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// 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.
package runtime
import (
"runtime/internal/atomic"
"unsafe"
)
const (
_EACCES = 13
_EINVAL = 22
)
// Don't split the stack as this method may be invoked without a valid G, which
// prevents us from allocating more stack.
//
//go:nosplit
func sysAllocOS(n uintptr) unsafe.Pointer {
p, err := mmap(nil, n, _PROT_READ|_PROT_WRITE, _MAP_ANON|_MAP_PRIVATE, -1, 0)
if err != 0 {
if err == _EACCES {
print("runtime: mmap: access denied\n")
exit(2)
}
if err == _EAGAIN {
print("runtime: mmap: too much locked memory (check 'ulimit -l').\n")
exit(2)
}
return nil
}
return p
}
var adviseUnused = uint32(_MADV_FREE)
func sysUnusedOS(v unsafe.Pointer, n uintptr) {
if uintptr(v)&(physPageSize-1) != 0 || n&(physPageSize-1) != 0 {
// madvise will round this to any physical page
// *covered* by this range, so an unaligned madvise
// will release more memory than intended.
throw("unaligned sysUnused")
}
var advise uint32
if debug.madvdontneed != 0 {
advise = _MADV_DONTNEED
} else {
advise = atomic.Load(&adviseUnused)
}
if errno := madvise(v, n, int32(advise)); advise == _MADV_FREE && errno != 0 {
// MADV_FREE was added in Linux 4.5. Fall back to MADV_DONTNEED if it is
// not supported.
atomic.Store(&adviseUnused, _MADV_DONTNEED)
madvise(v, n, _MADV_DONTNEED)
}
if debug.harddecommit > 0 {
p, err := mmap(v, n, _PROT_NONE, _MAP_ANON|_MAP_FIXED|_MAP_PRIVATE, -1, 0)
if p != v || err != 0 {
throw("runtime: cannot disable permissions in address space")
}
}
}
func sysUsedOS(v unsafe.Pointer, n uintptr) {
if debug.harddecommit > 0 {
p, err := mmap(v, n, _PROT_READ|_PROT_WRITE, _MAP_ANON|_MAP_FIXED|_MAP_PRIVATE, -1, 0)
if err == _ENOMEM {
throw("runtime: out of memory")
}
if p != v || err != 0 {
throw("runtime: cannot remap pages in address space")
}
return
}
}
func sysHugePageOS(v unsafe.Pointer, n uintptr) {
if physHugePageSize != 0 {
// Round v up to a huge page boundary.
beg := alignUp(uintptr(v), physHugePageSize)
// Round v+n down to a huge page boundary.
end := alignDown(uintptr(v)+n, physHugePageSize)
if beg < end {
madvise(unsafe.Pointer(beg), end-beg, _MADV_HUGEPAGE)
}
}
}
func sysNoHugePageOS(v unsafe.Pointer, n uintptr) {
if uintptr(v)&(physPageSize-1) != 0 {
// The Linux implementation requires that the address
// addr be page-aligned, and allows length to be zero.
throw("unaligned sysNoHugePageOS")
}
madvise(v, n, _MADV_NOHUGEPAGE)
}
// Don't split the stack as this function may be invoked without a valid G,
// which prevents us from allocating more stack.
//
//go:nosplit
func sysFreeOS(v unsafe.Pointer, n uintptr) {
munmap(v, n)
}
func sysFaultOS(v unsafe.Pointer, n uintptr) {
mmap(v, n, _PROT_NONE, _MAP_ANON|_MAP_PRIVATE|_MAP_FIXED, -1, 0)
}
func sysReserveOS(v unsafe.Pointer, n uintptr) unsafe.Pointer {
p, err := mmap(v, n, _PROT_NONE, _MAP_ANON|_MAP_PRIVATE, -1, 0)
if err != 0 {
return nil
}
return p
}
func sysMapOS(v unsafe.Pointer, n uintptr) {
p, err := mmap(v, n, _PROT_READ|_PROT_WRITE, _MAP_ANON|_MAP_FIXED|_MAP_PRIVATE, -1, 0)
if err == _ENOMEM {
throw("runtime: out of memory")
}
if p != v || err != 0 {
print("runtime: mmap(", v, ", ", n, ") returned ", p, ", ", err, "\n")
throw("runtime: cannot map pages in arena address space")
}
}
|
