}
	}
	return nil, nil
}

// kernelBase calculates the base for kernel mappings, which usually require
// special handling. For kernel mappings, tools (like perf) use the address of
// the kernel relocation symbol (_text or _stext) as the mmap start. Additionally,
// for obfuscation, ChromeOS profiles have the kernel image remapped to the 0-th page.

//
TEXT cas<>(SB),NOSPLIT,$0
	MOVW	$0xffff0fc0, R15 // R15 is hardware PC.

TEXT ·Cas(SB),NOSPLIT|NOFRAME,$0
	MOVB	runtime·goarm(SB), R11
	CMP	$7, R11
	BLT	2(PC)
	JMP	·armcas(SB)
	JMP	kernelcas<>(SB)

TEXT kernelcas<>(SB),NOSPLIT,$0
	MOVW	ptr+0(FP), R2
	// trigger potential paging fault here,
	// because we don't know how to traceback through __kuser_cmpxchg
	MOVW    (R2), R0
	MOVW	old+4(FP), R0
	MOVW	new+8(FP), R1

		sigsetWords := (_C__NSIG - 1 + wordBits - 1) / (wordBits)

		sigsetBytes := uintptr(sigsetWords * (wordBits / 8))
		kernelMask = &sigset_argpack{
			ss:    sigmask,
			ssLen: sigsetBytes,
		}
	}

	return pselect6(nfd, r, w, e, mutableTimeout, kernelMask)
}

//sys	schedSetattr(pid int, attr *SchedAttr, flags uint) (err error)