1 /* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include "thread.h" 18 19 #include "asm_support_x86_64.h" 20 #include "base/macros.h" 21 #include "thread-current-inl.h" 22 #include "thread_list.h" 23 24 #if defined(__linux__) 25 #include <asm/prctl.h> 26 #include <sys/prctl.h> 27 #include <sys/syscall.h> 28 #endif 29 30 namespace art { 31 32 #if defined(__linux__) 33 static void arch_prctl(int code, void* val) { 34 syscall(__NR_arch_prctl, code, val); 35 } 36 #endif 37 38 void Thread::InitCpu() { 39 MutexLock mu(nullptr, *Locks::modify_ldt_lock_); 40 41 #if defined(__linux__) 42 arch_prctl(ARCH_SET_GS, this); 43 #else 44 UNIMPLEMENTED(FATAL) << "Need to set GS"; 45 #endif 46 47 // Allow easy indirection back to Thread*. 48 tlsPtr_.self = this; 49 50 // Sanity check that reads from %gs point to this Thread*. 51 Thread* self_check; 52 __asm__ __volatile__("movq %%gs:(%1), %0" 53 : "=r"(self_check) // output 54 : "r"(THREAD_SELF_OFFSET) // input 55 :); // clobber 56 CHECK_EQ(self_check, this); 57 } 58 59 void Thread::CleanupCpu() { 60 // Sanity check that reads from %gs point to this Thread*. 61 Thread* self_check; 62 __asm__ __volatile__("movq %%gs:(%1), %0" 63 : "=r"(self_check) // output 64 : "r"(THREAD_SELF_OFFSET) // input 65 :); // clobber 66 CHECK_EQ(self_check, this); 67 68 // Do nothing. 69 } 70 71 } // namespace art 72
