1 // Copyright 2016 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 // +build darwin dragonfly freebsd linux nacl netbsd openbsd solaris 6 7 package runtime_test 8 9 import ( 10 "runtime" 11 "testing" 12 "unsafe" 13 ) 14 15 // Test that the error value returned by mmap is positive, as that is 16 // what the code in mem_bsd.go, mem_darwin.go, and mem_linux.go expects. 17 // See the uses of ENOMEM in sysMap in those files. 18 func TestMmapErrorSign(t *testing.T) { 19 p := runtime.Mmap(nil, ^uintptr(0)&^(runtime.GetPhysPageSize()-1), 0, runtime.MAP_ANON|runtime.MAP_PRIVATE, -1, 0) 20 21 // The runtime.mmap function is nosplit, but t.Errorf is not. 22 // Reset the pointer so that we don't get an "invalid stack 23 // pointer" error from t.Errorf if we call it. 24 v := uintptr(p) 25 p = nil 26 27 if v != runtime.ENOMEM { 28 t.Errorf("mmap = %v, want %v", v, runtime.ENOMEM) 29 } 30 } 31 32 func TestPhysPageSize(t *testing.T) { 33 // Mmap fails if the address is not page aligned, so we can 34 // use this to test if the page size is the true page size. 35 ps := runtime.GetPhysPageSize() 36 37 // Get a region of memory to play with. This should be page-aligned. 38 b := uintptr(runtime.Mmap(nil, 2*ps, 0, runtime.MAP_ANON|runtime.MAP_PRIVATE, -1, 0)) 39 if b < 4096 { 40 t.Fatalf("Mmap: %v", b) 41 } 42 43 // Mmap should fail at a half page into the buffer. 44 err := uintptr(runtime.Mmap(unsafe.Pointer(uintptr(b)+ps/2), ps, 0, runtime.MAP_ANON|runtime.MAP_PRIVATE|runtime.MAP_FIXED, -1, 0)) 45 if err >= 4096 { 46 t.Errorf("Mmap should have failed with half-page alignment %d, but succeeded: %v", ps/2, err) 47 } 48 49 // Mmap should succeed at a full page into the buffer. 50 err = uintptr(runtime.Mmap(unsafe.Pointer(uintptr(b)+ps), ps, 0, runtime.MAP_ANON|runtime.MAP_PRIVATE|runtime.MAP_FIXED, -1, 0)) 51 if err < 4096 { 52 t.Errorf("Mmap at full-page alignment %d failed: %v", ps, err) 53 } 54 } 55
