/* * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved. * Copyright (c) 2014, Red Hat Inc. All rights reserved. * Copyright (c) 2015, Linaro Ltd. All rights reserved. * Copyright (c) 2015-2018, Azul Systems, Inc. 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 "jvm.h" #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 "memory/allocation.inline.hpp" #include "nativeInst_aarch32.hpp" #include "os_share_linux.hpp" #include "prims/jniFastGetField.hpp" #include "prims/jvm_misc.hpp" #include "runtime/arguments.hpp" #include "runtime/extendedPC.hpp" #include "runtime/frame.inline.hpp" #include "runtime/interfaceSupport.inline.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/debug.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 # include # include #define SPELL_REG_SP "sp" #define SPELL_REG_FP "fp" extern "C" { void *linux_aarch32_current_frame_pointer(); void *linux_aarch32_previous_frame_pointer(); } address os::current_stack_pointer() { return (address) linux_aarch32_current_frame_pointer(); } 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*) 0xfffffffful; } void os::initialize_thread(Thread *thr) { } address os::Linux::ucontext_get_pc(const ucontext_t * uc) { return (address)uc->uc_mcontext.arm_pc; } void os::Linux::ucontext_set_pc(ucontext_t * uc, address pc) { uc->uc_mcontext.arm_pc = (intptr_t)pc; } intptr_t* os::Linux::ucontext_get_sp(const ucontext_t * uc) { return (intptr_t*)uc->uc_mcontext.arm_sp; } intptr_t* os::Linux::ucontext_get_fp(const ucontext_t * uc) { return (intptr_t*)uc->uc_mcontext.arm_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(). 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; ucontext_t* uc = (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()); } 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_context(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 before LR // has been saved in the frame. LR is live, and SP and FP // belong to the caller. intptr_t* fp = os::Linux::ucontext_get_fp(uc); intptr_t* sp = os::Linux::ucontext_get_sp(uc); //TODO: XXX: Merge // could be pc = os::Linux::ucontext_get_pc(uc) ? address pc = (address)(uc->uc_mcontext.arm_lr - NativeInstruction::arm_insn_sz); *fr = frame(sp, fp, pc); 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 saves frame pointer rfp on this stack. This // may get turned off by -fomit-frame-pointer. frame os::get_sender_for_C_frame(frame* fr) { #ifdef __thumb__ return frame(); #else address sender_pc = *(address*) fr->addr_at(fr->get_return_addr_offset(JNIFrameAPCS)); intptr_t* link = *(intptr_t**) fr->addr_at(fr->get_link_offset(JNIFrameAPCS)); return frame(fr->sender_sp(), link, sender_pc); #endif } frame os::current_frame() { #ifdef __thumb__ return frame(); #else intptr_t* fp = (intptr_t*)linux_aarch32_previous_frame_pointer(); frame myframe((intptr_t*)os::current_stack_pointer(), (intptr_t*)fp, CAST_FROM_FN_PTR(address, os::current_frame)); // check for C2 frame first, those to not have valid FP if (!CodeCache::find_blob( *(address*)myframe.addr_at(myframe.get_return_addr_offset(JNIFrameAPCS))) && os::is_first_C_frame(&myframe)) { // stack is not walkable return frame(); } else { return os::get_sender_for_C_frame(&myframe); } #endif } // Utility functions // From IA32 System Programming Guide enum { trap_page_fault = 0xE }; // An operation in Unsafe has faulted. We're going to return to the // instruction after the faulting load or store. We also set // pending_unsafe_access_error so that at some point in the future our // user will get a helpful message. static address handle_unsafe_access(JavaThread* thread, address pc) { // pc is the instruction which we must emulate // doing a no-op is fine: return garbage from the load // therefore, compute npc address npc = pc + NativeInstruction::arm_insn_sz; // request an async exception thread->set_pending_unsafe_access_error(); // return address of next instruction to execute return npc; } 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::ThreadCrashProtection::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 { if (PrintMiscellaneous && (WizardMode || Verbose)) { char buf[64]; warning("Ignoring %s - see bugs 4229104 or 646499219", os::exception_name(sig, buf, sizeof(buf))); } return true; } } #ifdef CAN_SHOW_REGISTERS_ON_ASSERT if ((sig == SIGSEGV || sig == SIGBUS) && info != NULL && info->si_addr == g_assert_poison) { handle_assert_poison_fault(ucVoid, info->si_addr); return 1; } #endif 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; } // 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)) { thread->disable_stack_yellow_reserved_zone(); 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. 