/* * Copyright (c) 1999, 2013, 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/icBuffer.hpp" #include "code/vtableStubs.hpp" #include "interpreter/interpreter.hpp" #include "jvm_bsd.h" #include "memory/allocation.inline.hpp" #include "mutex_bsd.inline.hpp" #include "os_share_bsd.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 "utilities/events.hpp" #include "utilities/vmError.hpp" // put OS-includes here # include # include # include # include # include # include # include # include # include # include # include # include # include # include # include # include # include # include #ifndef __OpenBSD__ # include #endif #if !defined(__APPLE__) && !defined(__NetBSD__) # include #endif // needed by current_stack_region() workaround for Mavericks #if defined(__APPLE__) # include # include # include # define DEFAULT_MAIN_THREAD_STACK_PAGES 2048 # define OS_X_10_9_0_KERNEL_MAJOR_VERSION 13 #endif #ifdef AMD64 #define SPELL_REG_SP "rsp" #define SPELL_REG_FP "rbp" #else #define SPELL_REG_SP "esp" #define SPELL_REG_FP "ebp" #endif // AMD64 #ifdef __FreeBSD__ # define context_trapno uc_mcontext.mc_trapno # ifdef AMD64 # define context_pc uc_mcontext.mc_rip # define context_sp uc_mcontext.mc_rsp # define context_fp uc_mcontext.mc_rbp # define context_rip uc_mcontext.mc_rip # define context_rsp uc_mcontext.mc_rsp # define context_rbp uc_mcontext.mc_rbp # define context_rax uc_mcontext.mc_rax # define context_rbx uc_mcontext.mc_rbx # define context_rcx uc_mcontext.mc_rcx # define context_rdx uc_mcontext.mc_rdx # define context_rsi uc_mcontext.mc_rsi # define context_rdi uc_mcontext.mc_rdi # define context_r8 uc_mcontext.mc_r8 # define context_r9 uc_mcontext.mc_r9 # define context_r10 uc_mcontext.mc_r10 # define context_r11 uc_mcontext.mc_r11 # define context_r12 uc_mcontext.mc_r12 # define context_r13 uc_mcontext.mc_r13 # define context_r14 uc_mcontext.mc_r14 # define context_r15 uc_mcontext.mc_r15 # define context_flags uc_mcontext.mc_flags # define context_err uc_mcontext.mc_err # else # define context_pc uc_mcontext.mc_eip # define context_sp uc_mcontext.mc_esp # define context_fp uc_mcontext.mc_ebp # define context_eip uc_mcontext.mc_eip # define context_esp uc_mcontext.mc_esp # define context_eax uc_mcontext.mc_eax # define context_ebx uc_mcontext.mc_ebx # define context_ecx uc_mcontext.mc_ecx # define context_edx uc_mcontext.mc_edx # define context_ebp uc_mcontext.mc_ebp # define context_esi uc_mcontext.mc_esi # define context_edi uc_mcontext.mc_edi # define context_eflags uc_mcontext.mc_eflags # define context_trapno uc_mcontext.mc_trapno # endif #endif #ifdef __APPLE__ # if __DARWIN_UNIX03 && (MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5) // 10.5 UNIX03 member name prefixes #define DU3_PREFIX(s, m) __ ## s.__ ## m # else #define DU3_PREFIX(s, m) s ## . ## m # endif # ifdef AMD64 # define context_pc context_rip # define context_sp context_rsp # define context_fp context_rbp # define context_rip uc_mcontext->DU3_PREFIX(ss,rip) # define context_rsp uc_mcontext->DU3_PREFIX(ss,rsp) # define context_rax uc_mcontext->DU3_PREFIX(ss,rax) # define context_rbx uc_mcontext->DU3_PREFIX(ss,rbx) # define context_rcx uc_mcontext->DU3_PREFIX(ss,rcx) # define context_rdx uc_mcontext->DU3_PREFIX(ss,rdx) # define context_rbp uc_mcontext->DU3_PREFIX(ss,rbp) # define context_rsi uc_mcontext->DU3_PREFIX(ss,rsi) # define context_rdi uc_mcontext->DU3_PREFIX(ss,rdi) # define context_r8 uc_mcontext->DU3_PREFIX(ss,r8) # define context_r9 uc_mcontext->DU3_PREFIX(ss,r9) # define context_r10 uc_mcontext->DU3_PREFIX(ss,r10) # define context_r11 uc_mcontext->DU3_PREFIX(ss,r11) # define context_r12 uc_mcontext->DU3_PREFIX(ss,r12) # define context_r13 uc_mcontext->DU3_PREFIX(ss,r13) # define context_r14 uc_mcontext->DU3_PREFIX(ss,r14) # define context_r15 uc_mcontext->DU3_PREFIX(ss,r15) # define context_flags uc_mcontext->DU3_PREFIX(ss,rflags) # define context_trapno uc_mcontext->DU3_PREFIX(es,trapno) # define context_err uc_mcontext->DU3_PREFIX(es,err) # else # define context_pc context_eip # define