1 files changed, 24 insertions, 4 deletions
diff --git a/src/runtime/os1_linux.go b/src/runtime/os1_linux.go
index e4b18c79b3..02f98d7c5f 100644
--- a/src/runtime/os1_linux.go
+++ b/src/runtime/os1_linux.go
@@ -6,7 +6,6 @@ package runtime
 
 import "unsafe"
 
-var sigset_none sigset
 var sigset_all sigset = sigset{^uint32(0), ^uint32(0)}
 
 // Linux futex.
@@ -190,17 +189,36 @@ func mpreinit(mp *m) {
 	mp.gsignal.m = mp
 }
 
+func msigsave(mp *m) {
+	smask := (*sigset)(unsafe.Pointer(&mp.sigmask))
+	if unsafe.Sizeof(*smask) > unsafe.Sizeof(mp.sigmask) {
+		throw("insufficient storage for signal mask")
+	}
+	rtsigprocmask(_SIG_SETMASK, nil, smask, int32(unsafe.Sizeof(*smask)))
+}
+
 // Called to initialize a new m (including the bootstrap m).
 // Called on the new thread, can not allocate memory.
 func minit() {
 	// Initialize signal handling.
 	_g_ := getg()
 	signalstack((*byte)(unsafe.Pointer(_g_.m.gsignal.stack.lo)), 32*1024)
-	rtsigprocmask(_SIG_SETMASK, &sigset_none, nil, int32(unsafe.Sizeof(sigset_none)))
+
+	// restore signal mask from m.sigmask and unblock essential signals
+	nmask := *(*sigset)(unsafe.Pointer(&_g_.m.sigmask))
+	for i := range sigtable {
+		if sigtable[i].flags&_SigUnblock != 0 {
+			nmask[(i-1)/32] &^= 1 << ((uint32(i) - 1) & 31)
+		}
+	}
+	rtsigprocmask(_SIG_SETMASK, &nmask, nil, int32(unsafe.Sizeof(nmask)))
 }
 
 // Called from dropm to undo the effect of an minit.
 func unminit() {
+	_g_ := getg()
+	smask := (*sigset)(unsafe.Pointer(&_g_.m.sigmask))
+	rtsigprocmask(_SIG_SETMASK, smask, nil, int32(unsafe.Sizeof(*smask)))
 	signalstack(nil, 0)
 }
 
@@ -304,6 +322,8 @@ func signalstack(p *byte, n int32) {
 	sigaltstack(&st, nil)
 }
 
-func unblocksignals() {
-	rtsigprocmask(_SIG_SETMASK, &sigset_none, nil, int32(unsafe.Sizeof(sigset_none)))
+func updatesigmask(m sigmask) {
+	var mask sigset
+	copy(mask[:], m[:])
+	rtsigprocmask(_SIG_SETMASK, &mask, nil, int32(unsafe.Sizeof(mask)))
 }