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play nicer with others w.r.t. signal masks

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rsc 2005-02-08 19:08:47 +00:00
parent 76164c00c3
commit f3ecd8ae84
1 changed files with 37 additions and 43 deletions
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80
src/lib9/notify.c
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@ -31,48 +31,44 @@ typedef struct Sig Sig;
struct Sig
{
int sig; /* signal number */
int restart; /* do we restart the system call after this signal is handled? */
int enabled; /* is this signal enabled (not masked)? */
int notified; /* do we call the notify function for this signal? */
int flags;
};
/*
* Bug. It is profoundly anti-social to play with the masks like this.
* For example, even though we don't want to see SIGTSTP, others do.
* Running bash inside a 9term that has disabled SIGTSTP makes ^Z not work.
* Instead we need to leave the signals enabled but notifyoff them.
*/
enum
{
Restart = 1<<0,
Ignore = 1<<1,
};
/* initial settings; for current status, ask the kernel */
static Sig sigs[] = {
SIGHUP, 0, 1, 1,
SIGINT, 0, 1, 1,
SIGQUIT, 0, 1, 1,
SIGILL, 0, 1, 1,
SIGTRAP, 0, 1, 1,
/* SIGABRT, 0, 1, 1, */
SIGHUP, 0,
SIGINT, 0,
SIGQUIT, 0,
SIGILL, 0,
SIGTRAP, 0,
/* SIGABRT, 0, */
#ifdef SIGEMT
SIGEMT, 0, 1, 1,
SIGEMT, 0,
#endif
SIGFPE, 0, 1, 1,
SIGBUS, 0, 1, 1,
/* SIGSEGV, 0, 1, 1, */
SIGCHLD, 1, 0, 1,
SIGSYS, 0, 1, 1,
SIGPIPE, 0, 0, 1,
SIGALRM, 0, 1, 1,
SIGTERM, 0, 1, 1,
SIGTSTP, 1, 0, 1,
SIGTTIN, 1, 0, 1,
SIGTTOU, 1, 0, 1,
SIGXCPU, 0, 1, 1,
SIGXFSZ, 0, 1, 1,
SIGVTALRM, 0, 1, 1,
SIGUSR1, 0, 1, 1,
SIGUSR2, 0, 1, 1,
SIGWINCH, 1, 0, 1,
SIGFPE, 0,
SIGBUS, 0,
/* SIGSEGV, 0, */
SIGCHLD, Restart|Ignore,
SIGSYS, 0,
SIGPIPE, Ignore,
SIGALRM, 0,
SIGTERM, 0,
SIGTSTP, Restart|Ignore,
SIGTTIN, Restart|Ignore,
SIGTTOU, Restart|Ignore,
SIGXCPU, 0,
SIGXFSZ, 0,
SIGVTALRM, 0,
SIGUSR1, 0,
SIGUSR2, 0,
SIGWINCH, Restart|Ignore,
#ifdef SIGINFO
SIGINFO, 1, 1, 1,
SIGINFO, Restart|Ignore,
#endif
};
@ -121,6 +117,7 @@ signotify(int sig)
{
char tmp[64];
Jmp *j;
Sig *s;
j = (*_notejmpbuf)();
switch(p9setjmp(j->b)){
@ -130,6 +127,9 @@ signotify(int sig)
/* fall through */
case 1: /* noted(NDFLT) */
if(0)print("DEFAULT %d\n", sig);
s = findsig(sig);
if(s && (s->flags&Ignore))
return;
signal(sig, SIG_DFL);
raise(sig);
_exit(1);
@ -216,7 +216,7 @@ notifyseton(int s, int on)
return -1;
memset(&sa, 0, sizeof sa);
sa.sa_handler = on ? signotify : signonotify;
if(sig->restart)
if(sig->flags&Restart)
sa.sa_flags |= SA_RESTART;
/*
@ -264,13 +264,7 @@ noteinit(void)
*/
if(handler(sig->sig) != SIG_DFL)
continue;
/*
* Should we only disable and not enable signals?
* (I.e. if parent has disabled for us, should we still enable?)
* Right now we always initialize to the state we want.
*/
notesetenable(sig->sig, sig->enabled);
notifyseton(sig->sig, sig->notified);
notifyseton(sig->sig, 1);
}
}