1 /*
   2  * Copyright (c) 1999, 2013, 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 /* pthread_getattr_np comes with LinuxThreads-0.9-7 on RedHat 7.1 */
  31 typedef int (*pthread_getattr_func_type) (pthread_t, pthread_attr_t *);
  32 
  33 // Information about the protection of the page at address '0' on this os.
  34 static bool zero_page_read_protected() { return true; }
  35 
  36 class Linux {
  37   friend class os;
  38   friend class TestReserveMemorySpecial;
  39 
  40   // For signal-chaining
  41 #define MAXSIGNUM 32
  42   static struct sigaction sigact[MAXSIGNUM]; // saved preinstalled sigactions
  43   static unsigned int sigs;             // mask of signals that have
  44                                         // preinstalled signal handlers
  45   static bool libjsig_is_loaded;        // libjsig that interposes sigaction(),
  46                                         // __sigaction(), signal() is loaded
  47   static struct sigaction *(*get_signal_action)(int);
  48   static struct sigaction *get_preinstalled_handler(int);
  49   static void save_preinstalled_handler(int, struct sigaction&);
  50 
  51   static void check_signal_handler(int sig);
  52 
  53   // For signal flags diagnostics
  54   static int sigflags[MAXSIGNUM];
  55 
  56   static int (*_clock_gettime)(clockid_t, struct timespec *);
  57   static int (*_pthread_getcpuclockid)(pthread_t, clockid_t *);
  58 
  59   static address   _initial_thread_stack_bottom;
  60   static uintptr_t _initial_thread_stack_size;
  61 
  62   static const char *_glibc_version;
  63   static const char *_libpthread_version;
  64 
  65   static bool _is_floating_stack;
  66   static bool _is_NPTL;
  67   static bool _supports_fast_thread_cpu_time;
  68 
  69   static GrowableArray<int>* _cpu_to_node;
  70   static GrowableArray<int>* _nindex_to_node;
  71 
  72  protected:
  73 
  74   static julong _physical_memory;
  75   static pthread_t _main_thread;
  76   static Mutex* _createThread_lock;
  77   static int _page_size;
  78   static const int _vm_default_page_size;
  79 
  80   static julong available_memory();
  81   static julong physical_memory() { return _physical_memory; }
  82   static void initialize_system_info();
  83 
  84   static int commit_memory_impl(char* addr, size_t bytes, bool exec);
  85   static int commit_memory_impl(char* addr, size_t bytes,
  86                                 size_t alignment_hint, bool exec);
  87 
  88   static void set_glibc_version(const char *s)      { _glibc_version = s; }
  89   static void set_libpthread_version(const char *s) { _libpthread_version = s; }
  90 
  91   static bool supports_variable_stack_size();
  92 
  93   static void set_is_NPTL()                   { _is_NPTL = true;  }
  94   static void set_is_LinuxThreads()           { _is_NPTL = false; }
  95   static void set_is_floating_stack()         { _is_floating_stack = true; }
  96 
  97   static void rebuild_cpu_to_node_map();
  98   static void rebuild_nindex_to_node_map();
  99   static GrowableArray<int>* cpu_to_node()    { return _cpu_to_node; }
 100   static GrowableArray<int>* nindex_to_node()  { return _nindex_to_node; }
 101 
 102   static size_t find_large_page_size();
 103   static size_t setup_large_page_size();
 104 
 105   static bool setup_large_page_type(size_t page_size);
 106   static bool transparent_huge_pages_sanity_check(bool warn, size_t pages_size);
 107   static bool hugetlbfs_sanity_check(bool warn, size_t page_size);
 108 
 109   static char* reserve_memory_special_shm(size_t bytes, size_t alignment, char* req_addr, bool exec);
 110   static char* reserve_memory_special_huge_tlbfs(size_t bytes, size_t alignment, char* req_addr, bool exec);
 111   static char* reserve_memory_special_huge_tlbfs_only(size_t bytes, char* req_addr, bool exec);
