jdk/test/hotspot/jtreg/serviceability/jvmti/GetLocalVariable/GetSetLocalSlotOverflow.java
2026-07-17 05:02:17 +00:00

78 lines
3.2 KiB
Java

/*
* Copyright (c) 2026, 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
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*/
/*
* @test
* @bug 8387718
* @summary VM_GetOrSetLocal slot bounds check overflows for long/double slots,
* allowing an out-of-bounds StackValueCollection access when slot == INT_MAX.
* @requires vm.jvmti
* @compile GetSetLocalSlotOverflow.java
* @run main/othervm/native -agentlib:GetSetLocalSlotOverflow GetSetLocalSlotOverflow
*/
/*
* Regression test / reproducer for the signed-overflow in
* VM_BaseGetOrSetLocal::check_slot_type_no_lvt (jvmtiImpl.cpp).
*
* For a T_LONG/T_DOUBLE access, the bounds check is
* if (_index < 0 || _index + extra_slot >= method->max_locals())
* with extra_slot == 1. When the agent passes slot == INT_MAX, the
* sub-expression _index + extra_slot overflows to INT_MIN, which is < max_locals(),
* so the guard passes and the code goes on to index locals->at(INT_MAX).
*
* Expected (fixed) behavior: GetLocalLong/Double and SetLocalLong/Double with
* slot == INT_MAX return JVMTI_ERROR_INVALID_SLOT.
*
* On an unfixed VM this test does not merely fail: the out-of-bounds access
* crashes the VM (assertion failure in fastdebug, SIGSEGV / silent corruption
* in product). A clean PASS is only possible once the bounds check is fixed.
*/
public class GetSetLocalSlotOverflow {
// Invoked from runner(); the agent inspects the runner() frame at depth 1.
// Returns false if any accessor did not return JVMTI_ERROR_INVALID_SLOT.
static native boolean testOverflow(Thread thread);
public static void main(String[] args) throws Exception {
if (!runner()) {
throw new RuntimeException("Test GetSetLocalSlotOverflow failed");
}
}
// A Java frame holding a few locals. The agent targets this frame (depth 1)
// with slot == INT_MAX. The actual local contents are irrelevant: the
// overflow happens in the slot bounds check, before any local is read.
public static boolean runner() {
long l = 0xCAFEBABEL;
double d = 3.14d;
boolean ok = testOverflow(Thread.currentThread());
// Keep locals live across the native call.
if (l == 0 && d == 0) {
throw new AssertionError("unreachable");
}
return ok;
}
}