/*

 * Copyright 1999-2008 Sun Microsystems, 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 *

 */

// do not include  precompiled  header file

#include "incls/_os_linux_sparc.cpp.incl"

// Linux/Sparc has rather obscure naming of registers in sigcontext

// different between 32 and 64 bits

#ifdef _LP64

#define SIG_PC(x) ((x)->sigc_regs.tpc)

#define SIG_NPC(x) ((x)->sigc_regs.tnpc)

#define SIG_REGS(x) ((x)->sigc_regs)

#else

#define SIG_PC(x) ((x)->si_regs.pc)

#define SIG_NPC(x) ((x)->si_regs.npc)

#define SIG_REGS(x) ((x)->si_regs)

#endif

// those are to reference registers in sigcontext

enum {

  CON_G0 = 0,

  CON_G1,

  CON_G2,

  CON_G3,

  CON_G4,

  CON_G5,

  CON_G6,

  CON_G7,

  CON_O0,

  CON_O1,

  CON_O2,

  CON_O3,

  CON_O4,

  CON_O5,

  CON_O6,

  CON_O7,

};

static inline void set_cont_address(sigcontext* ctx, address addr) {

  SIG_PC(ctx)  = (intptr_t)addr;

  SIG_NPC(ctx) = (intptr_t)(addr+4);

}

// 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,

                                                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) {

  ucontext_t* uc = (ucontext_t*) ucVoid;

  ExtendedPC  epc;

  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(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::get_sender_for_C_frame(frame* fr) {

  return frame(fr->sender_sp(), fr->link(), fr->sender_pc());

}

frame os::current_frame() {

  fprintf(stderr, "current_frame()");

  intptr_t* sp = StubRoutines::Sparc::flush_callers_register_windows_func()();

  frame myframe(sp, frame::unpatchable,

                CAST_FROM_FN_PTR(address, os::current_frame));

  if (os::is_first_C_frame(&myframe)) {

    // stack is not walkable

    return frame(NULL, frame::unpatchable, NULL);

  } else {

    return os::get_sender_for_C_frame(&myframe);

  }

}

address os::current_stack_pointer() {

  register void *sp __asm__ ("sp");

  return (address)sp;

}

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, "pthread_getattr_np");

      } else {

        fatal1("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;

}

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).

  // On SPARC, 0 != %hi(any real address), because there is no

  // allocation in the first 1Kb of the virtual address space.

  return (char*) 0;

}

void os::initialize_thread() {}

void os::print_context(outputStream *st, void *context) {

  if (context == NULL) return;

  ucontext_t* uc = (ucontext_t*)context;

  sigcontext* sc = (sigcontext*)context;

  st->print_cr("Registers:");

  st->print_cr(" O0=" INTPTR_FORMAT " O1=" INTPTR_FORMAT

               " O2=" INTPTR_FORMAT " O3=" INTPTR_FORMAT,

               SIG_REGS(sc).u_regs[CON_O0],

               SIG_REGS(sc).u_regs[CON_O1],

               SIG_REGS(sc).u_regs[CON_O2],

               SIG_REGS(sc).u_regs[CON_O3]);

  st->print_cr(" O4=" INTPTR_FORMAT " O5=" INTPTR_FORMAT

               " O6=" INTPTR_FORMAT " O7=" INTPTR_FORMAT,

               SIG_REGS(sc).u_regs[CON_O4],

               SIG_REGS(sc).u_regs[CON_O5],

               SIG_REGS(sc).u_regs[CON_O6],

               SIG_REGS(sc).u_regs[CON_O7]);

  st->print_cr(" G1=" INTPTR_FORMAT " G2=" INTPTR_FORMAT

               " G3=" INTPTR_FORMAT " G4=" INTPTR_FORMAT,

               SIG_REGS(sc).u_regs[CON_G1],

               SIG_REGS(sc).u_regs[CON_G2],

               SIG_REGS(sc).u_regs[CON_G3],

               SIG_REGS(sc).u_regs[CON_G4]);

  st->print_cr(" G5=" INTPTR_FORMAT " G6=" INTPTR_FORMAT

               " G7=" INTPTR_FORMAT " Y=" INTPTR_FORMAT,

               SIG_REGS(sc).u_regs[CON_G5],

               SIG_REGS(sc).u_regs[CON_G6],

               SIG_REGS(sc).u_regs[CON_G7],

               SIG_REGS(sc).y);

  st->print_cr(" PC=" INTPTR_FORMAT " nPC=" INTPTR_FORMAT,

               SIG_PC(sc),

               SIG_NPC(sc));

  st->cr();

  st->cr();

  intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc);

  st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp);

  print_hex_dump(st, (address)sp, (address)(sp + 32), 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 ")", pc);

  print_hex_dump(st, pc - 16, pc + 16, sizeof(char));

}

address os::Linux::ucontext_get_pc(ucontext_t* uc) {

  return (address) SIG_PC((sigcontext*)uc);

}

intptr_t* os::Linux::ucontext_get_sp(ucontext_t *uc) {

  return (intptr_t*)

    ((intptr_t)SIG_REGS((sigcontext*)uc).u_regs[CON_O6] + STACK_BIAS);

}

// not used on Sparc

intptr_t* os::Linux::ucontext_get_fp(ucontext_t *uc) {

  ShouldNotReachHere();

  return NULL;

}

// Utility functions

extern "C" void Fetch32PFI();

extern "C" void Fetch32Resume();

extern "C" void FetchNPFI();

extern "C" void FetchNResume();

inline static bool checkPrefetch(sigcontext* uc, address pc) {

  if (pc == (address) Fetch32PFI) {

    set_cont_address(uc, address(Fetch32Resume));

    return true;

  }

  if (pc == (address) FetchNPFI) {

    set_cont_address(uc, address(FetchNResume));

    return true;