 112   static char* reserve_memory_special_huge_tlbfs_mixed(size_t bytes, size_t alignment, char* req_addr, bool exec);
 113 
 114   static bool release_memory_special_impl(char* base, size_t bytes);
 115   static bool release_memory_special_shm(char* base, size_t bytes);
 116   static bool release_memory_special_huge_tlbfs(char* base, size_t bytes);
 117 
 118   static void print_full_memory_info(outputStream* st);
 119   static void print_distro_info(outputStream* st);
 120   static void print_libversion_info(outputStream* st);
 121 
 122  public:
 123   static bool _stack_is_executable;
 124   static void *dlopen_helper(const char *name, char *ebuf, int ebuflen);
 125   static void *dll_load_in_vmthread(const char *name, char *ebuf, int ebuflen);
 126 
 127   static void init_thread_fpu_state();
 128   static int  get_fpu_control_word();
 129   static void set_fpu_control_word(int fpu_control);
 130   static pthread_t main_thread(void)                                { return _main_thread; }
 131   // returns kernel thread id (similar to LWP id on Solaris), which can be
 132   // used to access /proc
 133   static pid_t gettid();
 134   static void set_createThread_lock(Mutex* lk)                      { _createThread_lock = lk; }
 135   static Mutex* createThread_lock(void)                             { return _createThread_lock; }
 136   static void hotspot_sigmask(Thread* thread);
 137 
 138   static address   initial_thread_stack_bottom(void)                { return _initial_thread_stack_bottom; }
 139   static uintptr_t initial_thread_stack_size(void)                  { return _initial_thread_stack_size; }
 140   static bool is_initial_thread(void);
 141 
 142   static int page_size(void)                                        { return _page_size; }
 143   static void set_page_size(int val)                                { _page_size = val; }
 144 
 145   static int vm_default_page_size(void)                             { return _vm_default_page_size; }
 146 
 147   static address   ucontext_get_pc(ucontext_t* uc);
 148   static intptr_t* ucontext_get_sp(ucontext_t* uc);
 149   static intptr_t* ucontext_get_fp(ucontext_t* uc);
 150 
 151   // For Analyzer Forte AsyncGetCallTrace profiling support:
 152   //
 153   // This interface should be declared in os_linux_i486.hpp, but
 154   // that file provides extensions to the os class and not the
 155   // Linux class.
 156   static ExtendedPC fetch_frame_from_ucontext(Thread* thread, ucontext_t* uc,
 157     intptr_t** ret_sp, intptr_t** ret_fp);
 158 
 159   // This boolean allows users to forward their own non-matching signals
 160   // to JVM_handle_linux_signal, harmlessly.
 161   static bool signal_handlers_are_installed;
 162 
 163   static int get_our_sigflags(int);
 164   static void set_our_sigflags(int, int);
 165   static void signal_sets_init();
 166   static void install_signal_handlers();
 167   static void set_signal_handler(int, bool);
 168   static bool is_sig_ignored(int sig);
 169 
 170   static sigset_t* unblocked_signals();
 171   static sigset_t* vm_signals();
 172   static sigset_t* allowdebug_blocked_signals();
 173 
 174   // For signal-chaining
 175   static struct sigaction *get_chained_signal_action(int sig);
 176   static bool chained_handler(int sig, siginfo_t* siginfo, void* context);
 177 
 178   // GNU libc and libpthread version strings
 179   static const char *glibc_version()          { return _glibc_version; }
 180   static const char *libpthread_version()     { return _libpthread_version; }
 181 
 182   // NPTL or LinuxThreads?
 183   static bool is_LinuxThreads()               { return !_is_NPTL; }
 184   static bool is_NPTL()                       { return _is_NPTL;  }
 185 
 186   // NPTL is always floating stack. LinuxThreads could be using floating
 187   // stack or fixed stack.