context_sp context_esp # define context_fp context_ebp # define context_eip uc_mcontext->DU3_PREFIX(ss,eip) # define context_esp uc_mcontext->DU3_PREFIX(ss,esp) # define context_eax uc_mcontext->DU3_PREFIX(ss,eax) # define context_ebx uc_mcontext->DU3_PREFIX(ss,ebx) # define context_ecx uc_mcontext->DU3_PREFIX(ss,ecx) # define context_edx uc_mcontext->DU3_PREFIX(ss,edx) # define context_ebp uc_mcontext->DU3_PREFIX(ss,ebp) # define context_esi uc_mcontext->DU3_PREFIX(ss,esi) # define context_edi uc_mcontext->DU3_PREFIX(ss,edi) # define context_eflags uc_mcontext->DU3_PREFIX(ss,eflags) # define context_trapno uc_mcontext->DU3_PREFIX(es,trapno) # endif #endif #ifdef __OpenBSD__ # define context_trapno sc_trapno # ifdef AMD64 # define context_pc sc_rip # define context_sp sc_rsp # define context_fp sc_rbp # define context_rip sc_rip # define context_rsp sc_rsp # define context_rbp sc_rbp # define context_rax sc_rax # define context_rbx sc_rbx # define context_rcx sc_rcx # define context_rdx sc_rdx # define context_rsi sc_rsi # define context_rdi sc_rdi # define context_r8 sc_r8 # define context_r9 sc_r9 # define context_r10 sc_r10 # define context_r11 sc_r11 # define context_r12 sc_r12 # define context_r13 sc_r13 # define context_r14 sc_r14 # define context_r15 sc_r15 # define context_flags sc_rflags # define context_err sc_err # else # define context_pc sc_eip # define context_sp sc_esp # define context_fp sc_ebp # define context_eip sc_eip # define context_esp sc_esp # define context_eax sc_eax # define context_ebx sc_ebx # define context_ecx sc_ecx # define context_edx sc_edx # define context_ebp sc_ebp # define context_esi sc_esi # define context_edi sc_edi # define context_eflags sc_eflags # define context_trapno sc_trapno # endif #endif #ifdef __NetBSD__ # define context_trapno uc_mcontext.__gregs[_REG_TRAPNO] # ifdef AMD64 # define __register_t __greg_t # define context_pc uc_mcontext.__gregs[_REG_RIP] # define context_sp uc_mcontext.__gregs[_REG_URSP] # define context_fp uc_mcontext.__gregs[_REG_RBP] # define context_rip uc_mcontext.__gregs[_REG_RIP] # define context_rsp uc_mcontext.__gregs[_REG_URSP] # define context_rax uc_mcontext.__gregs[_REG_RAX] # define context_rbx uc_mcontext.__gregs[_REG_RBX] # define context_rcx uc_mcontext.__gregs[_REG_RCX] # define context_rdx uc_mcontext.__gregs[_REG_RDX] # define context_rbp uc_mcontext.__gregs[_REG_RBP] # define context_rsi uc_mcontext.__gregs[_REG_RSI] # define context_rdi uc_mcontext.__gregs[_REG_RDI] # define context_r8 uc_mcontext.__gregs[_REG_R8] # define context_r9 uc_mcontext.__gregs[_REG_R9] # define context_r10 uc_mcontext.__gregs[_REG_R10] # define context_r11 uc_mcontext.__gregs[_REG_R11] # define context_r12 uc_mcontext.__gregs[_REG_R12] # define context_r13 uc_mcontext.__gregs[_REG_R13] # define context_r14 uc_mcontext.__gregs[_REG_R14] # define context_r15 uc_mcontext.__gregs[_REG_R15] # define context_flags uc_mcontext.__gregs[_REG_RFL] # define context_err uc_mcontext.__gregs[_REG_ERR] # else # define context_pc uc_mcontext.__gregs[_REG_EIP] # define context_sp uc_mcontext.__gregs[_REG_UESP] # define context_fp uc_mcontext.__gregs[_REG_EBP] # define context_eip uc_mcontext.__gregs[_REG_EIP] # define context_esp uc_mcontext.__gregs[_REG_UESP] # define context_eax uc_mcontext.__gregs[_REG_EAX] # define context_ebx uc_mcontext.__gregs[_REG_EBX] # define context_ecx uc_mcontext.__gregs[_REG_ECX] # define context_edx uc_mcontext.__gregs[_REG_EDX] # define context_ebp uc_mcontext.__gregs[_REG_EBP] # define context_esi uc_mcontext.__gregs[_REG_ESI] # define context_edi uc_mcontext.__gregs[_REG_EDI] # define context_eflags uc_mcontext.__gregs[_REG_EFL] # define context_trapno uc_mcontext.