1 /*
   2  * Copyright (c) 1999, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef OS_LINUX_VM_OS_LINUX_HPP
  26 #define OS_LINUX_VM_OS_LINUX_HPP
  27 
  28 // Linux_OS defines the interface to Linux operating systems
  29 
  30 // Information about the protection of the page at address '0' on this os.
  31 static bool zero_page_read_protected() { return true; }
  32 
  33 class Linux {
  34   friend class os;
  35   friend class TestReserveMemorySpecial;
  36 
  37   // For signal-chaining
  38 #define MAXSIGNUM 32
  39   static struct sigaction sigact[MAXSIGNUM]; // saved preinstalled sigactions
  40   static unsigned int sigs;             // mask of signals that have
  41                                         // preinstalled signal handlers
  42   static bool libjsig_is_loaded;        // libjsig that interposes sigaction(),
  43                                         // __sigaction(), signal() is loaded
  44   static struct sigaction *(*get_signal_action)(int);
  45   static struct sigaction *get_preinstalled_handler(int);
  46   static void save_preinstalled_handler(int, struct sigaction&);
  47 
  48   static void check_signal_handler(int sig);
  49 
  50   // For signal flags diagnostics
  51   static int sigflags[MAXSIGNUM];
  52 
  53   static int (*_clock_gettime)(clockid_t, struct timespec *);
  54   static int (*_pthread_getcpuclockid)(pthread_t, clockid_t *);
  55   static int (*_pthread_setname_np)(pthread_t, const char*);
  56 
  57   static address   _initial_thread_stack_bottom;
  58   static uintptr_t _initial_thread_stack_size;
  59 
  60   static const char *_glibc_version;
  61   static const char *_libpthread_version;
  62 
  63   static bool _supports_fast_thread_cpu_time;
  64 
  65   static GrowableArray<int>* _cpu_to_node;
  66 
  67  protected:
  68 
  69   static julong _physical_memory;
  70   static pthread_t _main_thread;
  71   static Mutex* _createThread_lock;
  72   static int _page_size;
  73   static const int _vm_default_page_size;
  74 
  75   static julong available_memory();
  76   static julong physical_memory() { return _physical_memory; }
  77   static void initialize_system_info();
  78 
  79   static int commit_memory_impl(char* addr, size_t bytes, bool exec);
  80   static int commit_memory_impl(char* addr, size_t bytes,
  81                                 size_t alignment_hint, bool exec);
  82 
  83   static void set_glibc_version(const char *s)      { _glibc_version = s; }
  84   static void set_libpthread_version(const char *s) { _libpthread_version = s; }
  85 
  86   static void rebuild_cpu_to_node_map();
  87   static GrowableArray<int>* cpu_to_node()    { return _cpu_to_node; }
  88 
  89   static size_t find_large_page_size();
  90   static size_t setup_large_page_size();
  91 
  92   static bool setup_large_page_type(size_t page_size);
  93   static bool transparent_huge_pages_sanity_check(bool warn, size_t pages_size);
  94   static bool hugetlbfs_sanity_check(bool warn, size_t page_size);
  95 
  96   static char* reserve_memory_special_shm(size_t bytes, size_t alignment, char* req_addr, bool exec);
  97   static char* reserve_memory_special_huge_tlbfs(size_t bytes, size_t alignment, char* req_addr, bool exec);
  98   static char* reserve_memory_special_huge_tlbfs_only(size_t bytes, char* req_addr, bool exec);
  99   static char* reserve_memory_special_huge_tlbfs_mixed(size_t bytes, size_t alignment, char* req_addr, bool exec);
 100 
 101   static bool release_memory_special_impl(char* base, size_t bytes);
 102   static bool release_memory_special_shm(char* base, size_t bytes);
 103   static bool release_memory_special_huge_tlbfs(char* base, size_t bytes);
 104 
 105   static void print_full_memory_info(outputStream* st);
 106   static void print_distro_info(outputStream* st);
 107   static void print_libversion_info(outputStream* st);
 108 
 109  public:
 110   static bool _stack_is_executable;
 111   static void *dlopen_helper(const char *name, char *ebuf, int ebuflen);
 112   static void *dll_load_in_vmthread(const char *name, char *ebuf, int ebuflen);
 113 
 114   static void init_thread_fpu_state();
 115   static int  get_fpu_control_word();
 116   static void set_fpu_control_word(int fpu_control);
 117   static pthread_t main_thread(void)                                { return _main_thread; }
 118   // returns kernel thread id (similar to LWP id on Solaris), which can be
 119   // used to access /proc
 120   static pid_t gettid();
 121   static void set_createThread_lock(Mutex* lk)                      { _createThread_lock = lk; }
 122   static Mutex* createThread_lock(void)                             { return _createThread_lock; }
 123   static void hotspot_sigmask(Thread* thread);
 124 
 125   static address   initial_thread_stack_bottom(void)                { return _initial_thread_stack_bottom; }
 126   static uintptr_t initial_thread_stack_size(void)                  { return _initial_thread_stack_size; }
 127   static bool is_initial_thread(void);
 128 
 129   static int page_size(void)                                        { return _page_size; }
 130   static void set_page_size(int val)                                { _page_size = val; }
 131 
 132   static int vm_default_page_size(void)                             { return _vm_default_page_size; }
 133 
 134   static address   ucontext_get_pc(ucontext_t* uc);
 135   static void ucontext_set_pc(ucontext_t* uc, address pc);
 136   static intptr_t* ucontext_get_sp(ucontext_t* uc);
 137   static intptr_t* ucontext_get_fp(ucontext_t* uc);
 138 
 139   // For Analyzer Forte AsyncGetCallTrace profiling support:
 140   //
 141   // This interface should be declared in os_linux_i486.hpp, but
 142   // that file provides extensions to the os class and not the
 143   // Linux class.
