hotspot/src/jdk.hotspot.agent/solaris/native/libsaproc/saproc.cpp
changeset 35217 ce4b5303a813
parent 26410 a34c8032e674
child 42035 10e6e31dc1aa
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/jdk.hotspot.agent/solaris/native/libsaproc/saproc.cpp	Wed Dec 23 13:12:15 2015 +0300
@@ -0,0 +1,1456 @@
+/*
+ * Copyright (c) 2002, 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.
+ *
+ */
+
+#include "salibproc.h"
+#include "sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal.h"
+#ifndef SOLARIS_11_B159_OR_LATER
+#include <sys/utsname.h>
+#endif
+#include <thread_db.h>
+#include <strings.h>
+#include <limits.h>
+#include <demangle.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <errno.h>
+
+#define CHECK_EXCEPTION_(value) if(env->ExceptionOccurred()) { return value; }
+#define CHECK_EXCEPTION if(env->ExceptionOccurred()) { return;}
+#define THROW_NEW_DEBUGGER_EXCEPTION_(str, value) { throwNewDebuggerException(env, str); return value; }
+#define THROW_NEW_DEBUGGER_EXCEPTION(str) { throwNewDebuggerException(env, str); return;}
+
+#define SYMBOL_BUF_SIZE  256
+#define ERR_MSG_SIZE     (PATH_MAX + 256)
+
+// debug modes
+static int _libsaproc_debug = 0;
+#ifndef SOLARIS_11_B159_OR_LATER
+static bool _Pstack_iter_debug = false;
+
+static void dprintf_2(const char* format,...) {
+  if (_Pstack_iter_debug) {
+    va_list alist;
+
+    va_start(alist, format);
+    fputs("Pstack_iter DEBUG: ", stderr);
+    vfprintf(stderr, format, alist);
+    va_end(alist);
+  }
+}
+#endif // !SOLARIS_11_B159_OR_LATER
+
+static void print_debug(const char* format,...) {
+  if (_libsaproc_debug) {
+    va_list alist;
+
+    va_start(alist, format);
+    fputs("libsaproc DEBUG: ", stderr);
+    vfprintf(stderr, format, alist);
+    va_end(alist);
+  }
+}
+
+struct Debugger {
+    JNIEnv* env;
+    jobject this_obj;
+};
+
+struct DebuggerWithObject : Debugger {
+    jobject obj;
+};
+
+struct DebuggerWith2Objects : DebuggerWithObject {
+    jobject obj2;
+};
+
+/*
+* Portions of user thread level detail gathering code is from pstack source
+* code. See pstack.c in Solaris 2.8 user commands source code.
+*/
+
+static void throwNewDebuggerException(JNIEnv* env, const char* errMsg) {
+  jclass clazz = env->FindClass("sun/jvm/hotspot/debugger/DebuggerException");
+  CHECK_EXCEPTION;
+  env->ThrowNew(clazz, errMsg);
+}
+
+// JNI ids for some fields, methods
+
+// libproc handler pointer
+static jfieldID p_ps_prochandle_ID = 0;
+
+// libthread.so dlopen handle, thread agent ptr and function pointers
+static jfieldID libthread_db_handle_ID   = 0;
+static jfieldID p_td_thragent_t_ID       = 0;
+static jfieldID p_td_init_ID             = 0;
+static jfieldID p_td_ta_new_ID           = 0;
+static jfieldID p_td_ta_delete_ID        = 0;
+static jfieldID p_td_ta_thr_iter_ID      = 0;
+static jfieldID p_td_thr_get_info_ID     = 0;
+static jfieldID p_td_ta_map_id2thr_ID    = 0;
+static jfieldID p_td_thr_getgregs_ID     = 0;
+
+// reg index fields
+static jfieldID pcRegIndex_ID            = 0;
+static jfieldID fpRegIndex_ID            = 0;
+
+// part of the class sharing workaround
+static jfieldID classes_jsa_fd_ID        = 0;
+static jfieldID p_file_map_header_ID     = 0;
+
+// method ids
+
+static jmethodID getThreadForThreadId_ID = 0;
+static jmethodID createSenderFrame_ID    = 0;
+static jmethodID createLoadObject_ID     = 0;
+static jmethodID createClosestSymbol_ID  = 0;
+static jmethodID listAdd_ID              = 0;
+
+/*
+ * Functions we need from libthread_db
+ */
+typedef td_err_e
+        (*p_td_init_t)(void);
+typedef td_err_e
+        (*p_td_ta_new_t)(void *, td_thragent_t **);
+typedef td_err_e
+        (*p_td_ta_delete_t)(td_thragent_t *);
+typedef td_err_e
+        (*p_td_ta_thr_iter_t)(const td_thragent_t *, td_thr_iter_f *, void *,
+                td_thr_state_e, int, sigset_t *, unsigned);
+typedef td_err_e
+        (*p_td_thr_get_info_t)(const td_thrhandle_t *, td_thrinfo_t *);
+typedef td_err_e
+        (*p_td_ta_map_id2thr_t)(const td_thragent_t *, thread_t,  td_thrhandle_t *);
+typedef td_err_e
+        (*p_td_thr_getgregs_t)(const td_thrhandle_t *, prgregset_t);
+
+static void
+clear_libthread_db_ptrs(JNIEnv* env, jobject this_obj) {
+  // release libthread_db agent, if we had created
+  p_td_ta_delete_t p_td_ta_delete = 0;
+  p_td_ta_delete = (p_td_ta_delete_t) env->GetLongField(this_obj, p_td_ta_delete_ID);
+
+  td_thragent_t *p_td_thragent_t = 0;
+  p_td_thragent_t = (td_thragent_t*) env->GetLongField(this_obj, p_td_thragent_t_ID);
+  if (p_td_thragent_t != 0 && p_td_ta_delete != 0) {
+     p_td_ta_delete(p_td_thragent_t);
+  }
+
+  // dlclose libthread_db.so
+  void* libthread_db_handle = (void*) env->GetLongField(this_obj, libthread_db_handle_ID);
+  if (libthread_db_handle != 0) {
+    dlclose(libthread_db_handle);
+  }
+
+  env->SetLongField(this_obj, libthread_db_handle_ID, (jlong)0);
+  env->SetLongField(this_obj, p_td_init_ID, (jlong)0);
+  env->SetLongField(this_obj, p_td_ta_new_ID, (jlong)0);
+  env->SetLongField(this_obj, p_td_ta_delete_ID, (jlong)0);
+  env->SetLongField(this_obj, p_td_ta_thr_iter_ID, (jlong)0);
+  env->SetLongField(this_obj, p_td_thr_get_info_ID, (jlong)0);
+  env->SetLongField(this_obj, p_td_ta_map_id2thr_ID, (jlong)0);
+  env->SetLongField(this_obj, p_td_thr_getgregs_ID, (jlong)0);
+}
+
+
+static void detach_internal(JNIEnv* env, jobject this_obj) {
+  // clear libthread_db stuff
+  clear_libthread_db_ptrs(env, this_obj);
+
+  // release ptr to ps_prochandle
+  jlong p_ps_prochandle;
+  p_ps_prochandle = env->GetLongField(this_obj, p_ps_prochandle_ID);
+  if (p_ps_prochandle != 0L) {
+    Prelease((struct ps_prochandle*) p_ps_prochandle, PRELEASE_CLEAR);
+  }
+
+  // part of the class sharing workaround
+  int classes_jsa_fd = env->GetIntField(this_obj, classes_jsa_fd_ID);
+  if (classes_jsa_fd != -1) {
+    close(classes_jsa_fd);
+    struct FileMapHeader* pheader = (struct FileMapHeader*) env->GetLongField(this_obj, p_file_map_header_ID);
+    if (pheader != NULL) {
+      free(pheader);
+    }
+  }
+}
+
+// Is it okay to ignore libthread_db failure? Set env var to ignore
+// libthread_db failure. You can still debug, but will miss threads
+// related functionality.
