| // Copyright 2022 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. |
| |
| #include "textflag.h" |
| |
| TEXT ·RewindAndSetgid(SB),NOSPLIT|NOFRAME,$0-0 |
| // Rewind stack pointer so anything that happens on the stack |
| // will clobber the test pattern created by the caller |
| ADDV $(1024*8), R3 |
| |
| // Ask signaller to setgid |
| MOVW $1, R12 |
| DBAR |
| MOVW R12, ·Baton(SB) |
| DBAR |
| |
| // Wait for setgid completion |
| loop: |
| DBAR |
| MOVW ·Baton(SB), R12 |
| OR R13, R13, R13 // hint that we're in a spin loop |
| BNE R12, loop |
| DBAR |
| |
| // Restore stack |
| ADDV $(-1024*8), R3 |
| RET |
