Mailing-List: contact harmony-dev-help@incubator.apache.org; run by ezmlm
Precedence: bulk
Reply-To: harmony-dev@incubator.apache.org
Received-SPF: pass (asf.osuosl.org: domain of gshimansky@gmail.com designates
 64.233.182.186 as permitted sender)
DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws;
        s=beta; d=gmail.com;
        h=received:from:reply-to:to:subject:date:user-agent:references:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:message-id;
        b=qdwy4uAqW1PGRuVVHhJlWNRSXWZkMfeX6G/UMaMUH2floNXFrBwRjO7gY7aG1p+aMOIhOzdS7o2BV2B3kO1Ky3swoM0HYiFrrvG6KNGKxx3hvE8gT8oPmbEhWYZCqPyTi43EJTBYkjbkwP4Ti/8p+W2ECS/KA4RPYxdS6EEdot0=
From: Gregory Shimansky <gshimansky@gmail.com>
Reply-To: harmony-dev@incubator.apache.org
To: harmony-dev@incubator.apache.org
Subject: Re: [drlvm] HARMONY-956 - problem w/ DRLVM classloader
Date: Mon, 7 Aug 2006 22:10:05 +0400
User-Agent: KMail/1.9.1
References: <44D48DC3.6070206@pobox.com>
 <ddda44ee0608071022u2bf1f057m716f2c1793f0278c@mail.gmail.com>
In-Reply-To: <ddda44ee0608071022u2bf1f057m716f2c1793f0278c@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain;
  charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
Message-Id: <200608072210.05619.gshimansky@gmail.com>

On Monday 07 August 2006 21:22 Anton Luht wrote:
> Hello,
>
> The problem is with verifier.
>
> The code in Verifier.cpp:
>
>         if( ( start_pc >= len ) || ( end_pc >= len ) || ( handler_pc >= len
> ) ) ...
>
>             result = VER_ErrorHandler;
>
> I've modified error logging a bit to log values of start_pc, end_pc,
> handler_pc and len and that's the output:
>
>
> Loading message broker from: xbean:activemq.xml
> vf_debug: VerifyError: (class:
> edu/emory/mathcs/backport/java/util/concurrent/lo
> cks/ReentrantLock$NonfairSync, method: lockInterruptibly()V, len: 103,
> start_pc: 87, end_pc: 103, handler_pc: 21) Handler pc is out of range
> vf_debug: verifying class
> edu/emory/mathcs/backport/java/util/concurrent/locks/R eentrantLock (method
> <init>()V) couldn't load class "edu/emory/mathcs/backport/j
> ava/util/concurrent/locks/ReentrantLock$NonfairSync"
> vf_debug: VerifyError:
> edu/emory/mathcs/backport/java/util/concurrent/locks/Reen
> trantLock$NonfairSync
> Failed to execute main task. Reason: java.lang.NoClassDefFoundError:
> edu/emory/m
> athcs/backport/java/util/concurrent/locks/ReentrantLock$NonfairSync
>
> I'm not an expert in verification but seems like
>
> end_pc >= len
> should be replaced with
> end_pc > len

I checked Java class file format spec [1] and it states in 4.7.3 that:

--------------------------------------------------------
start_pc, end_pc
    The values of the two items start_pc and end_pc indicate the ranges in the 
code array at which the exception handler is active. The value of start_pc 
must be a valid index into the code array of the opcode of an instruction. 
The value of end_pc either must be a valid index into the code array of the 
opcode of an instruction or must be equal to code_length, the length of the 
code array. The value of start_pc must be less than the value of end_pc.

    The start_pc is inclusive and end_pc is exclusive; that is, the exception 
handler must be active while the program counter is within the interval 
[start_pc, end_pc).
--------------------------------------------------------

In this case the code length is 103 and end_pc is 103. It looks to be a legal 
exception handler entry so I agree with your correction to verifier code.

-- 
Gregory Shimansky, Intel Middleware Products Division

---------------------------------------------------------------------
Terms of use : http://incubator.apache.org/harmony/mailing.html
To unsubscribe, e-mail: harmony-dev-unsubscribe@incubator.apache.org
For additional commands, e-mail: harmony-dev-help@incubator.apache.org