__gregs[_REG_TRAPNO] # endif #endif address os::current_stack_pointer() { #if defined(__clang__) || defined(__llvm__) register void *esp; __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp)); return (address) esp; #elif defined(SPARC_WORKS) register void *esp; __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp)); return (address) ((char*)esp + sizeof(long)*2); #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::Bsd::ucontext_get_pc(ucontext_t * uc) { return (address)uc->context_pc; } intptr_t* os::Bsd::ucontext_get_sp(ucontext_t * uc) { return (intptr_t*)uc->context_sp; } intptr_t* os::Bsd::ucontext_get_fp(ucontext_t * uc) { return (intptr_t*)uc->context_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 Bsd, so it's the same as // os::fetch_frame_from_context(). ExtendedPC os::Bsd::fetch_frame_from_ucontext(Thread* thread, 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(void* ucVoid, intptr_t** ret_sp, intptr_t** ret_fp) { ExtendedPC epc; ucontext_t* uc = (ucontext_t*)ucVoid; if (uc != NULL) { epc = ExtendedPC(os::Bsd::ucontext_get_pc(uc)); if (ret_sp) *ret_sp = os::Bsd::ucontext_get_sp(uc); if (ret_fp) *ret_fp = os::Bsd::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(void* ucVoid) { intptr_t* sp; intptr_t* fp; ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp); return frame(sp, fp, epc.pc()); } // 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() { #if defined(SPARC_WORKS) || defined(__clang__) || defined(__llvm__) register intptr_t **ebp; __asm__("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_bsd_signal(int sig, siginfo_t* info, void* ucVoid, int abort_if_unrecognized) { ucontext_t* uc = (ucontext_t*) ucVoid; Thread* t = ThreadLocalStorage::get_thread_slow(); // 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_bsd_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::Bsd::chained_handler(sig, info, ucVoid)) { return true; } else { if (PrintMiscellaneous && (WizardMode || Verbose)) { char buf[64]; warning("Ignoring %s - see bugs 4229104 or 646499219", os::exception_name(sig, buf, sizeof(buf))); } return true; } } JavaThread* thread = NULL; VMThread* vmthread = NULL; if (os::Bsd::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 bsd. 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::Bsd::ucontext_get_pc(uc); if (StubRoutines::is_safefetch_fault(pc)) { uc->context_pc = intptr_t(StubRoutines::continuation_for_safefetch_fault(pc)); return 1; } // Handle ALL stack overflow variations here if (sig == SIGSEGV || sig == SIGBUS) { address addr = (address) info->si_addr; // check if fault address is within thread stack if (addr < thread->stack_base() && addr >= thread->stack_base() - thread->stack_size()) { // stack overflow if (thread->in_stack_yellow_zone(addr)) { thread->disable_stack_yellow_zone(); if (thread->thread_state() == _thread_in_Java) { // Throw a stack overflow exception. Guard pages will be reenabled // while unwinding the stack. 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. 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."); } } } if ((sig == SIGSEGV || sig == SIGBUS) && VM_Version::is_cpuinfo_segv_addr(pc)) { // Verify that OS save/restore AVX registers. stub = VM_Version::cpuinfo_cont_addr(); } // We test if stub is already set (by the stack overflow code // above) so it is not overwritten by the code that follows. This // check is not required on other platforms, because on other // platforms we check for SIGSEGV only or SIGBUS only, where here // we have to check for both SIGSEGV and SIGBUS. if (thread->thread_state() == _thread_in_Java && stub == NULL) { // Java thread running in Java code => find exception handler if any // a fault inside compiled code, the interpreter, or a stub if ((sig == SIGSEGV || sig == SIGBUS) && os::is_poll_address((address)info->si_addr)) { stub = SharedRuntime::get_poll_stub(pc); #if defined(__APPLE__) // 32-bit Darwin reports a SIGBUS for nearly all memory access exceptions. // 64-bit Darwin may also use a SIGBUS (seen with compressed oops). // Catching SIGBUS here prevents the implicit SIGBUS NULL check below from // being called, so only do so if the implicit NULL check is not necessary. } else if (sig == SIGBUS && MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) { #else } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) { #endif // 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); #ifdef __APPLE__ } else if (sig == SIGFPE && info->si_code == FPE_NOOP) { int op = pc[0]; // Skip REX if ((pc[0] & 0xf0) == 0x40) { op = pc[1]; } else { op = pc[0]; } // Check for IDIV if (op == 0xF7) { 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. tty->print_cr("unknown opcode 0x%X with SIGFPE.", op); fatal("please update this code."); } #endif /* __APPLE__ */ #else if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) { // HACK: si_code does not work on bsd 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 bsd. tty->print_cr("unknown opcode 0x%X with SIGFPE.", op); fatal("please update this code."); } #endif // AMD64 } else if ((sig == SIGSEGV || sig == SIGBUS) && !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_GetField 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 || sig == SIGBUS) && 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->context_trapno == trap_page_fault) { int page_size = os::vm_page_size(); address addr = (address) info->si_addr; address pc = os::Bsd::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); if (PrintMiscellaneous && Verbose) { char buf[256]; jio_snprintf(buf, sizeof(buf), "Execution protection violation " "at " INTPTR_FORMAT ", unguarding " INTPTR_FORMAT ": %s, errno=%d", addr, page_start, (res ? "success" : "failed"), errno); tty->print_raw_cr(buf); } 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); uc->context_pc = (intptr_t)stub; return true; } // signal-chaining if (os::Bsd::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::Bsd::ucontext_get_pc(uc); } // unmask current signal sigset_t newset; sigemptyset(&newset); sigaddset(&newset, sig); sigprocmask(SIG_UNBLOCK, &newset, NULL); VMError err(t, sig, pc, info, ucVoid); err.report_and_die(); ShouldNotReachHere(); return false; } // From solaris_i486.s ported to bsd_i486.s extern "C" void fixcw(); void os::Bsd::init_thread_fpu_state(void) { #ifndef AMD64 // Set fpu to 53 bit precision. This happens too early to use a stub. fixcw(); #endif // !AMD64 } // Check that the bsd kernel version is 2.4 or higher since earlier // versions do not support SSE without patches. bool os::supports_sse() { return true; } 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::Bsd::min_stack_allowed = 64 * K; // amd64: pthread on amd64 is always in floating stack mode bool os::Bsd::supports_variable_stack_size() { return true; } #else size_t os::Bsd::min_stack_allowed = (48 DEBUG_ONLY(+4))*K; #ifdef __GNUC__ #define GET_GS() ({int gs; __asm__ volatile("movw %%gs, %w0":"=q"(gs)); gs&0xffff;}) #endif bool os::Bsd::supports_variable_stack_size() { return true; } #endif // AMD64 // return default stack size for thr_type size_t os::Bsd::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::Bsd::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) { #ifdef __APPLE__ pthread_t self = pthread_self(); void *stacktop = pthread_get_stackaddr_np(self); *size = pthread_get_stacksize_np(self); // workaround for OS X 10.9.0 (Mavericks) // pthread_get_stacksize_np returns 128 pages even though the actual size is 2048 pages if (pthread_main_np() == 1) { if ((*size) < (DEFAULT_MAIN_THREAD_STACK_PAGES * (size_t)getpagesize())) { char kern_osrelease[256]; size_t kern_osrelease_size = sizeof(kern_osrelease); int ret = sysctlbyname("kern.osrelease", kern_osrelease, &kern_osrelease_size, NULL, 0); if (ret == 0) { // get the major number, atoi will ignore the minor amd micro portions of the version string if (atoi(kern_osrelease) >= OS_X_10_9_0_KERNEL_MAJOR_VERSION) { *size = (DEFAULT_MAIN_THREAD_STACK_PAGES*getpagesize()); } } } } *bottom = (address) stacktop - *size; #elif defined(__OpenBSD__) stack_t ss; int rslt = pthread_stackseg_np(pthread_self(), &ss); if (rslt != 0) fatal(err_msg("pthread_stackseg_np failed with err = %d", rslt)); *bottom = (address)((char *)ss.ss_sp - ss.ss_size); *size = ss.ss_size; #else pthread_attr_t attr; int rslt = pthread_attr_init(&attr); // JVM needs to know exact stack location, abort if it fails if (rslt != 0) fatal(err_msg("pthread_attr_init failed