1 /*
   2  * Copyright (c) 1999, 2017, 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 OSContainer;
  36   friend class TestReserveMemorySpecial;
  37 
  38   static bool libjsig_is_loaded;        // libjsig that interposes sigaction(),
  39                                         // __sigaction(), signal() is loaded
  40   static struct sigaction *(*get_signal_action)(int);
  41   static struct sigaction *get_preinstalled_handler(int);
  42   static void save_preinstalled_handler(int, struct sigaction&);
  43 
  44   static void check_signal_handler(int sig);
  45 
  46   static int (*_clock_gettime)(clockid_t, struct timespec *);
  47   static int (*_pthread_getcpuclockid)(pthread_t, clockid_t *);
  48   static int (*_pthread_setname_np)(pthread_t, const char*);
  49 
  50   static address   _initial_thread_stack_bottom;
  51   static uintptr_t _initial_thread_stack_size;
  52 
  53   static const char *_glibc_version;
  54   static const char *_libpthread_version;
  55 
  56   static bool _supports_fast_thread_cpu_time;
  57 
  58   static GrowableArray<int>* _cpu_to_node;
  59   static GrowableArray<int>* _nindex_to_node;
  60 
  61   // 0x00000000 = uninitialized,
  62   // 0x01000000 = kernel version unknown,
  63   // otherwise a 32-bit number:
  64   // Ox00AABBCC
  65   // AA, Major Version
  66   // BB, Minor Version
  67   // CC, Fix   Version
  68   static uint32_t _os_version;
  69 
  70  protected:
  71 
  72   static julong _physical_memory;
  73   static pthread_t _main_thread;
  74   static Mutex* _createThread_lock;
  75   static int _page_size;
  76 
  77   static julong available_memory();
  78   static julong physical_memory() { return _physical_memory; }
  79   static void set_physical_memory(julong phys_mem) { _physical_memory = phys_mem; }
  80   static int active_processor_count();
  81 
  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 void rebuild_cpu_to_node_map();
  92   static void rebuild_nindex_to_node_map();
  93   static GrowableArray<int>* cpu_to_node()    { return _cpu_to_node; }
  94   static GrowableArray<int>* nindex_to_node()  { return _nindex_to_node; }
  95 
  96   static size_t find_large_page_size();
  97   static size_t setup_large_page_size();
  98 
  99   static bool setup_large_page_type(size_t page_size);
 100   static bool transparent_huge_pages_sanity_check(bool warn, size_t pages_size);
 101   static bool hugetlbfs_sanity_check(bool warn, size_t page_size);
 102 
 103   static char* reserve_memory_special_shm(size_t bytes, size_t alignment, char* req_addr, bool exec);
 104   static char* reserve_memory_special_huge_tlbfs(size_t bytes, size_t alignment, char* req_addr, bool exec);
 105   static char* reserve_memory_special_huge_tlbfs_only(size_t bytes, char* req_addr, bool exec);
 106   static char* reserve_memory_special_huge_tlbfs_mixed(size_t bytes, size_t alignment, char* req_addr, bool exec);
 107 
 108   static bool release_memory_special_impl(char* base, size_t bytes);
 109   static bool release_memory_special_shm(char* base, size_t bytes);
 110   static bool release_memory_special_huge_tlbfs(char* base, size_t bytes);
 111 
 112   static void print_full_memory_info(outputStream* st);
 113   static void print_container_info(outputStream* st);
 114   static void print_distro_info(outputStream* st);
 115   static void print_libversion_info(outputStream* st);
 116 
 117  public:
 118   static bool _stack_is_executable;
 119   static void *dlopen_helper(const char *name, char *ebuf, int ebuflen);
 120   static void *dll_load_in_vmthread(const char *name, char *ebuf, int ebuflen);
