msg)
240 aa200fe3 2004-10-22 devnull {
241 10f14b04 2005-01-16 devnull 	return notifyseton(_p9strsig(msg), 1);
242 fd04aace 2003-11-23 devnull }
243 aa200fe3 2004-10-22 devnull 
244 10f14b04 2005-01-16 devnull int
245 9acaad45 2004-10-23 devnull notifyoff(char *msg)
246 aa200fe3 2004-10-22 devnull {
247 10f14b04 2005-01-16 devnull 	return notifyseton(_p9strsig(msg), 0);
248 aa200fe3 2004-10-22 devnull }
249 aa200fe3 2004-10-22 devnull 
250 9acaad45 2004-10-23 devnull /*
251 9acaad45 2004-10-23 devnull  * Initialization follows sigs table.
252 9acaad45 2004-10-23 devnull  */
253 9acaad45 2004-10-23 devnull static void
254 9acaad45 2004-10-23 devnull noteinit(void)
255 aa200fe3 2004-10-22 devnull {
256 aa200fe3 2004-10-22 devnull 	int i;
257 9acaad45 2004-10-23 devnull 	Sig *sig;
258 aa200fe3 2004-10-22 devnull 
259 9acaad45 2004-10-23 devnull 	for(i=0; i<nelem(sigs); i++){
260 9acaad45 2004-10-23 devnull 		sig = &sigs[i];
261 9acaad45 2004-10-23 devnull 		/*
262 9acaad45 2004-10-23 devnull 		 * If someone has already installed a handler,
263 9acaad45 2004-10-23 devnull 		 * It's probably some ld preload nonsense,
264 9acaad45 2004-10-23 devnull 		 * like pct (a SIGVTALRM-based profiler).
265 5f8fa947 2004-12-26 devnull 		 * Or maybe someone has already called notifyon/notifyoff.
266 9acaad45 2004-10-23 devnull 		 * Leave it alone.
267 9acaad45 2004-10-23 devnull 		 */
268 9acaad45 2004-10-23 devnull 		if(handler(sig->sig) != SIG_DFL)
269 9acaad45 2004-10-23 devnull 			continue;
270 d35c1bb2 2008-07-12 rsc 		notifyseton(sig->sig, !(sig->flags&NoNotify));
271 9acaad45 2004-10-23 devnull 	}
272 aa200fe3 2004-10-22 devnull }