runtime: if os/signal is not in use, crash on
most signals, so that ordinary programs
can be killed, for example.
Fixes #434.
R=dsymonds1
CC=golang-dev, hoisie
https://golang.org/cl/180064
diff --git a/src/pkg/runtime/darwin/386/signal.c b/src/pkg/runtime/darwin/386/signal.c
index 4023439..7978739 100644
--- a/src/pkg/runtime/darwin/386/signal.c
+++ b/src/pkg/runtime/darwin/386/signal.c
@@ -41,8 +41,9 @@
Regs *r;
if(sigtab[sig].flags & SigQueue) {
- sigsend(sig);
- return;
+ if(sigsend(sig) || (sigtab[sig].flags & SigIgnore))
+ return;
+ exit(2); // SIGINT, SIGTERM, etc
}
if(panicking) // traceback already printed
diff --git a/src/pkg/runtime/darwin/amd64/signal.c b/src/pkg/runtime/darwin/amd64/signal.c
index 5e26a71..bf1bca9 100644
--- a/src/pkg/runtime/darwin/amd64/signal.c
+++ b/src/pkg/runtime/darwin/amd64/signal.c
@@ -49,8 +49,9 @@
Regs *r;
if(sigtab[sig].flags & SigQueue) {
- sigsend(sig);
- return;
+ if(sigsend(sig) || (sigtab[sig].flags & SigIgnore))
+ return;
+ exit(2); // SIGINT, SIGTERM, etc
}
if(panicking) // traceback already printed
diff --git a/src/pkg/runtime/darwin/signals.h b/src/pkg/runtime/darwin/signals.h
index 48a5db1..449a6a7 100644
--- a/src/pkg/runtime/darwin/signals.h
+++ b/src/pkg/runtime/darwin/signals.h
@@ -22,24 +22,24 @@
/* 11 */ C, "SIGSEGV: segmentation violation",
/* 12 */ C, "SIGSYS: bad system call",
/* 13 */ I, "SIGPIPE: write to broken pipe",
- /* 14 */ Q+R, "SIGALRM: alarm clock",
+ /* 14 */ Q+I+R, "SIGALRM: alarm clock",
/* 15 */ Q+R, "SIGTERM: termination",
- /* 16 */ Q+R, "SIGURG: urgent condition on socket",
+ /* 16 */ Q+I+R, "SIGURG: urgent condition on socket",
/* 17 */ 0, "SIGSTOP: stop",
- /* 18 */ Q+R, "SIGTSTP: keyboard stop",
+ /* 18 */ Q+I+R, "SIGTSTP: keyboard stop",
/* 19 */ 0, "SIGCONT: continue after stop",
/* 20 */ I+R, "SIGCHLD: child status has changed",
- /* 21 */ Q+R, "SIGTTIN: background read from tty",
- /* 22 */ Q+R, "SIGTTOU: background write to tty",
- /* 23 */ Q+R, "SIGIO: i/o now possible",
- /* 24 */ Q+R, "SIGXCPU: cpu limit exceeded",
- /* 25 */ Q+R, "SIGXFSZ: file size limit exceeded",
- /* 26 */ Q+R, "SIGVTALRM: virtual alarm clock",
- /* 27 */ Q+R, "SIGPROF: profiling alarm clock",
- /* 28 */ Q+R, "SIGWINCH: window size change",
- /* 29 */ Q+R, "SIGINFO: status request from keyboard",
- /* 30 */ Q+R, "SIGUSR1: user-defined signal 1",
- /* 31 */ Q+R, "SIGUSR2: user-defined signal 2",
+ /* 21 */ Q+I+R, "SIGTTIN: background read from tty",
+ /* 22 */ Q+I+R, "SIGTTOU: background write to tty",
+ /* 23 */ Q+I+R, "SIGIO: i/o now possible",
+ /* 24 */ Q+I+R, "SIGXCPU: cpu limit exceeded",
+ /* 25 */ Q+I+R, "SIGXFSZ: file size limit exceeded",
+ /* 26 */ Q+I+R, "SIGVTALRM: virtual alarm clock",
+ /* 27 */ Q+I+R, "SIGPROF: profiling alarm clock",
+ /* 28 */ Q+I+R, "SIGWINCH: window size change",
+ /* 29 */ Q+I+R, "SIGINFO: status request from keyboard",
+ /* 30 */ Q+I+R, "SIGUSR1: user-defined signal 1",
+ /* 31 */ Q+I+R, "SIGUSR2: user-defined signal 2",
};
#undef C
#undef I
diff --git a/src/pkg/runtime/extern.go b/src/pkg/runtime/extern.go
index 27cb73c..85b1659 100644
--- a/src/pkg/runtime/extern.go
+++ b/src/pkg/runtime/extern.go
@@ -66,3 +66,7 @@
// Signame returns a string describing the signal, or "" if the signal is unknown.
