| /* |
| * Copyright (c) 1999, 2016, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| // no precompiled headers |
| #include "asm/macroAssembler.hpp" |
| #include "classfile/classLoader.hpp" |
| #include "classfile/systemDictionary.hpp" |
| #include "classfile/vmSymbols.hpp" |
| #include "code/codeCache.hpp" |
| #include "code/icBuffer.hpp" |
| #include "code/vtableStubs.hpp" |
| #include "interpreter/interpreter.hpp" |
| #include "jvm_linux.h" |
| #include "memory/allocation.inline.hpp" |
| #include "mutex_linux.inline.hpp" |
| #include "os_share_linux.hpp" |
| #include "prims/jniFastGetField.hpp" |
| #include "prims/jvm.h" |
| #include "prims/jvm_misc.hpp" |
| #include "runtime/arguments.hpp" |
| #include "runtime/extendedPC.hpp" |
| #include "runtime/frame.inline.hpp" |
| #include "runtime/interfaceSupport.hpp" |
| #include "runtime/java.hpp" |
| #include "runtime/javaCalls.hpp" |
| #include "runtime/mutexLocker.hpp" |
| #include "runtime/osThread.hpp" |
| #include "runtime/sharedRuntime.hpp" |
| #include "runtime/stubRoutines.hpp" |
| #include "runtime/thread.inline.hpp" |
| #include "runtime/timer.hpp" |
| #include "services/memTracker.hpp" |
| #include "utilities/events.hpp" |
| #include "utilities/vmError.hpp" |
| |
| // put OS-includes here |
| # include <sys/types.h> |
| # include <sys/mman.h> |
| # include <pthread.h> |
| # include <signal.h> |
| # include <errno.h> |
| # include <dlfcn.h> |
| # include <stdlib.h> |
| # include <stdio.h> |
| # include <unistd.h> |
| # include <sys/resource.h> |
| # include <pthread.h> |
| # include <sys/stat.h> |
| # include <sys/time.h> |
| # include <sys/utsname.h> |
| # include <sys/socket.h> |
| # include <sys/wait.h> |
| # include <pwd.h> |
| # include <poll.h> |
| # include <ucontext.h> |
| # include <fpu_control.h> |
| |
| #ifdef AMD64 |
| #define REG_SP REG_RSP |
| #define REG_PC REG_RIP |
| #define REG_FP REG_RBP |
| #define SPELL_REG_SP "rsp" |
| #define SPELL_REG_FP "rbp" |
| #else |
| #define REG_SP REG_UESP |
| #define REG_PC REG_EIP |
| #define REG_FP REG_EBP |
| #define SPELL_REG_SP "esp" |
| #define SPELL_REG_FP "ebp" |
| #endif // AMD64 |
| |
| address os::current_stack_pointer() { |
| #ifdef SPARC_WORKS |
| register void *esp; |
| __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp)); |
| return (address) ((char*)esp + sizeof(long)*2); |
| #elif defined(__clang__) |
| intptr_t* esp; |
| __asm__ __volatile__ ("mov %%"SPELL_REG_SP", %0":"=r"(esp):); |
| return (address) esp; |
| #else |
| register void *esp __asm__ (SPELL_REG_SP); |
| return (address) esp; |
| #endif |
| } |
| |
| char* os::non_memory_address_word() { |
| // Must never look like an address returned by reserve_memory, |
| // even in its subfields (as defined by the CPU immediate fields, |
| // if the CPU splits constants across multiple instructions). |
| |
| return (char*) -1; |
| } |
| |
| void os::initialize_thread(Thread* thr) { |
| // Nothing to do. |
| } |
| |
| address os::Linux::ucontext_get_pc(const ucontext_t * uc) { |
| return (address)uc->uc_mcontext.gregs[REG_PC]; |
| } |
| |
| void os::Linux::ucontext_set_pc(ucontext_t * uc, address pc) { |
| uc->uc_mcontext.gregs[REG_PC] = (intptr_t)pc; |
| } |
| |
| intptr_t* os::Linux::ucontext_get_sp(const ucontext_t * uc) { |
| return (intptr_t*)uc->uc_mcontext.gregs[REG_SP]; |
| } |
| |
| intptr_t* os::Linux::ucontext_get_fp(const ucontext_t * uc) { |
| return (intptr_t*)uc->uc_mcontext.gregs[REG_FP]; |
| } |
| |
| // For Forte Analyzer AsyncGetCallTrace profiling support - thread |
| // is currently interrupted by SIGPROF. |
| // os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal |
| // frames. Currently we don't do that on Linux, so it's the same as |
| // os::fetch_frame_from_context(). |
| // This method is also used for stack overflow signal handling. |
| ExtendedPC os::Linux::fetch_frame_from_ucontext(Thread* thread, |
| const ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) { |
| |
| assert(thread != NULL, "just checking"); |
| assert(ret_sp != NULL, "just checking"); |
| assert(ret_fp != NULL, "just checking"); |
| |
| return os::fetch_frame_from_context(uc, ret_sp, ret_fp); |
| } |
| |