 121 
 122   static void init_thread_fpu_state();
 123   static int  get_fpu_control_word();
 124   static void set_fpu_control_word(int fpu_control);
 125   static pthread_t main_thread(void)                                { return _main_thread; }
 126   // returns kernel thread id (similar to LWP id on Solaris), which can be
 127   // used to access /proc
 128   static pid_t gettid();
 129   static void set_createThread_lock(Mutex* lk)                      { _createThread_lock = lk; }
 130   static Mutex* createThread_lock(void)                             { return _createThread_lock; }
 131   static void hotspot_sigmask(Thread* thread);
 132 
 133   static address   initial_thread_stack_bottom(void)                { return _initial_thread_stack_bottom; }
 134   static uintptr_t initial_thread_stack_size(void)                  { return _initial_thread_stack_size; }
 135 
 136   static int page_size(void)                                        { return _page_size; }
 137   static void set_page_size(int val)                                { _page_size = val; }
 138 
 139   static address   ucontext_get_pc(const ucontext_t* uc);
 140   static void ucontext_set_pc(ucontext_t* uc, address pc);
 141   static intptr_t* ucontext_get_sp(const ucontext_t* uc);
 142   static intptr_t* ucontext_get_fp(const ucontext_t* uc);
 143 
 144   // For Analyzer Forte AsyncGetCallTrace profiling support:
 145   //
 146   // This interface should be declared in os_linux_i486.hpp, but
 147   // that file provides extensions to the os class and not the
 148   // Linux class.
 149   static ExtendedPC fetch_frame_from_ucontext(Thread* thread, const ucontext_t* uc,
 150                                               intptr_t** ret_sp, intptr_t** ret_fp);
 151 
 152   static bool get_frame_at_stack_banging_point(JavaThread* thread, ucontext_t* uc, frame* fr);
 153 
 154   // This boolean allows users to forward their own non-matching signals
 155   // to JVM_handle_linux_signal, harmlessly.
 156   static bool signal_handlers_are_installed;
 157 
 158   static int get_our_sigflags(int);
 159   static void set_our_sigflags(int, int);
 160   static void signal_sets_init();
 161   static void install_signal_handlers();
 162   static void set_signal_handler(int, bool);
 163   static bool is_sig_ignored(int sig);
 164 
 165   static sigset_t* unblocked_signals();
 166   static sigset_t* vm_signals();
 167 
 168   // For signal-chaining
 169   static struct sigaction *get_chained_signal_action(int sig);
 170   static bool chained_handler(int sig, siginfo_t* siginfo, void* context);
 171 
 172   // GNU libc and libpthread version strings
 173   static const char *glibc_version()          { return _glibc_version; }
 174   static const char *libpthread_version()     { return _libpthread_version; }
 175 
 176   static void libpthread_init();
 177   static void sched_getcpu_init();
 178   static bool libnuma_init();
 179   static void* libnuma_dlsym(void* handle, const char* name);
 180   // libnuma v2 (libnuma_1.2) symbols
 181   static void* libnuma_v2_dlsym(void* handle, const char* name);
 182 
 183   // Return default guard size for the specified thread type
 184   static size_t default_guard_size(os::ThreadType thr_type);
 185 
 186   static void capture_initial_stack(size_t max_size);
 187 
 188   // Stack overflow handling
 189   static bool manually_expand_stack(JavaThread * t, address addr);
 190   static int max_register_window_saves_before_flushing();
 191 
 192   // Real-time clock functions
 193   static void clock_init(void);
 194 
 195   // fast POSIX clocks support
