entry := ((*[2]uintptr)(unsafe.Pointer(f)))[1]
	preamp := ((*[4]uint32)(unsafe.Pointer(entry - eyecatcherOffset)))

	offsetPpa1 := preamp[2]
	if offsetPpa1 > 0x0ffff {
		return "", fmt.Errorf("PPA1 offset seems too big 0x%x\n", offsetPpa1)
	}

	ppa1 := uintptr(unsafe.Pointer(preamp)) + uintptr(offsetPpa1)
	res := ptrtest(ppa1)
	if res != 0 {

import "unsafe"

type mremapMmapper struct {
	mmapper
	mremap func(oldaddr uintptr, oldlength uintptr, newlength uintptr, flags int, newaddr uintptr) (xaddr uintptr, err error)
}

var mapper = &mremapMmapper{
	mmapper: mmapper{
		active: make(map[*byte][]byte),
		mmap:   mmap,
		munmap: munmap,
	},
	mremap: mremap,
}

func (m *mremapMmapper) Mremap(oldData []byte, newLength int, flags int) (data []byte, err error) {

			if gp.preemptStop && gp.preempt && gp.stackguard0 == stackPreempt && asyncM == gp.m && asyncM.preemptGen.Load() == asyncGen {
				break
			}

			// Temporarily block state transitions.
			if !castogscanstatus(gp, _Grunning, _Gscanrunning) {
				break
			}

			// Request synchronous preemption.
			gp.preemptStop = true
			gp.preempt = true
			gp.stackguard0 = stackPreempt

	debug.SetGCPercent(-1)
	// Out of an abundance of caution, also make sure that there are
	// no GCs actively in progress. The sweep phase of a GC cycle
	// for instance tries to preempt Ps at the very beginning.
	runtime.GC()

	// Start a goroutine with no sync safe-points.
	var ready, ready2 uint32
	go func() {
		for {
			atomic.StoreUint32(&ready, 1)
			dummy()
			dummy()
		}
	}()

Stefan Weil <******@****.***> 1501426192 +0200

zirain <******@****.***> 1680812305 +0800

	p256PointAddAsm(&t1, &t1, p)
	p256PointAddAsm(&t2, &t2, p)
	precomp[2] = t0 // 3
	precomp[4] = t1 // 5
	precomp[8] = t2 // 9

	p256PointDoubleAsm(&t0, &t0)
	p256PointDoubleAsm(&t1, &t1)
	precomp[5] = t0 // 6
	precomp[9] = t1 // 10

	p256PointAddAsm(&t2, &t0, p)
	p256PointAddAsm(&t1, &t1, p)
	precomp[6] = t2  // 7
	precomp[10] = t1 // 11

	p256PointDoubleAsm(&t0, &t0)

//go:build illumos && amd64

package unix

import (
	"unsafe"
)

//go:cgo_import_dynamic libc_readv readv "libc.so"
//go:cgo_import_dynamic libc_preadv preadv "libc.so"
//go:cgo_import_dynamic libc_writev writev "libc.so"
//go:cgo_import_dynamic libc_pwritev pwritev "libc.so"
//go:cgo_import_dynamic libc_accept4 accept4 "libsocket.so"

//go:linkname procreadv libc_readv

func Readv(fd int, iovs [][]byte) (n int, err error) {
	iovecs := bytes2iovec(iovs)
	n, err = readv(fd, iovecs)
	return n, err
}

//sys	preadv(fd int, iovs []Iovec, off int64) (n int, err error)

func Preadv(fd int, iovs [][]byte, off int64) (n int, err error) {
	iovecs := bytes2iovec(iovs)
	n, err = preadv(fd, iovecs, off)
	return n, err
}

//sys	writev(fd int, iovs []Iovec) (n int, err error)

	}
	fd, err := open(file)
	if err != nil {
		return nil, err
	}
	defer closefd(fd)

	buf := make([]byte, headersize)
	if err := preadn(fd, buf, 0); err != nil {
		return nil, errors.New("corrupt tzdata file " + file)
	}
	d := dataIO{buf, false}
	if magic := d.read(6); string(magic) != "tzdata" {
		return nil, errors.New("corrupt tzdata file " + file)
	}