| ExtendedPC os::fetch_frame_from_context(const void* ucVoid, |
| intptr_t** ret_sp, intptr_t** ret_fp) { |
| |
| ExtendedPC epc; |
| const ucontext_t* uc = (const ucontext_t*)ucVoid; |
| |
| if (uc != NULL) { |
| epc = ExtendedPC(os::Linux::ucontext_get_pc(uc)); |
| if (ret_sp) *ret_sp = os::Linux::ucontext_get_sp(uc); |
| if (ret_fp) *ret_fp = os::Linux::ucontext_get_fp(uc); |
| } else { |
| // construct empty ExtendedPC for return value checking |
| epc = ExtendedPC(NULL); |
| if (ret_sp) *ret_sp = (intptr_t *)NULL; |
| if (ret_fp) *ret_fp = (intptr_t *)NULL; |
| } |
| |
| return epc; |
| } |
| |
| frame os::fetch_frame_from_context(const void* ucVoid) { |
| intptr_t* sp; |
| intptr_t* fp; |
| ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp); |
| return frame(sp, fp, epc.pc()); |
| } |
| |
| frame os::fetch_frame_from_ucontext(Thread* thread, void* ucVoid) { |
| intptr_t* sp; |
| intptr_t* fp; |
| ExtendedPC epc = os::Linux::fetch_frame_from_ucontext(thread, (ucontext_t*)ucVoid, &sp, &fp); |
| return frame(sp, fp, epc.pc()); |
| } |
| |
| bool os::Linux::get_frame_at_stack_banging_point(JavaThread* thread, ucontext_t* uc, frame* fr) { |
| address pc = (address) os::Linux::ucontext_get_pc(uc); |
| if (Interpreter::contains(pc)) { |
| // interpreter performs stack banging after the fixed frame header has |
| // been generated while the compilers perform it before. To maintain |
| // semantic consistency between interpreted and compiled frames, the |
| // method returns the Java sender of the current frame. |
| *fr = os::fetch_frame_from_ucontext(thread, uc); |
| if (!fr->is_first_java_frame()) { |
| assert(fr->safe_for_sender(thread), "Safety check"); |
| *fr = fr->java_sender(); |
| } |
| } else { |
| // more complex code with compiled code |
| assert(!Interpreter::contains(pc), "Interpreted methods should have been handled above"); |
| CodeBlob* cb = CodeCache::find_blob(pc); |
| if (cb == NULL || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) { |
| // Not sure where the pc points to, fallback to default |
| // stack overflow handling |
| return false; |
| } else { |
| // in compiled code, the stack banging is performed just after the return pc |
| // has been pushed on the stack |
| intptr_t* fp = os::Linux::ucontext_get_fp(uc); |
| intptr_t* sp = os::Linux::ucontext_get_sp(uc); |
| *fr = frame(sp + 1, fp, (address)*sp); |
| if (!fr->is_java_frame()) { |
| assert(fr->safe_for_sender(thread), "Safety check"); |
| assert(!fr->is_first_frame(), "Safety check"); |
| *fr = fr->java_sender(); |
| } |
| } |
| } |
| assert(fr->is_java_frame(), "Safety check"); |
| return true; |
| } |
| |
| // By default, gcc always save frame pointer (%ebp/%rbp) on stack. It may get |
| // turned off by -fomit-frame-pointer, |
| frame os::get_sender_for_C_frame(frame* fr) { |
| return frame(fr->sender_sp(), fr->link(), fr->sender_pc()); |
| } |
| |
| intptr_t* _get_previous_fp() { |
| #ifdef SPARC_WORKS |
| register intptr_t **ebp; |
| __asm__("mov %%"SPELL_REG_FP", %0":"=r"(ebp)); |
| #elif defined(__clang__) |
| intptr_t **ebp; |
| __asm__ __volatile__ ("mov %%"SPELL_REG_FP", %0":"=r"(ebp):); |
| #else |
| register intptr_t **ebp __asm__ (SPELL_REG_FP); |
| #endif |
| return (intptr_t*) *ebp; // we want what it points to. |
| } |
| |
| |
| frame os::current_frame() { |
| intptr_t* fp = _get_previous_fp(); |
| frame myframe((intptr_t*)os::current_stack_pointer(), |
| (intptr_t*)fp, |
| CAST_FROM_FN_PTR(address, os::current_frame)); |
| if (os::is_first_C_frame(&myframe)) { |
| // stack is not walkable |
| return frame(); |
| } else { |
| return os::get_sender_for_C_frame(&myframe); |
| } |
| } |
| |
| // Utility functions |
| |
| // From IA32 System Programming Guide |
| enum { |
| trap_page_fault = 0xE |
| }; |
| |
| extern "C" JNIEXPORT int |
| JVM_handle_linux_signal(int sig, |
| siginfo_t* info, |
| void* ucVoid, |
| int abort_if_unrecognized) { |
| ucontext_t* uc = (ucontext_t*) ucVoid; |
| |
| Thread* t = Thread::current_or_null_safe(); |
| |
| // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away |
| // (no destructors can be run) |
| os::WatcherThreadCrashProtection::check_crash_protection(sig, t); |
| |
| SignalHandlerMark shm(t); |