 144   static ExtendedPC fetch_frame_from_ucontext(Thread* thread, ucontext_t* uc,
 145                                               intptr_t** ret_sp, intptr_t** ret_fp);
 146 
 147   // This boolean allows users to forward their own non-matching signals
 148   // to JVM_handle_linux_signal, harmlessly.
 149   static bool signal_handlers_are_installed;
 150 
 151   static int get_our_sigflags(int);
 152   static void set_our_sigflags(int, int);
 153   static void signal_sets_init();
 154   static void install_signal_handlers();
 155   static void set_signal_handler(int, bool);
 156   static bool is_sig_ignored(int sig);
 157 
 158   static sigset_t* unblocked_signals();
 159   static sigset_t* vm_signals();
 160   static sigset_t* allowdebug_blocked_signals();
 161 
 162   // For signal-chaining
 163   static struct sigaction *get_chained_signal_action(int sig);
 164   static bool chained_handler(int sig, siginfo_t* siginfo, void* context);
 165 
 166   // GNU libc and libpthread version strings
 167   static const char *glibc_version()          { return _glibc_version; }
 168   static const char *libpthread_version()     { return _libpthread_version; }
 169 
 170   static void libpthread_init();
 171   static bool libnuma_init();
 172   static void* libnuma_dlsym(void* handle, const char* name);
 173   // Minimum stack size a thread can be created with (allowing
 174   // the VM to completely create the thread and enter user code)
 175   static size_t min_stack_allowed;
 176 
 177   // Return default stack size or guard size for the specified thread type
 178   static size_t default_stack_size(os::ThreadType thr_type);
 179   static size_t default_guard_size(os::ThreadType thr_type);
 180 
 181   static void capture_initial_stack(size_t max_size);
 182 
 183   // Stack overflow handling
 184   static bool manually_expand_stack(JavaThread * t, address addr);
 185   static int max_register_window_saves_before_flushing();
 186 
 187   // Real-time clock functions
 188   static void clock_init(void);
 189 
 190   // fast POSIX clocks support
 191   static void fast_thread_clock_init(void);
 192 
 193   static int clock_gettime(clockid_t clock_id, struct timespec *tp) {
 194     return _clock_gettime ? _clock_gettime(clock_id, tp) : -1;
 195   }
 196 
 197   static int pthread_getcpuclockid(pthread_t tid, clockid_t *clock_id) {
 198     return _pthread_getcpuclockid ? _pthread_getcpuclockid(tid, clock_id) : -1;
 199   }
 200 
 201   static bool supports_fast_thread_cpu_time() {
 202     return _supports_fast_thread_cpu_time;
 203   }
 204 
 205   static jlong fast_thread_cpu_time(clockid_t clockid);
 206 
 207   // pthread_cond clock suppport
 208  private:
 209   static pthread_condattr_t _condattr[1];
 210 
 211  public:
 212   static pthread_condattr_t* condAttr() { return _condattr; }
 213 
 214   // Stack repair handling
 215 
 216   // none present
 217 
 218  private:
 219   typedef int (*sched_getcpu_func_t)(void);
 220   typedef int (*numa_node_to_cpus_func_t)(int node, unsigned long *buffer, int bufferlen);
 221   typedef int (*numa_max_node_func_t)(void);
 222   typedef int (*numa_available_func_t)(void);
 223   typedef int (*numa_tonode_memory_func_t)(void *start, size_t size, int node);
 224   typedef void (*numa_interleave_memory_func_t)(void *start, size_t size, unsigned long *nodemask);
 225   typedef void (*numa_set_bind_policy_func_t)(int policy);
 226 
 227   static sched_getcpu_func_t _sched_getcpu;
 228   static numa_node_to_cpus_func_t _numa_node_to_cpus;
 229   static numa_max_node_func_t _numa_max_node;
 230   static numa_available_func_t _numa_available;
 231   static numa_tonode_memory_func_t _numa_tonode_memory;
 232   static numa_interleave_memory_func_t _numa_interleave_memory;
 233   static numa_set_bind_policy_func_t _numa_set_bind_policy;
 234   static unsigned long* _numa_all_nodes;
 235 
 236   static void set_sched_getcpu(sched_getcpu_func_t func) { _sched_getcpu = func; }
