| // Copyright 2014 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| // +build !gccgo |
| |
| #include "textflag.h" |
| |
| TEXT cas<>(SB),NOSPLIT,$0 |
| MOVW $0xffff0fc0, R15 // R15 is PC |
| |
| TEXT ·RewindAndSetgid(SB),NOSPLIT|NOFRAME,$0-0 |
| // Save link register |
| MOVW R14, R4 |
| |
| // Rewind stack pointer so anything that happens on the stack |
| // will clobber the test pattern created by the caller |
| ADD $(1024 * 8), R13 |
| |
| // Ask signaller to setgid |
| MOVW $·Baton(SB), R2 |
| storeloop: |
| MOVW 0(R2), R0 |
| MOVW $1, R1 |
| BL cas<>(SB) |
| BCC storeloop |
| |
| // Wait for setgid completion |
| loop: |
| MOVW $0, R0 |
| MOVW $0, R1 |
| BL cas<>(SB) |
| BCC loop |
| |
| // Restore stack |
| SUB $(1024 * 8), R13 |
| |
| MOVW R4, R14 |
| RET |
