alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Java example source code file (os_solaris_x86.cpp)

This example Java source code file (os_solaris_x86.cpp) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

amd64, cast_from_fn_ptr, cast_to_fn_ptr, debug_only, extendedpc, intptr_format, null, sharedruntime\:\:continuation_for_implicit_exception, sigbus, sigfpe, sigsegv, sse_not_supported, sse_supported, sse_unknown

The os_solaris_x86.cpp Java example source code

/*
 * Copyright (c) 1999, 2013, 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 

#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 


#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);
  }
}

static int threadgetstate(thread_t tid, int *flags, lwpid_t *lwp, stack_t *ss, gregset_t rs, lwpstatus_t *lwpstatus) {
  char lwpstatusfile[PROCFILE_LENGTH];
  int lwpfd, err;

  if (err = os::Solaris::thr_getstate(tid, flags, lwp, ss, rs))
    return (err);
  if (*flags == TRS_LWPID) {
    sprintf(lwpstatusfile, "/proc/%d/lwp/%d/lwpstatus", getpid(),
            *lwp);
    if ((lwpfd = open(lwpstatusfile, O_RDONLY)) < 0) {
      perror("thr_mutator_status: open lwpstatus");
      return (EINVAL);
    }
    if (pread(lwpfd, lwpstatus, sizeof (lwpstatus_t), (off_t)0) !=
        sizeof (lwpstatus_t)) {
      perror("thr_mutator_status: read lwpstatus");
      (void) close(lwpfd);
      return (EINVAL);
    }
    (void) close(lwpfd);
  }
  return (0);
}

#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 (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);
        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.
    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;
    }
  }

  // Execution protection violation
  //
  // Preventative code for future versions of Solaris which may
  // enable execution protection when running the 32-bit VM on AMD64.
  //
  // This should be kept as the last step in the triage.  We don't
  // have a dedicated trap number for a no-execute fault, so be
  // conservative and allow other handlers the first shot.
  //
  // Note: We don't test that info->si_code == SEGV_ACCERR here.
  // this si_code is so generic that it is almost meaningless; and
  // the si_code for this condition may change in the future.
  // Furthermore, a false-positive should be harmless.
  if (UnguardOnExecutionViolation > 0 &&
      (sig == SIGSEGV || sig == SIGBUS) &&
      uc->uc_mcontext.gregs[TRAPNO] == T_PGFLT) {  // page fault
    int page_size = os::vm_page_size();
    address addr = (address) info->si_addr;
    address pc = (address) uc->uc_mcontext.gregs[REG_PC];
    // Make sure the pc and the faulting address are sane.
    //
    // If an instruction spans a page boundary, and the page containing
    // the beginning of the instruction is executable but the following
    // page is not, the pc and the faulting address might be slightly
    // different - we still want to unguard the 2nd page in this case.
    //
    // 15 bytes seems to be a (very) safe value for max instruction size.
    bool pc_is_near_addr =
      (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15);
    bool instr_spans_page_boundary =
      (align_size_down((intptr_t) pc ^ (intptr_t) addr,
                       (intptr_t) page_size) > 0);

    if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) {
      static volatile address last_addr =
        (address) os::non_memory_address_word();

      // In conservative mode, don't unguard unless the address is in the VM
      if (addr != last_addr &&
          (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) {

        // Make memory rwx and retry
        address page_start =
          (address) align_size_down((intptr_t) addr, (intptr_t) page_size);
        bool res = os::protect_memory((char*) page_start, page_size,
                                      os::MEM_PROT_RWX);

        if (PrintMiscellaneous && Verbose) {
          char buf[256];
          jio_snprintf(buf, sizeof(buf), "Execution protection violation "
                       "at " INTPTR_FORMAT
                       ", unguarding " INTPTR_FORMAT ": %s, errno=%d", addr,
                       page_start, (res ? "success" : "failed"), errno);
          tty->print_raw_cr(buf);
        }
        stub = pc;

