blob: 19d25f69905671f6036cf27bc57314ebd54de0fd [file] [log] [blame]
/*
* Copyright (C) 2011 The Android Open Source Project
*
* 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 "thread.h"
#include "asm_support_x86_64.h"
#include "base/macros.h"
#include "thread-current-inl.h"
#include "thread_list.h"
#if defined(__linux__)
#include <asm/prctl.h>
#include <sys/prctl.h>
#include <sys/syscall.h>
#endif
namespace art {
#if defined(__linux__)
static void arch_prctl(int code, void* val) {
syscall(__NR_arch_prctl, code, val);
}
#endif
void Thread::InitCpu() {
MutexLock mu(nullptr, *Locks::modify_ldt_lock_);
#if defined(__linux__)
arch_prctl(ARCH_SET_GS, this);
#else
UNIMPLEMENTED(FATAL) << "Need to set GS";
#endif
// Allow easy indirection back to Thread*.
tlsPtr_.self = this;
// Sanity check that reads from %gs point to this Thread*.
Thread* self_check;
__asm__ __volatile__("movq %%gs:(%1), %0"
: "=r"(self_check) // output
: "r"(THREAD_SELF_OFFSET) // input
:); // clobber
CHECK_EQ(self_check, this);
}
void Thread::CleanupCpu() {
// Sanity check that reads from %gs point to this Thread*.
Thread* self_check;
__asm__ __volatile__("movq %%gs:(%1), %0"
: "=r"(self_check) // output
: "r"(THREAD_SELF_OFFSET) // input
:); // clobber
CHECK_EQ(self_check, this);
// Do nothing.
}
} // namespace art