+static bool sa_ignore_threaddb = (getenv("SA_IGNORE_THREADDB") != 0);
+
+#define HANDLE_THREADDB_FAILURE(msg)          \
+  if (sa_ignore_threaddb) {                   \
+     printf("libsaproc WARNING: %s\n", msg);  \
+     return;                                  \
+  } else {                                    \
+     THROW_NEW_DEBUGGER_EXCEPTION(msg);       \
+  }
+
+#define HANDLE_THREADDB_FAILURE_(msg, ret)    \
+  if (sa_ignore_threaddb) {                   \
+     printf("libsaproc WARNING: %s\n", msg);  \
+     return ret;                              \
+  } else {                                    \
+     THROW_NEW_DEBUGGER_EXCEPTION_(msg, ret); \
+  }
+
+static const char * alt_root = NULL;
+static int alt_root_len = -1;
+
+#define SA_ALTROOT "SA_ALTROOT"
+
+static void init_alt_root() {
+  if (alt_root_len == -1) {
+    alt_root = getenv(SA_ALTROOT);
+    if (alt_root)
+      alt_root_len = strlen(alt_root);
+    else
+      alt_root_len = 0;
+  }
+}
+
+// This function is a complete substitute for the open system call
+// since it's also used to override open calls from libproc to
+// implement as a pathmap style facility for the SA.  If libproc
+// starts using other interfaces then this might have to extended to
+// cover other calls.
+extern "C" int libsaproc_open(const char * name, int oflag, ...) {
+  if (oflag == O_RDONLY) {
+    init_alt_root();
+
+    if (_libsaproc_debug) {
+      printf("libsaproc DEBUG: libsaproc_open %s\n", name);
+    }
+
+    if (alt_root_len > 0) {
+      int fd = -1;
+      char alt_path[PATH_MAX+1];
+
+      strcpy(alt_path, alt_root);
+      strcat(alt_path, name);
+      fd = open(alt_path, O_RDONLY);
+      if (fd >= 0) {
+        if (_libsaproc_debug) {
+          printf("libsaproc DEBUG: libsaproc_open substituted %s\n", alt_path);
+        }
+        return fd;
+      }
+
+      if (strrchr(name, '/')) {
+        strcpy(alt_path, alt_root);
+        strcat(alt_path, strrchr(name, '/'));
+        fd = open(alt_path, O_RDONLY);
+        if (fd >= 0) {
+          if (_libsaproc_debug) {
+            printf("libsaproc DEBUG: libsaproc_open substituted %s\n", alt_path);
+          }
+          return fd;
+        }
+      }
+    }
+  }
+
+  {
+    mode_t mode;
+    va_list ap;
+    va_start(ap, oflag);
+    mode = va_arg(ap, mode_t);
+    va_end(ap);
+
+    return open(name, oflag, mode);
+  }
+}
+
+
+static void * pathmap_dlopen(const char * name, int mode) {
+  init_alt_root();
+
+  if (_libsaproc_debug) {
+    printf("libsaproc DEBUG: pathmap_dlopen %s\n", name);
+  }
+
+  void * handle = NULL;
+  if (alt_root_len > 0) {
+    char alt_path[PATH_MAX+1];
+    strcpy(alt_path, alt_root);
+    strcat(alt_path, name);
+    handle = dlopen(alt_path, mode);
+    if (_libsaproc_debug && handle) {
+      printf("libsaproc DEBUG: pathmap_dlopen substituted %s\n", alt_path);
+    }
+
+    if (handle == NULL && strrchr(name, '/')) {
+      strcpy(alt_path, alt_root);
+      strcat(alt_path, strrchr(name, '/'));
+      handle = dlopen(alt_path, mode);
+      if (_libsaproc_debug && handle) {
+        printf("libsaproc DEBUG: pathmap_dlopen substituted %s\n", alt_path);
+      }
+    }
+  }
+  if (handle == NULL) {
+    handle = dlopen(name, mode);
+  }
+  if (_libsaproc_debug) {
+    printf("libsaproc DEBUG: pathmap_dlopen %s return 0x%lx\n", name, (unsigned long) handle);
+  }
+  return handle;
+}
+
+// libproc and libthread_db callback functions
+
+extern "C" {
+
+static int
+init_libthread_db_ptrs(void *cd, const prmap_t *pmp, const char *object_name) {
+  Debugger* dbg = (Debugger*) cd;
+  JNIEnv* env = dbg->env;
+  jobject this_obj = dbg->this_obj;
+  struct ps_prochandle* ph = (struct ps_prochandle*) env->GetLongField(this_obj, p_ps_prochandle_ID);
+
+  char *s1 = 0, *s2 = 0;
+  char libthread_db[PATH_MAX];
+
+  if (strstr(object_name, "/libthread.so.") == NULL)
+     return (0);
+
+  /*
+   * We found a libthread.
+   * dlopen() the matching libthread_db and get the thread agent handle.
+   */
+  if (Pstatus(ph)->pr_dmodel == PR_MODEL_NATIVE) {
+     (void) strcpy(libthread_db, object_name);
+     s1 = (char*) strstr(object_name, ".so.");
+     s2 = (char*) strstr(libthread_db, ".so.");
+     (void) strcpy(s2, "_db");
+     s2 += 3;
+     (void) strcpy(s2, s1);
+  } else {
+#ifdef _LP64
+     /*
+      * The victim process is 32-bit, we are 64-bit.
+      * We have to find the 64-bit version of libthread_db
+      * that matches the victim's 32-bit version of libthread.
