/*

 * Copyright (c) 1999, 2014, 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_solaris.h"

#include "memory/allocation.inline.hpp"

#include "mutex_solaris.inline.hpp"

#include "os_share_solaris.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 <setjmp.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/trap.h>

# include <sys/lwp.h>

# include <pwd.h>

# include <poll.h>

# include <sys/lwp.h>

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

#ifndef AMD64

// QQQ seems useless at this point

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

#endif // AMD64

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

#define MAX_PATH (2 * K)

// Minimum stack size for the VM.  It's easier to document a constant value

// but it's different for x86 and sparc because the page sizes are different.

#ifdef AMD64

size_t os::Solaris::min_stack_allowed = 224*K;

#define REG_SP REG_RSP

#define REG_PC REG_RIP

#define REG_FP REG_RBP

#else

size_t os::Solaris::min_stack_allowed = 64*K;

#define REG_SP UESP

#define REG_PC EIP

#define REG_FP EBP

// 4900493 counter to prevent runaway LDTR refresh attempt

static volatile int ldtr_refresh = 0;

// the libthread instruction that faults because of the stale LDTR

static const unsigned char movlfs[] = { 0x8e, 0xe0    // movl %eax,%fs

                       };

#endif // AMD64

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;

}

//

// 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, ucontext_t* valid, 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;

    }

    if (!valid_stack_address(thread,  (address) suspect->uc_mcontext.gregs[REG_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.

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

  ucontext_t *uc) {

  ucontext_t *retuc = NULL;

  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(ucontext_t *uc) {

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

}

// Assumes ucontext is valid

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

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

}

// Assumes ucontext is valid

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

  return (intptr_t*)uc->uc_mcontext.gregs[REG_FP];

}

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

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

}

// For Forte Analyzer AsyncGetCallTrace profiling support - thread

// is currently interrupted by SIGPROF.

//

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

// here we try to skip nested signal frames.

ExtendedPC os::Solaris::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");

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

  return os::fetch_frame_from_context(luc, 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 = os::Solaris::ucontext_get_ExtendedPC(uc);

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

    if (ret_fp) *ret_fp = os::Solaris::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());

}

extern "C" intptr_t *_get_current_sp();  // in .il file

address os::current_stack_pointer() {

  return (address)_get_current_sp();

}

extern "C" intptr_t *_get_current_fp();  // in .il file

frame os::current_frame() {

  intptr_t* fp = _get_current_fp();  // it's inlined so want current 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

    frame ret; // This will be a null useless frame

    return ret;

  } else {

    return os::get_sender_for_C_frame(&myframe);

  }

}

#ifndef AMD64

// Detecting SSE support by OS

// From solaris_i486.s

extern "C" bool sse_check();

extern "C" bool sse_unavailable();

enum { SSE_UNKNOWN, SSE_NOT_SUPPORTED, SSE_SUPPORTED};

static int sse_status = SSE_UNKNOWN;

static void  check_for_sse_support() {

  if (!VM_Version::supports_sse()) {

    sse_status = SSE_NOT_SUPPORTED;

    return;

  }

  // looking for _sse_hw in libc.so, if it does not exist or

  // the value (int) is 0, OS has no support for SSE

  int *sse_hwp;

  void *h;

  if ((h=dlopen("/usr/lib/libc.so", RTLD_LAZY)) == NULL) {

    //open failed, presume no support for SSE

    sse_status = SSE_NOT_SUPPORTED;

    return;

  }

  if ((sse_hwp = (int *)dlsym(h, "_sse_hw")) == NULL) {

    sse_status = SSE_NOT_SUPPORTED;

  } else if (*sse_hwp == 0) {

    sse_status = SSE_NOT_SUPPORTED;

  }

  dlclose(h);

  if (sse_status == SSE_UNKNOWN) {

    bool (*try_sse)() = (bool (*)())sse_check;

    sse_status = (*try_sse)() ? SSE_SUPPORTED : SSE_NOT_SUPPORTED;

  }

}

#endif // AMD64

bool os::supports_sse() {

#ifdef AMD64

  return true;

#else

  if (sse_status == SSE_UNKNOWN)

    check_for_sse_support();

  return sse_status == SSE_SUPPORTED;

#endif // AMD64

}

bool os::is_allocatable(size_t bytes) {

#ifdef 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

}

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;

#ifndef AMD64

  if (sig == SIGILL && info->si_addr == (caddr_t)sse_check) {

    // the SSE instruction faulted. supports_sse() need return false.

    uc->uc_mcontext.gregs[EIP] = (greg_t)sse_unavailable;

    return true;

  }

#endif // !AMD64

  Thread* t = ThreadLocalStorage::get_thread_slow();  // slow & steady

  // 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);

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

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

      return true;

    } else {

      if (PrintMiscellaneous && (WizardMode || Verbose)) {

        char buf[64];

        warning("Ignoring %s - see 4229104 or 6499219",

                os::exception_name(sig, buf, sizeof(buf)));

      }

      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;

      }

    }

  }

  guarantee(sig != os::Solaris::SIGinterrupt(), "Can not chain VM interrupt signal, try -XX:+UseAltSigs");

  if (sig == os::Solaris::SIGasync()) {

    if(thread || vmthread){

      OSThread::SR_handler(t, uc);

      return true;

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

      return true;

    } else {

      // If os::Solaris::SIGasync 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;

  //%note os_trap_1

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

    // factor me: getPCfromContext

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

    if (StubRoutines::is_safefetch_fault(pc)) {

      uc->uc_mcontext.gregs[REG_PC] = intptr_t(StubRoutines::continuation_for_safefetch_fault(pc));

      return true;

    }

    // 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_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.");

      }

    }

    if ((sig == SIGSEGV) && VM_Version::is_cpuinfo_segv_addr(pc)) {

      // Verify that OS save/restore AVX registers.

      stub = VM_Version::cpuinfo_cont_addr();

    }

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

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

        stub = StubRoutines::handler_for_unsafe_access();

      }

    }

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

      // Support Safepoint Polling

      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);

        if (cb != NULL) {

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

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

            stub = StubRoutines::handler_for_unsafe_access();

          }

        }

      }

      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);

      }

#ifndef AMD64

      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);

      }

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

        // 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. QQQ TODO

        // Note that we take the exception at the NEXT floating point instruction.

        if (pc[0] == 0xDB) {

            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 {

            assert(pc[-3] == 0xDB, "not an flt invalid opcode");

            assert(pc[-2] == 0x14, "not an flt invalid opcode");

            assert(pc[-1] == 0x24, "not an flt invalid opcode");

        }

      }

      else if (sig == SIGFPE ) {

        tty->print_cr("caught SIGFPE, info 0x%x.", info->si_code);

      }

#endif // !AMD64

        // QQQ It doesn't seem that we need to do this on x86 because we should be able

        // to return properly from the handler without this extra stuff on the back side.

      else if (sig == SIGSEGV && info->si_code > 0 && !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);

      }

    }

    // jni_fast_Get<Primitive>Field 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.