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 9acaad45 2004-10-23 devnull int restart; /* do we restart the system call after this signal is handled? */
35 9acaad45 2004-10-23 devnull int enabled; /* is this signal enabled (not masked)? */
36 9acaad45 2004-10-23 devnull int notified; /* do we call the notify function for this signal? */
39 9acaad45 2004-10-23 devnull /* initial settings; for current status, ask the kernel */
40 9acaad45 2004-10-23 devnull static Sig sigs[] = {
41 9acaad45 2004-10-23 devnull SIGHUP, 0, 1, 1,
42 9acaad45 2004-10-23 devnull SIGINT, 0, 1, 1,
43 9acaad45 2004-10-23 devnull SIGQUIT, 0, 1, 1,
44 9acaad45 2004-10-23 devnull SIGILL, 0, 1, 1,
45 9acaad45 2004-10-23 devnull SIGTRAP, 0, 1, 1,
46 9acaad45 2004-10-23 devnull /* SIGABRT, 0, 1, 1, */
47 d2c4ee9e 2003-11-24 devnull #ifdef SIGEMT
48 9acaad45 2004-10-23 devnull SIGEMT, 0, 1, 1,
50 9acaad45 2004-10-23 devnull SIGFPE, 0, 1, 1,
51 9acaad45 2004-10-23 devnull SIGBUS, 0, 1, 1,
52 9acaad45 2004-10-23 devnull /* SIGSEGV, 0, 1, 1, */
53 9acaad45 2004-10-23 devnull SIGCHLD, 1, 0, 1,
54 9acaad45 2004-10-23 devnull SIGSYS, 0, 1, 1,
55 9acaad45 2004-10-23 devnull SIGPIPE, 0, 0, 1,
56 9acaad45 2004-10-23 devnull SIGALRM, 0, 1, 1,
57 9acaad45 2004-10-23 devnull SIGTERM, 0, 1, 1,
58 9acaad45 2004-10-23 devnull SIGTSTP, 1, 0, 1,
59 9acaad45 2004-10-23 devnull SIGTTIN, 1, 0, 1,
60 9acaad45 2004-10-23 devnull SIGTTOU, 1, 0, 1,
61 9acaad45 2004-10-23 devnull SIGXCPU, 0, 1, 1,
62 9acaad45 2004-10-23 devnull SIGXFSZ, 0, 1, 1,
63 9acaad45 2004-10-23 devnull SIGVTALRM, 0, 1, 1,
64 9acaad45 2004-10-23 devnull SIGUSR1, 0, 1, 1,
65 9acaad45 2004-10-23 devnull SIGUSR2, 0, 1, 1,
66 9acaad45 2004-10-23 devnull SIGWINCH, 1, 0, 1,
67 d2c4ee9e 2003-11-24 devnull #ifdef SIGINFO
68 9acaad45 2004-10-23 devnull SIGINFO, 1, 1, 1,
72 9acaad45 2004-10-23 devnull static Sig*
73 9acaad45 2004-10-23 devnull findsig(int s)
77 9acaad45 2004-10-23 devnull for(i=0; i<nelem(sigs); i++)
78 9acaad45 2004-10-23 devnull if(sigs[i].sig == s)
79 9acaad45 2004-10-23 devnull return &sigs[i];
80 9acaad45 2004-10-23 devnull return nil;
84 9acaad45 2004-10-23 devnull * The thread library initializes _notejmpbuf to its own
85 9acaad45 2004-10-23 devnull * routine which provides a per-pthread jump buffer.
86 9acaad45 2004-10-23 devnull * If we're not using the thread library, we assume we are
87 9acaad45 2004-10-23 devnull * single-threaded.
89 05d8c6df 2004-09-23 devnull typedef struct Jmp Jmp;
90 05d8c6df 2004-09-23 devnull struct Jmp
92 05d8c6df 2004-09-23 devnull p9jmp_buf b;
95 05d8c6df 2004-09-23 devnull static Jmp onejmp;
97 05d8c6df 2004-09-23 devnull static Jmp*
98 05d8c6df 2004-09-23 devnull getonejmp(void)
100 05d8c6df 2004-09-23 devnull return &onejmp;
103 05d8c6df 2004-09-23 devnull Jmp *(*_notejmpbuf)(void) = getonejmp;
104 9acaad45 2004-10-23 devnull static void noteinit(void);
107 9acaad45 2004-10-23 devnull * Actual signal handler.
