2 9acaad45 2004-10-23 devnull * Signal handling for Plan 9 programs.
3 9acaad45 2004-10-23 devnull * We stubbornly use the strings from Plan 9 instead
4 9acaad45 2004-10-23 devnull * 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.
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.
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.
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>
27 fd04aace 2003-11-23 devnull extern char *_p9sigstr(int, char*);
28 9acaad45 2004-10-23 devnull extern int _p9strsig(char*);
30 9acaad45 2004-10-23 devnull typedef struct Sig Sig;
31 9acaad45 2004-10-23 devnull struct Sig
33 9acaad45 2004-10-23 devnull int sig; /* signal number */
34 f3ecd8ae 2005-02-08 devnull int flags;
39 f3ecd8ae 2005-02-08 devnull Restart = 1<<0,
40 cbeb0b26 2006-04-01 devnull Ignore = 1<<1
43 9acaad45 2004-10-23 devnull static Sig sigs[] = {
44 f3ecd8ae 2005-02-08 devnull SIGHUP, 0,
45 f3ecd8ae 2005-02-08 devnull SIGINT, 0,
46 f3ecd8ae 2005-02-08 devnull SIGQUIT, 0,
47 f3ecd8ae 2005-02-08 devnull SIGILL, 0,
48 f3ecd8ae 2005-02-08 devnull SIGTRAP, 0,
49 f3ecd8ae 2005-02-08 devnull /* SIGABRT, 0, */
50 d2c4ee9e 2003-11-24 devnull #ifdef SIGEMT
51 f3ecd8ae 2005-02-08 devnull SIGEMT, 0,
53 f3ecd8ae 2005-02-08 devnull SIGFPE, 0,
54 f3ecd8ae 2005-02-08 devnull SIGBUS, 0,
55 f3ecd8ae 2005-02-08 devnull /* SIGSEGV, 0, */
56 f3ecd8ae 2005-02-08 devnull SIGCHLD, Restart|Ignore,
57 f3ecd8ae 2005-02-08 devnull SIGSYS, 0,
58 f3ecd8ae 2005-02-08 devnull SIGPIPE, Ignore,
59 f3ecd8ae 2005-02-08 devnull SIGALRM, 0,
60 f3ecd8ae 2005-02-08 devnull SIGTERM, 0,
61 f3ecd8ae 2005-02-08 devnull SIGTSTP, Restart|Ignore,
62 1dd11f59 2005-03-18 devnull /* SIGTTIN, Restart|Ignore, */
63 1dd11f59 2005-03-18 devnull /* SIGTTOU, Restart|Ignore, */
64 f3ecd8ae 2005-02-08 devnull SIGXCPU, 0,
65 f3ecd8ae 2005-02-08 devnull SIGXFSZ, 0,
66 f3ecd8ae 2005-02-08 devnull SIGVTALRM, 0,
67 f3ecd8ae 2005-02-08 devnull SIGUSR1, 0,
68 f3ecd8ae 2005-02-08 devnull SIGUSR2, 0,
69 bc7da029 2005-05-07 devnull #ifdef SIGWINCH
70 f3ecd8ae 2005-02-08 devnull SIGWINCH, Restart|Ignore,
72 d2c4ee9e 2003-11-24 devnull #ifdef SIGINFO
73 f3ecd8ae 2005-02-08 devnull SIGINFO, Restart|Ignore,
77 9acaad45 2004-10-23 devnull static Sig*
78 9acaad45 2004-10-23 devnull findsig(int s)
82 9acaad45 2004-10-23 devnull for(i=0; i<nelem(sigs); i++)
83 9acaad45 2004-10-23 devnull if(sigs[i].sig == s)
84 9acaad45 2004-10-23 devnull return &sigs[i];
85 9acaad45 2004-10-23 devnull return nil;
89 9acaad45 2004-10-23 devnull * The thread library initializes _notejmpbuf to its own
90 9acaad45 2004-10-23 devnull * routine which provides a per-pthread jump buffer.
