| // Copyright 2020 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. |
| |
| //go:build riscv64 && gc |
| |
| #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 |
| ADD $(1024*8), X2 |
| |
| // Ask signaller to setgid |
| MOV $1, X5 |
| FENCE |
| MOVW X5, ·Baton(SB) |
| FENCE |
| |
| // Wait for setgid completion |
| loop: |
| FENCE |
| MOVW ·Baton(SB), X5 |
| OR X6, X6, X6 // hint that we're in a spin loop |
| BNE ZERO, X5, loop |
| FENCE |
| |
| // Restore stack |
| ADD $(-1024*8), X2 |
| RET |
