1// Copyright 2018 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
5package runtime
6
7import (
8	"unsafe"
9)
10
11// Don't split the stack as this method may be invoked without a valid G, which
12// prevents us from allocating more stack.
13//
14//go:nosplit
15func sysAllocOS(n uintptr) unsafe.Pointer {
16	p, err := mmap(nil, n, _PROT_READ|_PROT_WRITE, _MAP_ANON|_MAP_PRIVATE, -1, 0)
17	if err != 0 {
18		if err == _EACCES {
19			print("runtime: mmap: access denied\n")
20			exit(2)
21		}
22		if err == _EAGAIN {
23			print("runtime: mmap: too much locked memory (check 'ulimit -l').\n")
24			exit(2)
25		}
26		return nil
27	}
28	return p
29}
30
31func sysUnusedOS(v unsafe.Pointer, n uintptr) {
32	madvise(v, n, _MADV_DONTNEED)
33}
34
35func sysUsedOS(v unsafe.Pointer, n uintptr) {
36}
37
38func sysHugePageOS(v unsafe.Pointer, n uintptr) {
39}
40
41func sysNoHugePageOS(v unsafe.Pointer, n uintptr) {
42}
43
44func sysHugePageCollapseOS(v unsafe.Pointer, n uintptr) {
45}
46
47// Don't split the stack as this function may be invoked without a valid G,
48// which prevents us from allocating more stack.
49//
50//go:nosplit
51func sysFreeOS(v unsafe.Pointer, n uintptr) {
52	munmap(v, n)
53}
54
55func sysFaultOS(v unsafe.Pointer, n uintptr) {
56	mmap(v, n, _PROT_NONE, _MAP_ANON|_MAP_PRIVATE|_MAP_FIXED, -1, 0)
57}
58
59func sysReserveOS(v unsafe.Pointer, n uintptr) unsafe.Pointer {
60	p, err := mmap(v, n, _PROT_NONE, _MAP_ANON|_MAP_PRIVATE, -1, 0)
61	if err != 0 {
62		return nil
63	}
64	return p
65}
66
67func sysMapOS(v unsafe.Pointer, n uintptr) {
68	// AIX does not allow mapping a range that is already mapped.
69	// So, call mprotect to change permissions.
70	// Note that sysMap is always called with a non-nil pointer
71	// since it transitions a Reserved memory region to Prepared,
72	// so mprotect is always possible.
73	_, err := mprotect(v, n, _PROT_READ|_PROT_WRITE)
74	if err == _ENOMEM {
75		throw("runtime: out of memory")
76	}
77	if err != 0 {
78		print("runtime: mprotect(", v, ", ", n, ") returned ", err, "\n")
79		throw("runtime: cannot map pages in arena address space")
80	}
81}
82