 196   static void fast_thread_clock_init(void);
 197 
 198   static int clock_gettime(clockid_t clock_id, struct timespec *tp) {
 199     return _clock_gettime ? _clock_gettime(clock_id, tp) : -1;
 200   }
 201 
 202   static int pthread_getcpuclockid(pthread_t tid, clockid_t *clock_id) {
 203     return _pthread_getcpuclockid ? _pthread_getcpuclockid(tid, clock_id) : -1;
 204   }
 205 
 206   static bool supports_fast_thread_cpu_time() {
 207     return _supports_fast_thread_cpu_time;
 208   }
 209 
 210   static jlong fast_thread_cpu_time(clockid_t clockid);
 211 
 212   static void initialize_os_info();
 213   static bool os_version_is_known();
 214   static uint32_t os_version();
 215 
 216   // Stack repair handling
 217 
 218   // none present
 219 
 220  private:
 221   typedef int (*sched_getcpu_func_t)(void);
 222   typedef int (*numa_node_to_cpus_func_t)(int node, unsigned long *buffer, int bufferlen);
 223   typedef int (*numa_max_node_func_t)(void);
 224   typedef int (*numa_num_configured_nodes_func_t)(void);
 225   typedef int (*numa_available_func_t)(void);
 226   typedef int (*numa_tonode_memory_func_t)(void *start, size_t size, int node);
 227   typedef void (*numa_interleave_memory_func_t)(void *start, size_t size, unsigned long *nodemask);
 228   typedef void (*numa_interleave_memory_v2_func_t)(void *start, size_t size, struct bitmask* mask);
 229 
 230   typedef void (*numa_set_bind_policy_func_t)(int policy);
 231   typedef int (*numa_bitmask_isbitset_func_t)(struct bitmask *bmp, unsigned int n);
 232   typedef int (*numa_distance_func_t)(int node1, int node2);
 233 
 234   static sched_getcpu_func_t _sched_getcpu;
 235   static numa_node_to_cpus_func_t _numa_node_to_cpus;
 236   static numa_max_node_func_t _numa_max_node;
 237   static numa_num_configured_nodes_func_t _numa_num_configured_nodes;
 238   static numa_available_func_t _numa_available;
 239   static numa_tonode_memory_func_t _numa_tonode_memory;
 240   static numa_interleave_memory_func_t _numa_interleave_memory;
 241   static numa_interleave_memory_v2_func_t _numa_interleave_memory_v2;
 242   static numa_set_bind_policy_func_t _numa_set_bind_policy;
 243   static numa_bitmask_isbitset_func_t _numa_bitmask_isbitset;
 244   static numa_distance_func_t _numa_distance;
 245   static unsigned long* _numa_all_nodes;
 246   static struct bitmask* _numa_all_nodes_ptr;
 247   static struct bitmask* _numa_nodes_ptr;
 248 
 249   static void set_sched_getcpu(sched_getcpu_func_t func) { _sched_getcpu = func; }
 250   static void set_numa_node_to_cpus(numa_node_to_cpus_func_t func) { _numa_node_to_cpus = func; }
 251   static void set_numa_max_node(numa_max_node_func_t func) { _numa_max_node = func; }
 252   static void set_numa_num_configured_nodes(numa_num_configured_nodes_func_t func) { _numa_num_configured_nodes = func; }
 253   static void set_numa_available(numa_available_func_t func) { _numa_available = func; }
 254   static void set_numa_tonode_memory(numa_tonode_memory_func_t func) { _numa_tonode_memory = func; }
 255   static void set_numa_interleave_memory(numa_interleave_memory_func_t func) { _numa_interleave_memory = func; }
 256   static void set_numa_interleave_memory_v2(numa_interleave_memory_v2_func_t func) { _numa_interleave_memory_v2 = func; }
 257   static void set_numa_set_bind_policy(numa_set_bind_policy_func_t func) { _numa_set_bind_policy = func; }
 258   static void set_numa_bitmask_isbitset(numa_bitmask_isbitset_func_t func) { _numa_bitmask_isbitset = func; }
 259   static void set_numa_distance(numa_distance_func_t func) { _numa_distance = func; }