| |
| // Note: it's not uncommon that JNI code uses signal/sigset to install |
| // then restore certain signal handler (e.g. to temporarily block SIGPIPE, |
| // or have a SIGILL handler when detecting CPU type). When that happens, |
| // JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To |
| // avoid unnecessary crash when libjsig is not preloaded, try handle signals |
| // that do not require siginfo/ucontext first. |
| |
| if (sig == SIGPIPE || sig == SIGXFSZ) { |
| // allow chained handler to go first |
| if (os::Linux::chained_handler(sig, info, ucVoid)) { |
| return true; |
| } else { |
| // Ignoring SIGPIPE/SIGXFSZ - see bugs 4229104 or 6499219 |
| return true; |
| } |
| } |
| |
| JavaThread* thread = NULL; |
| VMThread* vmthread = NULL; |
| if (os::Linux::signal_handlers_are_installed) { |
| if (t != NULL ){ |
| if(t->is_Java_thread()) { |
| thread = (JavaThread*)t; |
| } |
| else if(t->is_VM_thread()){ |
| vmthread = (VMThread *)t; |
| } |
| } |
| } |
| /* |
| NOTE: does not seem to work on linux. |
| if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) { |
| // can't decode this kind of signal |
| info = NULL; |
| } else { |
| assert(sig == info->si_signo, "bad siginfo"); |
| } |
| */ |
| // decide if this trap can be handled by a stub |
| address stub = NULL; |
| |
| address pc = NULL; |
| |
| //%note os_trap_1 |
| if (info != NULL && uc != NULL && thread != NULL) { |
| pc = (address) os::Linux::ucontext_get_pc(uc); |
| |
| if (StubRoutines::is_safefetch_fault(pc)) { |
| os::Linux::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc)); |
| return 1; |
| } |
| |
| #ifndef AMD64 |
| // Halt if SI_KERNEL before more crashes get misdiagnosed as Java bugs |
| // This can happen in any running code (currently more frequently in |
| // interpreter code but has been seen in compiled code) |
| if (sig == SIGSEGV && info->si_addr == 0 && info->si_code == SI_KERNEL) { |
| fatal("An irrecoverable SI_KERNEL SIGSEGV has occurred due " |
| "to unstable signal handling in this distribution."); |
| } |
| #endif // AMD64 |
| |
| // Handle ALL stack overflow variations here |
| if (sig == SIGSEGV) { |
| address addr = (address) info->si_addr; |
| |
| // check if fault address is within thread stack |
| if (thread->on_local_stack(addr)) { |
| // stack overflow |
| if (thread->in_stack_yellow_reserved_zone(addr)) { |
| if (thread->thread_state() == _thread_in_Java) { |
| if (thread->in_stack_reserved_zone(addr)) { |
| frame fr; |
| if (os::Linux::get_frame_at_stack_banging_point(thread, uc, &fr)) { |
| assert(fr.is_java_frame(), "Must be a Java frame"); |
| frame activation = |
| SharedRuntime::look_for_reserved_stack_annotated_method(thread, fr); |
| if (activation.sp() != NULL) { |
| thread->disable_stack_reserved_zone(); |
| if (activation.is_interpreted_frame()) { |
| thread->set_reserved_stack_activation((address)( |
| activation.fp() + frame::interpreter_frame_initial_sp_offset)); |
| } else { |
| thread->set_reserved_stack_activation((address)activation.unextended_sp()); |
| } |
| return 1; |
| } |
| } |
| } |
| // Throw a stack overflow exception. Guard pages will be reenabled |
| // while unwinding the stack. |
| thread->disable_stack_yellow_reserved_zone(); |
| stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW); |
| } else { |
| // Thread was in the vm or native code. Return and try to finish. |
| thread->disable_stack_yellow_reserved_zone(); |
| return 1; |
| } |
| } else if (thread->in_stack_red_zone(addr)) { |
| // Fatal red zone violation. Disable the guard pages and fall through |
| // to handle_unexpected_exception way down below. |
| thread->disable_stack_red_zone(); |
| tty->print_raw_cr("An irrecoverable stack overflow has occurred."); |
| |
| // This is a likely cause, but hard to verify. Let's just print |
| // it as a hint. |
| tty->print_raw_cr("Please check if any of your loaded .so files has " |
| "enabled executable stack (see man page execstack(8))"); |
| } else { |
| // Accessing stack address below sp may cause SEGV if current |
| // thread has MAP_GROWSDOWN stack. This should only happen when |
| // current thread was created by user code with MAP_GROWSDOWN flag |
