--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/os_cpu/linux_ppc/os_linux_ppc.cpp Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,616 @@
+/*
+ * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2016 SAP SE. 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/assembler.inline.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 "nativeInst_ppc.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 "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>
+
+
+address os::current_stack_pointer() {
+ intptr_t* csp;
+
+ // inline assembly `mr regno(csp), R1_SP':
+ __asm__ __volatile__ ("mr %0, 1":"=r"(csp):);
+
+ return (address) csp;
+}
+
+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 *thread) { }
+
+// Frame information (pc, sp, fp) retrieved via ucontext
+// always looks like a C-frame according to the frame
+// conventions in frame_ppc64.hpp.
+address os::Linux::ucontext_get_pc(const ucontext_t * uc) {
+ // On powerpc64, ucontext_t is not selfcontained but contains
+ // a pointer to an optional substructure (mcontext_t.regs) containing the volatile
+ // registers - NIP, among others.
+ // This substructure may or may not be there depending where uc came from:
+ // - if uc was handed over as the argument to a sigaction handler, a pointer to the
+ // substructure was provided by the kernel when calling the signal handler, and
+ // regs->nip can be accessed.
+ // - if uc was filled by getcontext(), it is undefined - getcontext() does not fill
+ // it because the volatile registers are not needed to make setcontext() work.
+ // Hopefully it was zero'd out beforehand.
+ guarantee(uc->uc_mcontext.regs != NULL, "only use ucontext_get_pc in sigaction context");
+ return (address)uc->uc_mcontext.regs->nip;
+}
+
+// modify PC in ucontext.
+// Note: Only use this for an ucontext handed down to a signal handler. See comment
+// in ucontext_get_pc.
+void os::Linux::ucontext_set_pc(ucontext_t * uc, address pc) {
+ guarantee(uc->uc_mcontext.regs != NULL, "only use ucontext_set_pc in sigaction context");
+ uc->uc_mcontext.regs->nip = (unsigned long)pc;
+}
+
+intptr_t* os::Linux::ucontext_get_sp(const ucontext_t * uc) {
+ return (intptr_t*)uc->uc_mcontext.regs->gpr[1/*REG_SP*/];
+}
+
+intptr_t* os::Linux::ucontext_get_fp(const ucontext_t * uc) {
+ return NULL;
+}
+
+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, 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. In compiled code, we bang before
+ // the frame is complete.
+ return false;
+ } else {
+ intptr_t* fp = os::Linux::ucontext_get_fp(uc);
+ intptr_t* sp = os::Linux::ucontext_get_sp(uc);
+ *fr = frame(sp, (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;
+}
+
+frame os::get_sender_for_C_frame(frame* fr) {
+ if (*fr->sp() == 0) {
+ // fr is the last C frame
+ return frame(NULL, NULL);
+ }
+ return frame(fr->sender_sp(), fr->sender_pc());
+}
+
+
+frame os::current_frame() {
+ intptr_t* csp = (intptr_t*) *((intptr_t*) os::current_stack_pointer());
+ // hack.
+ frame topframe(csp, (address)0x8);
+ // Return sender of sender of current topframe which hopefully
+ // both have pc != NULL.
+ frame tmp = os::get_sender_for_C_frame(&topframe);
+ return os::get_sender_for_C_frame(&tmp);
+}
+
+// Utility functions
+
+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();
+
+ 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) {
+ if (os::Linux::chained_handler(sig, info, ucVoid)) {
+ return true;
+ } else {
+ // Ignoring SIGPIPE - see bugs 4229104
+ return true;
+ }
+ }
+
+ // Make the signal handler transaction-aware by checking the existence of a
+ // second (transactional) context with MSR TS bits active. If the signal is
+ // caught during a transaction, then just return to the HTM abort handler.
+ // Please refer to Linux kernel document powerpc/transactional_memory.txt,
+ // section "Signals".