110 9acaad45 2004-10-23 devnull static void (*notifyf)(void*, char*); /* Plan 9 handler */
112 aa200fe3 2004-10-22 devnull static void
113 9acaad45 2004-10-23 devnull signotify(int sig)
115 fd04aace 2003-11-23 devnull char tmp[64];
118 05d8c6df 2004-09-23 devnull j = (*_notejmpbuf)();
119 9acaad45 2004-10-23 devnull switch(p9setjmp(j->b)){
121 9acaad45 2004-10-23 devnull if(notifyf)
122 9acaad45 2004-10-23 devnull (*notifyf)(nil, _p9sigstr(sig, tmp));
123 9acaad45 2004-10-23 devnull /* fall through */
124 9acaad45 2004-10-23 devnull case 1: /* noted(NDFLT) */
125 9acaad45 2004-10-23 devnull if(0)print("DEFAULT %d\n", sig);
126 9acaad45 2004-10-23 devnull signal(sig, SIG_DFL);
127 9acaad45 2004-10-23 devnull raise(sig);
128 9acaad45 2004-10-23 devnull _exit(1);
129 9acaad45 2004-10-23 devnull case 2: /* noted(NCONT) */
130 05d8c6df 2004-09-23 devnull if(0)print("HANDLED %d\n", sig);
135 9acaad45 2004-10-23 devnull static void
136 9acaad45 2004-10-23 devnull signonotify(int sig)
138 9acaad45 2004-10-23 devnull USED(sig);
142 05d8c6df 2004-09-23 devnull noted(int v)
144 05d8c6df 2004-09-23 devnull p9longjmp((*_notejmpbuf)()->b, v==NCONT ? 2 : 1);
145 05d8c6df 2004-09-23 devnull abort();
146 05d8c6df 2004-09-23 devnull return 0;
150 9acaad45 2004-10-23 devnull notify(void (*f)(void*, char*))
152 9acaad45 2004-10-23 devnull static int init;
154 9acaad45 2004-10-23 devnull notifyf = f;
155 9acaad45 2004-10-23 devnull if(!init){
156 9acaad45 2004-10-23 devnull init = 1;
157 9acaad45 2004-10-23 devnull noteinit();
159 9acaad45 2004-10-23 devnull return 0;
163 9acaad45 2004-10-23 devnull * Nonsense about enabling and disabling signals.
165 5f8fa947 2004-12-26 devnull typedef void Sighandler(int);
166 5f8fa947 2004-12-26 devnull static Sighandler*
167 9acaad45 2004-10-23 devnull handler(int s)
169 9acaad45 2004-10-23 devnull struct sigaction sa;
171 9acaad45 2004-10-23 devnull sigaction(s, nil, &sa);
172 9acaad45 2004-10-23 devnull return sa.sa_handler;
175 aa200fe3 2004-10-22 devnull static void
176 5f8fa947 2004-12-26 devnull notesetenable(int sig, int enabled)
178 9acaad45 2004-10-23 devnull sigset_t mask;
180 9acaad45 2004-10-23 devnull if(sig == 0)
183 9acaad45 2004-10-23 devnull sigemptyset(&mask);
184 9acaad45 2004-10-23 devnull sigaddset(&mask, sig);
185 9acaad45 2004-10-23 devnull sigprocmask(enabled ? SIG_UNBLOCK : SIG_BLOCK, &mask, nil);
189 5f8fa947 2004-12-26 devnull noteenable(char *msg)
191 5f8fa947 2004-12-26 devnull notesetenable(_p9strsig(msg), 1);
195 5f8fa947 2004-12-26 devnull notedisable(char *msg)
197 5f8fa947 2004-12-26 devnull notesetenable(_p9strsig(msg), 0);
200 9acaad45 2004-10-23 devnull static void
201 9acaad45 2004-10-23 devnull notifyseton(int s, int on)
203 9acaad45 2004-10-23 devnull Sig *sig;
204 9acaad45 2004-10-23 devnull struct sigaction sa;
206 9acaad45 2004-10-23 devnull sig = findsig(s);
207 9acaad45 2004-10-23 devnull if(sig == nil)
209 669250d1 2003-12-03 devnull memset(&sa, 0, sizeof sa);
210 9acaad45 2004-10-23 devnull sa.sa_handler = on ? signotify : signonotify;
211 9acaad45 2004-10-23 devnull if(sig->restart)
212 9acaad45 2004-10-23 devnull sa.sa_flags |= SA_RESTART;
215 9acaad45 2004-10-23 devnull * We can't allow signals within signals because there's
216 9acaad45 2004-10-23 devnull * only one jump buffer.
218 aa200fe3 2004-10-22 devnull sigfillset(&sa.sa_mask);
221 9acaad45 2004-10-23 devnull * Install handler.
223 9acaad45 2004-10-23 devnull sigaction(sig->sig, &sa, nil);
227 9acaad45 2004-10-23 devnull notifyon(char *msg)
229 9acaad45 2004-10-23 devnull notifyseton(_p9strsig(msg), 1);
233 9acaad45 2004-10-23 devnull notifyoff(char *msg)
235 5f8fa947 2004-12-26 devnull notifyseton(_p9strsig(msg), 0);
239 9acaad45 2004-10-23 devnull * Initialization follows sigs table.
241 9acaad45 2004-10-23 devnull static void
242 9acaad45 2004-10-23 devnull noteinit(void)
245 9acaad45 2004-10-23 devnull Sig *sig;
247 9acaad45 2004-10-23 devnull for(i=0; i<nelem(sigs); i++){
248 9acaad45 2004-10-23 devnull sig = &sigs[i];
250 9acaad45 2004-10-23 devnull * If someone has already installed a handler,
251 9acaad45 2004-10-23 devnull * It's probably some ld preload nonsense,
252 9acaad45 2004-10-23 devnull * like pct (a SIGVTALRM-based profiler).
253 5f8fa947 2004-12-26 devnull * Or maybe someone has already called notifyon/notifyoff.
254 9acaad45 2004-10-23 devnull * Leave it alone.
256 9acaad45 2004-10-23 devnull if(handler(sig->sig) != SIG_DFL)
257 9acaad45 2004-10-23 devnull continue;
259 9acaad45 2004-10-23 devnull * Should we only disable and not enable signals?
260 9acaad45 2004-10-23 devnull * (I.e. if parent has disabled for us, should we still enable?)
261 9acaad45 2004-10-23 devnull * Right now we always initialize to the state we want.
263 5f8fa947 2004-12-26 devnull notesetenable(sig->sig, sig->enabled);
264 9acaad45 2004-10-23 devnull notifyseton(sig->sig, sig->notified);