 237   static void set_numa_node_to_cpus(numa_node_to_cpus_func_t func) { _numa_node_to_cpus = func; }
 238   static void set_numa_max_node(numa_max_node_func_t func) { _numa_max_node = func; }
 239   static void set_numa_available(numa_available_func_t func) { _numa_available = func; }
 240   static void set_numa_tonode_memory(numa_tonode_memory_func_t func) { _numa_tonode_memory = func; }
 241   static void set_numa_interleave_memory(numa_interleave_memory_func_t func) { _numa_interleave_memory = func; }
 242   static void set_numa_set_bind_policy(numa_set_bind_policy_func_t func) { _numa_set_bind_policy = func; }
 243   static void set_numa_all_nodes(unsigned long* ptr) { _numa_all_nodes = ptr; }
 244   static int sched_getcpu_syscall(void);
 245  public:
 246   static int sched_getcpu()  { return _sched_getcpu != NULL ? _sched_getcpu() : -1; }
 247   static int numa_node_to_cpus(int node, unsigned long *buffer, int bufferlen) {
 248     return _numa_node_to_cpus != NULL ? _numa_node_to_cpus(node, buffer, bufferlen) : -1;
 249   }
 250   static int numa_max_node() { return _numa_max_node != NULL ? _numa_max_node() : -1; }
 251   static int numa_available() { return _numa_available != NULL ? _numa_available() : -1; }
 252   static int numa_tonode_memory(void *start, size_t size, int node) {
 253     return _numa_tonode_memory != NULL ? _numa_tonode_memory(start, size, node) : -1;
 254   }
 255   static void numa_interleave_memory(void *start, size_t size) {
 256     if (_numa_interleave_memory != NULL && _numa_all_nodes != NULL) {
 257       _numa_interleave_memory(start, size, _numa_all_nodes);
 258     }
 259   }
 260   static void numa_set_bind_policy(int policy) {
 261     if (_numa_set_bind_policy != NULL) {
 262       _numa_set_bind_policy(policy);
 263     }
 264   }
 265   static int get_node_by_cpu(int cpu_id);
 266 };
 267 
 268 
 269 class PlatformEvent : public CHeapObj<mtInternal> {
 270  private:
 271   double CachePad[4];   // increase odds that _mutex is sole occupant of cache line
 272   volatile int _Event;
 273   volatile int _nParked;
 274   pthread_mutex_t _mutex[1];
 275   pthread_cond_t  _cond[1];
 276   double PostPad[2];
 277   Thread * _Assoc;
 278 
 279  public:       // TODO-FIXME: make dtor private
 280   ~PlatformEvent() { guarantee(0, "invariant"); }
 281 
 282  public:
 283   PlatformEvent() {
 284     int status;
 285     status = pthread_cond_init(_cond, os::Linux::condAttr());
 286     assert_status(status == 0, status, "cond_init");
 287     status = pthread_mutex_init(_mutex, NULL);
 288     assert_status(status == 0, status, "mutex_init");
 289     _Event   = 0;
 290     _nParked = 0;
 291     _Assoc   = NULL;
 292   }
 293 
 294   // Use caution with reset() and fired() -- they may require MEMBARs
 295   void reset() { _Event = 0; }
 296   int  fired() { return _Event; }
 297   void park();
 298   void unpark();
 299   int  park(jlong millis); // relative timed-wait only
 300   void SetAssociation(Thread * a) { _Assoc = a; }
 301 };
 302 
 303 class PlatformParker : public CHeapObj<mtInternal> {
 304  protected:
 305   enum {
 306     REL_INDEX = 0,
 307     ABS_INDEX = 1
 308   };
 309   int _cur_index;  // which cond is in use: -1, 0, 1
 310   pthread_mutex_t _mutex[1];
 311   pthread_cond_t  _cond[2]; // one for relative times and one for abs.
 312 
 313  public:       // TODO-FIXME: make dtor private
 314   ~PlatformParker() { guarantee(0, "invariant"); }
 315 
 316  public:
 317   PlatformParker() {
 318     int status;
 319     status = pthread_cond_init(&_cond[REL_INDEX], os::Linux::condAttr());
 320     assert_status(status == 0, status, "cond_init rel");
 321     status = pthread_cond_init(&_cond[ABS_INDEX], NULL);
 322     assert_status(status == 0, status, "cond_init abs");
 323     status = pthread_mutex_init(_mutex, NULL);
 324     assert_status(status == 0, status, "mutex_init");
 325     _cur_index = -1; // mark as unused
 326   }
 327 };
 328 
 329 #endif // OS_LINUX_VM_OS_LINUX_HPP