| // and then attached to VM. See notes in os_linux.cpp. |
| if (thread->osthread()->expanding_stack() == 0) { |
| thread->osthread()->set_expanding_stack(); |
| if (os::Linux::manually_expand_stack(thread, addr)) { |
| thread->osthread()->clear_expanding_stack(); |
| return 1; |
| } |
| thread->osthread()->clear_expanding_stack(); |
| } else { |
| fatal("recursive segv. expanding stack."); |
| } |
| } |
| } |
| } |
| |
| if ((sig == SIGSEGV) && VM_Version::is_cpuinfo_segv_addr(pc)) { |
| // Verify that OS save/restore AVX registers. |
| stub = VM_Version::cpuinfo_cont_addr(); |
| } |
| |
| if (thread->thread_state() == _thread_in_Java) { |
| // Java thread running in Java code => find exception handler if any |
| // a fault inside compiled code, the interpreter, or a stub |
| |
| if (sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) { |
| stub = SharedRuntime::get_poll_stub(pc); |
| } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) { |
| // BugId 4454115: A read from a MappedByteBuffer can fault |
| // here if the underlying file has been truncated. |
| // Do not crash the VM in such a case. |
| CodeBlob* cb = CodeCache::find_blob_unsafe(pc); |
| nmethod* nm = (cb != NULL && cb->is_nmethod()) ? (nmethod*)cb : NULL; |
| if (nm != NULL && nm->has_unsafe_access()) { |
| stub = StubRoutines::handler_for_unsafe_access(); |
| } |
| } |
| else |
| |
| #ifdef AMD64 |
| if (sig == SIGFPE && |
| (info->si_code == FPE_INTDIV || info->si_code == FPE_FLTDIV)) { |
| stub = |
| SharedRuntime:: |
| continuation_for_implicit_exception(thread, |
| pc, |
| SharedRuntime:: |
| IMPLICIT_DIVIDE_BY_ZERO); |
| #else |
| if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) { |
| // HACK: si_code does not work on linux 2.2.12-20!!! |
| int op = pc[0]; |
| if (op == 0xDB) { |
| // FIST |
| // TODO: The encoding of D2I in i486.ad can cause an exception |
| // prior to the fist instruction if there was an invalid operation |
| // pending. We want to dismiss that exception. From the win_32 |
| // side it also seems that if it really was the fist causing |
| // the exception that we do the d2i by hand with different |
| // rounding. Seems kind of weird. |
| // NOTE: that we take the exception at the NEXT floating point instruction. |
| assert(pc[0] == 0xDB, "not a FIST opcode"); |
| assert(pc[1] == 0x14, "not a FIST opcode"); |
| assert(pc[2] == 0x24, "not a FIST opcode"); |
| return true; |
| } else if (op == 0xF7) { |
| // IDIV |
| stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO); |
| } else { |
| // TODO: handle more cases if we are using other x86 instructions |
| // that can generate SIGFPE signal on linux. |
| tty->print_cr("unknown opcode 0x%X with SIGFPE.", op); |
| fatal("please update this code."); |
| } |
| #endif // AMD64 |
| } else if (sig == SIGSEGV && |
| !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) { |
| // Determination of interpreter/vtable stub/compiled code null exception |
| stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); |
| } |
| } else if (thread->thread_state() == _thread_in_vm && |
| sig == SIGBUS && /* info->si_code == BUS_OBJERR && */ |
| thread->doing_unsafe_access()) { |
| stub = StubRoutines::handler_for_unsafe_access(); |
| } |
| |
| // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in |
| // and the heap gets shrunk before the field access. |
| if ((sig == SIGSEGV) || (sig == SIGBUS)) { |
| address addr = JNI_FastGetField::find_slowcase_pc(pc); |
| if (addr != (address)-1) { |
| stub = addr; |
| } |
| } |
| |
| // Check to see if we caught the safepoint code in the |
| // process of write protecting the memory serialization page. |
| // It write enables the page immediately after protecting it |
| // so we can just return to retry the write. |
| if ((sig == SIGSEGV) && |
| os::is_memory_serialize_page(thread, (address) info->si_addr)) { |
| // Block current thread until the memory serialize page permission restored. |
| os::block_on_serialize_page_trap(); |
| return true; |
| } |
| } |
| |
| #ifndef AMD64 |
| // Execution protection violation |
| // |
| // This should be kept as the last step in the triage. We don't |
| // have a dedicated trap number for a no-execute fault, so be |