with err = %d", rslt)); rslt = pthread_attr_get_np(pthread_self(), &attr); if (rslt != 0) fatal(err_msg("pthread_attr_get_np failed with err = %d", rslt)); if (pthread_attr_getstackaddr(&attr, (void **)bottom) != 0 || pthread_attr_getstacksize(&attr, size) != 0) { fatal("Can not locate current stack attributes!"); } pthread_attr_destroy(&attr); #endif 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, void *context) { if (context == NULL) return; ucontext_t *uc = (ucontext_t*)context; st->print_cr("Registers:"); #ifdef AMD64 st->print( "RAX=" INTPTR_FORMAT, uc->context_rax); st->print(", RBX=" INTPTR_FORMAT, uc->context_rbx); st->print(", RCX=" INTPTR_FORMAT, uc->context_rcx); st->print(", RDX=" INTPTR_FORMAT, uc->context_rdx); st->cr(); st->print( "RSP=" INTPTR_FORMAT, uc->context_rsp); st->print(", RBP=" INTPTR_FORMAT, uc->context_rbp); st->print(", RSI=" INTPTR_FORMAT, uc->context_rsi); st->print(", RDI=" INTPTR_FORMAT, uc->context_rdi); st->cr(); st->print( "R8 =" INTPTR_FORMAT, uc->context_r8); st->print(", R9 =" INTPTR_FORMAT, uc->context_r9); st->print(", R10=" INTPTR_FORMAT, uc->context_r10); st->print(", R11=" INTPTR_FORMAT, uc->context_r11); st->cr(); st->print( "R12=" INTPTR_FORMAT, uc->context_r12); st->print(", R13=" INTPTR_FORMAT, uc->context_r13); st->print(", R14=" INTPTR_FORMAT, uc->context_r14); st->print(", R15=" INTPTR_FORMAT, uc->context_r15); st->cr(); st->print( "RIP=" INTPTR_FORMAT, uc->context_rip); st->print(", EFLAGS=" INTPTR_FORMAT, uc->context_flags); st->print(", ERR=" INTPTR_FORMAT, uc->context_err); st->cr(); st->print(" TRAPNO=" INTPTR_FORMAT, uc->context_trapno); #else st->print( "EAX=" INTPTR_FORMAT, uc->context_eax); st->print(", EBX=" INTPTR_FORMAT, uc->context_ebx); st->print(", ECX=" INTPTR_FORMAT, uc->context_ecx); st->print(", EDX=" INTPTR_FORMAT, uc->context_edx); st->cr(); st->print( "ESP=" INTPTR_FORMAT, uc->context_esp); st->print(", EBP=" INTPTR_FORMAT, uc->context_ebp); st->print(", ESI=" INTPTR_FORMAT, uc->context_esi); st->print(", EDI=" INTPTR_FORMAT, uc->context_edi); st->cr(); st->print( "EIP=" INTPTR_FORMAT, uc->context_eip); st->print(", EFLAGS=" INTPTR_FORMAT, uc->context_eflags); #endif // AMD64 st->cr(); st->cr(); intptr_t *sp = (intptr_t *)os::Bsd::ucontext_get_sp(uc); st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", 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::Bsd::ucontext_get_pc(uc); st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc); print_hex_dump(st, pc - 32, pc + 32, sizeof(char)); } void os::print_register_info(outputStream *st, void *context) { if (context == NULL) return; ucontext_t *uc = (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->context_rax); st->print("RBX="); print_location(st, uc->context_rbx); st->print("RCX="); print_location(st, uc->context_rcx); st->print("RDX="); print_location(st, uc->context_rdx); st->print("RSP="); print_location(st, uc->context_rsp); st->print("RBP="); print_location(st, uc->context_rbp); st->print("RSI="); print_location(st, uc->context_rsi); st->print("RDI="); print_location(st, uc->context_rdi); st->print("R8 ="); print_location(st, uc->context_r8); st->print("R9 ="); print_location(st, uc->context_r9); st->print("R10="); print_location(st, uc->context_r10); st->print("R11="); print_location(st, uc->context_r11); st->print("R12="); print_location(st, uc->context_r12); st->print("R13="); print_location(st, uc->context_r13); st->print("R14="); print_location(st, uc->context_r14); st->print("R15="); print_location(st, uc->context_r15); #else st->print("EAX="); print_location(st, uc->context_eax); st->print("EBX="); print_location(st, uc->context_ebx); st->print("ECX="); print_location(st, uc->context_ecx); st->print("EDX="); print_location(st, uc->context_edx); st->print("ESP="); print_location(st, uc->context_esp); st->print("EBP="); print_location(st, uc->context_ebp); st->print("ESI="); print_location(st, uc->context_esi); st->print("EDI="); print_location(st, uc->context_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() { } #endif