+ if (uc && uc->uc_link) {
+ ucontext_t* second_uc = uc->uc_link;
+
+ // MSR TS bits are 29 and 30 (Power ISA, v2.07B, Book III-S, pp. 857-858,
+ // 3.2.1 "Machine State Register"), however note that ISA notation for bit
+ // numbering is MSB 0, so for normal bit numbering (LSB 0) they come to be
+ // bits 33 and 34. It's not related to endianness, just a notation matter.
+ if (second_uc->uc_mcontext.regs->msr & 0x600000000) {
+ if (TraceTraps) {
+ tty->print_cr("caught signal in transaction, "
+ "ignoring to jump to abort handler");
+ }
+ // Return control to the HTM abort handler.
+ 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;
+ }
+ }
+ }
+
+ // Moved SafeFetch32 handling outside thread!=NULL conditional block to make
+ // it work if no associated JavaThread object exists.
+ if (uc) {
+ address const pc = os::Linux::ucontext_get_pc(uc);
+ if (pc && StubRoutines::is_safefetch_fault(pc)) {
+ os::Linux::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));
+ return true;
+ }
+ }
+
+ // 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);
+
+ // Handle ALL stack overflow variations here
+ if (sig == SIGSEGV) {
+ // Si_addr may not be valid due to a bug in the linux-ppc64 kernel (see
+ // comment below). Use get_stack_bang_address instead of si_addr.
+ address addr = ((NativeInstruction*)pc)->get_stack_bang_address(uc);
+
+ // 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 Javac 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());
+ } 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 (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
+
+ // A VM-related SIGILL may only occur if we are not in the zero page.
+ // On AIX, we get a SIGILL if we jump to 0x0 or to somewhere else
+ // in the zero page, because it is filled with 0x0. We ignore
+ // explicit SIGILLs in the zero page.
+ if (sig == SIGILL && (pc < (address) 0x200)) {
+ if (TraceTraps) {
+ tty->print_raw_cr("SIGILL happened inside zero page.");
+ }
+ goto report_and_die;
+ }
+
+ CodeBlob *cb = NULL;
+ // Handle signal from NativeJump::patch_verified_entry().
+ if (( TrapBasedNotEntrantChecks && sig == SIGTRAP && nativeInstruction_at(pc)->is_sigtrap_zombie_not_entrant()) ||
+ (!TrapBasedNotEntrantChecks && sig == SIGILL && 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 &&
+ // A linux-ppc64 kernel before 2.6.6 doesn't set si_addr on some segfaults
+ // in 64bit mode (cf. http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.6),
+ // especially when we try to read from the safepoint polling page. So the check
+ // (address)info->si_addr == os::get_standard_polling_page()
+ // doesn't work for us. We use:
+ ((NativeInstruction*)pc)->is_safepoint_poll() &&
+ CodeCache::contains((void*) pc) &&
+ ((cb = CodeCache::find_blob(pc)) != NULL) &&
+ cb->is_compiled()) {
+ if (TraceTraps) {
+ tty->print_cr("trap: safepoint_poll at " INTPTR_FORMAT " (SIGSEGV)", p2i(pc));
+ }
+ stub = SharedRuntime::get_poll_stub(pc);
+ }
+
+ // SIGTRAP-based ic miss check in compiled code.
+ else if (sig == SIGTRAP && TrapBasedICMissChecks &&
+ nativeInstruction_at(pc)->is_sigtrap_ic_miss_check()) {
+ if (TraceTraps) {
+ tty->print_cr("trap: ic_miss_check at " INTPTR_FORMAT " (SIGTRAP)", p2i(pc));
+ }
+ stub = SharedRuntime::get_ic_miss_stub();
+ }
+
+ // SIGTRAP-based implicit null check in compiled code.
+ else if (sig == SIGTRAP && TrapBasedNullChecks &&
+ nativeInstruction_at(pc)->is_sigtrap_null_check()) {
+ if (TraceTraps) {
+ tty->print_cr("trap: null_check at " INTPTR_FORMAT " (SIGTRAP)", p2i(pc));
+ }
+ stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
+ }
+
+ // SIGSEGV-based implicit null check in compiled code.
