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Diffstat (limited to 'pkg/sentry/hostcpu/getcpu_amd64.s')
| -rw-r--r-- | pkg/sentry/hostcpu/getcpu_amd64.s | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/pkg/sentry/hostcpu/getcpu_amd64.s b/pkg/sentry/hostcpu/getcpu_amd64.s new file mode 100644 index 000000000..aa00316da --- /dev/null +++ b/pkg/sentry/hostcpu/getcpu_amd64.s @@ -0,0 +1,24 @@ +// Copyright 2018 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +#include "textflag.h" + +// func GetCPU() (cpu uint32) +TEXT ·GetCPU(SB), NOSPLIT, $0-4 + BYTE $0x0f; BYTE $0x01; BYTE $0xf9; // RDTSCP + // On Linux, the bottom 12 bits of IA32_TSC_AUX are CPU and the upper 20 + // are node. See arch/x86/entry/vdso/vma.c:vgetcpu_cpu_init(). + ANDL $0xfff, CX + MOVL CX, cpu+0(FP) + RET |