1 // Copyright 2020 The gVisor Authors.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 15 //go:build race && arm64
16 // +build race,arm64
17 18 #include "textflag.h"
19 20 // func RaceUncheckedAtomicCompareAndSwapUintptr(ptr *uintptr, old, new uintptr) bool
21 TEXT ·RaceUncheckedAtomicCompareAndSwapUintptr(SB),NOSPLIT,$0-25
22 MOVD ptr+0(FP), R0
23 MOVD old+8(FP), R1
24 MOVD new+16(FP), R1
25 again:
26 LDAXR (R0), R3
27 CMP R1, R3
28 BNE ok
29 STLXR R2, (R0), R3
30 CBNZ R3, again
31 ok:
32 CSET EQ, R0
33 MOVB R0, ret+24(FP)
34 RET
35 36