code review 7405045: runtime: remove PROT_EXEC from mmap calls.

src/pkg/runtime/mem_linux.c

 // Copyright 2010 The Go Authors.  All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 #include "runtime.h"
 #include "arch_GOARCH.h"
 #include "defs_GOOS_GOARCH.h"
 #include "os_GOOS.h"
 #include "malloc.h"
 
@@ skipping 39 matching lines @@
         }
         return p;
 }
 
 void*
 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");
                         runtime·printf("if you're running SELinux, enable execmem for this process.\n");
                         runtime·exit(2);
                 }
                 if(p == (void*)EAGAIN) {
                         runtime·printf("runtime: mmap: too much locked memory (check 'ulimit -l').\n");
                         runtime·exit(2);
                 }
@@ skipping 40 matching lines @@
 
 void
 runtime·SysMap(void *v, uintptr n)
 {
         void *p;
 ········
         mstats.sys += 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) {
                         runtime·printf("runtime: address space conflict: map(%p) = %p\n", v, p);
                         runtime·throw("runtime: address space conflict");
                 }
                 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)
                 runtime·throw("runtime: cannot map pages in arena address space");
 }