// Copyright 2016 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. package runtime_test import ( "runtime" "testing" "unsafe" ) // Test that the error value returned by mmap is positive, as that is // what the code in mem_bsd.go, mem_darwin.go, and mem_linux.go expects. // See the uses of ENOMEM in sysMap in those files. func TestMmapErrorSign(t *testing.T) { p := runtime.Mmap(nil, ^uintptr(0)&^(runtime.GetPhysPageSize()-1), 0, runtime.MAP_ANON|runtime.MAP_PRIVATE, -1, 0) // The runtime.mmap function is nosplit, but t.Errorf is not. // Reset the pointer so that we don't get an "invalid stack // pointer" error from t.Errorf if we call it. v := uintptr(p) p = nil err := runtime.Errno() if v != ^uintptr(0) || err != runtime.ENOMEM { t.Errorf("mmap = %v, %v, want %v", v, err, runtime.ENOMEM) } } func TestPhysPageSize(t *testing.T) { // Mmap fails if the address is not page aligned, so we can // use this to test if the page size is the true page size. ps := runtime.GetPhysPageSize() // Get a region of memory to play with. This should be page-aligned. b := uintptr(runtime.Mmap(nil, 2*ps, 0, runtime.MAP_ANON|runtime.MAP_PRIVATE, -1, 0)) if b == ^uintptr(0) { t.Fatalf("Mmap: %v %v", b, runtime.Errno()) } // Mmap should fail at a half page into the buffer. err := uintptr(runtime.Mmap(unsafe.Pointer(uintptr(b)+ps/2), ps, 0, runtime.MAP_ANON|runtime.MAP_PRIVATE|runtime.MAP_FIXED, -1, 0)) if err != ^uintptr(0) { t.Errorf("Mmap should have failed with half-page alignment %d, but succeeded: %v", ps/2, err) } // Mmap should succeed at a full page into the buffer. err = uintptr(runtime.Mmap(unsafe.Pointer(uintptr(b)+ps), ps, 0, runtime.MAP_ANON|runtime.MAP_PRIVATE|runtime.MAP_FIXED, -1, 0)) if err == ^uintptr(0) { t.Errorf("Mmap at full-page alignment %d failed: %v %v", ps, err, runtime.Errno()) } }