  }

  return false;

}

inline static bool checkOverflow(sigcontext* uc,

                                 address pc,

                                 address addr,

                                 JavaThread* thread,

                                 address* stub) {

  // 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 true;

      }

    } 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.");

    } 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 true;

        }

        thread->osthread()->clear_expanding_stack();

      } else {

        fatal("recursive segv. expanding stack.");

      }

    }

  }

  return false;

}

inline static bool checkPollingPage(address pc, address fault, address* stub) {

  if (fault == os::get_polling_page()) {

    *stub = SharedRuntime::get_poll_stub(pc);

    return true;

  }

  return false;

}

inline static bool checkByteBuffer(address pc, address* stub) {

  // 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->is_nmethod() ? (nmethod*)cb : NULL;

  if (nm != NULL && nm->has_unsafe_access()) {

    *stub = StubRoutines::handler_for_unsafe_access();

    return true;

  }

  return false;

}

inline static bool checkVerifyOops(address pc, address fault, address* stub) {

  if (pc >= MacroAssembler::_verify_oop_implicit_branch[0]

      && pc <  MacroAssembler::_verify_oop_implicit_branch[1] ) {

    *stub     =  MacroAssembler::_verify_oop_implicit_branch[2];

    warning("fixed up memory fault in +VerifyOops at address "

            INTPTR_FORMAT, fault);

    return true;

  }

  return false;

}

inline static bool checkFPFault(address pc, int code,

                                JavaThread* thread, address* stub) {

  if (code == FPE_INTDIV || code == FPE_FLTDIV) {

    *stub =

      SharedRuntime::

      continuation_for_implicit_exception(thread,

                                          pc,

                                          SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);

    return true;

  }

  return false;

}

inline static bool checkNullPointer(address pc, intptr_t fault,

                                    JavaThread* thread, address* stub) {

  if (!MacroAssembler::needs_explicit_null_check(fault)) {

    // Determination of interpreter/vtable stub/compiled code null

    // exception

    *stub =

      SharedRuntime::

      continuation_for_implicit_exception(thread, pc,

                                          SharedRuntime::IMPLICIT_NULL);

    return true;

  }

  return false;

}

inline static bool checkFastJNIAccess(address pc, address* stub) {

  address addr = JNI_FastGetField::find_slowcase_pc(pc);

  if (addr != (address)-1) {

    *stub = addr;

    return true;

  }

  return false;

}

inline static bool checkSerializePage(JavaThread* thread, address addr) {

  return os::is_memory_serialize_page(thread, addr);

}

inline static bool checkZombie(sigcontext* uc, address* pc, address* stub) {

  if (nativeInstruction_at(*pc)->is_zombie()) {

    // zombie method (ld [%g0],%o7 instruction)

    *stub = SharedRuntime::get_handle_wrong_method_stub();

    // At the stub it needs to look like a call from the caller of this

    // method (not a call from the segv site).

    *pc = (address)SIG_REGS(uc).u_regs[CON_O7];

    return true;

  }

  return false;

}

inline static bool checkICMiss(sigcontext* uc, address* pc, address* stub) {

#ifdef COMPILER2

  if (nativeInstruction_at(*pc)->is_ic_miss_trap()) {

#ifdef ASSERT

#ifdef TIERED

    CodeBlob* cb = CodeCache::find_blob_unsafe(pc);

    assert(cb->is_compiled_by_c2(), "Wrong compiler");

#endif // TIERED

#endif // ASSERT

    // Inline cache missed and user trap "Tne G0+ST_RESERVED_FOR_USER_0+2" taken.

    *stub = SharedRuntime::get_ic_miss_stub();

    // At the stub it needs to look like a call from the caller of this

    // method (not a call from the segv site).

    *pc = (address)SIG_REGS(uc).u_regs[CON_O7];

    return true;

  }

#endif  // COMPILER2

  return false;

}

extern "C" int

JVM_handle_linux_signal(int sig,

                        siginfo_t* info,

                        void* ucVoid,

                        int abort_if_unrecognized) {

  // in fact this isn't ucontext_t* at all, but struct sigcontext*

  // but Linux porting layer uses ucontext_t, so to minimize code change

  // we cast as needed

  ucontext_t* ucFake = (ucontext_t*) ucVoid;

  sigcontext* uc = (sigcontext*)ucVoid;

  Thread* t = ThreadLocalStorage::get_thread_slow();

  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;

    }

  }

  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;

      }

    }

  }

  // decide if this trap can be handled by a stub

  address stub = NULL;

  address pc = NULL;

  address npc = NULL;

  //%note os_trap_1

  if (info != NULL && uc != NULL && thread != NULL) {

    pc = address(SIG_PC(uc));

    npc = address(SIG_NPC(uc));

    // 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) && checkSerializePage(thread, (address)info->si_addr)) {

      // Block current thread until the memory serialize page permission restored.

      os::block_on_serialize_page_trap();

      return 1;

    }

    if (checkPrefetch(uc, pc)) {

      return 1;

    }

    // Handle ALL stack overflow variations here

    if (sig == SIGSEGV) {

      if (checkOverflow(uc, pc, (address)info->si_addr, thread, &stub)) {

        return 1;

      }

    }

    if (sig == SIGBUS &&

        thread->thread_state() == _thread_in_vm &&

        thread->doing_unsafe_access()) {

      stub = StubRoutines::handler_for_unsafe_access();

    }

    if (thread->thread_state() == _thread_in_Java) {

      do {

        // Java thread running in Java code => find exception handler if any

        // a fault inside compiled code, the interpreter, or a stub

        if ((sig == SIGSEGV) && checkPollingPage(pc, (address)info->si_addr, &stub)) {

          break;

        }