91 9acaad45 2004-10-23 devnull * If we're not using the thread library, we assume we are
92 9acaad45 2004-10-23 devnull * single-threaded.
94 05d8c6df 2004-09-23 devnull typedef struct Jmp Jmp;
95 05d8c6df 2004-09-23 devnull struct Jmp
97 05d8c6df 2004-09-23 devnull p9jmp_buf b;
100 05d8c6df 2004-09-23 devnull static Jmp onejmp;
102 05d8c6df 2004-09-23 devnull static Jmp*
103 05d8c6df 2004-09-23 devnull getonejmp(void)
105 05d8c6df 2004-09-23 devnull return &onejmp;
108 05d8c6df 2004-09-23 devnull Jmp *(*_notejmpbuf)(void) = getonejmp;
109 9acaad45 2004-10-23 devnull static void noteinit(void);
112 9acaad45 2004-10-23 devnull * Actual signal handler.
115 9acaad45 2004-10-23 devnull static void (*notifyf)(void*, char*); /* Plan 9 handler */
117 aa200fe3 2004-10-22 devnull static void
118 9acaad45 2004-10-23 devnull signotify(int sig)
120 fd04aace 2003-11-23 devnull char tmp[64];
124 05d8c6df 2004-09-23 devnull j = (*_notejmpbuf)();
125 9acaad45 2004-10-23 devnull switch(p9setjmp(j->b)){
127 9acaad45 2004-10-23 devnull if(notifyf)
128 9acaad45 2004-10-23 devnull (*notifyf)(nil, _p9sigstr(sig, tmp));
129 9acaad45 2004-10-23 devnull /* fall through */
130 9acaad45 2004-10-23 devnull case 1: /* noted(NDFLT) */
131 9acaad45 2004-10-23 devnull if(0)print("DEFAULT %d\n", sig);
132 f3ecd8ae 2005-02-08 devnull s = findsig(sig);
133 f3ecd8ae 2005-02-08 devnull if(s && (s->flags&Ignore))
135 9acaad45 2004-10-23 devnull signal(sig, SIG_DFL);
136 9acaad45 2004-10-23 devnull raise(sig);
137 9acaad45 2004-10-23 devnull _exit(1);
138 9acaad45 2004-10-23 devnull case 2: /* noted(NCONT) */
139 05d8c6df 2004-09-23 devnull if(0)print("HANDLED %d\n", sig);
144 9acaad45 2004-10-23 devnull static void
145 9acaad45 2004-10-23 devnull signonotify(int sig)
147 9acaad45 2004-10-23 devnull USED(sig);
151 05d8c6df 2004-09-23 devnull noted(int v)
153 05d8c6df 2004-09-23 devnull p9longjmp((*_notejmpbuf)()->b, v==NCONT ? 2 : 1);
154 05d8c6df 2004-09-23 devnull abort();
155 05d8c6df 2004-09-23 devnull return 0;
159 9acaad45 2004-10-23 devnull notify(void (*f)(void*, char*))
161 9acaad45 2004-10-23 devnull static int init;
163 9acaad45 2004-10-23 devnull notifyf = f;
164 9acaad45 2004-10-23 devnull if(!init){
165 9acaad45 2004-10-23 devnull init = 1;
166 9acaad45 2004-10-23 devnull noteinit();
168 9acaad45 2004-10-23 devnull return 0;
172 9acaad45 2004-10-23 devnull * Nonsense about enabling and disabling signals.