+ else if (sig == SIGSEGV && ImplicitNullChecks &&
+ CodeCache::contains((void*) pc) &&
+ !MacroAssembler::needs_explicit_null_check((intptr_t) info->si_addr)) {
+ if (TraceTraps) {
+ tty->print_cr("trap: null_check at " INTPTR_FORMAT " (SIGSEGV)", p2i(pc));
+ }
+ stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
+ }
+
+#ifdef COMPILER2
+ // SIGTRAP-based implicit range check in compiled code.
+ else if (sig == SIGTRAP && TrapBasedRangeChecks &&
+ nativeInstruction_at(pc)->is_sigtrap_range_check()) {
+ if (TraceTraps) {
+ tty->print_cr("trap: range_check at " INTPTR_FORMAT " (SIGTRAP)", p2i(pc));
+ }
+ stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
+ }
+#endif
+ else if (sig == SIGBUS) {
+ // 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()) {
+ address next_pc = pc + 4;
+ next_pc = SharedRuntime::handle_unsafe_access(thread, next_pc);
+ os::Linux::ucontext_set_pc(uc, next_pc);
+ return true;
+ }
+ }
+ }
+
+ else { // thread->thread_state() != _thread_in_Java
+ if (sig == SIGILL && VM_Version::is_determine_features_test_running()) {
+ // SIGILL must be caused by VM_Version::determine_features().
+ *(int *)pc = 0; // patch instruction to 0 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 && thread->doing_unsafe_access()) {
+ address next_pc = pc + 4;
+ next_pc = SharedRuntime::handle_unsafe_access(thread, next_pc);
+ os::Linux::ucontext_set_pc(uc, pc + 4);
+ return true;
+ }
+ }
+
+ // 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) &&
+ // Si_addr may not be valid due to a bug in the linux-ppc64 kernel (see comment above).
+ // Use is_memory_serialization instead of si_addr.
+ ((NativeInstruction*)pc)->is_memory_serialization(thread, ucVoid)) {
+ // Synchronization problem in the pseudo memory barrier code (bug id 6546278)
+ // 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);
+ }
+
+report_and_die:
+ // 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 false;
+}
+
+void os::Linux::init_thread_fpu_state(void) {
+ // Disable FP exceptions.
+ __asm__ __volatile__ ("mtfsfi 6,0");
+}
+
+int os::Linux::get_fpu_control_word(void) {
+ // x86 has problems with FPU precision after pthread_cond_timedwait().
+ // nothing to do on ppc64.
+ return 0;
+}
+
+void os::Linux::set_fpu_control_word(int fpu_control) {
+ // x86 has problems with FPU precision after pthread_cond_timedwait().
+ // nothing to do on ppc64.
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// 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 = 64 * K;
+size_t os::Posix::_java_thread_min_stack_allowed = 64 * K;
+size_t os::Posix::_vm_internal_thread_min_stack_allowed = 64 * 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 ? 4 * M : 1024 * K);
+ return s;
+}
+
+/////////////////////////////////////////////////////////////////////////////
+// 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:");
+ st->print("pc =" INTPTR_FORMAT " ", uc->uc_mcontext.regs->nip);
+ st->print("lr =" INTPTR_FORMAT " ", uc->uc_mcontext.regs->link);
+ st->print("ctr=" INTPTR_FORMAT " ", uc->uc_mcontext.regs->ctr);
+ st->cr();
+ for (int i = 0; i < 32; i++) {
+ st->print("r%-2d=" INTPTR_FORMAT " ", i, uc->uc_mcontext.regs->gpr[i]);
+ if (i % 3 == 2) st->cr();
+ }
+ 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 + 128), 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 - 64, pc + 64, /*instrsize=*/4);
+ st->cr();
+}
+
+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 only for the "general purpose" registers
+ for (int i = 0; i < 32; i++) {
+ st->print("r%-2d=", i);
+ print_location(st, uc->uc_mcontext.regs->gpr[i]);
+ }
+ st->cr();
+}
+
+extern "C" {
+ int SpinPause() {
+ return 0;
+ }
+}
+
+#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() {
+ // PPC does not require the additional stack bang.
+ return 0;
+}