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authorGoogler <noreply@google.com>2018-04-27 10:37:02 -0700
committerAdin Scannell <ascannell@google.com>2018-04-28 01:44:26 -0400
commitd02b74a5dcfed4bfc8f2f8e545bca4d2afabb296 (patch)
tree54f95eef73aee6bacbfc736fffc631be2605ed53 /pkg/sentry/hostcpu/getcpu_amd64.s
parentf70210e742919f40aa2f0934a22f1c9ba6dada62 (diff)
Check in gVisor.
PiperOrigin-RevId: 194583126 Change-Id: Ica1d8821a90f74e7e745962d71801c598c652463
Diffstat (limited to 'pkg/sentry/hostcpu/getcpu_amd64.s')
-rw-r--r--pkg/sentry/hostcpu/getcpu_amd64.s24
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diff --git a/pkg/sentry/hostcpu/getcpu_amd64.s b/pkg/sentry/hostcpu/getcpu_amd64.s
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+// Copyright 2018 Google Inc.
+//
+// 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