1// Copyright 2010 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//go:build dragonfly || freebsd || netbsd || openbsd || solaris
6
7package runtime
8
9import (
10	"unsafe"
11)
12
13// Don't split the stack as this function may be invoked without a valid G,
14// which prevents us from allocating more stack.
15//
16//go:nosplit
17func sysAllocOS(n uintptr) unsafe.Pointer {
18	v, err := mmap(nil, n, _PROT_READ|_PROT_WRITE, _MAP_ANON|_MAP_PRIVATE, -1, 0)
19	if err != 0 {
20		return nil
21	}
22	return v
23}
24
25func sysUnusedOS(v unsafe.Pointer, n uintptr) {
26	if debug.madvdontneed != 0 {
27		madvise(v, n, _MADV_DONTNEED)
28	} else {
29		madvise(v, n, _MADV_FREE)
30	}
31}
32
33func sysUsedOS(v unsafe.Pointer, n uintptr) {
34}
35
36func sysHugePageOS(v unsafe.Pointer, n uintptr) {
37}
38
39func sysNoHugePageOS(v unsafe.Pointer, n uintptr) {
40}
41
42func sysHugePageCollapseOS(v unsafe.Pointer, n uintptr) {
43}
44
45// Don't split the stack as this function may be invoked without a valid G,
46// which prevents us from allocating more stack.
47//
48//go:nosplit
49func sysFreeOS(v unsafe.Pointer, n uintptr) {
50	munmap(v, n)
51}
52
53func sysFaultOS(v unsafe.Pointer, n uintptr) {
54	mmap(v, n, _PROT_NONE, _MAP_ANON|_MAP_PRIVATE|_MAP_FIXED, -1, 0)
55}
56
57// Indicates not to reserve swap space for the mapping.
58const _sunosMAP_NORESERVE = 0x40
59
60func sysReserveOS(v unsafe.Pointer, n uintptr) unsafe.Pointer {
61	flags := int32(_MAP_ANON | _MAP_PRIVATE)
62	if GOOS == "solaris" || GOOS == "illumos" {
63		// Be explicit that we don't want to reserve swap space
64		// for PROT_NONE anonymous mappings. This avoids an issue
65		// wherein large mappings can cause fork to fail.
66		flags |= _sunosMAP_NORESERVE
67	}
68	p, err := mmap(v, n, _PROT_NONE, flags, -1, 0)
69	if err != 0 {
70		return nil
71	}
72	return p
73}
74
75const _sunosEAGAIN = 11
76const _ENOMEM = 12
77
78func sysMapOS(v unsafe.Pointer, n uintptr) {
79	p, err := mmap(v, n, _PROT_READ|_PROT_WRITE, _MAP_ANON|_MAP_FIXED|_MAP_PRIVATE, -1, 0)
80	if err == _ENOMEM || ((GOOS == "solaris" || GOOS == "illumos") && err == _sunosEAGAIN) {
81		throw("runtime: out of memory")
82	}
83	if p != v || err != 0 {
84		print("runtime: mmap(", v, ", ", n, ") returned ", p, ", ", err, "\n")
85		throw("runtime: cannot map pages in arena address space")
86	}
87}
88