func syscall_chdir(path uintptr) (err uintptr) {
	call := libcall{
		fn:   uintptr(unsafe.Pointer(&libc_chdir)),
		n:    1,
		args: uintptr(unsafe.Pointer(&path)),
	}
	asmcgocall(unsafe.Pointer(&asmsysvicall6x), unsafe.Pointer(&call))
	return call.err
}

//go:nosplit
//go:linkname syscall_chroot
func syscall_chroot(path uintptr) (err uintptr) {
	call := libcall{
		fn:   uintptr(unsafe.Pointer(&libc_chroot)),
		n:    1,

	MOVM.DB.W [R4, R5, R14], (R13)	// push {r4, r5, lr}
	MOVW	R0, R4			// put libcall * in r4
	MOVW	R13, R5			// save stack pointer in r5

	// SetLastError(0)
	MOVW	$0, R0
	MRC	15, 0, R1, C13, C0, 2
	MOVW	R0, 0x34(R1)

	MOVW	8(R4), R12	// libcall->args

	// Do we have more than 4 arguments?
	MOVW	4(R4), R0	// libcall->n
	SUB.S	$4, R0, R2
	BLE	loadregs

	// Reserve stack space for remaining args

	freelink    *m // on sched.freem
	trace       mTraceState

	// these are here because they are too large to be on the stack
	// of low-level NOSPLIT functions.
	libcall    libcall
	libcallpc  uintptr // for cpu profiler
	libcallsp  uintptr
	libcallg   guintptr
	winsyscall winlibcall // stores syscall parameters on windows

	vdsoSP uintptr // SP for traceback while in VDSO call (0 if not in call)

//
//go:nosplit
//go:cgo_unsafe_args
//go:linkname syscall_syscall6
func syscall_syscall6(fn, nargs, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr) {
	c := libcall{
		fn:   fn,
		n:    nargs,
		args: uintptr(unsafe.Pointer(&a1)),
	}

	entersyscallblock()
	asmcgocall(unsafe.Pointer(&asmsyscall6), unsafe.Pointer(&c))
	exitsyscall()
	return c.r1, 0, c.err
}

// rewind it into the CALL instruction.)
// If gp.m.libcall{g,pc,sp} information is available, it uses that information in preference to
// the pc/sp/lr passed in.
func tracebacktrap(pc, sp, lr uintptr, gp *g) {
	if gp.m.libcallsp != 0 {
		// We're in C code somewhere, traceback from the saved position.
		traceback1(gp.m.libcallpc, gp.m.libcallsp, 0, gp.m.libcallg.ptr(), 0)
		return
	}
	traceback1(pc, sp, lr, gp, unwindTrap)

	}
	if !isShrinkStackSafe(gp) {
		throw("shrinkstack at bad time")
	}
	// Check for self-shrinks while in a libcall. These may have
	// pointers into the stack disguised as uintptrs, but these
	// code paths should all be nosplit.
	if gp == getg().m.curg && gp.m.libcallsp != 0 {
		throw("shrinking stack in libcall")
	}

	if debug.gcshrinkstackoff > 0 {
		return
	}
	f := findfunc(gp.startpc)

		u.initAt(mp.curg.syscallpc, mp.curg.syscallsp, 0, mp.curg, unwindSilentErrors)
	} else if usesLibcall() && mp.libcallg != 0 && mp.libcallpc != 0 && mp.libcallsp != 0 {
		// Libcall, i.e. runtime syscall on windows.
		// Collect Go stack that leads to the call.
		u.initAt(mp.libcallpc, mp.libcallsp, 0, mp.libcallg.ptr(), unwindSilentErrors)
	} else if mp != nil && mp.vdsoSP != 0 {
		// VDSO call, e.g. nanotime1 on Linux.

		releasem(mp)
		return false
	}
	status := readgstatus(gp)
	if status&^_Gscan != _Grunning || gp.syscallsp != 0 {
		releasem(mp)
		return false
	}
	if GOOS == "windows" && mp.libcallsp != 0 {
		releasem(mp)
		return false
	}
	releasem(mp)
	return true
}

// shouldPushSigpanic reports whether pc should be used as sigpanic's