+      */
+     (void) strcpy(libthread_db, object_name);
+     s1 = (char*) strstr(object_name, "/libthread.so.");
+     s2 = (char*) strstr(libthread_db, "/libthread.so.");
+     (void) strcpy(s2, "/64");
+     s2 += 3;
+     (void) strcpy(s2, s1);
+     s1 = (char*) strstr(s1, ".so.");
+     s2 = (char*) strstr(s2, ".so.");
+     (void) strcpy(s2, "_db");
+     s2 += 3;
+     (void) strcpy(s2, s1);
+#else
+     return (0);
+#endif  /* _LP64 */
+  }
+
+  void* libthread_db_handle = 0;
+  if ((libthread_db_handle = pathmap_dlopen(libthread_db, RTLD_LAZY|RTLD_LOCAL)) == NULL) {
+     char errMsg[PATH_MAX + 256];
+     sprintf(errMsg, "Can't load %s!", libthread_db);
+     HANDLE_THREADDB_FAILURE_(errMsg, 0);
+  }
+  env->SetLongField(this_obj, libthread_db_handle_ID, (jlong)(uintptr_t)libthread_db_handle);
+
+  void* tmpPtr = 0;
+  tmpPtr = dlsym(libthread_db_handle, "td_init");
+  if (tmpPtr == 0) {
+     HANDLE_THREADDB_FAILURE_("dlsym failed on td_init!", 0);
+  }
+  env->SetLongField(this_obj, p_td_init_ID, (jlong)(uintptr_t) tmpPtr);
+
+  tmpPtr =dlsym(libthread_db_handle, "td_ta_new");
+  if (tmpPtr == 0) {
+     HANDLE_THREADDB_FAILURE_("dlsym failed on td_ta_new!", 0);
+  }
+  env->SetLongField(this_obj, p_td_ta_new_ID, (jlong)(uintptr_t) tmpPtr);
+
+  tmpPtr = dlsym(libthread_db_handle, "td_ta_delete");
+  if (tmpPtr == 0) {
+     HANDLE_THREADDB_FAILURE_("dlsym failed on td_ta_delete!", 0);
+  }
+  env->SetLongField(this_obj, p_td_ta_delete_ID, (jlong)(uintptr_t) tmpPtr);
+
+  tmpPtr = dlsym(libthread_db_handle, "td_ta_thr_iter");
+  if (tmpPtr == 0) {
+     HANDLE_THREADDB_FAILURE_("dlsym failed on td_ta_thr_iter!", 0);
+  }
+  env->SetLongField(this_obj, p_td_ta_thr_iter_ID, (jlong)(uintptr_t) tmpPtr);
+
+  tmpPtr = dlsym(libthread_db_handle, "td_thr_get_info");
+  if (tmpPtr == 0) {
+     HANDLE_THREADDB_FAILURE_("dlsym failed on td_thr_get_info!", 0);
+  }
+  env->SetLongField(this_obj, p_td_thr_get_info_ID, (jlong)(uintptr_t) tmpPtr);
+
+  tmpPtr = dlsym(libthread_db_handle, "td_ta_map_id2thr");
+  if (tmpPtr == 0) {
+     HANDLE_THREADDB_FAILURE_("dlsym failed on td_ta_map_id2thr!", 0);
+  }
+  env->SetLongField(this_obj, p_td_ta_map_id2thr_ID, (jlong)(uintptr_t) tmpPtr);
+
+  tmpPtr = dlsym(libthread_db_handle, "td_thr_getgregs");
+  if (tmpPtr == 0) {
+     HANDLE_THREADDB_FAILURE_("dlsym failed on td_thr_getgregs!", 0);
+  }
+  env->SetLongField(this_obj, p_td_thr_getgregs_ID, (jlong)(uintptr_t) tmpPtr);
+
+  return 1;
+}
+
+static int
+fill_thread_list(const td_thrhandle_t *p_td_thragent_t, void* cd) {
+  DebuggerWithObject* dbgo = (DebuggerWithObject*) cd;
+  JNIEnv* env = dbgo->env;
+  jobject this_obj = dbgo->this_obj;
+  jobject list = dbgo->obj;
+
+  td_thrinfo_t thrinfo;
+  p_td_thr_get_info_t p_td_thr_get_info = (p_td_thr_get_info_t) env->GetLongField(this_obj, p_td_thr_get_info_ID);
+
+  if (p_td_thr_get_info(p_td_thragent_t, &thrinfo) != TD_OK)
+    return (0);
+
+  jobject threadProxy = env->CallObjectMethod(this_obj, getThreadForThreadId_ID, (jlong)(uintptr_t) thrinfo.ti_tid);
+  CHECK_EXCEPTION_(1);
+  env->CallBooleanMethod(list, listAdd_ID, threadProxy);
+  CHECK_EXCEPTION_(1);
+  return 0;
+}
+
+static int
+fill_load_object_list(void *cd, const prmap_t* pmp, const char* obj_name) {
+
+  if (obj_name) {
+     DebuggerWithObject* dbgo = (DebuggerWithObject*) cd;
+     JNIEnv* env = dbgo->env;
+     jobject this_obj = dbgo->this_obj;
+     jobject list = dbgo->obj;
+
+     jstring objectName = env->NewStringUTF(obj_name);
+     CHECK_EXCEPTION_(1);
+
+     jlong mapSize = (jlong) pmp->pr_size;
+     jobject sharedObject = env->CallObjectMethod(this_obj, createLoadObject_ID,
+                                  objectName, mapSize, (jlong)(uintptr_t)pmp->pr_vaddr);
+     CHECK_EXCEPTION_(1);
+     env->CallBooleanMethod(list, listAdd_ID, sharedObject);
+     CHECK_EXCEPTION_(1);
+  }
+
+  return 0;
+}
+
+// Pstack_iter() proc_stack_f callback prior to Nevada-B159
+static int
+fill_cframe_list(void *cd, const prgregset_t regs, uint_t argc, const long *argv) {
+  DebuggerWith2Objects* dbgo2 = (DebuggerWith2Objects*) cd;
+  JNIEnv* env = dbgo2->env;
+  jobject this_obj = dbgo2->this_obj;
+  jobject curFrame = dbgo2->obj2;
+
+  jint pcRegIndex = env->GetIntField(this_obj, pcRegIndex_ID);
+  jint fpRegIndex = env->GetIntField(this_obj, fpRegIndex_ID);
+
+  jlong pc = (jlong) (uintptr_t) regs[pcRegIndex];
+  jlong fp = (jlong) (uintptr_t) regs[fpRegIndex];
+
+  dbgo2->obj2 = env->CallObjectMethod(this_obj, createSenderFrame_ID,
+                                    curFrame, pc, fp);
+  CHECK_EXCEPTION_(1);
+  if (dbgo2->obj == 0) {
+     dbgo2->obj = dbgo2->obj2;
+  }
+  return 0;
+}
+
+// Pstack_iter() proc_stack_f callback in Nevada-B159 or later
+/*ARGSUSED*/
+static int
+wrapper_fill_cframe_list(void *cd, const prgregset_t regs, uint_t argc,
+                         const long *argv, int frame_flags, int sig) {
+  return(fill_cframe_list(cd, regs, argc, argv));
+}
+
+// part of the class sharing workaround
+
+// FIXME: !!HACK ALERT!!
+
+// The format of sharing achive file header is needed to read shared heap
+// file mappings. For now, I am hard coding portion of FileMapHeader here.
+// Refer to filemap.hpp.
+
+// FileMapHeader describes the shared space data in the file to be
+// mapped.  This structure gets written to a file.  It is not a class, so
+// that the compilers don't add any compiler-private data to it.
+
+const int NUM_SHARED_MAPS = 4;
+
+// Refer to FileMapInfo::_current_version in filemap.hpp
+const int CURRENT_ARCHIVE_VERSION = 1;
+
+struct FileMapHeader {
+ int   _magic;              // identify file type.
+ int   _version;            // (from enum, above.)
+ size_t _alignment;         // how shared archive should be aligned
+
+
+ struct space_info {
+   int    _file_offset;     // sizeof(this) rounded to vm page size
+   char*  _base;            // copy-on-write base address
+   size_t _capacity;        // for validity checking
+   size_t _used;            // for setting space top on read
+
+   bool   _read_only;       // read only space?
+   bool   _allow_exec;      // executable code in space?
+
+ } _space[NUM_SHARED_MAPS];
+
+ // Ignore the rest of the FileMapHeader. We don't need those fields here.
+};
+
+static bool
+read_jboolean(struct ps_prochandle* ph, psaddr_t addr, jboolean* pvalue) {
+  jboolean i;
+  if (ps_pread(ph, addr, &i, sizeof(i)) == PS_OK) {
+    *pvalue = i;
+    return true;
+  } else {
+    return false;
+  }
+}
+
+static bool
+read_pointer(struct ps_prochandle* ph, psaddr_t addr, uintptr_t* pvalue) {
+  uintptr_t uip;
+  if (ps_pread(ph, addr, &uip, sizeof(uip)) == PS_OK) {
+    *pvalue = uip;
+    return true;
+  } else {
+    return false;
+  }
+}
+
+static bool
+read_string(struct ps_prochandle* ph, psaddr_t addr, char* buf, size_t size) {
+  char ch = ' ';
+  size_t i = 0;
+
+  while (ch != '\0') {
+    if (ps_pread(ph, addr, &ch, sizeof(ch)) != PS_OK)
+      return false;
+
+    if (i < size - 1) {
+      buf[i] = ch;
+    } else { // smaller buffer
+      return false;
+    }
+
+    i++; addr++;
+  }
+
+  buf[i] = '\0';
+  return true;
+}
+
+#define USE_SHARED_SPACES_SYM   "UseSharedSpaces"
+// mangled symbol name for Arguments::SharedArchivePath
+#define SHARED_ARCHIVE_PATH_SYM "__1cJArgumentsRSharedArchivePath_"
+
+static int
+init_classsharing_workaround(void *cd, const prmap_t* pmap, const char* obj_name) {
+  Debugger* dbg = (Debugger*) cd;
+  JNIEnv*   env = dbg->env;
+  jobject this_obj = dbg->this_obj;
+  const char* jvm_name = 0;
+  if ((jvm_name = strstr(obj_name, "libjvm.so")) != NULL) {
+    jvm_name = obj_name;
+  } else {
+    return 0;
+  }
+
+  struct ps_prochandle* ph = (struct ps_prochandle*) env->GetLongField(this_obj, p_ps_prochandle_ID);
+
+  // initialize classes.jsa file descriptor field.