| // conservative and allow other handlers the first shot. |
| // |
| // Note: We don't test that info->si_code == SEGV_ACCERR here. |
| // this si_code is so generic that it is almost meaningless; and |
| // the si_code for this condition may change in the future. |
| // Furthermore, a false-positive should be harmless. |
| if (UnguardOnExecutionViolation > 0 && |
| (sig == SIGSEGV || sig == SIGBUS) && |
| uc->uc_mcontext.gregs[REG_TRAPNO] == trap_page_fault) { |
| int page_size = os::vm_page_size(); |
| address addr = (address) info->si_addr; |
| address pc = os::Linux::ucontext_get_pc(uc); |
| // Make sure the pc and the faulting address are sane. |
| // |
| // If an instruction spans a page boundary, and the page containing |
| // the beginning of the instruction is executable but the following |
| // page is not, the pc and the faulting address might be slightly |
| // different - we still want to unguard the 2nd page in this case. |
| // |
| // 15 bytes seems to be a (very) safe value for max instruction size. |
| bool pc_is_near_addr = |
| (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15); |
| bool instr_spans_page_boundary = |
| (align_size_down((intptr_t) pc ^ (intptr_t) addr, |
| (intptr_t) page_size) > 0); |
| |
| if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) { |
| static volatile address last_addr = |
| (address) os::non_memory_address_word(); |
| |
| // In conservative mode, don't unguard unless the address is in the VM |
| if (addr != last_addr && |
| (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) { |
| |
| // Set memory to RWX and retry |
| address page_start = |
| (address) align_size_down((intptr_t) addr, (intptr_t) page_size); |
| bool res = os::protect_memory((char*) page_start, page_size, |
| os::MEM_PROT_RWX); |
| |
| log_debug(os)("Execution protection violation " |
| "at " INTPTR_FORMAT |
| ", unguarding " INTPTR_FORMAT ": %s, errno=%d", p2i(addr), |
| p2i(page_start), (res ? "success" : "failed"), errno); |
| stub = pc; |
| |
| // Set last_addr so if we fault again at the same address, we don't end |
| // up in an endless loop. |
| // |
| // There are two potential complications here. Two threads trapping at |
| // the same address at the same time could cause one of the threads to |
| // think it already unguarded, and abort the VM. Likely very rare. |
| // |
| // The other race involves two threads alternately trapping at |
| // different addresses and failing to unguard the page, resulting in |
| // an endless loop. This condition is probably even more unlikely than |
| // the first. |
| // |
| // Although both cases could be avoided by using locks or thread local |
| // last_addr, these solutions are unnecessary complication: this |
| // handler is a best-effort safety net, not a complete solution. It is |
| // disabled by default and should only be used as a workaround in case |
| // we missed any no-execute-unsafe VM code. |
| |
| last_addr = addr; |
| } |
| } |
| } |
| #endif // !AMD64 |
| |
| if (stub != NULL) { |
| // save all thread context in case we need to restore it |
| if (thread != NULL) thread->set_saved_exception_pc(pc); |
| |
| os::Linux::ucontext_set_pc(uc, stub); |
| return true; |
| } |
| |
| // signal-chaining |
| if (os::Linux::chained_handler(sig, info, ucVoid)) { |
| return true; |
| } |
| |
| if (!abort_if_unrecognized) { |
| // caller wants another chance, so give it to him |
| return false; |
| } |
| |
| if (pc == NULL && uc != NULL) { |
| pc = os::Linux::ucontext_get_pc(uc); |
| } |
| |
| // unmask current signal |
| sigset_t newset; |
| sigemptyset(&newset); |
| sigaddset(&newset, sig); |
| sigprocmask(SIG_UNBLOCK, &newset, NULL); |
| |
| VMError::report_and_die(t, sig, pc, info, ucVoid); |
| |
| ShouldNotReachHere(); |
| return true; // Mute compiler |
| } |
| |
| void os::Linux::init_thread_fpu_state(void) { |
| #ifndef AMD64 |
| // set fpu to 53 bit precision |
| set_fpu_control_word(0x27f); |
| #endif // !AMD64 |
| } |
| |
| int os::Linux::get_fpu_control_word(void) { |
| #ifdef AMD64 |
| return 0; |
| #else |
| int fpu_control; |
| _FPU_GETCW(fpu_control); |
| return fpu_control & 0xffff; |
| #endif // AMD64 |
