diff options
Diffstat (limited to 'src/pkg/runtime/linux/arm/sys.s')
| -rw-r--r-- | src/pkg/runtime/linux/arm/sys.s | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/src/pkg/runtime/linux/arm/sys.s b/src/pkg/runtime/linux/arm/sys.s index d866b0e22..2b5365bd8 100644 --- a/src/pkg/runtime/linux/arm/sys.s +++ b/src/pkg/runtime/linux/arm/sys.s @@ -258,11 +258,22 @@ TEXT cas<>(SB),7,$0 TEXT runtime·cas(SB),7,$0 MOVW valptr+0(FP), R2 MOVW old+4(FP), R0 +casagain: MOVW new+8(FP), R1 BL cas<>(SB) - MOVW $0, R0 - MOVW.CS $1, R0 + BCC cascheck + MOVW $1, R0 RET +cascheck: + // Kernel lies; double-check. + MOVW valptr+0(FP), R2 + MOVW old+4(FP), R0 + MOVW 0(R2), R3 + CMP R0, R3 + BEQ casagain + MOVW $0, R0 + RET + TEXT runtime·casp(SB),7,$0 B runtime·cas(SB) |