+  dbg->env->SetIntField(this_obj, classes_jsa_fd_ID, -1);
+
+  // check whether class sharing is on by reading variable "UseSharedSpaces"
+  psaddr_t useSharedSpacesAddr = 0;
+  ps_pglobal_lookup(ph, jvm_name, USE_SHARED_SPACES_SYM, &useSharedSpacesAddr);
+  if (useSharedSpacesAddr == 0) {
+    THROW_NEW_DEBUGGER_EXCEPTION_("can't find 'UseSharedSpaces' flag\n", 1);
+  }
+
+  // read the value of the flag "UseSharedSpaces"
+  // Since hotspot types are not available to build this library. So
+  // equivalent type "jboolean" is used to read the value of "UseSharedSpaces"
+  // which is same as hotspot type "bool".
+  jboolean value = 0;
+  if (read_jboolean(ph, useSharedSpacesAddr, &value) != true) {
+    THROW_NEW_DEBUGGER_EXCEPTION_("can't read 'UseSharedSpaces' flag", 1);
+  } else if ((int)value == 0) {
+    print_debug("UseSharedSpaces is false, assuming -Xshare:off!\n");
+    return 1;
+  }
+
+  char classes_jsa[PATH_MAX];
+  psaddr_t sharedArchivePathAddrAddr = 0;
+  ps_pglobal_lookup(ph, jvm_name, SHARED_ARCHIVE_PATH_SYM, &sharedArchivePathAddrAddr);
+  if (sharedArchivePathAddrAddr == 0) {
+    print_debug("can't find symbol 'Arguments::SharedArchivePath'\n");
+    THROW_NEW_DEBUGGER_EXCEPTION_("can't get shared archive path from debuggee", 1);
+  }
+
+  uintptr_t sharedArchivePathAddr = 0;
+  if (read_pointer(ph, sharedArchivePathAddrAddr, &sharedArchivePathAddr) != true) {
+    print_debug("can't find read pointer 'Arguments::SharedArchivePath'\n");
+    THROW_NEW_DEBUGGER_EXCEPTION_("can't get shared archive path from debuggee", 1);
+  }
+
+  if (read_string(ph, (psaddr_t)sharedArchivePathAddr, classes_jsa, sizeof(classes_jsa)) != true) {
+    print_debug("can't find read 'Arguments::SharedArchivePath' value\n");
+    THROW_NEW_DEBUGGER_EXCEPTION_("can't get shared archive path from debuggee", 1);
+  }
+
+  print_debug("looking for %s\n", classes_jsa);
+
+  // open the classes.jsa
+  int fd = libsaproc_open(classes_jsa, O_RDONLY);
+  if (fd < 0) {
+    char errMsg[ERR_MSG_SIZE];
+    sprintf(errMsg, "can't open shared archive file %s", classes_jsa);
+    THROW_NEW_DEBUGGER_EXCEPTION_(errMsg, 1);
+  } else {
+    print_debug("opened shared archive file %s\n", classes_jsa);
+  }
+
+  // parse classes.jsa
+  struct FileMapHeader* pheader = (struct FileMapHeader*) malloc(sizeof(struct FileMapHeader));
+  if (pheader == NULL) {
+    close(fd);
+    THROW_NEW_DEBUGGER_EXCEPTION_("can't allocate memory for shared file map header", 1);
+  }
+
+  memset(pheader, 0, sizeof(struct FileMapHeader));
+  // read FileMapHeader
+  size_t n = read(fd, pheader, sizeof(struct FileMapHeader));
+  if (n != sizeof(struct FileMapHeader)) {
+    char errMsg[ERR_MSG_SIZE];
+    sprintf(errMsg, "unable to read shared archive file map header from %s", classes_jsa);
+    close(fd);
+    free(pheader);
+    THROW_NEW_DEBUGGER_EXCEPTION_(errMsg, 1);
+  }
+
+  // check file magic
+  if (pheader->_magic != 0xf00baba2) {
+    char errMsg[ERR_MSG_SIZE];
+    sprintf(errMsg, "%s has bad shared archive magic 0x%x, expecting 0xf00baba2",
+                   classes_jsa, pheader->_magic);
+    close(fd);
+    free(pheader);
+    THROW_NEW_DEBUGGER_EXCEPTION_(errMsg, 1);
+  }
+
+  // check version
+  if (pheader->_version != CURRENT_ARCHIVE_VERSION) {
+    char errMsg[ERR_MSG_SIZE];
+    sprintf(errMsg, "%s has wrong shared archive version %d, expecting %d",
+                   classes_jsa, pheader->_version, CURRENT_ARCHIVE_VERSION);
+    close(fd);
+    free(pheader);
+    THROW_NEW_DEBUGGER_EXCEPTION_(errMsg, 1);
+  }
+
+  if (_libsaproc_debug) {
+    for (int m = 0; m < NUM_SHARED_MAPS; m++) {
+       print_debug("shared file offset %d mapped at 0x%lx, size = %ld, read only? = %d\n",
+          pheader->_space[m]._file_offset, pheader->_space[m]._base,
+          pheader->_space[m]._used, pheader->_space[m]._read_only);
+    }
+  }
+
+  // FIXME: For now, omitting other checks such as VM version etc.
+
+  // store class archive file fd and map header in debugger object fields
+  dbg->env->SetIntField(this_obj, classes_jsa_fd_ID, fd);
+  dbg->env->SetLongField(this_obj, p_file_map_header_ID, (jlong)(uintptr_t) pheader);
+  return 1;
+}
+
+} // extern "C"
+
+// error messages for proc_arg_grab failure codes. The messages are
+// modified versions of comments against corresponding #defines in
+// libproc.h.
+static const char* proc_arg_grab_errmsgs[] = {
+                      "",
+ /* G_NOPROC */       "No such process",
+ /* G_NOCORE */       "No such core file",
+ /* G_NOPROCORCORE */ "No such process or core",
+ /* G_NOEXEC */       "Cannot locate executable file",
+ /* G_ZOMB   */       "Zombie processs",
+ /* G_PERM   */       "No permission to attach",
+ /* G_BUSY   */       "Another process has already attached",
+ /* G_SYS    */       "System process - can not attach",
+ /* G_SELF   */       "Process is self - can't debug myself!",
+ /* G_INTR   */       "Interrupt received while grabbing",
+ /* G_LP64   */       "debuggee is 64 bit, use java -d64 for debugger",
+ /* G_FORMAT */       "File is not an ELF format core file - corrupted core?",
+ /* G_ELF    */       "Libelf error while parsing an ELF file",
+ /* G_NOTE   */       "Required PT_NOTE Phdr not present - corrupted core?",
+};
+
+static void attach_internal(JNIEnv* env, jobject this_obj, jstring cmdLine, jboolean isProcess) {
+  jboolean isCopy;
+  int gcode;
+  const char* cmdLine_cstr = env->GetStringUTFChars(cmdLine, &isCopy);
+  CHECK_EXCEPTION;
+
+  // some older versions of libproc.so crash when trying to attach 32 bit
+  // debugger to 64 bit core file. check and throw error.
+#ifndef _LP64
+  atoi(cmdLine_cstr);
+  if (errno) {
+     // core file
+     int core_fd;
+     if ((core_fd = open64(cmdLine_cstr, O_RDONLY)) >= 0) {
+        Elf32_Ehdr e32;
+        if (pread64(core_fd, &e32, sizeof (e32), 0) == sizeof (e32) &&
+            memcmp(&e32.e_ident[EI_MAG0], ELFMAG, SELFMAG) == 0 &&
+            e32.e_type == ET_CORE && e32.e_ident[EI_CLASS] == ELFCLASS64) {
+              close(core_fd);
+              THROW_NEW_DEBUGGER_EXCEPTION("debuggee is 64 bit, use java -d64 for debugger");
+        }
+        close(core_fd);
+     }
+     // all other conditions are handled by libproc.so.