func Signame(sig int32) string
+
+// Siginit enables receipt of signals via Sigrecv. It should typically
+// be called during initialization.
+func Siginit()
diff --git a/src/pkg/runtime/freebsd/386/signal.c b/src/pkg/runtime/freebsd/386/signal.c
index 7bad780..d687767 100644
--- a/src/pkg/runtime/freebsd/386/signal.c
+++ b/src/pkg/runtime/freebsd/386/signal.c
@@ -51,8 +51,9 @@
Mcontext *mc;
if(sigtab[sig].flags & SigQueue) {
- sigsend(sig);
- return;
+ if(sigsend(sig) || (sigtab[sig].flags & SigIgnore))
+ return;
+ exit(2); // SIGINT, SIGTERM, etc
}
if(panicking) // traceback already printed
diff --git a/src/pkg/runtime/freebsd/amd64/signal.c b/src/pkg/runtime/freebsd/amd64/signal.c
index ed03db1..d59259b 100644
--- a/src/pkg/runtime/freebsd/amd64/signal.c
+++ b/src/pkg/runtime/freebsd/amd64/signal.c
@@ -59,8 +59,9 @@
Mcontext *mc;
if(sigtab[sig].flags & SigQueue) {
- sigsend(sig);
- return;
+ if(sigsend(sig) || (sigtab[sig].flags & SigIgnore))
+ return;
+ exit(2); // SIGINT, SIGTERM, etc
}
if(panicking) // traceback already printed
diff --git a/src/pkg/runtime/freebsd/signals.h b/src/pkg/runtime/freebsd/signals.h
index 91ddef8..b986bcb 100644
--- a/src/pkg/runtime/freebsd/signals.h
+++ b/src/pkg/runtime/freebsd/signals.h
@@ -22,25 +22,25 @@
/* 11 */ C, "SIGSEGV: segmentation violation",
/* 12 */ C, "SIGSYS: bad system call",
/* 13 */ I, "SIGPIPE: write to broken pipe",
- /* 14 */ Q+R, "SIGALRM: alarm clock",
+ /* 14 */ Q+I+R, "SIGALRM: alarm clock",
/* 15 */ Q+R, "SIGTERM: termination",
- /* 16 */ Q+R, "SIGURG: urgent condition on socket",
+ /* 16 */ Q+I+R, "SIGURG: urgent condition on socket",
/* 17 */ 0, "SIGSTOP: stop, unblockable",
- /* 18 */ Q+R, "SIGTSTP: stop from tty",
+ /* 18 */ Q+I+R, "SIGTSTP: stop from tty",
/* 19 */ 0, "SIGCONT: continue",
/* 20 */ I+R, "SIGCHLD: child status has changed",
- /* 21 */ Q+R, "SIGTTIN: background read from tty",
- /* 22 */ Q+R, "SIGTTOU: background write to tty",
- /* 23 */ Q+R, "SIGIO: i/o now possible",
- /* 24 */ Q+R, "SIGXCPU: cpu limit exceeded",
- /* 25 */ Q+R, "SIGXFSZ: file size limit exceeded",
- /* 26 */ Q+R, "SIGVTALRM: virtual alarm clock",
- /* 27 */ Q+R, "SIGPROF: profiling alarm clock",
- /* 28 */ I+R, "SIGWINCH: window size change",
- /* 29 */ Q+R, "SIGINFO: information request",
- /* 30 */ Q+R, "SIGUSR1: user-defined signal 1",
- /* 31 */ Q+R, "SIGUSR2: user-defined signal 2",
- /* 32 */ Q+R, "SIGTHR: reserved",
+ /* 21 */ Q+I+R, "SIGTTIN: background read from tty",
+ /* 22 */ Q+I+R, "SIGTTOU: background write to tty",