 260   static void set_numa_all_nodes(unsigned long* ptr) { _numa_all_nodes = ptr; }
 261   static void set_numa_all_nodes_ptr(struct bitmask **ptr) { _numa_all_nodes_ptr = (ptr == NULL ? NULL : *ptr); }
 262   static void set_numa_nodes_ptr(struct bitmask **ptr) { _numa_nodes_ptr = (ptr == NULL ? NULL : *ptr); }
 263   static int sched_getcpu_syscall(void);
 264  public:
 265   static int sched_getcpu()  { return _sched_getcpu != NULL ? _sched_getcpu() : -1; }
 266   static int numa_node_to_cpus(int node, unsigned long *buffer, int bufferlen) {
 267     return _numa_node_to_cpus != NULL ? _numa_node_to_cpus(node, buffer, bufferlen) : -1;
 268   }
 269   static int numa_max_node() { return _numa_max_node != NULL ? _numa_max_node() : -1; }
 270   static int numa_num_configured_nodes() {
 271     return _numa_num_configured_nodes != NULL ? _numa_num_configured_nodes() : -1;
 272   }
 273   static int numa_available() { return _numa_available != NULL ? _numa_available() : -1; }
 274   static int numa_tonode_memory(void *start, size_t size, int node) {
 275     return _numa_tonode_memory != NULL ? _numa_tonode_memory(start, size, node) : -1;
 276   }
 277   static void numa_interleave_memory(void *start, size_t size) {
 278     // Use v2 api if available
 279     if (_numa_interleave_memory_v2 != NULL && _numa_all_nodes_ptr != NULL) {
 280       _numa_interleave_memory_v2(start, size, _numa_all_nodes_ptr);
 281     } else if (_numa_interleave_memory != NULL && _numa_all_nodes != NULL) {
 282       _numa_interleave_memory(start, size, _numa_all_nodes);
 283     }
 284   }
 285   static void numa_set_bind_policy(int policy) {
 286     if (_numa_set_bind_policy != NULL) {
 287       _numa_set_bind_policy(policy);
 288     }
 289   }
 290   static int numa_distance(int node1, int node2) {
 291     return _numa_distance != NULL ? _numa_distance(node1, node2) : -1;
 292   }
 293   static int get_node_by_cpu(int cpu_id);
 294   static int get_existing_num_nodes();
 295   // Check if numa node is configured (non-zero memory node).
 296   static bool isnode_in_configured_nodes(unsigned int n) {
 297     if (_numa_bitmask_isbitset != NULL && _numa_all_nodes_ptr != NULL) {
 298       return _numa_bitmask_isbitset(_numa_all_nodes_ptr, n);
 299     } else
 300       return 0;
 301   }
 302   // Check if numa node exists in the system (including zero memory nodes).
 303   static bool isnode_in_existing_nodes(unsigned int n) {
 304     if (_numa_bitmask_isbitset != NULL && _numa_nodes_ptr != NULL) {
 305       return _numa_bitmask_isbitset(_numa_nodes_ptr, n);
 306     } else if (_numa_bitmask_isbitset != NULL && _numa_all_nodes_ptr != NULL) {
 307       // Not all libnuma API v2 implement numa_nodes_ptr, so it's not possible
 308       // to trust the API version for checking its absence. On the other hand,
 309       // numa_nodes_ptr found in libnuma 2.0.9 and above is the only way to get
 310       // a complete view of all numa nodes in the system, hence numa_nodes_ptr
 311       // is used to handle CPU and nodes on architectures (like PowerPC) where
 312       // there can exist nodes with CPUs but no memory or vice-versa and the
 313       // nodes may be non-contiguous. For most of the architectures, like
 314       // x86_64, numa_node_ptr presents the same node set as found in
 315       // numa_all_nodes_ptr so it's possible to use numa_all_nodes_ptr as a
 316       // substitute.
 317       return _numa_bitmask_isbitset(_numa_all_nodes_ptr, n);
 318     } else
 319       return 0;
 320   }
 321 };
 322 
 323 #endif // OS_LINUX_VM_OS_LINUX_HPP