diff src/share/vm/utilities/elfFuncDescTable.cpp @ 14441:e7cbc95179c4

8019929: PPC64 (part 107): Extend ELF-decoder to support PPC64 function descriptor tables Summary: Extend ELF-decoder to support PPC64 function descriptor tables Reviewed-by: kvn, zgu
author simonis
date Thu, 05 Dec 2013 19:19:09 +0100
parents
children
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/utilities/elfFuncDescTable.cpp	Thu Dec 05 19:19:09 2013 +0100
@@ -0,0 +1,104 @@
+/*
+ * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright 2012, 2013 SAP AG. 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 "precompiled.hpp"
+
+#if !defined(_WINDOWS) && !defined(__APPLE__)
+
+#include "memory/allocation.inline.hpp"
+#include "utilities/elfFuncDescTable.hpp"
+
+ElfFuncDescTable::ElfFuncDescTable(FILE* file, Elf_Shdr shdr, int index) {
+  assert(file, "null file handle");
+  // The actual function address (i.e. function entry point) is always the
+  // first value in the function descriptor (on IA64 and PPC64 they look as follows):
+  // PPC64: [function entry point, TOC pointer, environment pointer]
+  // IA64 : [function entry point, GP (global pointer) value]
+  // Unfortunately 'shdr.sh_entsize' doesn't always seem to contain this size (it's zero on PPC64) so we can't assert
+  // assert(IA64_ONLY(2) PPC64_ONLY(3) * sizeof(address) == shdr.sh_entsize, "Size mismatch for '.opd' section entries");
+
+  m_funcDescs = NULL;
+  m_file = file;
+  m_index = index;
+  m_status = NullDecoder::no_error;
+
+  // try to load the function descriptor table
+  long cur_offset = ftell(file);
+  if (cur_offset != -1) {
+    // call malloc so we can back up if memory allocation fails.
+    m_funcDescs = (address*)os::malloc(shdr.sh_size, mtInternal);
+    if (m_funcDescs) {
+      if (fseek(file, shdr.sh_offset, SEEK_SET) ||
+          fread((void*)m_funcDescs, shdr.sh_size, 1, file) != 1 ||
+          fseek(file, cur_offset, SEEK_SET)) {
+        m_status = NullDecoder::file_invalid;
+        os::free(m_funcDescs);
+        m_funcDescs = NULL;
+      }
+    }
+    if (!NullDecoder::is_error(m_status)) {
+      memcpy(&m_shdr, &shdr, sizeof(Elf_Shdr));
+    }
+  } else {
+    m_status = NullDecoder::file_invalid;
+  }
+}
+
+ElfFuncDescTable::~ElfFuncDescTable() {
+  if (m_funcDescs != NULL) {
+    os::free(m_funcDescs);
+  }
+}
+
+address ElfFuncDescTable::lookup(Elf_Word index) {
+  if (NullDecoder::is_error(m_status)) {
+    return NULL;
+  }
+
+  if (m_funcDescs != NULL) {
+    if (m_shdr.sh_size > 0 && m_shdr.sh_addr <= index && index <= m_shdr.sh_addr + m_shdr.sh_size) {
+      // Notice that 'index' is a byte-offset into the function descriptor table.
+      return m_funcDescs[(index - m_shdr.sh_addr) / sizeof(address)];
+    }
+    return NULL;
+  } else {
+    long cur_pos;
+    address addr;
+    if (!(m_shdr.sh_size > 0 && m_shdr.sh_addr <= index && index <= m_shdr.sh_addr + m_shdr.sh_size)) {
+      // don't put the whole decoder in error mode if we just tried a wrong index
+      return NULL;
+    }
+    if ((cur_pos = ftell(m_file)) == -1 ||
+        fseek(m_file, m_shdr.sh_offset + index - m_shdr.sh_addr, SEEK_SET) ||
+        fread(&addr, sizeof(addr), 1, m_file) != 1 ||
+        fseek(m_file, cur_pos, SEEK_SET)) {
+      m_status = NullDecoder::file_invalid;
+      return NULL;
+    }
+    return addr;
+  }
+}
+
+#endif // !_WINDOWS && !__APPLE__