+ /* 23 */ Q+I+R, "SIGIO: i/o now possible",
+ /* 24 */ Q+I+R, "SIGXCPU: cpu limit exceeded",
+ /* 25 */ Q+I+R, "SIGXFSZ: file size limit exceeded",
+ /* 26 */ Q+I+R, "SIGVTALRM: virtual alarm clock",
+ /* 27 */ Q+I+R, "SIGPROF: profiling alarm clock",
+ /* 28 */ Q+I+R, "SIGWINCH: window size change",
+ /* 29 */ Q+I+R, "SIGINFO: information request",
+ /* 30 */ Q+I+R, "SIGUSR1: user-defined signal 1",
+ /* 31 */ Q+I+R, "SIGUSR2: user-defined signal 2",
+ /* 32 */ Q+I+R, "SIGTHR: reserved",
};
#undef C
#undef I
diff --git a/src/pkg/runtime/linux/386/signal.c b/src/pkg/runtime/linux/386/signal.c
index 2e6c7a5..c540083 100644
--- a/src/pkg/runtime/linux/386/signal.c
+++ b/src/pkg/runtime/linux/386/signal.c
@@ -48,8 +48,9 @@
Sigcontext *sc;
if(sigtab[sig].flags & SigQueue) {
- sigsend(sig);
- return;
+ if(sigsend(sig) || (sigtab[sig].flags & SigIgnore))
+ return;
+ exit(2); // SIGINT, SIGTERM, etc
}
if(panicking) // traceback already printed
diff --git a/src/pkg/runtime/linux/amd64/signal.c b/src/pkg/runtime/linux/amd64/signal.c
index 693b8c7..dba6fb1 100644
--- a/src/pkg/runtime/linux/amd64/signal.c
+++ b/src/pkg/runtime/linux/amd64/signal.c
@@ -57,8 +57,9 @@
Sigcontext *sc;
if(sigtab[sig].flags & SigQueue) {
- sigsend(sig);
- return;
+ if(sigsend(sig) || (sigtab[sig].flags & SigIgnore))
+ return;
+ exit(2); // SIGINT, SIGTERM, etc
}
if(panicking) // traceback already printed
diff --git a/src/pkg/runtime/linux/signals.h b/src/pkg/runtime/linux/signals.h
index 883ac4e..3431cd2 100644
--- a/src/pkg/runtime/linux/signals.h
+++ b/src/pkg/runtime/linux/signals.h
@@ -18,27 +18,27 @@
/* 7 */ C, "SIGBUS: bus error",
/* 8 */ C, "SIGFPE: floating-point exception",
/* 9 */ 0, "SIGKILL: kill",
- /* 10 */ Q+R, "SIGUSR1: user-defined signal 1",
+ /* 10 */ Q+I+R, "SIGUSR1: user-defined signal 1",
/* 11 */ C, "SIGSEGV: segmentation violation",
- /* 12 */ Q+R, "SIGUSR2: user-defined signal 2",
+ /* 12 */ Q+I+R, "SIGUSR2: user-defined signal 2",
/* 13 */ I, "SIGPIPE: write to broken pipe",
- /* 14 */ Q+R, "SIGALRM: alarm clock",
+ /* 14 */ Q+I+R, "SIGALRM: alarm clock",
/* 15 */ Q+R, "SIGTERM: termination",
- /* 16 */ Q+R, "SIGSTKFLT: stack fault",
- /* 17 */ Q+R, "SIGCHLD: child status has changed",
+ /* 16 */ C, "SIGSTKFLT: stack fault",
+ /* 17 */ I+R, "SIGCHLD: child status has changed",
/* 18 */ 0, "SIGCONT: continue",
/* 19 */ 0, "SIGSTOP: stop, unblockable",
- /* 20 */ Q+R, "SIGTSTP: keyboard stop",
- /* 21 */ Q+R, "SIGTTIN: background read from tty",