| } |
| |
| void os::Linux::set_fpu_control_word(int fpu_control) { |
| #ifndef AMD64 |
| _FPU_SETCW(fpu_control); |
| #endif // !AMD64 |
| } |
| |
| // Check that the linux kernel version is 2.4 or higher since earlier |
| // versions do not support SSE without patches. |
| bool os::supports_sse() { |
| #ifdef AMD64 |
| return true; |
| #else |
| struct utsname uts; |
| if( uname(&uts) != 0 ) return false; // uname fails? |
| char *minor_string; |
| int major = strtol(uts.release,&minor_string,10); |
| int minor = strtol(minor_string+1,NULL,10); |
| bool result = (major > 2 || (major==2 && minor >= 4)); |
| log_info(os)("OS version is %d.%d, which %s support SSE/SSE2", |
| major,minor, result ? "DOES" : "does NOT"); |
| return result; |
| #endif // AMD64 |
| } |
| |
| bool os::is_allocatable(size_t bytes) { |
| #ifdef AMD64 |
| // unused on amd64? |
| return true; |
| #else |
| |
| if (bytes < 2 * G) { |
| return true; |
| } |
| |
| char* addr = reserve_memory(bytes, NULL); |
| |
| if (addr != NULL) { |
| release_memory(addr, bytes); |
| } |
| |
| return addr != NULL; |
| #endif // AMD64 |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| // thread stack |
| |
| #ifdef AMD64 |
| size_t os::Linux::min_stack_allowed = 64 * K; |
| #else |
| size_t os::Linux::min_stack_allowed = (48 DEBUG_ONLY(+4))*K; |
| #endif // AMD64 |
| |
| // return default stack size for thr_type |
| size_t os::Linux::default_stack_size(os::ThreadType thr_type) { |
| // default stack size (compiler thread needs larger stack) |
| #ifdef AMD64 |
| size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M); |
| #else |
| size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K); |
| #endif // AMD64 |
| return s; |
| } |
| |
| size_t os::Linux::default_guard_size(os::ThreadType thr_type) { |
| // Creating guard page is very expensive. Java thread has HotSpot |
| // guard page, only enable glibc guard page for non-Java threads. |
| return (thr_type == java_thread ? 0 : page_size()); |
| } |
| |
| // Java thread: |
| // |
| // Low memory addresses |
| // +------------------------+ |
| // | |\ JavaThread created by VM does not have glibc |
| // | glibc guard page | - guard, attached Java thread usually has |
| // | |/ 1 page glibc guard. |
| // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() |
| // | |\ |
| // | HotSpot Guard Pages | - red and yellow pages |
| // | |/ |
| // +------------------------+ JavaThread::stack_yellow_zone_base() |
| // | |\ |
| // | Normal Stack | - |
| // | |/ |
| // P2 +------------------------+ Thread::stack_base() |
| // |
| // Non-Java thread: |
| // |
| // Low memory addresses |
| // +------------------------+ |
| // | |\ |
| // | glibc guard page | - usually 1 page |
| // | |/ |
| // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() |
| // | |\ |
| // | Normal Stack | - |
| // | |/ |
| // P2 +------------------------+ Thread::stack_base() |
| // |
| // ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from |
| // pthread_attr_getstack() |
| |
| static void current_stack_region(address * bottom, size_t * size) { |
| if (os::Linux::is_initial_thread()) { |
| // initial thread needs special handling because pthread_getattr_np() |
| // may return bogus value. |
| *bottom = os::Linux::initial_thread_stack_bottom(); |
| *size = os::Linux::initial_thread_stack_size(); |
| } else { |
| pthread_attr_t attr; |
| |
| int rslt = pthread_getattr_np(pthread_self(), &attr); |
| |
| // JVM needs to know exact stack location, abort if it fails |
| if (rslt != 0) { |
| if (rslt == ENOMEM) { |
| vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np"); |
| } else { |
| fatal("pthread_getattr_np failed with errno = %d", rslt); |
| } |
| } |
| |
| if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) { |
| fatal("Can not locate current stack attributes!"); |
| } |
| |
| pthread_attr_destroy(&attr); |
| |
| } |
| assert(os::current_stack_pointer() >= *bottom && |
| os::current_stack_pointer() < *bottom + *size, "just checking"); |
| } |
| |
| address os::current_stack_base() { |
| address bottom; |
| size_t size; |
| current_stack_region(&bottom, &size); |
| return (bottom + size); |
| } |
| |
| size_t os::current_stack_size() { |
