| // Copyright 2018 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 ( |
| "unsafe" |
| ) |
| |
| // 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 sysAllocOS(n uintptr) unsafe.Pointer { |
| v, err := mmap(nil, n, _PROT_READ|_PROT_WRITE, _MAP_ANON|_MAP_PRIVATE, -1, 0) |
| if err != 0 { |
| return nil |
| } |
| return v |
| } |
| |
| func sysUnusedOS(v unsafe.Pointer, n uintptr) { |
| // MADV_FREE_REUSABLE is like MADV_FREE except it also propagates |
| // accounting information about the process to task_info. |
| madvise(v, n, _MADV_FREE_REUSABLE) |
| } |
| |
| func sysUsedOS(v unsafe.Pointer, n uintptr) { |
| // MADV_FREE_REUSE is necessary to keep the kernel's accounting |
| // accurate. If called on any memory region that hasn't been |
| // MADV_FREE_REUSABLE'd, it's a no-op. |
| madvise(v, n, _MADV_FREE_REUSE) |
| } |
| |
| func sysHugePageOS(v unsafe.Pointer, n uintptr) { |
| } |
| |
| func sysNoHugePageOS(v unsafe.Pointer, n uintptr) { |
| } |
| |
| // 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 |
| } |
| |
| const _ENOMEM = 12 |
| |
| 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") |
| } |
| } |