174 5f8fa947 2004-12-26 devnull typedef void Sighandler(int);
175 5f8fa947 2004-12-26 devnull static Sighandler*
176 9acaad45 2004-10-23 devnull handler(int s)
178 9acaad45 2004-10-23 devnull struct sigaction sa;
180 9acaad45 2004-10-23 devnull sigaction(s, nil, &sa);
181 9acaad45 2004-10-23 devnull return sa.sa_handler;
184 10f14b04 2005-01-16 devnull static int
185 5f8fa947 2004-12-26 devnull notesetenable(int sig, int enabled)
187 10f14b04 2005-01-16 devnull sigset_t mask, omask;
189 9acaad45 2004-10-23 devnull if(sig == 0)
190 10f14b04 2005-01-16 devnull return -1;
192 9acaad45 2004-10-23 devnull sigemptyset(&mask);
193 9acaad45 2004-10-23 devnull sigaddset(&mask, sig);
194 10f14b04 2005-01-16 devnull sigprocmask(enabled ? SIG_UNBLOCK : SIG_BLOCK, &mask, &omask);
195 10f14b04 2005-01-16 devnull return !sigismember(&omask, sig);
199 5f8fa947 2004-12-26 devnull noteenable(char *msg)
201 10f14b04 2005-01-16 devnull return notesetenable(_p9strsig(msg), 1);
205 5f8fa947 2004-12-26 devnull notedisable(char *msg)
207 10f14b04 2005-01-16 devnull return notesetenable(_p9strsig(msg), 0);
210 10f14b04 2005-01-16 devnull static int
211 9acaad45 2004-10-23 devnull notifyseton(int s, int on)
213 9acaad45 2004-10-23 devnull Sig *sig;
214 10f14b04 2005-01-16 devnull struct sigaction sa, osa;
216 9acaad45 2004-10-23 devnull sig = findsig(s);
217 9acaad45 2004-10-23 devnull if(sig == nil)
218 10f14b04 2005-01-16 devnull return -1;
219 669250d1 2003-12-03 devnull memset(&sa, 0, sizeof sa);
220 9acaad45 2004-10-23 devnull sa.sa_handler = on ? signotify : signonotify;
221 f3ecd8ae 2005-02-08 devnull if(sig->flags&Restart)
222 9acaad45 2004-10-23 devnull sa.sa_flags |= SA_RESTART;
225 9acaad45 2004-10-23 devnull * We can't allow signals within signals because there's
226 9acaad45 2004-10-23 devnull * only one jump buffer.
228 aa200fe3 2004-10-22 devnull sigfillset(&sa.sa_mask);
231 9acaad45 2004-10-23 devnull * Install handler.
233 10f14b04 2005-01-16 devnull sigaction(sig->sig, &sa, &osa);
234 10f14b04 2005-01-16 devnull return osa.sa_handler == signotify;
238 9acaad45 2004-10-23 devnull notifyon(char *msg)
240 10f14b04 2005-01-16 devnull return notifyseton(_p9strsig(msg), 1);
244 9acaad45 2004-10-23 devnull notifyoff(char *msg)
246 10f14b04 2005-01-16 devnull return notifyseton(_p9strsig(msg), 0);
250 9acaad45 2004-10-23 devnull * Initialization follows sigs table.
252 9acaad45 2004-10-23 devnull static void
253 9acaad45 2004-10-23 devnull noteinit(void)
256 9acaad45 2004-10-23 devnull Sig *sig;
258 9acaad45 2004-10-23 devnull for(i=0; i<nelem(sigs); i++){
259 9acaad45 2004-10-23 devnull sig = &sigs[i];
261 9acaad45 2004-10-23 devnull * If someone has already installed a handler,
262 9acaad45 2004-10-23 devnull * It's probably some ld preload nonsense,
263 9acaad45 2004-10-23 devnull * like pct (a SIGVTALRM-based profiler).
264 5f8fa947 2004-12-26 devnull * Or maybe someone has already called notifyon/notifyoff.
265 9acaad45 2004-10-23 devnull * Leave it alone.
267 9acaad45 2004-10-23 devnull if(handler(sig->sig) != SIG_DFL)
268 9acaad45 2004-10-23 devnull continue;
269 f3ecd8ae 2005-02-08 devnull notifyseton(sig->sig, 1);