runtime: remove PROT_EXEC from mmap calls.

Executable heap is gone on Unix!

R=golang-dev, dave, bradfitz
CC=golang-dev
https://golang.org/cl/7405045

src/pkg/runtime/mem_darwin.c

@@ -14,7 +14,7 @@ runtime·SysAlloc(uintptr n)
 	void *v;
 
 	mstats.sys += n;
-	v = runtime·mmap(nil, n, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_PRIVATE, -1, 0);
+	v = runtime·mmap(nil, n, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, 0);
 	if(v < (void*)4096)
 		return nil;
 	return v;
@@ -51,7 +51,7 @@ runtime·SysMap(void *v, uintptr n)
 	void *p;
 	
 	mstats.sys += n;
-	p = runtime·mmap(v, n, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_FIXED|MAP_PRIVATE, -1, 0);
+	p = runtime·mmap(v, n, PROT_READ|PROT_WRITE, MAP_ANON|MAP_FIXED|MAP_PRIVATE, -1, 0);
 	if(p == (void*)-ENOMEM)
 		runtime·throw("runtime: out of memory");
 	if(p != v)

src/pkg/runtime/mem_freebsd.c

@@ -14,7 +14,7 @@ runtime·SysAlloc(uintptr n)
 	void *v;
 
 	mstats.sys += n;
-	v = runtime·mmap(nil, n, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_PRIVATE, -1, 0);
+	v = runtime·mmap(nil, n, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, 0);
 	if(v < (void*)4096)
 		return nil;
 	return v;
@@ -59,7 +59,7 @@ runtime·SysMap(void *v, uintptr n)
 
 	// On 64-bit, we don't actually have v reserved, so tread carefully.
 	if(sizeof(void*) == 8) {
-		p = runtime·mmap(v, n, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_PRIVATE, -1, 0);
+		p = runtime·mmap(v, n, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, 0);
 		if(p == (void*)-ENOMEM)
 			runtime·throw("runtime: out of memory");
 		if(p != v) {
@@ -69,7 +69,7 @@ runtime·SysMap(void *v, uintptr n)
 		return;
 	}
 
-	p = runtime·mmap(v, n, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_FIXED|MAP_PRIVATE, -1, 0);
+	p = runtime·mmap(v, n, PROT_READ|PROT_WRITE, MAP_ANON|MAP_FIXED|MAP_PRIVATE, -1, 0);
 	if(p == (void*)-ENOMEM)
 		runtime·throw("runtime: out of memory");
 	if(p != v)

src/pkg/runtime/mem_linux.c

@@ -57,7 +57,7 @@ runtime·SysAlloc(uintptr n)
 	void *p;
 
 	mstats.sys += n;
-	p = runtime·mmap(nil, n, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_PRIVATE, -1, 0);
+	p = runtime·mmap(nil, n, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, 0);
 	if(p < (void*)4096) {
 		if(p == (void*)EACCES) {
 			runtime·printf("runtime: mmap: access denied\n");
@@ -118,7 +118,7 @@ runtime·SysMap(void *v, uintptr n)
 
 	// On 64-bit, we don't actually have v reserved, so tread carefully.
 	if(sizeof(void*) == 8 && (uintptr)v >= 0xffffffffU) {
-		p = mmap_fixed(v, n, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_PRIVATE, -1, 0);
+		p = mmap_fixed(v, n, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, 0);
 		if(p == (void*)ENOMEM)
 			runtime·throw("runtime: out of memory");
 		if(p != v) {
@@ -128,7 +128,7 @@ runtime·SysMap(void *v, uintptr n)
 		return;
 	}
 
-	p = runtime·mmap(v, n, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_FIXED|MAP_PRIVATE, -1, 0);
+	p = runtime·mmap(v, n, PROT_READ|PROT_WRITE, MAP_ANON|MAP_FIXED|MAP_PRIVATE, -1, 0);
 	if(p == (void*)ENOMEM)
 		runtime·throw("runtime: out of memory");
 	if(p != v)

src/pkg/runtime/mem_netbsd.c

@@ -19,7 +19,7 @@ runtime·SysAlloc(uintptr n)
 	void *v;
 
 	mstats.sys += n;
-	v = runtime·mmap(nil, n, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_PRIVATE, -1, 0);
+	v = runtime·mmap(nil, n, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, 0);
 	if(v < (void*)4096)
 		return nil;
 	return v;
@@ -65,7 +65,7 @@ runtime·SysMap(void *v, uintptr n)
 
 	// On 64-bit, we don't actually have v reserved, so tread carefully.
 	if(sizeof(void*) == 8) {
-		p = runtime·mmap(v, n, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_PRIVATE, -1, 0);
+		p = runtime·mmap(v, n, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, 0);
 		if(p == (void*)-ENOMEM)
 			runtime·throw("runtime: out of memory");
 		if(p != v) {
@@ -75,7 +75,7 @@ runtime·SysMap(void *v, uintptr n)
 		return;
 	}
 
-	p = runtime·mmap(v, n, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_FIXED|MAP_PRIVATE, -1, 0);
+	p = runtime·mmap(v, n, PROT_READ|PROT_WRITE, MAP_ANON|MAP_FIXED|MAP_PRIVATE, -1, 0);
 	if(p == (void*)-ENOMEM)
 		runtime·throw("runtime: out of memory");
 	if(p != v)

src/pkg/runtime/mem_openbsd.c

@@ -19,7 +19,7 @@ runtime·SysAlloc(uintptr n)
 	void *v;
 
 	mstats.sys += n;
-	v = runtime·mmap(nil, n, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_PRIVATE, -1, 0);
+	v = runtime·mmap(nil, n, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, 0);
 	if(v < (void*)4096)
 		return nil;
 	return v;
@@ -65,7 +65,7 @@ runtime·SysMap(void *v, uintptr n)
 
 	// On 64-bit, we don't actually have v reserved, so tread carefully.
 	if(sizeof(void*) == 8) {
-		p = runtime·mmap(v, n, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_PRIVATE, -1, 0);
+		p = runtime·mmap(v, n, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, 0);
 		if(p == (void*)-ENOMEM)
 			runtime·throw("runtime: out of memory");
 		if(p != v) {
@@ -75,7 +75,7 @@ runtime·SysMap(void *v, uintptr n)
 		return;
 	}
 
-	p = runtime·mmap(v, n, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_FIXED|MAP_PRIVATE, -1, 0);
+	p = runtime·mmap(v, n, PROT_READ|PROT_WRITE, MAP_ANON|MAP_FIXED|MAP_PRIVATE, -1, 0);
 	if(p == (void*)-ENOMEM)
 		runtime·throw("runtime: out of memory");
 	if(p != v)