1// Copyright 2014 The Go Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style 3// license that can be found in the LICENSE file. 4 5//go:build gc 6 7#include "textflag.h" 8 9TEXT cas<>(SB),NOSPLIT,$0 10 MOVW $0xffff0fc0, R15 // R15 is PC 11 12TEXT ·RewindAndSetgid(SB),NOSPLIT|NOFRAME,$0-0 13 // Save link register 14 MOVW R14, R4 15 16 // Rewind stack pointer so anything that happens on the stack 17 // will clobber the test pattern created by the caller 18 ADD $(1024 * 8), R13 19 20 // Ask signaller to setgid 21 MOVW $·Baton(SB), R2 22storeloop: 23 MOVW 0(R2), R0 24 MOVW $1, R1 25 BL cas<>(SB) 26 BCC storeloop 27 28 // Wait for setgid completion 29loop: 30 MOVW $0, R0 31 MOVW $0, R1 32 BL cas<>(SB) 33 BCC loop 34 35 // Restore stack 36 SUB $(1024 * 8), R13 37 38 MOVW R4, R14 39 RET 40