| // stack size includes normal stack and HotSpot guard pages |
| address bottom; |
| size_t size; |
| current_stack_region(&bottom, &size); |
| return size; |
| } |
| |
| ///////////////////////////////////////////////////////////////////////////// |
| // helper functions for fatal error handler |
| |
| void os::print_context(outputStream *st, const void *context) { |
| if (context == NULL) return; |
| |
| const ucontext_t *uc = (const ucontext_t*)context; |
| st->print_cr("Registers:"); |
| #ifdef AMD64 |
| st->print( "RAX=" INTPTR_FORMAT, (intptr_t)uc->uc_mcontext.gregs[REG_RAX]); |
| st->print(", RBX=" INTPTR_FORMAT, (intptr_t)uc->uc_mcontext.gregs[REG_RBX]); |
| st->print(", RCX=" INTPTR_FORMAT, (intptr_t)uc->uc_mcontext.gregs[REG_RCX]); |
| st->print(", RDX=" INTPTR_FORMAT, (intptr_t)uc->uc_mcontext.gregs[REG_RDX]); |
| st->cr(); |
| st->print( "RSP=" INTPTR_FORMAT, (intptr_t)uc->uc_mcontext.gregs[REG_RSP]); |
| st->print(", RBP=" INTPTR_FORMAT, (intptr_t)uc->uc_mcontext.gregs[REG_RBP]); |
| st->print(", RSI=" INTPTR_FORMAT, (intptr_t)uc->uc_mcontext.gregs[REG_RSI]); |
| st->print(", RDI=" INTPTR_FORMAT, (intptr_t)uc->uc_mcontext.gregs[REG_RDI]); |
| st->cr(); |
| st->print( "R8 =" INTPTR_FORMAT, (intptr_t)uc->uc_mcontext.gregs[REG_R8]); |
| st->print(", R9 =" INTPTR_FORMAT, (intptr_t)uc->uc_mcontext.gregs[REG_R9]); |
| st->print(", R10=" INTPTR_FORMAT, (intptr_t)uc->uc_mcontext.gregs[REG_R10]); |
| st->print(", R11=" INTPTR_FORMAT, (intptr_t)uc->uc_mcontext.gregs[REG_R11]); |
| st->cr(); |
| st->print( "R12=" INTPTR_FORMAT, (intptr_t)uc->uc_mcontext.gregs[REG_R12]); |
| st->print(", R13=" INTPTR_FORMAT, (intptr_t)uc->uc_mcontext.gregs[REG_R13]); |
| st->print(", R14=" INTPTR_FORMAT, (intptr_t)uc->uc_mcontext.gregs[REG_R14]); |
| st->print(", R15=" INTPTR_FORMAT, (intptr_t)uc->uc_mcontext.gregs[REG_R15]); |
| st->cr(); |
| st->print( "RIP=" INTPTR_FORMAT, (intptr_t)uc->uc_mcontext.gregs[REG_RIP]); |
| st->print(", EFLAGS=" INTPTR_FORMAT, (intptr_t)uc->uc_mcontext.gregs[REG_EFL]); |
| st->print(", CSGSFS=" INTPTR_FORMAT, (intptr_t)uc->uc_mcontext.gregs[REG_CSGSFS]); |
| st->print(", ERR=" INTPTR_FORMAT, (intptr_t)uc->uc_mcontext.gregs[REG_ERR]); |
| st->cr(); |
| st->print(" TRAPNO=" INTPTR_FORMAT, (intptr_t)uc->uc_mcontext.gregs[REG_TRAPNO]); |
| #else |
| st->print( "EAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EAX]); |
| st->print(", EBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EBX]); |
| st->print(", ECX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ECX]); |
| st->print(", EDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EDX]); |
| st->cr(); |
| st->print( "ESP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_UESP]); |
| st->print(", EBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EBP]); |
| st->print(", ESI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ESI]); |
| st->print(", EDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EDI]); |
| st->cr(); |
| st->print( "EIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EIP]); |
| st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EFL]); |
| st->print(", CR2=" PTR64_FORMAT, (uint64_t)uc->uc_mcontext.cr2); |
| #endif // AMD64 |
| st->cr(); |
| st->cr(); |
| |
| intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc); |
| st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", p2i(sp)); |
| print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t)); |
| st->cr(); |
| |
| // Note: it may be unsafe to inspect memory near pc. For example, pc may |
| // point to garbage if entry point in an nmethod is corrupted. Leave |
| // this at the end, and hope for the best. |
| address pc = os::Linux::ucontext_get_pc(uc); |
| st->print_cr("Instructions: (pc=" PTR_FORMAT ")", p2i(pc)); |
| print_hex_dump(st, pc - 32, pc + 32, sizeof(char)); |
| } |
| |
| void os::print_register_info(outputStream *st, const void *context) { |
| if (context == NULL) return; |
| |
| const ucontext_t *uc = (const ucontext_t*)context; |
| |
| st->print_cr("Register to memory mapping:"); |
| st->cr(); |
| |
| // this is horrendously verbose but the layout of the registers in the |
| // context does not match how we defined our abstract Register set, so |
