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 bool supports_variable_stack_size();
87
88 static void rebuild_cpu_to_node_map();
89 static GrowableArray<int>* cpu_to_node() { return _cpu_to_node; }
90
91 static size_t find_large_page_size();
92 static size_t setup_large_page_size();
93
94 static bool setup_large_page_type(size_t page_size);
95 static bool transparent_huge_pages_sanity_check(bool warn, size_t pages_size);
96 static bool hugetlbfs_sanity_check(bool warn, size_t page_size);
97
98 static char* reserve_memory_special_shm(size_t bytes, size_t alignment, char* req_addr, bool exec);
99 static char* reserve_memory_special_huge_tlbfs(size_t bytes, size_t alignment, char* req_addr, bool exec);
100 static char* reserve_memory_special_huge_tlbfs_only(size_t bytes, char* req_addr, bool exec);
101 static char* reserve_memory_special_huge_tlbfs_mixed(size_t bytes, size_t alignment, char* req_addr, bool exec);
102
103 static bool release_memory_special_impl(char* base, size_t bytes);
104 static bool release_memory_special_shm(char* base, size_t bytes);
105 static bool release_memory_special_huge_tlbfs(char* base, size_t bytes);
106
107 static void print_full_memory_info(outputStream* st);
108 static void print_distro_info(outputStream* st);
109 static void print_libversion_info(outputStream* st);
110
111 public:
112 static bool _stack_is_executable;
113 static void *dlopen_helper(const char *name, char *ebuf, int ebuflen);
114 static void *dll_load_in_vmthread(const char *name, char *ebuf, int ebuflen);
115
116 static void init_thread_fpu_state();
117 static int get_fpu_control_word();
118 static void set_fpu_control_word(int fpu_control);
119 static pthread_t main_thread(void) { return _main_thread; }
120 // returns kernel thread id (similar to LWP id on Solaris), which can be
121 // used to access /proc
122 static pid_t gettid();
123 static void set_createThread_lock(Mutex* lk) { _createThread_lock = lk; }
124 static Mutex* createThread_lock(void) { return _createThread_lock; }
125 static void hotspot_sigmask(Thread* thread);
126
127 static address initial_thread_stack_bottom(void) { return _initial_thread_stack_bottom; }
128 static uintptr_t initial_thread_stack_size(void) { return _initial_thread_stack_size; }
129 static bool is_initial_thread(void);
130
131 static int page_size(void) { return _page_size; }
132 static void set_page_size(int val) { _page_size = val; }
133
134 static int vm_default_page_size(void) { return _vm_default_page_size; }
135
136 static address ucontext_get_pc(ucontext_t* uc);
137 static void ucontext_set_pc(ucontext_t* uc, address pc);
138 static intptr_t* ucontext_get_sp(ucontext_t* uc);
139 static intptr_t* ucontext_get_fp(ucontext_t* uc);
140
141 // For Analyzer Forte AsyncGetCallTrace profiling support:
142 //
143 // This interface should be declared in os_linux_i486.hpp, but
144 // that file provides extensions to the os class and not the
145 // Linux class.
146 static ExtendedPC fetch_frame_from_ucontext(Thread* thread, ucontext_t* uc,
147 intptr_t** ret_sp, intptr_t** ret_fp);
148
149 // This boolean allows users to forward their own non-matching signals
150 // to JVM_handle_linux_signal, harmlessly.
151 static bool signal_handlers_are_installed;
152
153 static int get_our_sigflags(int);
154 static void set_our_sigflags(int, int);
155 static void signal_sets_init();
156 static void install_signal_handlers();
157 static void set_signal_handler(int, bool);
158 static bool is_sig_ignored(int sig);
159
160 static sigset_t* unblocked_signals();
161 static sigset_t* vm_signals();
162 static sigset_t* allowdebug_blocked_signals();
163
164 // For signal-chaining
165 static struct sigaction *get_chained_signal_action(int sig);
166 static bool chained_handler(int sig, siginfo_t* siginfo, void* context);
167
168 // GNU libc and libpthread version strings
169 static const char *glibc_version() { return _glibc_version; }
170 static const char *libpthread_version() { return _libpthread_version; }
171
172 static void libpthread_init();
173 static bool libnuma_init();
174 static void* libnuma_dlsym(void* handle, const char* name);
175 // Minimum stack size a thread can be created with (allowing
176 // the VM to completely create the thread and enter user code)
177 static size_t min_stack_allowed;
178
179 // Return default stack size or guard size for the specified thread type
180 static size_t default_stack_size(os::ThreadType thr_type);
181 static size_t default_guard_size(os::ThreadType thr_type);
182
183 static void capture_initial_stack(size_t max_size);
184
185 // Stack overflow handling
186 static bool manually_expand_stack(JavaThread * t, address addr);
187 static int max_register_window_saves_before_flushing();
188
189 // Real-time clock functions
190 static void clock_init(void);
191
192 // fast POSIX clocks support
193 static void fast_thread_clock_init(void);
194
195 static int clock_gettime(clockid_t clock_id, struct timespec *tp) {
196 return _clock_gettime ? _clock_gettime(clock_id, tp) : -1;
197 }
