8283441: C2: segmentation fault in ciMethodBlocks::make_block_at(int)

Reviewed-by: kvn, thartmann

src/hotspot/share/c1/c1_GraphBuilder.cpp

@@ -224,8 +224,10 @@ void BlockListBuilder::handle_exceptions(BlockBegin* current, int cur_bci) {
 }
 
 void BlockListBuilder::handle_jsr(BlockBegin* current, int sr_bci, int next_bci) {
-  // start a new block after jsr-bytecode and link this block into cfg
-  make_block_at(next_bci, current);
+  if (next_bci < method()->code_size()) {
+    // start a new block after jsr-bytecode and link this block into cfg
+    make_block_at(next_bci, current);
+  }
 
   // start a new block at the subroutine entry at mark it with special flag
   BlockBegin* sr_block = make_block_at(sr_bci, current);
@@ -245,6 +247,8 @@ void BlockListBuilder::set_leaders() {
   // branch target and a modification of the successor lists.
   const BitMap& bci_block_start = method()->bci_block_start();
 
+  int end_bci = method()->code_size();
+
   ciBytecodeStream s(method());
   while (s.next() != ciBytecodeStream::EOBC()) {
     int cur_bci = s.cur_bci();
@@ -315,7 +319,9 @@ void BlockListBuilder::set_leaders() {
       case Bytecodes::_if_acmpne: // fall through
       case Bytecodes::_ifnull:    // fall through
       case Bytecodes::_ifnonnull:
-        make_block_at(s.next_bci(), current);
+        if (s.next_bci() < end_bci) {
+          make_block_at(s.next_bci(), current);
+        }
         make_block_at(s.get_dest(), current);
         current = NULL;
         break;

src/hotspot/share/ci/ciMethodBlocks.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2006, 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2006, 2022, 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
@@ -33,12 +33,13 @@
 
 
 ciBlock *ciMethodBlocks::block_containing(int bci) {
+  assert(bci >= 0 && bci < _code_size, "valid bytecode range");
   ciBlock *blk = _bci_to_block[bci];
   return blk;
 }
 
 bool ciMethodBlocks::is_block_start(int bci) {
-  assert(bci >=0 && bci < _code_size, "valid bytecode range");
+  assert(bci >= 0 && bci < _code_size, "valid bytecode range");
   ciBlock *b = _bci_to_block[bci];
   assert(b != NULL, "must have block for bytecode");
   return b->start_bci() == bci;
@@ -146,7 +147,9 @@ void ciMethodBlocks::do_analysis() {
       case Bytecodes::_ifnonnull   :
       {
         cur_block->set_control_bci(bci);
-        ciBlock *fall_through = make_block_at(s.next_bci());
+        if (s.next_bci() < limit_bci) {
+          ciBlock *fall_through = make_block_at(s.next_bci());
+        }
         int dest_bci = s.get_dest();
         ciBlock *dest = make_block_at(dest_bci);
         break;
@@ -166,7 +169,9 @@ void ciMethodBlocks::do_analysis() {
       case Bytecodes::_jsr         :
       {
         cur_block->set_control_bci(bci);
-        ciBlock *ret = make_block_at(s.next_bci());
+        if (s.next_bci() < limit_bci) {
+          ciBlock *ret = make_block_at(s.next_bci());
+        }
         int dest_bci = s.get_dest();
         ciBlock *dest = make_block_at(dest_bci);
         break;
@@ -224,7 +229,9 @@ void ciMethodBlocks::do_analysis() {
       case Bytecodes::_jsr_w       :
       {
         cur_block->set_control_bci(bci);
-        ciBlock *ret = make_block_at(s.next_bci());
+        if (s.next_bci() < limit_bci) {
+          ciBlock *ret = make_block_at(s.next_bci());
+        }
         int dest_bci = s.get_far_dest();
         ciBlock *dest = make_block_at(dest_bci);
         break;

src/hotspot/share/compiler/methodLiveness.cpp

@@ -162,10 +162,11 @@ void MethodLiveness::init_basic_blocks() {
       case Bytecodes::_ifnull:
       case Bytecodes::_ifnonnull:
         // Two way branch.  Set predecessors at each destination.
-        dest = _block_map->at(bytes.next_bci());
-        assert(dest != NULL, "must be a block immediately following this one.");
-        dest->add_normal_predecessor(current_block);
-
+        if (bytes.next_bci() < method_len) {
+          dest = _block_map->at(bytes.next_bci());
+          assert(dest != NULL, "must be a block immediately following this one.");
+          dest->add_normal_predecessor(current_block);
+        }
         dest = _block_map->at(bytes.get_dest());
         assert(dest != NULL, "branch destination must start a block.");
         dest->add_normal_predecessor(current_block);

test/hotspot/jtreg/compiler/parsing/Custom.jasm

@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2022, 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.
+ */
+
+package compiler/parsing;
+
+super public class Custom {
+
+    public static Method test:"(I)V" stack 2 locals 1 {
+        return;
+Loop:
+        // Unreachable block
+        iload_0;
+        bipush        100;
+        if_icmpge     Loop;
+        // Falls through
+    }
+
+}

test/hotspot/jtreg/compiler/parsing/UnreachableBlockFallsThroughEndOfCode.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2022, 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.
+ *
+ */
+
+/*
+ * @test UnreachableBlockFallsThroughEndOfCode.java
+ * @bug 8283441
+ * @compile Custom.jasm UnreachableBlockFallsThroughEndOfCode.java
+ * @summary Compiling method that falls off the end of the code array
+ * @run main/othervm -XX:TieredStopAtLevel=1 -Xbatch compiler.parsing.UnreachableBlockFallsThroughEndOfCode
+ * @run main/othervm -XX:-TieredCompilation -Xbatch compiler.parsing.UnreachableBlockFallsThroughEndOfCode
+ */
+
+package compiler.parsing;
+
+public class UnreachableBlockFallsThroughEndOfCode {
+    public static void main(String[] strArr) {
+        for (int i = 0; i < 20000; i++) {
+            Custom.test(i);
+        }
+    }
+}