- /* 22 */ Q+R, "SIGTTOU: background write to tty",
- /* 23 */ Q+R, "SIGURG: urgent condition on socket",
- /* 24 */ Q+R, "SIGXCPU: cpu limit exceeded",
- /* 25 */ Q+R, "SIGXFSZ: file size limit exceeded",
- /* 26 */ Q+R, "SIGVTALRM: virtual alarm clock",
- /* 27 */ Q+R, "SIGPROF: profiling alarm clock",
- /* 28 */ Q+R, "SIGWINCH: window size change",
- /* 29 */ Q+R, "SIGIO: i/o now possible",
- /* 30 */ Q+R, "SIGPWR: power failure restart",
+ /* 20 */ Q+I+R, "SIGTSTP: keyboard stop",
+ /* 21 */ Q+I+R, "SIGTTIN: background read from tty",
+ /* 22 */ Q+I+R, "SIGTTOU: background write to tty",
+ /* 23 */ Q+I+R, "SIGURG: urgent condition on socket",
+ /* 24 */ Q+I+R, "SIGXCPU: cpu limit exceeded",
+ /* 25 */ Q+I+R, "SIGXFSZ: file size limit exceeded",
+ /* 26 */ Q+I+R, "SIGVTALRM: virtual alarm clock",
+ /* 27 */ Q+I+R, "SIGPROF: profiling alarm clock",
+ /* 28 */ Q+I+R, "SIGWINCH: window size change",
+ /* 29 */ Q+I+R, "SIGIO: i/o now possible",
+ /* 30 */ Q+I+R, "SIGPWR: power failure restart",
/* 31 */ C, "SIGSYS: bad system call",
};
#undef C
diff --git a/src/pkg/runtime/runtime.h b/src/pkg/runtime/runtime.h
index 46df412..91130a0 100644
--- a/src/pkg/runtime/runtime.h
+++ b/src/pkg/runtime/runtime.h
@@ -374,10 +374,10 @@
void gosched(void);
void goexit(void);
void runcgo(void (*fn)(void*), void*);
-void entersyscall(void);
-void exitsyscall(void);
+void runtime·entersyscall(void);
+void runtime·exitsyscall(void);
void siginit(void);
-void sigsend(int32 sig);
+bool sigsend(int32 sig);
#pragma varargck argpos printf 1
diff --git a/src/pkg/runtime/sigqueue.cgo b/src/pkg/runtime/sigqueue.cgo
index 059d3ed..c3751c5d 100644
--- a/src/pkg/runtime/sigqueue.cgo
+++ b/src/pkg/runtime/sigqueue.cgo
@@ -43,6 +43,7 @@
static struct {
Note;
uint32 mask;
+ bool inuse;
} sig;
void
@@ -52,24 +53,27 @@
}
// Called from sighandler to send a signal back out of the signal handling thread.
-void
+bool
sigsend(int32 s)
{
uint32 bit, mask;
+ if(!sig.inuse)
+ return false;
bit = 1 << s;
for(;;) {
mask = sig.mask;
if(mask & bit)
- return; // signal already in queue
+ break; // signal already in queue
if(cas(&sig.mask, mask, mask|bit)) {
// Added to queue.
// Only send a wakeup for the first signal in each round.
if(mask == 0)
notewakeup(&sig);
- return;
+ break;
}
}
+ return true;
}
// Called to receive a bitmask of queued signals.
@@ -88,3 +92,7 @@
func Signame(sig int32) (name String) {
name = signame(sig);
}
+
+func Siginit() {
+ sig.inuse = true; // enable reception of signals; cannot disable
+}
