/*

 * Copyright (c) 1999, 2018, 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 "jvm.h"

#include "asm/macroAssembler.hpp"

#include "macroAssembler_sparc.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 "memory/allocation.inline.hpp"

#include "nativeInst_sparc.hpp"

#include "os_share_solaris.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/events.hpp"

#include "utilities/vmError.hpp"

# include <signal.h>        // needed first to avoid name collision for "std" with SC 5.0

// put OS-includes here

# include <sys/types.h>

# include <sys/mman.h>

# include <pthread.h>

# include <errno.h>

# include <dlfcn.h>

# include <stdio.h>

# include <unistd.h>

# include <sys/resource.h>

# include <thread.h>

# include <sys/stat.h>

# include <sys/time.h>

# include <sys/filio.h>

# include <sys/utsname.h>

# include <sys/systeminfo.h>

# include <sys/socket.h>

# include <sys/lwp.h>

# include <poll.h>

# include <sys/lwp.h>

# define _STRUCTURED_PROC 1  //  this gets us the new structured proc interfaces of 5.6 & later

# include <sys/procfs.h>     //  see comment in <sys/procfs.h>

#define MAX_PATH (2 * K)

// 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 = 104 * K;

size_t os::Posix::_java_thread_min_stack_allowed = 86 * K;

size_t os::Posix::_vm_internal_thread_min_stack_allowed = 128 * K;

int os::Solaris::max_register_window_saves_before_flushing() {

  // We should detect this at run time. For now, filling

  // in with a constant.

  return 8;

}

static void handle_unflushed_register_windows(gwindows_t *win) {

  int restore_count = win->wbcnt;

  int i;

  for(i=0; i<restore_count; i++) {

    address sp = ((address)win->spbuf[i]) + STACK_BIAS;

    address reg_win = (address)&win->wbuf[i];

    memcpy(sp,reg_win,sizeof(struct rwindow));

  }

}

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;

}

// Validate a ucontext retrieved from walking a uc_link of a ucontext.

// There are issues with libthread giving out uc_links for different threads

// on the same uc_link chain and bad or circular links.

//

bool os::Solaris::valid_ucontext(Thread* thread, const ucontext_t* valid, const ucontext_t* suspect) {

  if (valid >= suspect ||

      valid->uc_stack.ss_flags != suspect->uc_stack.ss_flags ||

      valid->uc_stack.ss_sp    != suspect->uc_stack.ss_sp    ||

      valid->uc_stack.ss_size  != suspect->uc_stack.ss_size) {

    DEBUG_ONLY(tty->print_cr("valid_ucontext: failed test 1");)

    return false;

  }

  if (thread->is_Java_thread()) {

    if (!valid_stack_address(thread, (address)suspect)) {

      DEBUG_ONLY(tty->print_cr("valid_ucontext: uc_link not in thread stack");)

      return false;

    }

    address _sp   = (address)((intptr_t)suspect->uc_mcontext.gregs[REG_SP] + STACK_BIAS);

    if (!valid_stack_address(thread, _sp) ||

        !frame::is_valid_stack_pointer(((JavaThread*)thread)->base_of_stack_pointer(), (intptr_t*)_sp)) {

      DEBUG_ONLY(tty->print_cr("valid_ucontext: stackpointer not in thread stack");)

      return false;

    }

  }

  return true;

}

// We will only follow one level of uc_link since there are libthread

// issues with ucontext linking and it is better to be safe and just

// let caller retry later.

const ucontext_t* os::Solaris::get_valid_uc_in_signal_handler(Thread *thread,

  const ucontext_t *uc) {

  const ucontext_t *retuc = NULL;

  // Sometimes the topmost register windows are not properly flushed.