198
199 static int pthread_getcpuclockid(pthread_t tid, clockid_t *clock_id) {
200 return _pthread_getcpuclockid ? _pthread_getcpuclockid(tid, clock_id) : -1;
201 }
202
203 static bool supports_fast_thread_cpu_time() {
204 return _supports_fast_thread_cpu_time;
205 }
206
207 static jlong fast_thread_cpu_time(clockid_t clockid);
208
209 // pthread_cond clock suppport
210 private:
211 static pthread_condattr_t _condattr[1];
212
213 public:
214 static pthread_condattr_t* condAttr() { return _condattr; }
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_available_func_t)(void);
225 typedef int (*numa_tonode_memory_func_t)(void *start, size_t size, int node);
226 typedef void (*numa_interleave_memory_func_t)(void *start, size_t size, unsigned long *nodemask);
227 typedef void (*numa_set_bind_policy_func_t)(int policy);
228
229 static sched_getcpu_func_t _sched_getcpu;
230 static numa_node_to_cpus_func_t _numa_node_to_cpus;
231 static numa_max_node_func_t _numa_max_node;
232 static numa_available_func_t _numa_available;
233 static numa_tonode_memory_func_t _numa_tonode_memory;
234 static numa_interleave_memory_func_t _numa_interleave_memory;
235 static numa_set_bind_policy_func_t _numa_set_bind_policy;
236 static unsigned long* _numa_all_nodes;
237
238 static void set_sched_getcpu(sched_getcpu_func_t func) { _sched_getcpu = func; }
239 static void set_numa_node_to_cpus(numa_node_to_cpus_func_t func) { _numa_node_to_cpus = func; }
240 static void set_numa_max_node(numa_max_node_func_t func) { _numa_max_node = func; }
241 static void set_numa_available(numa_available_func_t func) { _numa_available = func; }
242 static void set_numa_tonode_memory(numa_tonode_memory_func_t func) { _numa_tonode_memory = func; }
243 static void set_numa_interleave_memory(numa_interleave_memory_func_t func) { _numa_interleave_memory = func; }
244 static void set_numa_set_bind_policy(numa_set_bind_policy_func_t func) { _numa_set_bind_policy = func; }
245 static void set_numa_all_nodes(unsigned long* ptr) { _numa_all_nodes = ptr; }
246 static int sched_getcpu_syscall(void);
247 public:
248 static int sched_getcpu() { return _sched_getcpu != NULL ? _sched_getcpu() : -1; }
249 static int numa_node_to_cpus(int node, unsigned long *buffer, int bufferlen) {
250 return _numa_node_to_cpus != NULL ? _numa_node_to_cpus(node, buffer, bufferlen) : -1;
251 }
252 static int numa_max_node() { return _numa_max_node != NULL ? _numa_max_node() : -1; }
253 static int numa_available() { return _numa_available != NULL ? _numa_available() : -1; }
254 static int numa_tonode_memory(void *start, size_t size, int node) {
255 return _numa_tonode_memory != NULL ? _numa_tonode_memory(start, size, node) : -1;
256 }
257 static void numa_interleave_memory(void *start, size_t size) {
258 if (_numa_interleave_memory != NULL && _numa_all_nodes != NULL) {
259 _numa_interleave_memory(start, size, _numa_all_nodes);
260 }
261 }
262 static void numa_set_bind_policy(int policy) {
263 if (_numa_set_bind_policy != NULL) {
264 _numa_set_bind_policy(policy);
265 }
266 }
267 static int get_node_by_cpu(int cpu_id);
268 };
269
270
271 class PlatformEvent : public CHeapObj<mtInternal> {
272 private:
273 double CachePad[4]; // increase odds that _mutex is sole occupant of cache line
274 volatile int _Event;
275 volatile int _nParked;
276 pthread_mutex_t _mutex[1];
277 pthread_cond_t _cond[1];
278 double PostPad[2];
279 Thread * _Assoc;
280
281 public: // TODO-FIXME: make dtor private
282 ~PlatformEvent() { guarantee(0, "invariant"); }
283
284 public:
285 PlatformEvent() {
286 int status;
287 status = pthread_cond_init(_cond, os::Linux::condAttr());
288 assert_status(status == 0, status, "cond_init");
289 status = pthread_mutex_init(_mutex, NULL);
290 assert_status(status == 0, status, "mutex_init");
291 _Event = 0;
292 _nParked = 0;
293 _Assoc = NULL;
294 }
295
296 // Use caution with reset() and fired() -- they may require MEMBARs
297 void reset() { _Event = 0; }
298 int fired() { return _Event; }
299 void park();
300 void unpark();
301 int park(jlong millis); // relative timed-wait only
302 void SetAssociation(Thread * a) { _Assoc = a; }
303 };
304
305 class PlatformParker : public CHeapObj<mtInternal> {
306 protected:
307 enum {
308 REL_INDEX = 0,
309 ABS_INDEX = 1
310 };
311 int _cur_index; // which cond is in use: -1, 0, 1
312 pthread_mutex_t _mutex[1];
313 pthread_cond_t _cond[2]; // one for relative times and one for abs.
314
315 public: // TODO-FIXME: make dtor private
316 ~PlatformParker() { guarantee(0, "invariant"); }
317
318 public:
319 PlatformParker() {
320 int status;
321 status = pthread_cond_init(&_cond[REL_INDEX], os::Linux::condAttr());
322 assert_status(status == 0, status, "cond_init rel");
323 status = pthread_cond_init(&_cond[ABS_INDEX], NULL);
324 assert_status(status == 0, status, "cond_init abs");
325 status = pthread_mutex_init(_mutex, NULL);
326 assert_status(status == 0, status, "mutex_init");
327 _cur_index = -1; // mark as unused
328 }
329 };
330
331 #endif // OS_LINUX_VM_OS_LINUX_HPP