verifyString(h.Gname, len(ustar.groupName()), "Gname", paxGname)
	verifyNumeric(h.Mode, len(v7.mode()), "Mode", paxNone)
	verifyNumeric(int64(h.Uid), len(v7.uid()), "Uid", paxUid)
	verifyNumeric(int64(h.Gid), len(v7.gid()), "Gid", paxGid)
	verifyNumeric(h.Size, len(v7.size()), "Size", paxSize)
	verifyNumeric(h.Devmajor, len(ustar.devMajor()), "Devmajor", paxNone)

starting with Go 1.21.6.
This setting may be removed in a future release, and users impacted by this issue
should adjust their Linux configuration according to the recommendations in the
[GC guide](/doc/gc-guide#Linux_transparent_huge_pages), or switch to a Linux
distribution that disables transparent huge pages altogether.

Go 1.22 added contention on runtime-internal locks to the [`mutex`

<!--{
	"Title": "A Quick Guide to Go's Assembler",
	"Path":  "/doc/asm"
}-->

<h2 id="introduction">A Quick Guide to Go's Assembler</h2>

<p>
This document is a quick outline of the unusual form of assembly language used by the <code>gc</code> Go compiler.
The document is not comprehensive.
</p>

<p>
The assembler is based on the input style of the Plan 9 assemblers, which is documented in detail

				Size:     15,
				Mode:     0644,
				Uid:      1000,
				Gid:      100,
				Uname:    "vbatts",
				Gname:    "users",
				ModTime:  time.Unix(1425484303, 0),
			}, nil},
			testWrite{"Slartibartfast\n", 15, nil},

			testHeader{Header{
				Typeflag: TypeLink,
				Name:     "hard.txt",
				Linkname: "file.txt",
				Mode:     0644,
				Uid:      1000,
				Gid:      100,
				Uname:    "vbatts",

		}
		if got, want := h2.Size, v.h.Size; got != want {
			t.Errorf("i=%d: Size: got %v, want %v", i, got, want)
		}
		if got, want := h2.Uid, v.h.Uid; got != want {
			t.Errorf("i=%d: Uid: got %d, want %d", i, got, want)
		}
		if got, want := h2.Gid, v.h.Gid; got != want {
			t.Errorf("i=%d: Gid: got %d, want %d", i, got, want)
		}
		if got, want := h2.Uname, v.h.Uname; got != want {

	hdr.Name = p.parseString(v7.name())
	hdr.Linkname = p.parseString(v7.linkName())
	hdr.Size = p.parseNumeric(v7.size())
	hdr.Mode = p.parseNumeric(v7.mode())
	hdr.Uid = int(p.parseNumeric(v7.uid()))
	hdr.Gid = int(p.parseNumeric(v7.gid()))
	hdr.ModTime = time.Unix(p.parseNumeric(v7.modTime()), 0)

	// Unpack format specific fields.
	if format > formatV7 {
		ustar := tr.blk.toUSTAR()

}

// userMap and groupMap caches UID and GID lookups for performance reasons.
// The downside is that renaming uname or gname by the OS never takes effect.
var userMap, groupMap sync.Map // map[int]string

func statUnix(fi fs.FileInfo, h *Header, doNameLookups bool) error {
	sys, ok := fi.Sys().(*syscall.Stat_t)
	if !ok {
		return nil
	}
	h.Uid = int(sys.Uid)
	h.Gid = int(sys.Gid)
	if doNameLookups {

	MSR	R6, ERXFR_EL1                                    // ERROR "system register is not writable"
	MSR	R6, ERXPFGF_EL1                                  // ERROR "system register is not writable"
	MSR	R6, GMID_EL1                                     // ERROR "system register is not writable"
	MSR	R6, ICC_HPPIR0_EL1                               // ERROR "system register is not writable"