10 files changed, 47 insertions, 2 deletions
diff --git a/src/runtime/os1_darwin.go b/src/runtime/os1_darwin.go
index 12642aa121..984b88161c 100644
--- a/src/runtime/os1_darwin.go
+++ b/src/runtime/os1_darwin.go
@@ -394,6 +394,10 @@ func setsig(i int32, fn uintptr, restart bool) {
 	sigaction(uint32(i), &sa, nil)
 }
 
+func setsigstack(i int32) {
+	gothrow("setsigstack")
+}
+
 func getsig(i int32) uintptr {
 	var sa sigactiont
 	memclr(unsafe.Pointer(&sa), unsafe.Sizeof(sa))
diff --git a/src/runtime/os1_dragonfly.go b/src/runtime/os1_dragonfly.go
index d02e925ec5..0d241bde79 100644
--- a/src/runtime/os1_dragonfly.go
+++ b/src/runtime/os1_dragonfly.go
@@ -189,6 +189,10 @@ func setsig(i int32, fn uintptr, restart bool) {
 	sigaction(i, &sa, nil)
 }
 
+func setsigstack(i int32) {
+	gothrow("setsigstack")
+}
+
 func getsig(i int32) uintptr {
 	var sa sigactiont
 	sigaction(i, nil, &sa)
diff --git a/src/runtime/os1_freebsd.go b/src/runtime/os1_freebsd.go
index 80e4532439..83e98f45e4 100644
--- a/src/runtime/os1_freebsd.go
+++ b/src/runtime/os1_freebsd.go
@@ -190,6 +190,11 @@ func setsig(i int32, fn uintptr, restart bool) {
 	sa.sa_handler = fn
 	sigaction(i, &sa, nil)
 }
+
+func setsigstack(i int32) {
+	gothrow("setsigstack")
+}
+
 func getsig(i int32) uintptr {
 	var sa sigactiont
 	sigaction(i, nil, &sa)
diff --git a/src/runtime/os1_linux.go b/src/runtime/os1_linux.go
index 2e12d74f44..0174856914 100644
--- a/src/runtime/os1_linux.go
+++ b/src/runtime/os1_linux.go
@@ -246,6 +246,20 @@ func setsig(i int32, fn uintptr, restart bool) {
 	}
 }
 
+func setsigstack(i int32) {
+	var sa sigactiont
+	if rt_sigaction(uintptr(i), nil, &sa, unsafe.Sizeof(sa.sa_mask)) != 0 {
+		gothrow("rt_sigaction failure")
+	}
+	if sa.sa_handler == 0 || sa.sa_handler == _SIG_DFL || sa.sa_handler == _SIG_IGN || sa.sa_flags&_SA_ONSTACK != 0 {
+		return
+	}
+	sa.sa_flags |= _SA_ONSTACK
+	if rt_sigaction(uintptr(i), &sa, nil, unsafe.Sizeof(sa.sa_mask)) != 0 {
+		gothrow("rt_sigaction failure")
+	}
+}
+
 func getsig(i int32) uintptr {
 	var sa sigactiont
 
diff --git a/src/runtime/os1_netbsd.go b/src/runtime/os1_netbsd.go
index b5068629ba..f4de988707 100644
--- a/src/runtime/os1_netbsd.go
+++ b/src/runtime/os1_netbsd.go
@@ -233,6 +233,10 @@ func setsig(i int32, fn uintptr, restart bool) {
 	sigaction(i, &sa, nil)
 }
 
+func setsigstack(i int32) {
+	gothrow("setsigstack")
+}
+
 func getsig(i int32) uintptr {
 	var sa sigactiont
 	sigaction(i, nil, &sa)
diff --git a/src/runtime/os1_openbsd.go b/src/runtime/os1_openbsd.go
index b1a16d582b..07a9751fe0 100644
--- a/src/runtime/os1_openbsd.go
+++ b/src/runtime/os1_openbsd.go
@@ -203,6 +203,10 @@ func setsig(i int32, fn uintptr, restart bool) {
 	sigaction(i, &sa, nil)
 }
 
+func setsigstack(i int32) {
+	gothrow("setsigstack")
+}
+
 func getsig(i int32) uintptr {
 	var sa sigactiont
 	sigaction(i, nil, &sa)
diff --git a/src/runtime/os3_solaris.go b/src/runtime/os3_solaris.go
index 6ccbbe29ee..72db958f99 100644
--- a/src/runtime/os3_solaris.go
+++ b/src/runtime/os3_solaris.go
@@ -252,6 +252,10 @@ func setsig(i int32, fn uintptr, restart bool) {
 	sigaction(i, &sa, nil)
 }
 
+func setsigstack(i int32) {
+	gothrow("setsigstack")
+}
+
 func getsig(i int32) uintptr {
 	var sa sigactiont
 	sigaction(i, nil, &sa)
diff --git a/src/runtime/runtime2.go b/src/runtime/runtime2.go
index 4d42153abb..3b7db1e412 100644
--- a/src/runtime/runtime2.go
+++ b/src/runtime/runtime2.go
@@ -372,6 +372,7 @@ const (
 	_SigHandling = 1 << 5 // our signal handler is registered
 	_SigIgnored  = 1 << 6 // the signal was ignored before we registered for it
 	_SigGoExit   = 1 << 7 // cause all runtime procs to exit (only used on Plan 9).
+	_SigSetStack = 1 << 8 // add SA_ONSTACK to libc handler
 )
 
 // Layout of in-memory per-function information prepared by linker
diff --git a/src/runtime/signal1_unix.go b/src/runtime/signal1_unix.go
index 25f01e056e..9613e0ae33 100644
--- a/src/runtime/signal1_unix.go
+++ b/src/runtime/signal1_unix.go
@@ -37,6 +37,11 @@ func initsig() {
 			}
 		}
 
+		if t.flags&_SigSetStack != 0 {
+			setsigstack(i)
+			continue
+		}
+
 		t.flags |= _SigHandling
 		setsig(i, funcPC(sighandler), true)
 	}
diff --git a/src/runtime/signal_linux.go b/src/runtime/signal_linux.go
index 1c3d6872b3..c71e619b1e 100644
--- a/src/runtime/signal_linux.go
+++ b/src/runtime/signal_linux.go
@@ -42,8 +42,8 @@ var sigtable = [...]sigTabT{
 	/* 29 */ {_SigNotify, "SIGIO: i/o now possible"},
 	/* 30 */ {_SigNotify, "SIGPWR: power failure restart"},
 	/* 31 */ {_SigNotify, "SIGSYS: bad system call"},
-	/* 32 */ {0, "signal 32"}, /* SIGCANCEL; see issue 6997 */
-	/* 33 */ {0, "signal 33"}, /* SIGSETXID; see issue 3871 */
+	/* 32 */ {_SigSetStack, "signal 32"}, /* SIGCANCEL; see issue 6997 */
+	/* 33 */ {_SigSetStack, "signal 33"}, /* SIGSETXID; see issue 3871, 9400 */
 	/* 34 */ {_SigNotify, "signal 34"},
 	/* 35 */ {_SigNotify, "signal 35"},
 	/* 36 */ {_SigNotify, "signal 36"},