        // Set last_addr so if we fault again at the same address, we don't end
        // up in an endless loop.
        //
        // There are two potential complications here.  Two threads trapping at
        // the same address at the same time could cause one of the threads to
        // think it already unguarded, and abort the VM.  Likely very rare.
        //
        // The other race involves two threads alternately trapping at
        // different addresses and failing to unguard the page, resulting in
        // an endless loop.  This condition is probably even more unlikely than
        // the first.
        //
        // Although both cases could be avoided by using locks or thread local
        // last_addr, these solutions are unnecessary complication: this
        // handler is a best-effort safety net, not a complete solution.  It is
        // disabled by default and should only be used as a workaround in case
        // we missed any no-execute-unsafe VM code.

        last_addr = addr;
      }
    }
  }

  if (stub != NULL) {
    // save all thread context in case we need to restore it

    if (thread != NULL) thread->set_saved_exception_pc(pc);
    // 12/02/99: On Sparc it appears that the full context is also saved
    // but as yet, no one looks at or restores that saved context
    // factor me: setPC
    uc->uc_mcontext.gregs[REG_PC] = (greg_t)stub;
    return true;
  }

  // signal-chaining
  if (os::Solaris::chained_handler(sig, info, ucVoid)) {
    return true;
  }

#ifndef AMD64
  // Workaround (bug 4900493) for Solaris kernel bug 4966651.
  // Handle an undefined selector caused by an attempt to assign
  // fs in libthread getipriptr(). With the current libthread design every 512
  // thread creations the LDT for a private thread data structure is extended
  // and thre is a hazard that and another thread attempting a thread creation
  // will use a stale LDTR that doesn't reflect the structure's growth,
  // causing a GP fault.
  // Enforce the probable limit of passes through here to guard against an
  // infinite loop if some other move to fs caused the GP fault. Note that
  // this loop counter is ultimately a heuristic as it is possible for
  // more than one thread to generate this fault at a time in an MP system.
  // In the case of the loop count being exceeded or if the poll fails
  // just fall through to a fatal error.
  // If there is some other source of T_GPFLT traps and the text at EIP is
  // unreadable this code will loop infinitely until the stack is exausted.
  // The key to diagnosis in this case is to look for the bottom signal handler
  // frame.

  if(! IgnoreLibthreadGPFault) {
    if (sig == SIGSEGV && uc->uc_mcontext.gregs[TRAPNO] == T_GPFLT) {
      const unsigned char *p =
                        (unsigned const char *) uc->uc_mcontext.gregs[EIP];

      // Expected instruction?

      if(p[0] == movlfs[0] && p[1] == movlfs[1]) {

        Atomic::inc(&ldtr_refresh);

        // Infinite loop?

        if(ldtr_refresh < ((2 << 16) / PAGESIZE)) {

          // No, force scheduling to get a fresh view of the LDTR

          if(poll(NULL, 0, 10) == 0) {

            // Retry the move

            return false;
          }
        }
      }
    }
  }
#endif // !AMD64

  if (!abort_if_unrecognized) {
    // caller wants another chance, so give it to him
    return false;
  }

  if (!os::Solaris::libjsig_is_loaded) {
    struct sigaction oldAct;
    sigaction(sig, (struct sigaction *)0, &oldAct);
    if (oldAct.sa_sigaction != signalHandler) {
      void* sighand = oldAct.sa_sigaction ? CAST_FROM_FN_PTR(void*,  oldAct.sa_sigaction)
                                          : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
      warning("Unexpected Signal %d occurred under user-defined signal handler %#lx", sig, (long)sighand);
    }
  }

  if (pc == NULL && uc != NULL) {
    pc = (address) uc->uc_mcontext.gregs[REG_PC];
  }

  // unmask current signal
  sigset_t newset;
  sigemptyset(&newset);
  sigaddset(&newset, sig);
  sigprocmask(SIG_UNBLOCK, &newset, NULL);

  // Determine which sort of error to throw.  Out of swap may signal
  // on the thread stack, which could get a mapping error when touched.
  address addr = (address) info->si_addr;
  if (sig == SIGBUS && info->si_code == BUS_OBJERR && info->si_errno == ENOMEM) {
    vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "Out of swap space to map in thread stack.");
  }

  VMError err(t, sig, pc, info, ucVoid);
  err.report_and_die();