+  }
+#endif
+
+  // connect to process/core
+  struct ps_prochandle* ph = proc_arg_grab(cmdLine_cstr, (isProcess? PR_ARG_PIDS : PR_ARG_CORES), PGRAB_FORCE, &gcode);
+  env->ReleaseStringUTFChars(cmdLine, cmdLine_cstr);
+  if (! ph) {
+     if (gcode > 0 && gcode < sizeof(proc_arg_grab_errmsgs)/sizeof(const char*)) {
+        char errMsg[ERR_MSG_SIZE];
+        sprintf(errMsg, "Attach failed : %s", proc_arg_grab_errmsgs[gcode]);
+        THROW_NEW_DEBUGGER_EXCEPTION(errMsg);
+    } else {
+        if (_libsaproc_debug && gcode == G_STRANGE) {
+           perror("libsaproc DEBUG: ");
+        }
+        if (isProcess) {
+           THROW_NEW_DEBUGGER_EXCEPTION("Not able to attach to process!");
+        } else {
+           THROW_NEW_DEBUGGER_EXCEPTION("Not able to attach to core file!");
+        }
+     }
+  }
+
+  // even though libproc.so supports 64 bit debugger and 32 bit debuggee, we don't
+  // support such cross-bit-debugging. check for that combination and throw error.
+#ifdef _LP64
+  int data_model;
+  if (ps_pdmodel(ph, &data_model) != PS_OK) {
+     Prelease(ph, PRELEASE_CLEAR);
+     THROW_NEW_DEBUGGER_EXCEPTION("can't determine debuggee data model (ILP32? or LP64?)");
+  }
+  if (data_model == PR_MODEL_ILP32) {
+     Prelease(ph, PRELEASE_CLEAR);
+     THROW_NEW_DEBUGGER_EXCEPTION("debuggee is 32 bit, use 32 bit java for debugger");
+  }
+#endif
+
+  env->SetLongField(this_obj, p_ps_prochandle_ID, (jlong)(uintptr_t)ph);
+
+  Debugger dbg;
+  dbg.env = env;
+  dbg.this_obj = this_obj;
+  jthrowable exception = 0;
+  if (! isProcess) {
+    /*
+     * With class sharing, shared perm. gen heap is allocated in with MAP_SHARED|PROT_READ.
+     * These pages are mapped from the file "classes.jsa". MAP_SHARED pages are not dumped
+     * in Solaris core.To read shared heap pages, we have to read classes.jsa file.
+     */
+    Pobject_iter(ph, init_classsharing_workaround, &dbg);
+    exception = env->ExceptionOccurred();
+    if (exception) {
+      env->ExceptionClear();
+      detach_internal(env, this_obj);
+      env->Throw(exception);
+      return;
+    }
+  }
+
+  /*
+   * Iterate over the process mappings looking
+   * for libthread and then dlopen the appropriate
+   * libthread_db and get function pointers.
+   */
+  Pobject_iter(ph, init_libthread_db_ptrs, &dbg);
+  exception = env->ExceptionOccurred();
+  if (exception) {
+    env->ExceptionClear();
+    if (!sa_ignore_threaddb) {
+      detach_internal(env, this_obj);
+      env->Throw(exception);
+    }
+    return;
+  }
+
+  // init libthread_db and create thread_db agent
+  p_td_init_t p_td_init = (p_td_init_t) env->GetLongField(this_obj, p_td_init_ID);
+  if (p_td_init == 0) {
+    if (!sa_ignore_threaddb) {
+      detach_internal(env, this_obj);
+    }
+    HANDLE_THREADDB_FAILURE("Did not find libthread in target process/core!");
+  }
+
+  if (p_td_init() != TD_OK) {
+    if (!sa_ignore_threaddb) {
+      detach_internal(env, this_obj);
+    }
+    HANDLE_THREADDB_FAILURE("Can't initialize thread_db!");
+  }
+
+  p_td_ta_new_t p_td_ta_new = (p_td_ta_new_t) env->GetLongField(this_obj, p_td_ta_new_ID);
+
+  td_thragent_t *p_td_thragent_t = 0;
+  if (p_td_ta_new(ph, &p_td_thragent_t) != TD_OK) {
+    if (!sa_ignore_threaddb) {
+      detach_internal(env, this_obj);
+    }
+    HANDLE_THREADDB_FAILURE("Can't create thread_db agent!");
+  }
+  env->SetLongField(this_obj, p_td_thragent_t_ID, (jlong)(uintptr_t) p_td_thragent_t);
+
+}
+
+/*
+ * Class:     sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal
+ * Method:    attach0
+ * Signature: (Ljava/lang/String;)V
+ * Description: process detach
+ */
+JNIEXPORT void JNICALL Java_sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal_attach0__Ljava_lang_String_2
+  (JNIEnv *env, jobject this_obj, jstring pid) {
+  attach_internal(env, this_obj, pid, JNI_TRUE);
+}
+
+/*
+ * Class:     sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal
+ * Method:    attach0
+ * Signature: (Ljava/lang/String;Ljava/lang/String;)V
+ * Description: core file detach
+ */
+JNIEXPORT void JNICALL Java_sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal_attach0__Ljava_lang_String_2Ljava_lang_String_2
+  (JNIEnv *env, jobject this_obj, jstring executable, jstring corefile) {
+  // ignore executable file name, libproc.so can detect a.out name anyway.
+  attach_internal(env, this_obj, corefile, JNI_FALSE);
+}
+
+
+/*
+ * Class:       sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal
+ * Method:      detach0
+ * Signature:   ()V
+ * Description: process/core file detach
+ */
+JNIEXPORT void JNICALL Java_sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal_detach0
+  (JNIEnv *env, jobject this_obj) {
+  detach_internal(env, this_obj);
+}
+
+/*
+ * Class:       sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal
+ * Method:      getRemoteProcessAddressSize0
+ * Signature:   ()I
+ * Description: get process/core address size
+ */
+JNIEXPORT jint JNICALL Java_sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal_getRemoteProcessAddressSize0
+  (JNIEnv *env, jobject this_obj) {
+  jlong p_ps_prochandle;
+  p_ps_prochandle = env->GetLongField(this_obj, p_ps_prochandle_ID);
+  int data_model = PR_MODEL_ILP32;
+  ps_pdmodel((struct ps_prochandle*) p_ps_prochandle, &data_model);
+  print_debug("debuggee is %d bit\n", data_model == PR_MODEL_ILP32? 32 : 64);
+  return (jint) data_model == PR_MODEL_ILP32? 32 : 64;
+}
+
+/*
+ * Class:       sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal
+ * Method:      getPageSize0
+ * Signature:   ()I
+ * Description: get process/core page size
+ */
+JNIEXPORT jint JNICALL Java_sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal_getPageSize0
+  (JNIEnv *env, jobject this_obj) {
+
+/*
+  We are not yet attached to a java process or core file. getPageSize is called from
+  the constructor of ProcDebuggerLocal. The following won't work!
+
+    jlong p_ps_prochandle;
+    p_ps_prochandle = env->GetLongField(this_obj, p_ps_prochandle_ID);
+    CHECK_EXCEPTION_(-1);
+    struct ps_prochandle* prochandle = (struct ps_prochandle*) p_ps_prochandle;
+    return (Pstate(prochandle) == PS_DEAD) ? Pgetauxval(prochandle, AT_PAGESZ)
+                                           : getpagesize();
+
+  So even though core may have been generated with a different page size settings, for now
+  call getpagesize.