  // i.e., if the kernel would have needed to take a page fault

  if (uc != NULL && uc->uc_mcontext.gwins != NULL) {

    ::handle_unflushed_register_windows(uc->uc_mcontext.gwins);

  }

  if (uc != NULL) {

    if (uc->uc_link == NULL) {

      // cannot validate without uc_link so accept current ucontext

      retuc = uc;

    } else if (os::Solaris::valid_ucontext(thread, uc, uc->uc_link)) {

      // first ucontext is valid so try the next one

      uc = uc->uc_link;

      if (uc->uc_link == NULL) {

        // cannot validate without uc_link so accept current ucontext

        retuc = uc;

      } else if (os::Solaris::valid_ucontext(thread, uc, uc->uc_link)) {

        // the ucontext one level down is also valid so return it

        retuc = uc;

      }

    }

  }

  return retuc;

}

// Assumes ucontext is valid

ExtendedPC os::Solaris::ucontext_get_ExtendedPC(const ucontext_t *uc) {

  address pc = (address)uc->uc_mcontext.gregs[REG_PC];

  // set npc to zero to avoid using it for safepoint, good for profiling only

  return ExtendedPC(pc);

}

void os::Solaris::ucontext_set_pc(ucontext_t* uc, address pc) {

  uc->uc_mcontext.gregs [REG_PC]  = (greg_t) pc;

  uc->uc_mcontext.gregs [REG_nPC] = (greg_t) (pc + 4);

}

// Assumes ucontext is valid

intptr_t* os::Solaris::ucontext_get_sp(const ucontext_t *uc) {

  return (intptr_t*)((intptr_t)uc->uc_mcontext.gregs[REG_SP] + STACK_BIAS);

}

// Solaris X86 only

intptr_t* os::Solaris::ucontext_get_fp(const ucontext_t *uc) {

  ShouldNotReachHere();

  return NULL;

}

address os::Solaris::ucontext_get_pc(const ucontext_t *uc) {

  return (address) uc->uc_mcontext.gregs[REG_PC];

}

// For Forte Analyzer AsyncGetCallTrace profiling support - thread

// is currently interrupted by SIGPROF.

//

// ret_fp parameter is only used by Solaris X86.

//

// The difference between this and os::fetch_frame_from_context() is that

// here we try to skip nested signal frames.

// This method is also used for stack overflow signal handling.

ExtendedPC os::Solaris::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");

  const ucontext_t *luc = os::Solaris::get_valid_uc_in_signal_handler(thread, uc);

  return os::fetch_frame_from_context(luc, ret_sp, ret_fp);

}

// ret_fp parameter is only used by Solaris X86.

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 = os::Solaris::ucontext_get_ExtendedPC(uc);

    if (ret_sp) *ret_sp = os::Solaris::ucontext_get_sp(uc);

  } else {

    // construct empty ExtendedPC for return value checking

    epc = ExtendedPC(NULL);

    if (ret_sp) *ret_sp = (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, frame::unpatchable, epc.pc());

}

frame os::fetch_frame_from_ucontext(Thread* thread, void* ucVoid) {

  intptr_t* sp;

  ExtendedPC epc = os::Solaris::fetch_frame_from_ucontext(thread, (ucontext_t*)ucVoid, &sp, NULL);

  return frame(sp, frame::unpatchable, epc.pc());

}

bool os::Solaris::get_frame_at_stack_banging_point(JavaThread* thread, ucontext_t* uc, frame* fr) {

  address pc = (address) os::Solaris::ucontext_get_pc(uc);

  if (Interpreter::contains(pc)) {

    *fr = os::fetch_frame_from_ucontext(thread, uc);

    if (!fr->is_first_java_frame()) {

      assert(fr->safe_for_sender(thread), "Safety check");

      *fr = fr->java_sender();

    }

  } else {

    // more complex code with compiled code

    assert(!Interpreter::contains(pc), "Interpreted methods should have been handled above");

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

    if (cb == NULL || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) {

      // Not sure where the pc points to, fallback to default

      // stack overflow handling

      return false;

    } else {

      // Returned frame will be the caller of the method that faults on the stack bang.

      // Register window not yet rotated (happens at SAVE after stack bang), so there is no new

      // frame to go with the faulting PC. Using caller SP that is still in SP, and caller PC

      // that was written to O7 at call.