  ShouldNotReachHere();
}

void os::print_context(outputStream *st, void *context) {
  if (context == NULL) return;

  ucontext_t *uc = (ucontext_t*)context;
  st->print_cr("Registers:");
#ifdef AMD64
  st->print(  "RAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RAX]);
  st->print(", RBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBX]);
  st->print(", RCX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RCX]);
  st->print(", RDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDX]);
  st->cr();
  st->print(  "RSP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSP]);
  st->print(", RBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBP]);
  st->print(", RSI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSI]);
  st->print(", RDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDI]);
  st->cr();
  st->print(  "R8 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R8]);
  st->print(", R9 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R9]);
  st->print(", R10=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R10]);
  st->print(", R11=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R11]);
  st->cr();
  st->print(  "R12=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R12]);
  st->print(", R13=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R13]);
  st->print(", R14=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R14]);
  st->print(", R15=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R15]);
  st->cr();
  st->print(  "RIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RIP]);
  st->print(", RFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RFL]);
#else
  st->print(  "EAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EAX]);
  st->print(", EBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EBX]);
  st->print(", ECX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[ECX]);
  st->print(", EDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EDX]);
  st->cr();
  st->print(  "ESP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[UESP]);
  st->print(", EBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EBP]);
  st->print(", ESI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[ESI]);
  st->print(", EDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EDI]);
  st->cr();
  st->print(  "EIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EIP]);
  st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EFL]);
#endif // AMD64
  st->cr();
  st->cr();

  intptr_t *sp = (intptr_t *)os::Solaris::ucontext_get_sp(uc);
  st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", 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.
  ExtendedPC epc = os::Solaris::ucontext_get_ExtendedPC(uc);
  address pc = epc.pc();
  st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc);
  print_hex_dump(st, pc - 32, pc + 32, sizeof(char));
}

void os::print_register_info(outputStream *st, void *context) {
  if (context == NULL) return;

  ucontext_t *uc = (ucontext_t*)context;

  st->print_cr("Register to memory mapping:");
  st->cr();

  // this is horrendously verbose but the layout of the registers in the
  // context does not match how we defined our abstract Register set, so
  // we can't just iterate through the gregs area

  // this is only for the "general purpose" registers

#ifdef AMD64
  st->print("RAX="); print_location(st, uc->uc_mcontext.gregs[REG_RAX]);
  st->print("RBX="); print_location(st, uc->uc_mcontext.gregs[REG_RBX]);
  st->print("RCX="); print_location(st, uc->uc_mcontext.gregs[REG_RCX]);
  st->print("RDX="); print_location(st, uc->uc_mcontext.gregs[REG_RDX]);
  st->print("RSP="); print_location(st, uc->uc_mcontext.gregs[REG_RSP]);
  st->print("RBP="); print_location(st, uc->uc_mcontext.gregs[REG_RBP]);
  st->print("RSI="); print_location(st, uc->uc_mcontext.gregs[REG_RSI]);
  st->print("RDI="); print_location(st, uc->uc_mcontext.gregs[REG_RDI]);
  st->print("R8 ="); print_location(st, uc->uc_mcontext.gregs[REG_R8]);
  st->print("R9 ="); print_location(st, uc->uc_mcontext.gregs[REG_R9]);
  st->print("R10="); print_location(st, uc->uc_mcontext.gregs[REG_R10]);
  st->print("R11="); print_location(st, uc->uc_mcontext.gregs[REG_R11]);
  st->print("R12="); print_location(st, uc->uc_mcontext.gregs[REG_R12]);
  st->print("R13="); print_location(st, uc->uc_mcontext.gregs[REG_R13]);
  st->print("R14="); print_location(st, uc->uc_mcontext.gregs[REG_R14]);
  st->print("R15="); print_location(st, uc->uc_mcontext.gregs[REG_R15]);
#else
  st->print("EAX="); print_location(st, uc->uc_mcontext.gregs[EAX]);
  st->print("EBX="); print_location(st, uc->uc_mcontext.gregs[EBX]);
  st->print("ECX="); print_location(st, uc->uc_mcontext.gregs[ECX]);
  st->print("EDX="); print_location(st, uc->uc_mcontext.gregs[EDX]);
  st->print("ESP="); print_location(st, uc->uc_mcontext.gregs[UESP]);
  st->print("EBP="); print_location(st, uc->uc_mcontext.gregs[EBP]);
  st->print("ESI="); print_location(st, uc->uc_mcontext.gregs[ESI]);
  st->print("EDI="); print_location(st, uc->uc_mcontext.gregs[EDI]);
#endif

  st->cr();
}


#ifdef AMD64
void os::Solaris::init_thread_fpu_state(void) {
  // Nothing to do
}
#else
// From solaris_i486.s
extern "C" void fixcw();

void os::Solaris::init_thread_fpu_state(void) {
  // Set fpu to 53 bit precision. This happens too early to use a stub.
  fixcw();
}