+*/
+
+  return getpagesize();
+}
+
+/*
+ * Class:       sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal
+ * Method:      getThreadIntegerRegisterSet0
+ * Signature:   (J)[J
+ * Description: get gregset for a given thread specified by thread id
+ */
+JNIEXPORT jlongArray JNICALL Java_sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal_getThreadIntegerRegisterSet0
+  (JNIEnv *env, jobject this_obj, jlong tid) {
+  // map the thread id to thread handle
+  p_td_ta_map_id2thr_t p_td_ta_map_id2thr = (p_td_ta_map_id2thr_t) env->GetLongField(this_obj, p_td_ta_map_id2thr_ID);
+
+  td_thragent_t* p_td_thragent_t = (td_thragent_t*) env->GetLongField(this_obj, p_td_thragent_t_ID);
+  if (p_td_thragent_t == 0) {
+     return 0;
+  }
+
+  td_thrhandle_t thr_handle;
+  if (p_td_ta_map_id2thr(p_td_thragent_t, (thread_t) tid, &thr_handle) != TD_OK) {
+     THROW_NEW_DEBUGGER_EXCEPTION_("can't map thread id to thread handle!", 0);
+  }
+
+  p_td_thr_getgregs_t p_td_thr_getgregs = (p_td_thr_getgregs_t) env->GetLongField(this_obj, p_td_thr_getgregs_ID);
+  prgregset_t gregs;
+  p_td_thr_getgregs(&thr_handle, gregs);
+
+  jlongArray res = env->NewLongArray(NPRGREG);
+  CHECK_EXCEPTION_(0);
+  jboolean isCopy;
+  jlong* ptr = env->GetLongArrayElements(res, &isCopy);
+  CHECK_EXCEPTION_(NULL);
+  for (int i = 0; i < NPRGREG; i++) {
+    ptr[i] = (jlong) (uintptr_t) gregs[i];
+  }
+  env->ReleaseLongArrayElements(res, ptr, JNI_COMMIT);
+  return res;
+}
+
+/*
+ * Class:       sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal
+ * Method:      fillThreadList0
+ * Signature:   (Ljava/util/List;)V
+ * Description: fills thread list of the debuggee process/core
+ */
+JNIEXPORT void JNICALL Java_sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal_fillThreadList0
+  (JNIEnv *env, jobject this_obj, jobject list) {
+
+  td_thragent_t* p_td_thragent_t = (td_thragent_t*) env->GetLongField(this_obj, p_td_thragent_t_ID);
+  if (p_td_thragent_t == 0) {
+     return;
+  }
+
+  p_td_ta_thr_iter_t p_td_ta_thr_iter = (p_td_ta_thr_iter_t) env->GetLongField(this_obj, p_td_ta_thr_iter_ID);
+
+  DebuggerWithObject dbgo;
+  dbgo.env = env;
+  dbgo.this_obj = this_obj;
+  dbgo.obj = list;
+
+  p_td_ta_thr_iter(p_td_thragent_t, fill_thread_list, &dbgo,
+                   TD_THR_ANY_STATE, TD_THR_LOWEST_PRIORITY, TD_SIGNO_MASK, TD_THR_ANY_USER_FLAGS);
+}
+
+#ifndef SOLARIS_11_B159_OR_LATER
+// building on Nevada-B158 or earlier so more hoops to jump through
+static bool has_newer_Pstack_iter = false;  // older version by default
+#endif
+
+/*
+ * Class:       sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal
+ * Method:      fillCFrameList0
+ * Signature:   ([J)Lsun/jvm/hotspot/debugger/proc/ProcCFrame;
+ * Description: fills CFrame list for a given thread
+ */
+JNIEXPORT jobject JNICALL Java_sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal_fillCFrameList0
+  (JNIEnv *env, jobject this_obj, jlongArray regsArray) {
+  jlong p_ps_prochandle = env->GetLongField(this_obj, p_ps_prochandle_ID);
+
+  DebuggerWith2Objects dbgo2;
+  dbgo2.env  = env;
+  dbgo2.this_obj = this_obj;
+  dbgo2.obj  = NULL;
+  dbgo2.obj2 = NULL;
+
+  jboolean isCopy;
+  jlong* ptr = env->GetLongArrayElements(regsArray, &isCopy);
+  CHECK_EXCEPTION_(0);
+
+  prgregset_t gregs;
+  for (int i = 0; i < NPRGREG; i++) {
+     gregs[i] = (uintptr_t) ptr[i];
+  }
+
+  env->ReleaseLongArrayElements(regsArray, ptr, JNI_ABORT);
+  CHECK_EXCEPTION_(0);
+
+#ifdef SOLARIS_11_B159_OR_LATER
+  // building on Nevada-B159 or later so use the new callback
+  Pstack_iter((struct ps_prochandle*) p_ps_prochandle, gregs,
+              wrapper_fill_cframe_list, &dbgo2);
+#else
+  // building on Nevada-B158 or earlier so figure out which callback to use
+
+  if (has_newer_Pstack_iter) {
+    // Since we're building on Nevada-B158 or earlier, we have to
+    // cast wrapper_fill_cframe_list to make the compiler happy.
+    Pstack_iter((struct ps_prochandle*) p_ps_prochandle, gregs,
+                (proc_stack_f *)wrapper_fill_cframe_list, &dbgo2);
+  } else {
+    Pstack_iter((struct ps_prochandle*) p_ps_prochandle, gregs,
+                fill_cframe_list, &dbgo2);
+  }
+#endif // SOLARIS_11_B159_OR_LATER
+  return dbgo2.obj;
+}
+
+/*
+ * Class:       sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal
+ * Method:      fillLoadObjectList0
+ * Signature:   (Ljava/util/List;)V
+ * Description: fills shared objects of the debuggee process/core
+ */
+JNIEXPORT void JNICALL Java_sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal_fillLoadObjectList0
+  (JNIEnv *env, jobject this_obj, jobject list) {
+  DebuggerWithObject dbgo;
+  dbgo.env = env;
+  dbgo.this_obj = this_obj;
+  dbgo.obj = list;
+
+  jlong p_ps_prochandle = env->GetLongField(this_obj, p_ps_prochandle_ID);
+  Pobject_iter((struct ps_prochandle*) p_ps_prochandle, fill_load_object_list, &dbgo);
+}
+
+/*
+ * Class:       sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal
+ * Method:      readBytesFromProcess0
+ * Signature:   (JJ)[B
+ * Description: read bytes from debuggee process/core
+ */
+JNIEXPORT jbyteArray JNICALL Java_sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal_readBytesFromProcess0
+  (JNIEnv *env, jobject this_obj, jlong address, jlong numBytes) {
+
+  jbyteArray array = env->NewByteArray(numBytes);
+  CHECK_EXCEPTION_(0);
+  jboolean isCopy;
+  jbyte* bufPtr = env->GetByteArrayElements(array, &isCopy);
+  CHECK_EXCEPTION_(0);
+
+  jlong p_ps_prochandle = env->GetLongField(this_obj, p_ps_prochandle_ID);
+  ps_err_e ret = ps_pread((struct ps_prochandle*) p_ps_prochandle,
+                       (psaddr_t)address, bufPtr, (size_t)numBytes);
+
+  if (ret != PS_OK) {
+    // part of the class sharing workaround. try shared heap area
+    int classes_jsa_fd = env->GetIntField(this_obj, classes_jsa_fd_ID);
+    if (classes_jsa_fd != -1 && address != (jlong)0) {
+      print_debug("read failed at 0x%lx, attempting shared heap area\n", (long) address);
+
+      struct FileMapHeader* pheader = (struct FileMapHeader*) env->GetLongField(this_obj, p_file_map_header_ID);
+      // walk through the shared mappings -- we just have 4 of them.
+      // so, linear walking is okay.