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

      address pc = (address)uc->uc_mcontext.gregs[REG_O7];

      *fr = frame(sp, frame::unpatchable, pc);

      if (!fr->is_java_frame()) {

        assert(fr->safe_for_sender(thread), "Safety check");

        *fr = fr->java_sender();

      }

    }

  }

  assert(fr->is_java_frame(), "Safety check");

  return true;

}

frame os::get_sender_for_C_frame(frame* fr) {

  return frame(fr->sender_sp(), frame::unpatchable, fr->sender_pc());

}

// Returns an estimate of the current stack pointer. Result must be guaranteed to

// point into the calling threads stack, and be no lower than the current stack

// pointer.

address os::current_stack_pointer() {

  volatile int dummy;

  address sp = (address)&dummy + 8;     // %%%% need to confirm if this is right

  return sp;

}

frame os::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, NULL, false);

  } else {

    return os::get_sender_for_C_frame(&myframe);

  }

}

bool os::is_allocatable(size_t bytes) {

   return true;

}

extern "C" JNIEXPORT int

JVM_handle_solaris_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);

  if(sig == SIGPIPE || sig == SIGXFSZ) {

    if (os::Solaris::chained_handler(sig, info, ucVoid)) {

      return true;

    } else {

      // Ignoring SIGPIPE/SIGXFSZ - see bugs 4229104 or 6499219

      return true;

    }

  }

  JavaThread* thread = NULL;

  VMThread* vmthread = NULL;

  if (os::Solaris::signal_handlers_are_installed) {

    if (t != NULL ){

      if(t->is_Java_thread()) {

        thread = (JavaThread*)t;

      }

      else if(t->is_VM_thread()){

        vmthread = (VMThread *)t;

      }

    }

  }

  if (sig == ASYNC_SIGNAL) {

    if (thread || vmthread) {

      OSThread::SR_handler(t, uc);

      return true;

    } else if (os::Solaris::chained_handler(sig, info, ucVoid)) {

      return true;

    } else {

      // If ASYNC_SIGNAL not chained, and this is a non-vm and

      // non-java thread

      return true;

    }

  }

  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;

  address npc         = NULL;

  //%note os_trap_1

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

    // factor me: getPCfromContext

    pc  = (address) uc->uc_mcontext.gregs[REG_PC];

    npc = (address) uc->uc_mcontext.gregs[REG_nPC];

    // SafeFetch() support

    if (StubRoutines::is_safefetch_fault(pc)) {

      os::Solaris::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));

      return 1;

    }

    // Handle ALL stack overflow variations here

    if (sig == SIGSEGV && info->si_code == SEGV_ACCERR) {

      address addr = (address) info->si_addr;

      if (thread->in_stack_yellow_reserved_zone(addr)) {

        // Sometimes the register windows are not properly flushed.

        if(uc->uc_mcontext.gwins != NULL) {

          ::handle_unflushed_register_windows(uc->uc_mcontext.gwins);

        }

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

          if (thread->in_stack_reserved_zone(addr)) {

            frame fr;

            if (os::Solaris::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();

                RegisterMap map(thread);

                int frame_size = activation.frame_size(&map);

                thread->set_reserved_stack_activation((address)(((address)activation.sp()) - STACK_BIAS));

                return true;

              }

            }

          }

          // 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 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.");

        // Sometimes the register windows are not properly flushed.

        if(uc->uc_mcontext.gwins != NULL) {

          ::handle_unflushed_register_windows(uc->uc_mcontext.gwins);

        }

      }

    }

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

      if (sig == SIGBUS && thread->doing_unsafe_access()) {

        stub = SharedRuntime::handle_unsafe_access(thread, npc);

      }

    }

    else 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

      // Support Safepoint Polling

      if (sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) {

        stub = SharedRuntime::get_poll_stub(pc);

      }

      // Not needed on x86 solaris because verify_oops doesn't generate

      // SEGV/BUS like sparc does.

      if ( (sig == SIGSEGV || sig == SIGBUS)

           && 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, info->si_addr);

      }

      // This is not factored because on x86 solaris the patching for

      // zombies does not generate a SEGV.

      else if (sig == SIGSEGV && 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)uc->uc_mcontext.gregs[REG_O7];

      }

      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->as_compiled_method_or_null();

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

          stub = SharedRuntime::handle_unsafe_access(thread, npc);

        }

      }

      else if (sig == SIGFPE && info->si_code == FPE_INTDIV) {

        // integer divide by zero

        stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);

      }

      else if (sig == SIGFPE && info->si_code == FPE_FLTDIV) {

        // floating-point divide by zero

        stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);

      }

#ifdef COMPILER2

      else if (sig == SIGILL && 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)uc->uc_mcontext.gregs[REG_O7];

      }

#endif  // COMPILER2

      else if (sig == SIGSEGV && info->si_code > 0 && MacroAssembler::uses_implicit_null_check(info->si_addr)) {

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

        stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);

      }

    }