// These routines are the initial value of atomic_xchg_entry(),
// atomic_cmpxchg_entry(), atomic_inc_entry() and fence_entry()
// until initialization is complete.
// TODO - replace with .il implementation when compiler supports it.

typedef jint  xchg_func_t        (jint,  volatile jint*);
typedef jint  cmpxchg_func_t     (jint,  volatile jint*,  jint);
typedef jlong cmpxchg_long_func_t(jlong, volatile jlong*, jlong);
typedef jint  add_func_t         (jint,  volatile jint*);

jint os::atomic_xchg_bootstrap(jint exchange_value, volatile jint* dest) {
  // try to use the stub:
  xchg_func_t* func = CAST_TO_FN_PTR(xchg_func_t*, StubRoutines::atomic_xchg_entry());

  if (func != NULL) {
    os::atomic_xchg_func = func;
    return (*func)(exchange_value, dest);
  }
  assert(Threads::number_of_threads() == 0, "for bootstrap only");

  jint old_value = *dest;
  *dest = exchange_value;
  return old_value;
}

jint os::atomic_cmpxchg_bootstrap(jint exchange_value, volatile jint* dest, jint compare_value) {
  // try to use the stub:
  cmpxchg_func_t* func = CAST_TO_FN_PTR(cmpxchg_func_t*, StubRoutines::atomic_cmpxchg_entry());

  if (func != NULL) {
    os::atomic_cmpxchg_func = func;
    return (*func)(exchange_value, dest, compare_value);
  }
  assert(Threads::number_of_threads() == 0, "for bootstrap only");

  jint old_value = *dest;
  if (old_value == compare_value)
    *dest = exchange_value;
  return old_value;
}

jlong os::atomic_cmpxchg_long_bootstrap(jlong exchange_value, volatile jlong* dest, jlong compare_value) {
  // try to use the stub:
  cmpxchg_long_func_t* func = CAST_TO_FN_PTR(cmpxchg_long_func_t*, StubRoutines::atomic_cmpxchg_long_entry());

  if (func != NULL) {
    os::atomic_cmpxchg_long_func = func;
    return (*func)(exchange_value, dest, compare_value);
  }
  assert(Threads::number_of_threads() == 0, "for bootstrap only");

  jlong old_value = *dest;
  if (old_value == compare_value)
    *dest = exchange_value;
  return old_value;
}

jint os::atomic_add_bootstrap(jint add_value, volatile jint* dest) {
  // try to use the stub:
  add_func_t* func = CAST_TO_FN_PTR(add_func_t*, StubRoutines::atomic_add_entry());

  if (func != NULL) {
    os::atomic_add_func = func;
    return (*func)(add_value, dest);
  }
  assert(Threads::number_of_threads() == 0, "for bootstrap only");

  return (*dest) += add_value;
}

xchg_func_t*         os::atomic_xchg_func         = os::atomic_xchg_bootstrap;
cmpxchg_func_t*      os::atomic_cmpxchg_func      = os::atomic_cmpxchg_bootstrap;
cmpxchg_long_func_t* os::atomic_cmpxchg_long_func = os::atomic_cmpxchg_long_bootstrap;
add_func_t*          os::atomic_add_func          = os::atomic_add_bootstrap;

extern "C" void _solaris_raw_setup_fpu(address ptr);
void os::setup_fpu() {
  address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std();
  _solaris_raw_setup_fpu(fpu_cntrl);
}
#endif // AMD64

#ifndef PRODUCT
void os::verify_stack_alignment() {
#ifdef AMD64
  assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment");
#endif
}
#endif

Other Java examples (source code examples)

Here is a short list of links related to this Java os_solaris_x86.cpp source code file:

... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.