+      for (int m = 0; m < NUM_SHARED_MAPS; m++) {
+
+        // We can skip the non-read-only maps. These are mapped as MAP_PRIVATE
+        // and hence will be read by libproc. Besides, the file copy may be
+        // stale because the process might have modified those pages.
+        if (pheader->_space[m]._read_only) {
+          jlong baseAddress = (jlong) (uintptr_t) pheader->_space[m]._base;
+          size_t usedSize = pheader->_space[m]._used;
+          if (address >= baseAddress && address < (baseAddress + usedSize)) {
+            // the given address falls in this shared heap area
+            print_debug("found shared map at 0x%lx\n", (long) baseAddress);
+
+
+            // If more data is asked than actually mapped from file, we need to zero fill
+            // till the end-of-page boundary. But, java array new does that for us. we just
+            // need to read as much as data available.
+
+#define MIN2(x, y) (((x) < (y))? (x) : (y))
+
+            jlong diff = address - baseAddress;
+            jlong bytesToRead = MIN2(numBytes, usedSize - diff);
+            off_t offset = pheader->_space[m]._file_offset  + off_t(diff);
+            ssize_t bytesRead = pread(classes_jsa_fd, bufPtr, bytesToRead, offset);
+            if (bytesRead != bytesToRead) {
+              env->ReleaseByteArrayElements(array, bufPtr, JNI_ABORT);
+              print_debug("shared map read failed\n");
+              return jbyteArray(0);
+            } else {
+              print_debug("shared map read succeeded\n");
+              env->ReleaseByteArrayElements(array, bufPtr, 0);
+              return array;
+            }
+          } // is in current map
+        } // is read only map
+      } // for shared maps
+    } // classes_jsa_fd != -1
+    env->ReleaseByteArrayElements(array, bufPtr, JNI_ABORT);
+    return jbyteArray(0);
+  } else {
+    env->ReleaseByteArrayElements(array, bufPtr, 0);
+    return array;
+  }
+}
+
+/*
+ * Class:       sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal
+ * Method:      writeBytesToProcess0
+ * Signature:   (JJ[B)V
+ * Description: write bytes into debugger process
+ */
+JNIEXPORT void JNICALL Java_sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal_writeBytesToProcess0
+  (JNIEnv *env, jobject this_obj, jlong address, jlong numBytes, jbyteArray data) {
+  jlong p_ps_prochandle = env->GetLongField(this_obj, p_ps_prochandle_ID);
+  jboolean isCopy;
+  jbyte* ptr = env->GetByteArrayElements(data, &isCopy);
+  CHECK_EXCEPTION;
+
+  if (ps_pwrite((struct ps_prochandle*) p_ps_prochandle, address, ptr, numBytes) != PS_OK) {
+     env->ReleaseByteArrayElements(data, ptr, JNI_ABORT);
+     THROW_NEW_DEBUGGER_EXCEPTION("Process write failed!");
+  }
+
+  env->ReleaseByteArrayElements(data, ptr, JNI_ABORT);
+}
+
+/*
+ * Class:     sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal
+ * Method:    suspend0
+ * Signature: ()V
+ */
+JNIEXPORT void JNICALL Java_sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal_suspend0
+  (JNIEnv *env, jobject this_obj) {
+  jlong p_ps_prochandle = env->GetLongField(this_obj, p_ps_prochandle_ID);
+  // for now don't check return value. revisit this again.
+  Pstop((struct ps_prochandle*) p_ps_prochandle, 1000);
+}
+
+/*
+ * Class:     sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal
+ * Method:    resume0
+ * Signature: ()V
+ */
+JNIEXPORT void JNICALL Java_sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal_resume0
+  (JNIEnv *env, jobject this_obj) {
+  jlong p_ps_prochandle = env->GetLongField(this_obj, p_ps_prochandle_ID);
+  // for now don't check return value. revisit this again.
+  Psetrun((struct ps_prochandle*) p_ps_prochandle, 0, PRCFAULT|PRSTOP);
+}
+
+/*
+  * Class:       sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal
+  * Method:      lookupByName0
+  * Signature:   (Ljava/lang/String;Ljava/lang/String;)J
+  * Description: symbol lookup by name
+*/
+JNIEXPORT jlong JNICALL Java_sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal_lookupByName0
+   (JNIEnv *env, jobject this_obj, jstring objectName, jstring symbolName) {
+   jlong p_ps_prochandle;
+   p_ps_prochandle = env->GetLongField(this_obj, p_ps_prochandle_ID);
+
+   jboolean isCopy;
+   const char* objectName_cstr = NULL;
+   if (objectName != NULL) {
+     objectName_cstr = env->GetStringUTFChars(objectName, &isCopy);
+     CHECK_EXCEPTION_(0);
+   } else {
+     objectName_cstr = PR_OBJ_EVERY;
+   }
+
+   const char* symbolName_cstr = env->GetStringUTFChars(symbolName, &isCopy);
+   CHECK_EXCEPTION_(0);
+
+   psaddr_t symbol_addr = (psaddr_t) 0;
+   ps_pglobal_lookup((struct ps_prochandle*) p_ps_prochandle,  objectName_cstr,
+                    symbolName_cstr, &symbol_addr);
+
+   if (symbol_addr == 0) {
+      print_debug("lookup for %s in %s failed\n", symbolName_cstr, objectName_cstr);
+   }
+
+   if (objectName_cstr != PR_OBJ_EVERY) {
+     env->ReleaseStringUTFChars(objectName, objectName_cstr);
+   }
+   env->ReleaseStringUTFChars(symbolName, symbolName_cstr);
+   return (jlong) (uintptr_t) symbol_addr;
+}
+
+/*
+ * Class:       sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal
+ * Method:      lookupByAddress0
+ * Signature:   (J)Lsun/jvm/hotspot/debugger/cdbg/ClosestSymbol;
+ * Description: lookup symbol name for a given address
+ */
+JNIEXPORT jobject JNICALL Java_sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal_lookupByAddress0
+   (JNIEnv *env, jobject this_obj, jlong address) {
+   jlong p_ps_prochandle;
+   p_ps_prochandle = env->GetLongField(this_obj, p_ps_prochandle_ID);
+
+   char nameBuf[SYMBOL_BUF_SIZE + 1];
+   GElf_Sym sym;
+   int res = Plookup_by_addr((struct ps_prochandle*) p_ps_prochandle, (uintptr_t) address,
+                                 nameBuf, sizeof(nameBuf), &sym);
+   if (res != 0) { // failed
+      return 0;
+   }
+
+   jstring resSym = env->NewStringUTF(nameBuf);
+   CHECK_EXCEPTION_(0);
+
+   return env->CallObjectMethod(this_obj, createClosestSymbol_ID, resSym, (address - sym.st_value));
+}
+
+/*
+ * Class:     sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal
+ * Method:    demangle0
+ * Signature: (Ljava/lang/String;)Ljava/lang/String;
+ */
+JNIEXPORT jstring JNICALL Java_sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal_demangle0
+  (JNIEnv *env, jobject this_object, jstring name) {
+  jboolean isCopy;
+  const char* ptr = env->GetStringUTFChars(name, &isCopy);
+  CHECK_EXCEPTION_(NULL);
+  char  buf[2*SYMBOL_BUF_SIZE + 1];
+  jstring res = 0;
+  if (cplus_demangle((char*) ptr, buf, sizeof(buf)) != DEMANGLE_ESPACE) {
+    res = env->NewStringUTF(buf);
+  } else {
+    res = name;
+  }
+  env->ReleaseStringUTFChars(name, ptr);
+  return res;
+}
+
+#ifndef SOLARIS_11_B159_OR_LATER
+// Determine if the OS we're running on has the newer version
+// of libproc's Pstack_iter.
+//
+// Set env var PSTACK_ITER_DEBUG=true to debug this logic.
+// Set env var PSTACK_ITER_DEBUG_RELEASE to simulate a 'release' value.
+// Set env var PSTACK_ITER_DEBUG_VERSION to simulate a 'version' value.
