debug.SetPanicOnFault(true)

	size := syscall.Getpagesize()

	// Map 16 pages of data with a 4-page hole in the middle.
	data, err := syscall.Mmap(-1, 0, 16*size, syscall.PROT_READ|syscall.PROT_WRITE, syscall.MAP_ANON|syscall.MAP_PRIVATE)
	if err != nil {
		log.Fatalf("mmap: %v", err)
	}

	// Create a hole in the mapping that's PROT_NONE.
	// Note that we can't use munmap here because the Go runtime

//go:build amd64 && (linux || darwin)

package sha1_test

import (
	"crypto/sha1"
	"syscall"
	"testing"
)

func TestOutOfBoundsRead(t *testing.T) {
	const pageSize = 4 << 10
	data, err := syscall.Mmap(0, 0, 2*pageSize, syscall.PROT_READ|syscall.PROT_WRITE, syscall.MAP_ANON|syscall.MAP_PRIVATE)
	if err != nil {
		panic(err)
	}
	if err := syscall.Mprotect(data[pageSize:], syscall.PROT_NONE); err != nil {
		panic(err)
	}

	}
	return data, false, nil
}

// SliceRO returns a slice containing the next length bytes of r
// backed by a read-only mmap'd data. If the mmap cannot be
// established (limit exceeded, region too small, etc) a nil slice
// will be returned. If mmap succeeds, it will never be unmapped.
func (r *Reader) SliceRO(length uint64) []byte {
	data, ok := r.sliceOS(length)
	if ok {
		return data
	}
	return nil

#include <stdlib.h>
#include <sys/mman.h>

#include "libcgo.h"

uintptr_t
x_cgo_mmap(void *addr, uintptr_t length, int32_t prot, int32_t flags, int32_t fd, uint32_t offset) {
	void *p;

	_cgo_tsan_acquire();
	p = mmap(addr, length, prot, flags, fd, offset);
	_cgo_tsan_release();
	if (p == MAP_FAILED) {
		/* This is what the Go code expects on failure.  */
		return (uintptr_t)errno;
	}
	return (uintptr_t)p;
}

void

	// On AIX, 64-bit addresses are split into 36-bit segment number and 28-bit
	// offset in segment.  Segment numbers in the range 0x0A0000000-0x0AFFFFFFF(LSA)
	// are available for mmap.
	// We assume all tagged addresses are from memory allocated with mmap.
	// We use one bit to distinguish between the two ranges.
	aixAddrBits = 57
	aixTagBits  = 64 - aixAddrBits + 3

	// riscv64 SV57 mode gives 56 bits of userspace VA.

//go:build aix && ppc

package unix

//sysnb	Getrlimit(resource int, rlim *Rlimit) (err error) = getrlimit64
//sys	Seek(fd int, offset int64, whence int) (off int64, err error) = lseek64

//sys	mmap(addr uintptr, length uintptr, prot int, flags int, fd int, offset int64) (xaddr uintptr, err error)

func setTimespec(sec, nsec int64) Timespec {
	return Timespec{Sec: int32(sec), Nsec: int32(nsec)}
}

		t.Skip("iOS doesn't provide fault addresses")
	}
	if runtime.GOOS == "netbsd" && runtime.GOARCH == "arm" {
		t.Skip("netbsd-arm doesn't provide fault address (golang.org/issue/45026)")
	}
	m, err := syscall.Mmap(-1, 0, 0x1000, syscall.PROT_READ /* Note: no PROT_WRITE */, syscall.MAP_SHARED|syscall.MAP_ANON)
	if err != nil {
		t.Fatalf("can't map anonymous memory: %s", err)
	}
	defer syscall.Munmap(m)

// Copyright 2011 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 mmap

import (
	"fmt"
	"os"
	"syscall"
	"unsafe"

	"internal/syscall/windows"
)

func mmapFile(f *os.File) (Data, error) {
	st, err := f.Stat()
	if err != nil {
		return Data{}, err
	}
	size := st.Size()
	if size == 0 {
		return Data{f, nil}, nil

	devPath[9] = digits[idx]

	fd := open(&devPath[0], 0 /* O_RDONLY */ |_O_CLOEXEC, 0)
	if fd < 0 {
		atomic.Casuintptr(&hpetDevMap[idx], 0, ^uintptr(0))
		return
	}

	addr, mmapErr := mmap(nil, physPageSize, _PROT_READ, _MAP_SHARED, fd, 0)
	closefd(fd)
	newP := uintptr(addr)
	if mmapErr != 0 {
		newP = ^uintptr(0)
	}
	if !atomic.Casuintptr(&hpetDevMap[idx], 0, newP) && mmapErr == 0 {

		i = len(n)
	}
	return i
}

// Mmap manager, for use by operating system-specific implementations.

type mmapper struct {
	sync.Mutex
	active map[*byte][]byte // active mappings; key is last byte in mapping
	mmap   func(addr, length uintptr, prot, flags, fd int, offset int64) (uintptr, error)
	munmap func(addr uintptr, length uintptr) error
}