 188   static bool is_floating_stack()             { return _is_floating_stack; }
 189 
 190   static void libpthread_init();
 191   static bool libnuma_init();
 192   static void* libnuma_dlsym(void* handle, const char* name);
 193   // Minimum stack size a thread can be created with (allowing
 194   // the VM to completely create the thread and enter user code)
 195   static size_t min_stack_allowed;
 196 
 197   // Return default stack size or guard size for the specified thread type
 198   static size_t default_stack_size(os::ThreadType thr_type);
 199   static size_t default_guard_size(os::ThreadType thr_type);
 200 
 201   static void capture_initial_stack(size_t max_size);
 202 
 203   // Stack overflow handling
 204   static bool manually_expand_stack(JavaThread * t, address addr);
 205   static int max_register_window_saves_before_flushing();
 206 
 207   // Real-time clock functions
 208   static void clock_init(void);
 209 
 210   // fast POSIX clocks support
 211   static void fast_thread_clock_init(void);
 212 
 213   static inline bool supports_monotonic_clock() {
 214     return _clock_gettime != NULL;
 215   }
 216 
 217   static int clock_gettime(clockid_t clock_id, struct timespec *tp) {
 218     return _clock_gettime ? _clock_gettime(clock_id, tp) : -1;
 219   }
 220 
 221   static int pthread_getcpuclockid(pthread_t tid, clockid_t *clock_id) {
 222     return _pthread_getcpuclockid ? _pthread_getcpuclockid(tid, clock_id) : -1;
 223   }
 224 
 225   static bool supports_fast_thread_cpu_time() {
 226     return _supports_fast_thread_cpu_time;
 227   }
 228 
 229   static jlong fast_thread_cpu_time(clockid_t clockid);
 230 
 231   // pthread_cond clock suppport
 232   private:
 233   static pthread_condattr_t _condattr[1];
 234 
 235   public:
 236   static pthread_condattr_t* condAttr() { return _condattr; }
 237 
 238   // Stack repair handling
 239 
 240   // none present
 241 
 242   // LinuxThreads work-around for 6292965
 243   static int safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime);
 244 
 245 private:
 246   typedef int (*sched_getcpu_func_t)(void);
 247   typedef int (*numa_node_to_cpus_func_t)(int node, unsigned long *buffer, int bufferlen);
 248   typedef int (*numa_max_node_func_t)(void);
 249   typedef int (*numa_num_configured_nodes_func_t)(void);
 250   typedef int (*numa_available_func_t)(void);
 251   typedef int (*numa_tonode_memory_func_t)(void *start, size_t size, int node);
 252   typedef void (*numa_interleave_memory_func_t)(void *start, size_t size, unsigned long *nodemask);
 253   typedef void (*numa_set_bind_policy_func_t)(int policy);
 254   typedef int (*numa_bitmask_isbitset_func_t)(struct bitmask *bmp, unsigned int n);
 255   typedef int (*numa_distance_func_t)(int node1, int node2);
 256 
 257   static sched_getcpu_func_t _sched_getcpu;
 258   static numa_node_to_cpus_func_t _numa_node_to_cpus;
 259   static numa_max_node_func_t _numa_max_node;
 260   static numa_num_configured_nodes_func_t _numa_num_configured_nodes;
 261   static numa_available_func_t _numa_available;
 262   static numa_tonode_memory_func_t _numa_tonode_memory;
 263   static numa_interleave_memory_func_t _numa_interleave_memory;
 264   static numa_set_bind_policy_func_t _numa_set_bind_policy;
 265   static numa_bitmask_isbitset_func_t _numa_bitmask_isbitset;
 266   static numa_distance_func_t _numa_distance;
 267   static unsigned long* _numa_all_nodes;
 268   static struct bitmask* _numa_all_nodes_ptr;
 269   static struct bitmask* _numa_nodes_ptr;
 270 
 271   static void set_sched_getcpu(sched_getcpu_func_t func) { _sched_getcpu = func; }
 272   static void set_numa_node_to_cpus(numa_node_to_cpus_func_t func) { _numa_node_to_cpus = func; }
 273   static void set_numa_max_node(numa_max_node_func_t func) { _numa_max_node = func; }
 274   static void set_numa_num_configured_nodes(numa_num_configured_nodes_func_t func) { _numa_num_configured_nodes = func; }
 275   static void set_numa_available(numa_available_func_t func) { _numa_available = func; }
 276   static void set_numa_tonode_memory(numa_tonode_memory_func_t func) { _numa_tonode_memory = func; }
 277   static void set_numa_interleave_memory(numa_interleave_memory_func_t func) { _numa_interleave_memory = func; }
 278   static void set_numa_set_bind_policy(numa_set_bind_policy_func_t func) { _numa_set_bind_policy = func; }
 279   static void set_numa_bitmask_isbitset(numa_bitmask_isbitset_func_t func) { _numa_bitmask_isbitset = func; }
 280   static void set_numa_distance(numa_distance_func_t func) { _numa_distance = func; }
 281   static void set_numa_all_nodes(unsigned long* ptr) { _numa_all_nodes = ptr; }
 282   static void set_numa_all_nodes_ptr(struct bitmask **ptr) { _numa_all_nodes_ptr = *ptr; }
 283   static void set_numa_nodes_ptr(struct bitmask **ptr) { _numa_nodes_ptr = *ptr; }
 284   static int sched_getcpu_syscall(void);
 285 public:
 286   static int sched_getcpu()  { return _sched_getcpu != NULL ? _sched_getcpu() : -1; }
 287   static int numa_node_to_cpus(int node, unsigned long *buffer, int bufferlen) {
 288     return _numa_node_to_cpus != NULL ? _numa_node_to_cpus(node, buffer, bufferlen) : -1;
 289   }
 290   static int numa_max_node() { return _numa_max_node != NULL ? _numa_max_node() : -1; }
 291   static int numa_num_configured_nodes() {
 292     return _numa_num_configured_nodes != NULL ? _numa_num_configured_nodes() : -1;
 293   }
 294   static int numa_available() { return _numa_available != NULL ? _numa_available() : -1; }
 295   static int numa_tonode_memory(void *start, size_t size, int node) {
 296     return _numa_tonode_memory != NULL ? _numa_tonode_memory(start, size, node) : -1;
 297   }
 298   static void numa_interleave_memory(void *start, size_t size) {
 299     if (_numa_interleave_memory != NULL && _numa_all_nodes != NULL) {
 300       _numa_interleave_memory(start, size, _numa_all_nodes);
 301     }
 302   }
 303   static void numa_set_bind_policy(int policy) {
 304     if (_numa_set_bind_policy != NULL) {
 305       _numa_set_bind_policy(policy);
 306     }
 307   }
 308   static int numa_distance(int node1, int node2) {
 309     return _numa_distance != NULL ? _numa_distance(node1, node2) : -1;
 310   }
 311   static int get_node_by_cpu(int cpu_id);
 312   static int get_existing_num_nodes();
 313   // Check if numa node is configured (non-zero memory node).