+//
+// frankenputer 'uname -r -v': 5.10 Generic_141445-09
+// jurassic 'uname -r -v':     5.11 snv_164
+// lonepeak 'uname -r -v':     5.11 snv_127
+//
+static void set_has_newer_Pstack_iter(JNIEnv *env) {
+  static bool done_set = false;
+
+  if (done_set) {
+    // already set has_newer_Pstack_iter
+    return;
+  }
+
+  struct utsname name;
+  if (uname(&name) == -1) {
+    THROW_NEW_DEBUGGER_EXCEPTION("uname() failed!");
+  }
+  dprintf_2("release='%s'  version='%s'\n", name.release, name.version);
+
+  if (_Pstack_iter_debug) {
+    char *override = getenv("PSTACK_ITER_DEBUG_RELEASE");
+    if (override != NULL) {
+      strncpy(name.release, override, SYS_NMLN - 1);
+      name.release[SYS_NMLN - 2] = '\0';
+      dprintf_2("overriding with release='%s'\n", name.release);
+    }
+    override = getenv("PSTACK_ITER_DEBUG_VERSION");
+    if (override != NULL) {
+      strncpy(name.version, override, SYS_NMLN - 1);
+      name.version[SYS_NMLN - 2] = '\0';
+      dprintf_2("overriding with version='%s'\n", name.version);
+    }
+  }
+
+  // the major number corresponds to the old SunOS major number
+  int major = atoi(name.release);
+  if (major >= 6) {
+    dprintf_2("release is SunOS 6 or later\n");
+    has_newer_Pstack_iter = true;
+    done_set = true;
+    return;
+  }
+  if (major < 5) {
+    dprintf_2("release is SunOS 4 or earlier\n");
+    done_set = true;
+    return;
+  }
+
+  // some SunOS 5.* build so now check for Solaris versions
+  char *dot = strchr(name.release, '.');
+  int minor = 0;
+  if (dot != NULL) {
+    // release is major.minor format
+    *dot = NULL;
+    minor = atoi(dot + 1);
+  }
+
+  if (minor <= 10) {
+    dprintf_2("release is Solaris 10 or earlier\n");
+    done_set = true;
+    return;
+  } else if (minor >= 12) {
+    dprintf_2("release is Solaris 12 or later\n");
+    has_newer_Pstack_iter = true;
+    done_set = true;
+    return;
+  }
+
+  // some Solaris 11 build so now check for internal build numbers
+  if (strncmp(name.version, "snv_", 4) != 0) {
+    dprintf_2("release is Solaris 11 post-GA or later\n");
+    has_newer_Pstack_iter = true;
+    done_set = true;
+    return;
+  }
+
+  // version begins with "snv_" so a pre-GA build of Solaris 11
+  int build = atoi(&name.version[4]);
+  if (build >= 159) {
+    dprintf_2("release is Nevada-B159 or later\n");
+    has_newer_Pstack_iter = true;
+  } else {
+    dprintf_2("release is Nevada-B158 or earlier\n");
+  }
+
+  done_set = true;
+}
+#endif // !SOLARIS_11_B159_OR_LATER
+
+/*
+ * Class:       sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal
+ * Method:      initIDs
+ * Signature:   ()V
+ * Description: get JNI ids for fields and methods of ProcDebuggerLocal class
+ */
+JNIEXPORT void JNICALL Java_sun_jvm_hotspot_debugger_proc_ProcDebuggerLocal_initIDs
+  (JNIEnv *env, jclass clazz) {
+  _libsaproc_debug = getenv("LIBSAPROC_DEBUG") != NULL;
+  if (_libsaproc_debug) {
+     // propagate debug mode to libproc.so
+     static const char* var = "LIBPROC_DEBUG=1";
+     putenv((char*)var);
+  }
+
+  void* libproc_handle = dlopen("libproc.so", RTLD_LAZY | RTLD_GLOBAL);
+  if (libproc_handle == 0)
+     THROW_NEW_DEBUGGER_EXCEPTION("can't load libproc.so, if you are using Solaris 5.7 or below, copy libproc.so from 5.8!");
+
+#ifndef SOLARIS_11_B159_OR_LATER
+  _Pstack_iter_debug = getenv("PSTACK_ITER_DEBUG") != NULL;
+
+  set_has_newer_Pstack_iter(env);
+  CHECK_EXCEPTION;
+  dprintf_2("has_newer_Pstack_iter=%d\n", has_newer_Pstack_iter);
+#endif
+
+  p_ps_prochandle_ID = env->GetFieldID(clazz, "p_ps_prochandle", "J");
+  CHECK_EXCEPTION;
+
+  libthread_db_handle_ID = env->GetFieldID(clazz, "libthread_db_handle", "J");
+  CHECK_EXCEPTION;
+
+  p_td_thragent_t_ID = env->GetFieldID(clazz, "p_td_thragent_t", "J");
+  CHECK_EXCEPTION;
+
+  p_td_init_ID = env->GetFieldID(clazz, "p_td_init", "J");
+  CHECK_EXCEPTION;
+
+  p_td_ta_new_ID = env->GetFieldID(clazz, "p_td_ta_new", "J");
+  CHECK_EXCEPTION;
+
+  p_td_ta_delete_ID = env->GetFieldID(clazz, "p_td_ta_delete", "J");
+  CHECK_EXCEPTION;
+
+  p_td_ta_thr_iter_ID = env->GetFieldID(clazz, "p_td_ta_thr_iter", "J");
+  CHECK_EXCEPTION;
+
+  p_td_thr_get_info_ID = env->GetFieldID(clazz, "p_td_thr_get_info", "J");
+  CHECK_EXCEPTION;
+
+  p_td_ta_map_id2thr_ID = env->GetFieldID(clazz, "p_td_ta_map_id2thr", "J");
+  CHECK_EXCEPTION;
+
+  p_td_thr_getgregs_ID = env->GetFieldID(clazz, "p_td_thr_getgregs", "J");
+  CHECK_EXCEPTION;
+
+  getThreadForThreadId_ID = env->GetMethodID(clazz,
+                            "getThreadForThreadId", "(J)Lsun/jvm/hotspot/debugger/ThreadProxy;");
+  CHECK_EXCEPTION;
+
+  pcRegIndex_ID = env->GetFieldID(clazz, "pcRegIndex", "I");
+  CHECK_EXCEPTION;
+
+  fpRegIndex_ID = env->GetFieldID(clazz, "fpRegIndex", "I");
+  CHECK_EXCEPTION;
+
+  createSenderFrame_ID = env->GetMethodID(clazz,
+                            "createSenderFrame", "(Lsun/jvm/hotspot/debugger/proc/ProcCFrame;JJ)Lsun/jvm/hotspot/debugger/proc/ProcCFrame;");
+  CHECK_EXCEPTION;
+
+  createLoadObject_ID = env->GetMethodID(clazz,
+                            "createLoadObject", "(Ljava/lang/String;JJ)Lsun/jvm/hotspot/debugger/cdbg/LoadObject;");
+  CHECK_EXCEPTION;
+
+  createClosestSymbol_ID = env->GetMethodID(clazz,
+                            "createClosestSymbol", "(Ljava/lang/String;J)Lsun/jvm/hotspot/debugger/cdbg/ClosestSymbol;");
+  CHECK_EXCEPTION;
+
+  jclass list_clazz = env->FindClass("java/util/List");
+  CHECK_EXCEPTION;
+  listAdd_ID = env->GetMethodID(list_clazz, "add", "(Ljava/lang/Object;)Z");
+  CHECK_EXCEPTION;
+
+  // part of the class sharing workaround
+  classes_jsa_fd_ID = env->GetFieldID(clazz, "classes_jsa_fd", "I");
+  CHECK_EXCEPTION;
+  p_file_map_header_ID = env->GetFieldID(clazz, "p_file_map_header", "J");
+  CHECK_EXCEPTION;
+}