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."); // 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 (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 // Handle signal from NativeJump::patch_verified_entry(). if ((sig == SIGILL || sig == SIGTRAP) && nativeInstruction_at(pc)->is_sigill_zombie_not_entrant()) { if (TraceTraps) { tty->print_cr("trap: zombie_not_entrant (%s)", (sig == SIGTRAP) ? "SIGTRAP" : "SIGILL"); } stub = SharedRuntime::get_handle_wrong_method_stub(); } else 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); CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL; if (nm != NULL && nm->has_unsafe_access()) { stub = handle_unsafe_access(thread, pc); } } else 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 == 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 (sig == SIGILL && VM_Version::is_determine_features_test_running()) { // SIGILL must be caused by VM_Version::get_processor_features(). *(int *)pc = Assembler::nop_insn; // patch instruction to NOP to indicate that it causes a SIGILL, // flushing of icache is not necessary. stub = pc + 4; // continue with next instruction. } else if (thread->thread_state() == _thread_in_vm && sig == SIGBUS && /* info->si_code == BUS_OBJERR && */ thread->doing_unsafe_access()) { stub = handle_unsafe_access(thread, pc); } // 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) && 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; } } 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) { } int os::Linux::get_fpu_control_word(void) { return 0; } void os::Linux::set_fpu_control_word(int fpu_control) { } // Check that the linux 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) { return true; } //////////////////////////////////////////////////////////////////////////////// // thread stack // Minimum usable stack sizes required to get to user code. Space for // HotSpot guard pages is added later. size_t os::Posix::_compiler_thread_min_stack_allowed = (32 DEBUG_ONLY(+ 4)) * K; size_t os::Posix::_java_thread_min_stack_allowed = (32 DEBUG_ONLY(+ 4)) * K; size_t os::Posix::_vm_internal_thread_min_stack_allowed = (48 DEBUG_ONLY(+ 4)) * K; // return default stack size for thr_type size_t os::Posix::default_stack_size(os::ThreadType thr_type) { // default stack size (compiler thread needs larger stack) size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K); return s; } // 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() ///////////////////////////////////////////////////////////////////////////// // helper functions for fatal error handler void os::print_context(outputStream *st, const void *context) { if (context == NULL) return; ucontext_t *uc = (ucontext_t*)context; st->print_cr("Registers:"); for (int r = 0; r < 16; r++) st->print_cr( "R%d=" INTPTR_FORMAT, r, *((unsigned int*)&uc->uc_mcontext.arm_r0 + r) ); 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; ucontext_t *uc = (ucontext_t*)context; st->print_cr("Register to memory mapping:"); st->cr(); for (int r = 0; r < 16; r++) { st->print( "R%d=", r); print_location(st, *((unsigned int*)&uc->uc_mcontext.arm_r0 + r)); } st->cr(); } void os::setup_fpu() { } #ifndef PRODUCT void os::verify_stack_alignment() { assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment"); } #endif int os::extra_bang_size_in_bytes() { // AArch64 does not require the additional stack bang. // does AArch32? return 0; } extern "C" { int SpinPause() { return 0; } void _Copy_conjoint_jshorts_atomic(jshort* from, jshort* to, size_t count) { if (from > to) { jshort *end = from + count; while (from < end) *(to++) = *(from++); } else if (from < to) { jshort *end = from; from += count - 1; to += count - 1; while (from >= end) *(to--) = *(from--); } } void _Copy_conjoint_jints_atomic(jint* from, jint* to, size_t count) { if (from > to) { jint *end = from + count; while (from < end) *(to++) = *(from++); } else if (from < to) { jint *end = from; from += count - 1; to += count - 1; while (from >= end) *(to--) = *(from--); } } void _Copy_conjoint_jlongs_atomic(jlong* from, jlong* to, size_t count) { if (from > to) { jlong *end = from + count; while (from < end) os::atomic_copy64(from++, to++); } else if (from < to) { jlong *end = from; from += count - 1; to += count - 1; while (from >= end) os::atomic_copy64(from--, to--); } } void _Copy_arrayof_conjoint_bytes(HeapWord* from, HeapWord* to, size_t count) { memmove(to, from, count); } void _Copy_arrayof_conjoint_jshorts(HeapWord* from, HeapWord* to, size_t count) { memmove(to, from, count * 2); } void _Copy_arrayof_conjoint_jints(HeapWord* from, HeapWord* to, size_t count) { memmove(to, from, count * 4); } void _Copy_arrayof_conjoint_jlongs(HeapWord* from, HeapWord* to, size_t count) { memmove(to, from, count * 8); } };