 314   static bool isnode_in_configured_nodes(unsigned int n) {
 315     if (_numa_bitmask_isbitset != NULL && _numa_all_nodes_ptr != NULL) {
 316       return _numa_bitmask_isbitset(_numa_all_nodes_ptr, n);
 317     } else
 318       return 0;
 319   }
 320   // Check if numa node exists in the system (including zero memory nodes).
 321   static bool isnode_in_existing_nodes(unsigned int n) {
 322     if (_numa_bitmask_isbitset != NULL && _numa_nodes_ptr != NULL) {
 323       return _numa_bitmask_isbitset(_numa_nodes_ptr, n);
 324     } else
 325       return 0;
 326   }
 327 };
 328 
 329 
 330 class PlatformEvent : public CHeapObj<mtInternal> {
 331   private:
 332     double CachePad [4] ;   // increase odds that _mutex is sole occupant of cache line
 333     volatile int _Event ;
 334     volatile int _nParked ;
 335     pthread_mutex_t _mutex  [1] ;
 336     pthread_cond_t  _cond   [1] ;
 337     double PostPad  [2] ;
 338     Thread * _Assoc ;
 339 
 340   public:       // TODO-FIXME: make dtor private
 341     ~PlatformEvent() { guarantee (0, "invariant") ; }
 342 
 343   public:
 344     PlatformEvent() {
 345       int status;
 346       status = pthread_cond_init (_cond, os::Linux::condAttr());
 347       assert_status(status == 0, status, "cond_init");
 348       status = pthread_mutex_init (_mutex, NULL);
 349       assert_status(status == 0, status, "mutex_init");
 350       _Event   = 0 ;
 351       _nParked = 0 ;
 352       _Assoc   = NULL ;
 353     }
 354 
 355     // Use caution with reset() and fired() -- they may require MEMBARs
 356     void reset() { _Event = 0 ; }
 357     int  fired() { return _Event; }
 358     void park () ;
 359     void unpark () ;
 360     int  TryPark () ;
 361     int  park (jlong millis) ; // relative timed-wait only
 362     void SetAssociation (Thread * a) { _Assoc = a ; }
 363 } ;
 364 
 365 class PlatformParker : public CHeapObj<mtInternal> {
 366   protected:
 367     enum {
 368         REL_INDEX = 0,
 369         ABS_INDEX = 1
 370     };
 371     int _cur_index;  // which cond is in use: -1, 0, 1
 372     pthread_mutex_t _mutex [1] ;
 373     pthread_cond_t  _cond  [2] ; // one for relative times and one for abs.
 374 
 375   public:       // TODO-FIXME: make dtor private
 376     ~PlatformParker() { guarantee (0, "invariant") ; }
 377 
 378   public:
 379     PlatformParker() {
 380       int status;
 381       status = pthread_cond_init (&_cond[REL_INDEX], os::Linux::condAttr());
 382       assert_status(status == 0, status, "cond_init rel");
 383       status = pthread_cond_init (&_cond[ABS_INDEX], NULL);
 384       assert_status(status == 0, status, "cond_init abs");
 385       status = pthread_mutex_init (_mutex, NULL);
 386       assert_status(status == 0, status, "mutex_init");
 387       _cur_index = -1; // mark as unused
 388     }
 389 };
 390 
 391 #endif // OS_LINUX_VM_OS_LINUX_HPP