| // we can't just iterate through the gregs area |
| |
| // this is only for the "general purpose" registers |
| |
| #ifdef AMD64 |
| st->print("RAX="); print_location(st, uc->uc_mcontext.gregs[REG_RAX]); |
| st->print("RBX="); print_location(st, uc->uc_mcontext.gregs[REG_RBX]); |
| st->print("RCX="); print_location(st, uc->uc_mcontext.gregs[REG_RCX]); |
| st->print("RDX="); print_location(st, uc->uc_mcontext.gregs[REG_RDX]); |
| st->print("RSP="); print_location(st, uc->uc_mcontext.gregs[REG_RSP]); |
| st->print("RBP="); print_location(st, uc->uc_mcontext.gregs[REG_RBP]); |
| st->print("RSI="); print_location(st, uc->uc_mcontext.gregs[REG_RSI]); |
| st->print("RDI="); print_location(st, uc->uc_mcontext.gregs[REG_RDI]); |
| st->print("R8 ="); print_location(st, uc->uc_mcontext.gregs[REG_R8]); |
| st->print("R9 ="); print_location(st, uc->uc_mcontext.gregs[REG_R9]); |
| st->print("R10="); print_location(st, uc->uc_mcontext.gregs[REG_R10]); |
| st->print("R11="); print_location(st, uc->uc_mcontext.gregs[REG_R11]); |
| st->print("R12="); print_location(st, uc->uc_mcontext.gregs[REG_R12]); |
| st->print("R13="); print_location(st, uc->uc_mcontext.gregs[REG_R13]); |
| st->print("R14="); print_location(st, uc->uc_mcontext.gregs[REG_R14]); |
| st->print("R15="); print_location(st, uc->uc_mcontext.gregs[REG_R15]); |
| #else |
| st->print("EAX="); print_location(st, uc->uc_mcontext.gregs[REG_EAX]); |
| st->print("EBX="); print_location(st, uc->uc_mcontext.gregs[REG_EBX]); |
| st->print("ECX="); print_location(st, uc->uc_mcontext.gregs[REG_ECX]); |
| st->print("EDX="); print_location(st, uc->uc_mcontext.gregs[REG_EDX]); |
| st->print("ESP="); print_location(st, uc->uc_mcontext.gregs[REG_ESP]); |
| st->print("EBP="); print_location(st, uc->uc_mcontext.gregs[REG_EBP]); |
| st->print("ESI="); print_location(st, uc->uc_mcontext.gregs[REG_ESI]); |
| st->print("EDI="); print_location(st, uc->uc_mcontext.gregs[REG_EDI]); |
| #endif // AMD64 |
| |
| st->cr(); |
| } |
| |
| void os::setup_fpu() { |
| #ifndef AMD64 |
| address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std(); |
| __asm__ volatile ( "fldcw (%0)" : |
| : "r" (fpu_cntrl) : "memory"); |
| #endif // !AMD64 |
| } |
| |
| #ifndef PRODUCT |
| void os::verify_stack_alignment() { |
| #ifdef AMD64 |
| assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment"); |
| #endif |
| } |
| #endif |
| |
| |
| /* |
| * IA32 only: execute code at a high address in case buggy NX emulation is present. I.e. avoid CS limit |
| * updates (JDK-8023956). |
| */ |
| void os::workaround_expand_exec_shield_cs_limit() { |
| #if defined(IA32) |
| size_t page_size = os::vm_page_size(); |
| /* |
| * Take the highest VA the OS will give us and exec |
| * |
| * Although using -(pagesz) as mmap hint works on newer kernel as you would |
| * think, older variants affected by this work-around don't (search forward only). |
| * |
| * On the affected distributions, we understand the memory layout to be: |
| * |
| * TASK_LIMIT= 3G, main stack base close to TASK_LIMT. |
| * |
| * A few pages south main stack will do it. |
| * |
| * If we are embedded in an app other than launcher (initial != main stack), |
| * we don't have much control or understanding of the address space, just let it slide. |
| */ |
| char* hint = (char*)(Linux::initial_thread_stack_bottom() - |
| (JavaThread::stack_guard_zone_size() + page_size)); |
| char* codebuf = os::attempt_reserve_memory_at(page_size, hint); |
| if ((codebuf == NULL) || (!os::commit_memory(codebuf, page_size, true))) { |
| return; // No matter, we tried, best effort. |
| } |
| |
| MemTracker::record_virtual_memory_type((address)codebuf, mtInternal); |
| |
| log_info(os)("[CS limit NX emulation work-around, exec code at: %p]", codebuf); |
| |
| // Some code to exec: the 'ret' instruction |
| codebuf[0] = 0xC3; |
| |
| // Call the code in the codebuf |
| __asm__ volatile("call *%0" : : "r"(codebuf)); |
| |
| // keep the page mapped so CS limit isn't reduced. |
| #endif |
| } |
| |
| int os::extra_bang_size_in_bytes() { |
| // JDK-8050147 requires the full cache line bang for x86. |
| return VM_Version::L1_line_size(); |
| } |